Search

Introduction: Multifarious selective pressures can interact to affect species' life history evolution, with predation and thermal exposure as selective pressures for nesting birds. Gray Vireos (Vireo vicinior) seemingly nest on the periphery of their nesting substrate because of lower predation rates, thereby increasing exposure to weather. We explored how nest placement and vegetation structure can be used to account for the increased weather exposure that Gray Vireos experience when nesting on the periphery of the nesting substrate to avoid predation. Methods: For each Gray Vireo nest, we placed temperature and light data loggers at three locations: at the nest site, at the opposite orientation of the nest within the nesting tree, and at the same orientation of the nest but in an adjacent tree. To measure nest orientation, we recorded the inverse compass azimuth (+/-1°) from the nest toward the trunk of the nesting tree, while accounting for declination. Nest temperatures and light exposure were compared across various dimensions of nest placement. Results: The orientation of nests was cooler than the opposite orientation in the mornings and in the late afternoons. When nests were placed in hotter orientations (e.g., south- or west-facing), nests surrounded by more foliage or placed closer to the interior of trees could compensate for the increased exposure. Discussion: Our findings suggest Gray Vireos accounted for the increased thermal exposure that comes from predator avoidance by using secondary dimensions of nest placement. Specifically, nests could be placed in orientations with cooler temperatures or in hotter orientations with greater shade potential. These results highlight how the interactive selection pressures of predation risk and microclimate can be tiered and shape life-history characteristics of birds. [ABSTRACT FROM AUTHOR]

Social insects have developed different nest defence strategies; for example, social wasps use nonaggressive mechanisms or aggressiveness, including stinging. This subject has been widely examined in the literature, and it may help improve our understanding of wasps' ecology. The nesting behaviour of some genera is still poorly known. In this paper, we report new information on the nesting behaviour of the species Clypearia in different Brazilian biomes. We observed six nesting events in natural and anthropic environments of the Amazon rainforest, Atlantic forest, and Cerrado domains, sporadically from 2004 to 2022. From our observations, we suggest that Clypearia nest defence includes (i) preference for nest camouflage rather than aggressive behaviour; (ii) selection of nesting sites close to water sources in natural or anthropic environments, and eventually obtaining food from the substrate; (iii) nesting association with ants for mutual protection against predators; and (iv) variations in the nests' height. Our records suggest nest camouflage and association with ants are strategies for nest defence. These may have influenced nest height in relation to the ground, which may also vary according to the environment explored by the species. [ABSTRACT FROM AUTHOR]

Nest reuse is often observed in large- and medium-sized birds, including hole-nesters, while in smaller passerines building open-cup nests it is rarely recorded. In this note we report a case of multiple nest reuse, observed in a residential garden in Poland. The nest was located on the wall of a farm building partly overgrown by Boston Ivy at the height of 2.3 m. The nest was occupied eight times between 2007 and 2023 by three bird species: Grey and Pied Wagtails and Common Blackbirds. The nest was built by Grey Wagtails in 2007, but in 2009 it was reconstructed considerably by blackbirds. The Blackbird cup with mud lining survived until 2023 and contained all other nests. We suggest that the most plausible reason for multiple nest reuse was the high quality of this nest site. However, we also found that the nest was used during warm, dry springs but avoided when weather conditions at the beginning of the breeding season were adverse. We hypothesize that cold and wet springs – thought to be associated with high costs of reproduction – may have influenced birds' decision not to reuse the nest. To our knowledge, this is the longest case of nest reuse reported for passerines building open-cup nests. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Field Ornithology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

IntroductionMultifarious selective pressures can interact to affect species’ life history evolution, with predation and thermal exposure as selective pressures for nesting birds. Gray Vireos (Vireo vicinior) seemingly nest on the periphery of their nesting substrate because of lower predation rates, thereby increasing exposure to weather. We explored how nest placement and vegetation structure can be used to account for the increased weather exposure that Gray Vireos experience when nesting on the periphery of the nesting substrate to avoid predation.MethodsFor each Gray Vireo nest, we placed temperature and light data loggers at three locations: at the nest site, at the opposite orientation of the nest within the nesting tree, and at the same orientation of the nest but in an adjacent tree. To measure nest orientation, we recorded the inverse compass azimuth (+/−1°) from the nest toward the trunk of the nesting tree, while accounting for declination. Nest temperatures and light exposure were compared across various dimensions of nest placement.ResultsThe orientation of nests was cooler than the opposite orientation in the mornings and in the late afternoons. When nests were placed in hotter orientations (e.g., south- or west-facing), nests surrounded by more foliage or placed closer to the interior of trees could compensate for the increased exposure.DiscussionOur findings suggest Gray Vireos accounted for the increased thermal exposure that comes from predator avoidance by using secondary dimensions of nest placement. Specifically, nests could be placed in orientations with cooler temperatures or in hotter orientations with greater shade potential. These results highlight how the interactive selection pressures of predation risk and microclimate can be tiered and shape life-history characteristics of birds.

Oviposition site selection by parents is an important factor that affects offspring survival and parental fitness. The relative importance of sexes in oviposition site selection in anurans is rarely evaluated, especially in species with resource‐defense mating systems, where males defend territory containing eventual oviposition sites before advertising for females. Using a phytotelm‐breeding frog (Kurixalus eiffingeri) with male territoriality, we examined 310 bamboo stumps (potential for oviposition sites) to determine whether male and female choice of oviposition site based on physical characteristics (stump height, inner diameter, stump depth, water depth, and water volume). We found that males preferred a site with higher stumps that were deeper and contained more water, while females showed no preference for sites based on the characteristics observed. Although we do not exclude the possibility that K. eiffingeri female oviposition site selection can be relied on and/or correlates to male advertisement calls, this study is one of few studies to examine the role of both sexes in oviposition site selection simultaneously, and provides empirical evidence that oviposition site selection is primarily determined by males in an amphibian with a resource‐defense mating system. [ABSTRACT FROM AUTHOR]

Nest reuse is often observed in large- and medium-sized birds, including hole-nesters, while in smaller passerines building open-cup nests it is rarely recorded. In this note we report a case of multiple nest reuse, observed in a residential garden in Poland. The nest was located on the wall of a farm building partly overgrown by Boston Ivy at the height of 2.3 m. The nest was occupied eight times between 2007 and 2023 by three bird species: Grey and Pied Wagtails and Common Blackbirds. The nest was built by Grey Wagtails in 2007, but in 2009 it was reconstructed considerably by blackbirds. The Blackbird cup with mud lining survived until 2023 and contained all other nests. We suggest that the most plausible reason for multiple nest reuse was the high quality of this nest site. However, we also found that the nest was used during warm, dry springs but avoided when weather conditions at the beginning of the breeding season were adverse. We hypothesize that cold and wet springs – thought to be associated with high costs of reproduction – may have influenced birds’ decision not to reuse the nest. To our knowledge, this is the longest case of nest reuse reported for passerines building open-cup nests.

Abstract In wild bird populations, the structure of vegetation around nest‐sites can influence the risk of predation of dependent offspring, generating selection for nest‐sites with vegetation characteristics associated with lower predation rates. However, vegetation structure can be difficult to quantify objectively in the field, which might explain why there remains a general lack of understanding of which characteristics are most important in determining predation rates. Airborne laser scanning (ALS) offers a powerful means of measuring vegetation structure at unprecedented resolution. Here, we combined ALS with 11 years of breeding data from a wild population of superb fairy‐wrens Malurus cyaneus in southeastern Australia, a species which nests relatively close to the ground and has high rates of nest and fledgling predation. We derived structural measurements of understorey (0–8 m) vegetation from a contiguous grid of 30 × 30 m resolution cells across our c. 65 hectares study area. We found that cells with nests (nest‐cells) differed in their understorey vegetation structure characteristics compared to unused cells, primarily in having denser vegetation in the lowest layer of the understorey (0–2 m; the ‘groundstorey’ layer). The average height of understorey vegetation was also lower in cells with nests than in those without nests. However, relationships between understorey vegetation structure characteristics and breeding performance were mixed. Nest success rates decreased with higher volumes of groundstorey vegetation, as did fledgling survival rates, though only in nest‐cells with lower height vegetation. Our results indicate that ALS can identify vegetation characteristics relevant for superb fairy‐wren nest‐site selection, but that nesting preferences are not beneficial under current predation pressures. The study illustrates the potential for using ALS to investigate how ecological conditions affect behaviour and life‐histories in wild animal populations.

Simple Summary: The fate and development of birds largely depend on their reproductive strategies, which vary, either diverging or converging among different species and populations. We studied the reproductive strategies of White-rumped Shama (Copsychus malabarica) and Oriental Magpie Robin (C. saularis), which may be convergent because of their kin relationships or divergent because of niche differentiation under sympatric competition. We observed that they differed in certain reproductive strategies, such as nest-site selection and egg incubation patterns, but were similar in others, including nestling heating, sexual synchronization in nestling feeding, and coordination of nestling feeding and nest cleaning. Reproduction plays a crucial role in determining the development, fate, and dynamics of bird populations. However, reproductive strategies vary among species and populations. In this study, we investigated the reproductive strategies of the Oriental Magpie Robin (Copsychus saularis) and White-rumped Shama (C. malabarica), which are closely related passerines that reproduce in sympatric areas. We found that although these two species were both cavity nesting, their nest-site selection differed; the Shama preferred nesting close to trees and forests, whereas the Magpie Robin nested close to human residential areas. Furthermore, their egg incubation patterns differed; the Shama increased daily incubation frequency with incubation time, but the Magpie Robin maintained its daily incubation time regardless of changes in incubation frequency. However, the nestling heating patterns of these two species were similar, indicating a critical demand for regulating hatchling body temperature during this crucial stage. The feeding frequencies of male parents were strongly correlated with those of females in both species, suggesting equal contribution and good synchronization between the sexes. Nestling feeding frequency was also correlated with nest cleaning frequency, implying coordination between feeding and defecation by parents and offspring, respectively. This research explored the divergence and convergence of reproductive strategies between these two sympatric species, providing valuable insights into the niche differentiation theory. [ABSTRACT FROM AUTHOR]

Effective coordination of group actions underlies the success of group-living organisms. Recent studies of animal personality have shown that groups composed of individuals with different behavioral propensities can outperform uniform groups in a range of different tasks, but we have only a rudimentary understanding of how differences in individual behavior influence the behavior of the group as a whole. In this study, we use natural variation in behavioral propensity among morphologically distinct worker castes of the small carpenter ant Camponotus yamaokai to shed new light on this. Iterative testing indicated that ants displayed consistent behavioral differences among individuals and between castes, with major workers exhibiting a lower exploratory tendency than minors. By constructing groups of different caste composition and quantifying their performance in the task of colony emigration, we show that group performance is an asymmetric humped function of caste ratio, with optimal performance achieved by groups with natural caste ratios. Using a simulation model based on our empirical data, we demonstrate that interindividual differences in social attraction and exploratory tendency are sufficient to explain the observed patterns. Our results provide new insights into how group performance in collective tasks can vary with group composition. [ABSTRACT FROM AUTHOR]

Studies show that birds cognize human disturbance as a potential predation risk. However, the responses of breeding birds to long‐term continuous disturbance by research activities and whether researcher disturbance affects the fitness of target species remain poorly understood. In this study, we used field observation data collected over 6 years to assess the potential impacts of research activities on nest‐site selection and nest success of the Emei Shan Liocichla (Liocichla omeiensis), a vulnerable babbler species endemic to Southwest China. Our results showed that Emei Shan Liocichlas tended to nest in taller nesting plants or the higher parts of nesting plants to increase nest‐site height following researcher disturbance. The average height of Emei Shan Liocichla nests increased by 52.2% over the 6‐year study period, from 129.8 ± 9.2 cm in 2009 (n = 11) to 197.5 ± 12.1 cm in 2015 (n = 18). While some pairs adopted a different strategy, placing their nests in Rosaceae plants with thorns instead of the bamboo Chimonobambusa szechuanensis (the favored nesting plant of the Emei Shan Liocichla) under high interference pressure, which made it more difficult for researchers to approach their nests. There were no significant differences both in clutch size and nest success between the low‐ and high‐disturbance groups. The study revealed the behavioral response pattern of breeding Emei Shan Liocichlas to researcher disturbance, which will contribute to conservation of this threatened songbird and the knowledge of reproductive strategies of birds. Developing specific guidelines for fieldwork and strengthening visitor management within its core habitat of Emei Shan Liocichla during breeding period should be considered. [ABSTRACT FROM AUTHOR]

Predation is the leading cause of avian nest failure, and parents should benefit from choosing nest locations that limit their predators' ability to detect nests (i.e., nest concealment hypothesis). To understand how nest concealment and other nest-site vegetation characteristics affect the likelihood of predation by specific predators, we used camera traps to monitor predator activity at the nests of Black-throated Sparrows (Amphispiza bilineata) in desert scrub habitat in central New Mexico. After a nest fledged or failed, we measured the dimensions of the nest shrub, the average number of branches offering lateral concealment of the nest, and distance between the nest shrub and the nearest neighboring vegetation. We also used 50 m transects to survey plant community diversity in the vicinity of the nest shrub. Nest-site vegetation characteristics did not differ between nests that fledged and those that failed. In addition to confirming predator activity by Brown-headed Cowbirds (Molothrus ater) and coachwhips (Masticophis flagellum), which have been reported previously, ours is the first study to report that striped skunks (Mephitis mephitis) and gray foxes (Urocyon cinereoargenteus) also prey on Black-throated Sparrow nests. This study broadens our understanding of the predator guild for Black-throated Sparrows and other low-nesting birds but suggests that vegetative concealment has limited effects on nest fate in this species. La depredación es la causa principal de fracaso de nido en aves y los padres deberían beneficiarse al escoger una ubicación de nido que limite la habilidad del depredador de detectar los nidos (es decir, la hipótesis de ocultamiento de nidos). Para entender cómo el ocultamiento de nidos y otras características de la vegetación afectan la probabilidad de depredación por depredadores específicos, usamos cámaras trampa para monitorear la actividad de depredadores en nidos de gorriones Amphispiza bilineata en matorral desértico en el centro de New Mexico. Después de la emancipación o el fracaso del nido, medimos las dimensiones del arbusto de anidación, el número promedio de ramas que brindaban camuflaje lateral al nido y la distancia entre el arbusto de anidación y la vegetación vecina más cercana. También usamos transeptos de 50 m para monitorear la diversidad de la comunidad de plantas vecinas al arbusto de anidación. Las características de la vegetación por sitio de anidación no difirieron entre nidos que se emanciparon y nidos fracasados. Además de confirmar la actividad de depredación del tordo Molothrus ater y de la serpiente Masticophis flagellum, que habían sido previamente reportados, nuestro estudio es el primero que reporta actividad de depredación de mofeta rayada (Mephitis mephitis) y de zorra gris (Urocyon cinereoargenteus) en nidos de gorrión Amphispiza bilineata. Este estudio amplía nuestro entendimiento de la red de depredación de los gorriones Amphispiza bilineata y otras aves que anidan en sitios bajos pero sugiere que el ocultamiento de nidos tiene un alcance limitado en el destino de la nidada en esta especie. Palabras clave: ambiente desértico, claves de depredación, hipótesis de follaje total, redes de depredación, selección de sitio de anidación. [ABSTRACT FROM AUTHOR]

In wild bird populations, the structure of vegetation around nest‐sites can influence the risk of predation of dependent offspring, generating selection for nest‐sites with vegetation characteristics associated with lower predation rates. However, vegetation structure can be difficult to quantify objectively in the field, which might explain why there remains a general lack of understanding of which characteristics are most important in determining predation rates. Airborne laser scanning (ALS) offers a powerful means of measuring vegetation structure at unprecedented resolution. Here, we combined ALS with 11 years of breeding data from a wild population of superb fairy‐wrens Malurus cyaneus in southeastern Australia, a species which nests relatively close to the ground and has high rates of nest and fledgling predation. We derived structural measurements of understorey (0–8 m) vegetation from a contiguous grid of 30 × 30 m resolution cells across our c. 65 hectares study area. We found that cells with nests (nest‐cells) differed in their understorey vegetation structure characteristics compared to unused cells, primarily in having denser vegetation in the lowest layer of the understorey (0–2 m; the 'groundstorey' layer). The average height of understorey vegetation was also lower in cells with nests than in those without nests. However, relationships between understorey vegetation structure characteristics and breeding performance were mixed. Nest success rates decreased with higher volumes of groundstorey vegetation, as did fledgling survival rates, though only in nest‐cells with lower height vegetation. Our results indicate that ALS can identify vegetation characteristics relevant for superb fairy‐wren nest‐site selection, but that nesting preferences are not beneficial under current predation pressures. The study illustrates the potential for using ALS to investigate how ecological conditions affect behaviour and life‐histories in wild animal populations. [ABSTRACT FROM AUTHOR]

Individuals may gather information about environmental conditions when deciding where to breed in order to maximize their lifetime fitness. They can obtain social information by observing conspecifics and heterospecifics with similar ecological needs. Many studies have shown that birds can rely on social information to select their nest sites. The location of active nests and the reproductive success of conspecifics and heterospecifics can provide accurate predictions about the quality of the breeding habitat. Some short-lived species can facultatively reproduce two and/or more times within a breeding season. However, few studies have focused on how multiple-brooding individuals select nest sites for their second breeding attempts. In this study, we use long-term data to test whether the Japanese Tit (Parus minor) can use social information from conspecifics and/or heterospecifics (the Eurasian Nuthatch Sitta europaea, the Daurian Redstart Phoenicurus auroreus and the Yellow-rumped Flycatcher Ficedula zanthopygia) to select a nest site for the second breeding attempt. Our results showed that the nest boxes occupied by tits on their second breeding attempt tended to be surrounded by more breeding conspecific nests, successful first nests of conspecifics, and fewer failed first nests of conspecifics than the nest boxes that remained unoccupied (the control group). However, the numbers of breeding heterospecific nests, successful heterospecific nests, and failed heterospecific nests did not differ between the nest boxes occupied by tits on their second breeding attempt and the unoccupied nest boxes. Furthermore, the tits with local successful breeding experience tended to choose areas with more successful first nests of conspecifics than those without successful breeding experience. Thus, we suggest that conspecifics' but not heterospecifics’ social information within the same breeding season is the major factor influencing the nest site selection of Japanese Tits during second breeding attempts.

Abstract Studies show that birds cognize human disturbance as a potential predation risk. However, the responses of breeding birds to long‐term continuous disturbance by research activities and whether researcher disturbance affects the fitness of target species remain poorly understood. In this study, we used field observation data collected over 6 years to assess the potential impacts of research activities on nest‐site selection and nest success of the Emei Shan Liocichla (Liocichla omeiensis), a vulnerable babbler species endemic to Southwest China. Our results showed that Emei Shan Liocichlas tended to nest in taller nesting plants or the higher parts of nesting plants to increase nest‐site height following researcher disturbance. The average height of Emei Shan Liocichla nests increased by 52.2% over the 6‐year study period, from 129.8 ± 9.2 cm in 2009 (n = 11) to 197.5 ± 12.1 cm in 2015 (n = 18). While some pairs adopted a different strategy, placing their nests in Rosaceae plants with thorns instead of the bamboo Chimonobambusa szechuanensis (the favored nesting plant of the Emei Shan Liocichla) under high interference pressure, which made it more difficult for researchers to approach their nests. There were no significant differences both in clutch size and nest success between the low‐ and high‐disturbance groups. The study revealed the behavioral response pattern of breeding Emei Shan Liocichlas to researcher disturbance, which will contribute to conservation of this threatened songbird and the knowledge of reproductive strategies of birds. Developing specific guidelines for fieldwork and strengthening visitor management within its core habitat of Emei Shan Liocichla during breeding period should be considered.

Landscape transformation by humans through habitat degradation, agriculture intensification and urbanization results in the loss of natural feeding areas. However, populations of certain species have adapted to these changes and benefit from some anthropogenic food sources as well as an absence of predators and milder environmental conditions in urban landscapes. Although breeding near landfills secures food availability and saves energy and time spent on foraging activities, the poor food quality and risks associated with these facilities imply some fitness costs. Our study shows the effects of landfills on nest‐site selection and breeding success in white storks (Ciconia ciconia). Birds breeding near landfills occupy more urban areas where many structures are available to nest, while breeding pairs 20–30 km from landfills select nest sites with high‐quality food sources in the vicinity such as pastures, meadows and agro‐forestry areas. Furthermore, we demonstrate that habitat quality in the surrounding area is more relevant than landfills for breeding outcomes, but both of these are crucial for brood size. The number of fledglings was higher at a medium distance to the landfill than at 20–30 km from the landfill, but not near the landfill (0–10 km). This suggests that the best strategy includes food from landfills as a complementary or alternative food source. Future studies should further investigate if these shifts in habitat preference are permanent, and the potential impact of habitat degradation and landfill closures at a population level, for this species. [ABSTRACT FROM AUTHOR]

Most bee species are ground-nesters, yet knowledge on the nesting behaviour of this diverse group remains sparse. Evidence on the effectiveness of ground-nesting bee species as crop pollinators is growing, but there is limited information on their nesting habits and preferences and how to manage habitats to enhance populations on farms. In this study, artificially prepared plots of bare soil were constructed with the aim to attract ground-nesting bees to nest in a commercial orchard in Kent, UK. Nine soil parameters were measured to determine their preferred soil properties: hydraulic conductivity, soil compaction, soil moisture, soil temperature, soil stoniness, soil organic matter, soil root biomass, soil texture and vegetation cover. Eighteen non-parasitic ground-nesting bee species (7 Andrena, 9 Lasioglossum, 1 Halictus and 1 Colletes spp.) were recorded in the study plots. Soil stoniness and soil temperature at 10cm depth were positively correlated, and vegetation cover and hydraulic conductivity were negatively correlated with the number of ground-nesting bees on the plots. We show that artificially created habitats can be exploited for nesting by several ground-nesting bee species. This study’s findings can inform management practices to enhance ground-nesting bee populations in agricultural and urban areas.

The aim of this study was to estimate the Eurasian Magpie (Pica pica) population and to give a detailed characterization of the nest site selection in the lower Zeta area. Data were collected in spring 2022. The findings of this study are compared to those obtained in other studies. A total of 73 active Magpie nests were censused in the River Zeta valley (lower part). One of the key factors is food availability. Breeding density, or nests, of Magpies in lower Zeta valley was 0.86 pairs/10 ha. The results showed that the first nest building occurred at the end of February, but most pairs started in March. Nests were found in 23 trees and in two shrub species. Magpies build nests in strong and tall trees. Taller tree species were preferred to shorter ones and also broadleaved trees (ca 93%) were preferred to coniferous ones (over 40 % of all nests in 2 tree species but also over 60% of all nests in 5 tree species). The type of tree arrangement most frequently used for nesting was single trees (57.5%). The nests distance from the top of the canopy was 0.5 to 4.0 m, demonstrating the Magpie's tendency to place their nests high in the very tops of trees in the rural areas. Distance of nests from the source of food (pigsty, hen house, cowshed, stable, barn, granary, etc.) was up to 50 m in 80.8% of nests. The study shows that Magpies can adapt to changing climate factors, and changes in the choice of introduction tree species help the Eurasian magpie to adapt to climatic and anthropogenic factors. [ABSTRACT FROM AUTHOR]

Nest provides space for inhabiting, shelter, and offspring nursery. Understanding characteristics of nest-site selection is therefore essential for species conservation and management. In order to investigate nest-site selection in reptiles, the nest-site characteristics (nest temperature, nest depth, nest humidity, orientation of nest entrance and nest angle) were quantified and the differences were compared between two sand lizard species (Phrynocephalus axillaris and Ph. forsythii) in Yuli County in the middle area of Xinjiang of China. Results showed that the two lizard species nested in relatively dry soil, with significantly lower nest temperature and higher nest angle in the ovoviviparous Ph. forsythia than that in the oviparous Ph. axillaris(p<0. 05). The difference of nest depth between the two species was not significant (p= 0. 126), and they showed no preference for the orientation of nest entrance. This study provides compensating ecological data for Ph. axillaris and Ph. forsythia by comparing their nest-site features. As baseline information, it will also help with future detailed nest-site research. [ABSTRACT FROM AUTHOR]

Reproduction plays a crucial role in determining the development, fate, and dynamics of bird populations. However, reproductive strategies vary among species and populations. In this study, we investigated the reproductive strategies of the Oriental Magpie Robin (Copsychus saularis) and White-rumped Shama (C. malabarica), which are closely related passerines that reproduce in sympatric areas. We found that although these two species were both cavity nesting, their nest-site selection differed; the Shama preferred nesting close to trees and forests, whereas the Magpie Robin nested close to human residential areas. Furthermore, their egg incubation patterns differed; the Shama increased daily incubation frequency with incubation time, but the Magpie Robin maintained its daily incubation time regardless of changes in incubation frequency. However, the nestling heating patterns of these two species were similar, indicating a critical demand for regulating hatchling body temperature during this crucial stage. The feeding frequencies of male parents were strongly correlated with those of females in both species, suggesting equal contribution and good synchronization between the sexes. Nestling feeding frequency was also correlated with nest cleaning frequency, implying coordination between feeding and defecation by parents and offspring, respectively. This research explored the divergence and convergence of reproductive strategies between these two sympatric species, providing valuable insights into the niche differentiation theory.

To assist conservationists make specific protection plans for the crested ibis (Nipponia nippon), promote the re⁃introduction success and increase its wild population size, we sampled 35 nest sites within 3 m×3 m quadrats to measure 22 habitat features from July to November during 2014-2019 in Dongzhai, Henan Province. Our results showed that the majority of nests were built in coniferous and broad-leaved mixed forests (n=23) and coniferous forests (n=10). At the early stage of rewilding, crested ibis had relatively diverse choices for nesting trees. At the later stage, however, they showed a clear preference for Pinus massoniana (n=27, 81. 8%) in the low Dabie Mountain. The average diameter at breast-height of the nesting trees was (35. 53±9. 82) cm, the average height was (16. 07±2. 27) m, and the average height of the nest from the ground was (12. 58±1. 70) m (n=33) . There were significant differences among diameters at breast height of the nesting trees, distance to the foraging sites from the nesting trees, distance to road, and the upper and lower canopy size at the nesting sites. Most nest sites were selected in the middle (n=18) or upper (n=11) positions of the trees. And nests adjacent to roads would interfere with the hatching success. Furthermore, distance to the foraging sites from the nesting trees had a significant impact on the survival rate of the young. This study further enhances the understanding of crested ibis nest site selection and provides certain reference significance for crested ibis conservation. [ABSTRACT FROM AUTHOR]

Information on breeding habits of grey crowned crane (Balearica regulorum) in Kenya is currently lacking. Investigations were therefore carried out between 2017 and 2020 to determine its nesting habits in Lake Ol' Bolossat basin including nest‐site features, number and distribution of territorial pairs, clutch size, eggs, and duration of breeding cycle. While 103 pairs were observed in the lake marshlands (mean density 5.00 pairs/km2), only 20 were found in upland wetlands. The number of pairs and densities (pairs/km2) in each of the lake's sections were as follows: north (24; 3.23), middle (47; 5.42), and south (32; 6.24). During this study, 61% (n = 63) of the lake marshland pairs attempted to breed compared to 80% (n = 16) in the upland wetlands. A mean of 2.23 eggs/clutch and a modal clutch of three eggs was recorded in 33 accessible nests. The range of influential factors in nest‐site selection were as follows: water depth (50–100 cm), vegetation height around the nest (60–90 cm), and an offshore distance of >100 m. Breeding cycle showed phenotypic plasticity in response to variations in local weather conditions. The number and density of cranes in this study area show its importance in the recovery and survival of the species, and which should subsequently be accorded effective protection. [ABSTRACT FROM AUTHOR]

The White-throated Cacholote Pseudoseisura gutturalis is a little studied, socially monogamous furnariid, endemic to arid Argentina. Here we provide novel information to characterize the breeding biology of the northern subspecies ochroleuca in the Monte Desert, Argentina, and discuss the similarities and differences with other Pseudoseisura species. Nests were bulky enclosed structures constructed with thorny sticks and twigs of native plant species (n = 15) and 47% of them had objects used as external decorations. Nests had an entrance tube oriented preferentially towards the northeast, probably to avoid the prevailing south-southeast winds at the study site, and were placed at a mean height of 2.1 m above the ground (n = 13). Most of the active nests (93%) were built in columnar cacti Trichocereus atacamensis that were healthier and with fewer branches than nearby available conspecifics. Mean clutch size was 3.2 white eggs (n = 9) and the incubation period was c. 18–20 days. Brood size ranged from one to three hatchlings (n = 12) and nestlings remained in the nest for 24–26 days until fledgling. Nests with complete clutches were found between 29 October and 1 February and nestlings were found between 1 November and 5 February. Nestlings were attended by both parents and were fed with arthropods (n = 63) and vertebrates (n = 7). Nest visitation rate per nestling was similar among nests with three and two nestlings and lower than for a nest with one nestling. The breeding success was high during the incubation (73%) and nestling rearing (82%) stages. Our data show that Pseudoseisura species are similar in some aspects of their breeding biology (e.g. nest dimensions, nest decorations, mating system, clutch size), whereas other aspects, such as nest-site selection, nestling period and nest attendance rate, are more variable among species. [ABSTRACT FROM AUTHOR]

A fundamental problem for any animal is how to weigh the benefits of making a rapid decision against the costs of making a poor decision, because time for detecting and evaluating all options is often restricted. For nest-site selection in birds, an important cost of a speedy decision would be nest predation, which is a major factor lowering reproductive success. I tested whether shorter time available for assessment of nest sites would lead to a decision with higher probability of nest predation. Where boreal owls (Aegolius funereus) had nested successfully in a box in the previous season, I manipulated nest box availability by offering a dyad of nest boxes. One box (kept or exchanged) was in the original nest tree and one box (new or taken from the original tree) was in a new tree for the season, each box containing either "post-nesting residue" from the successful nesting or new wood shavings. Hence, the owls could assess the risk of nest predation at a familiar site relative to that at a new site. The timing of nest box installation and relocation was such that time for assessment varied among localities, from the whole non-breeding season to just a few days prior to laying in spring. Owls that had had longer time in which to make their assessment and selection were less likely to have their nest predated by pine martens (Martes martes). Boreal owls are non-migratory and probably gained information on the relative safety of the two options by a Bayesian-like updating process in the days, weeks or months before the decision had to be made. A migratory cavity-nester exposed to the same landscape of nest predation would be more time-constrained and forced to rely on the win-stay loose-shift tactic, which underperforms relative to Bayesian-like updating. [ABSTRACT FROM AUTHOR]

Understanding how livestock grazing strategies of native warm season grasses (NWSG) can impact facultative grassland bird nesting can provide insight for conservation efforts. We compared pre and post treatment effects of rotational grazing (ROT) and patch-burn grazing (PBG) for facultative grassland bird species nest success and nest-site selection on NWSG pastures at three Mid-South research sites. We established 14, 9.7 ha NWSG pastures and randomly assigned each to either ROT or PBG and monitored avian nest-site selection and nest success, 2014-2016. We collected nesting and vegetation data in 2014, before treatment implementation, as an experimental pre-treatment. We implemented treatments across all research sites in spring 2015. We used a step-wise model selection framework to estimate treatment effect for ROT or PBG on avian nest daily survival rate (DSR) and resource selection function (RSF) at the temporal scale and within-field variables. Daily survival rates were 0.93% (SE D 0.006) for field sparrow (Spizella pusilla), 0.96% (SE D 0.008) for red-winged blackbird (Agelaius phoeniceus), and 0.92% (SE D 0.01) for indigo bunting (Passerina cyanea). Model support for PBG treatment and vegetation height were indicated as negative and positive influences for field sparrow DSR, respectively. Red-winged blackbirds' DSR were negatively influenced byROTwhile vegetation height positively affected DSR, and DSR for indigo bunting did not differ among treatments. Combined RSF models indicated nest-site selection for all species was positively related to vegetation height and only weakly associated with other within-field variables. We provide evidence that ROT and/or PBG effects vary by species for DSR for these three facultative grassland birds, and vegetation characteristics affected their nest-site selection in the Mid-South USA. A lack of disturbance in Mid-South grasslands can lead to higher successional stages (i.e., mix shrub-grassland), but some combination of ROT, PBG, and unburned/ungrazed areas can provide adequate nesting habitat on small pasture lands (~1.8 -7.8 ha) for various facultative grassland birds and potentially offer the opportunity to simultaneously maintain livestock production and grassland bird nesting habitat. [ABSTRACT FROM AUTHOR]

Summary: Understanding how birds select breeding sites plays an important role in habitat protection, especially for the conservation of endangered species. With the increase in population size of the endangered Crested Ibis Nipponia nippon, its distribution range has expanded from mountain areas to plains located outside protected areas, representing a new challenge for conservation of the species. Identifying the current nesting habitat requirements is thus needed and can provide valuable information for the planning of new nature reserves. In this research, we surveyed a total of 117 nests across the whole distribution range from 2015 to 2019. We used generalized linear mixed-effects models to assess nesting preferences of the Crested Ibis in the wild. Results showed that in mountain areas, Masson pines Pinus massoniana were preferred (64.6%), whereas elms Ulmus pumila (44.9%) and aspens Populus davidiana (40.6%) were used more frequently lower down, probably because of their higher availability. In both mountain areas and plains the ibises selected tall nesting trees with larger diameter at breast height and preferred nesting rather high above ground, especially in plains where taller trees provided higher suitable nesting positions. The ibises also preferred nesting close to tree trunks, especially in mountain areas, probably for more safety from collapsing. Furthermore, in mountain areas, slope and distance to path had positive effects on nesting occurrence, and understorey coverage was avoided by nesting ibises, while these variables had little impact in plains. Our results indicate that, despite their range expansion, Crested Ibises rely on very specific habitat characteristics for nesting. We suggest relatively tall trees like elms and aspens should be preserved in plains. In addition, we highlight how selection patterns of Crested Ibises may vary, and that such variation should be addressed in conservation planning, especially in future reintroduction. [ABSTRACT FROM AUTHOR]

Abstract Nest‐site characteristics are thought to play an important role in reproductive performance in birds (e.g., influencing reproductive success and predation risk). Nest‐site characteristics such as concealment may be particularly critical at high elevation where nests are exposed to challenging environmental conditions. In this study, we conducted both conventional and phylogenetically controlled analyses to investigate whether nest concealment affected several reproductive traits across 21 sympatric bird species living on Tibet Plateau (3,400 m altitude). Qualitatively equivalent results were reached in analyses, regardless of phylogenetic controls. We found that clutch size, incubation period, nestling period, and nest success were strongly and positively associated with nest concealment across species. Our study addressed such a high‐elevation bird community that is lacking in the previous studies. This study adds to theory that while there are a few exceptions, overall evidence supports a positive effect of nest concealment on reproductive performance across coexisting alpine species.

Abstract Background Interspecific interactions within ecological networks can influence animal fitness and behaviour, including nest-site selection of birds and ants. Previous studies revealed that nesting birds and ants may benefit from cohabitation, with interspecific attraction through their nest-site choice, but mutual interactions have not yet been tested. We explored a previously undescribed ecological link between ground-nesting birds and ants raising their own broods (larvae and pupae) within the birds’ nests in a temperate primeval forest of lowland Europe. We tested whether the occurrence of ant broods within bird nests resulted from a mutual or one-sided interspecific attraction that operated through nest-site choice and was modified by weather conditions. Results We found a non-random occupation of bird nests by ants raising their own broods within them, which indicated interspecific attraction driven solely by the ants. The birds’ preference to nest near tussocks of vegetation showed little overlap with the most frequent placement of ant colonies among fallen deciduous tree-leaves, dead wood and moss. Additionally, birds did not appear to select forest localities with high densities of ant colonies. The occurrence of ant broods within bird nests was also unrelated to bird nest placement near to specific habitat features. The attractiveness of bird nests to ants appeared to increase with the thermal activity of the birds warming their nests, and also during cool and wet weather when the occurrence of ant broods within bird nests was most frequent. Ants often remained in the nests after the birds had vacated them, with only a slight reduction in the probability of ant brood occurrence over time. Conclusions The natural patterns of bird nest colonisation by ants support the hypothesis of ants’ attraction to warm nests of birds to raise their broods under advantageous thermal conditions. Similar relationships may occur between other warm-blooded, nest-building vertebrates and nest-dwelling invertebrates, which depend on ambient temperatures. The findings advance our understanding of these poorly recognised interspecific interactions, and can inform future studies of ecological networks.

Greater Prairie-chickens (Tympanuchus cupido) historically occupied 20 states within the contiguous United States; however, due to habitat degradation and loss, they are currently found in 11 states, only four of which have a stable population. Kansas supports a relatively large abundance of Greater Prairie-chickens, where the Flint Hills ecoregion historically supported the largest population density of all ecoregions. In the past decade, the Flint Hills population has declined by 75 % to an estimated 8,334 individuals in 2021 from 34,180 individuals in 2015 due to landscape changes and intensification of grassland management practices. The Fort Riley Military Reservation in the northwest portion of the Flint Hills ecoregion is one of a few areas within the ecoregion that does not implement grazing or vast annual burning. The Greater Prairie-chicken population within Fort Riley has remained relatively stable over the past 25 years despite being constrained by surrounding landscape features and development. We analyzed multiple scales of resource selection by 46 female Greater Prairie-chickens during March-April 2019–2021 on Fort Riley to investigate why this population is doing relatively well compared to populations in surrounding areas. We tested landscape feature, vegetation, and burn mosaic variables to evaluate which variables had the greatest influence on resource selection. Landscape features had the greatest influence on resource selection. Females avoided trees within Fort Riley for both breeding season use and nest-site selection at a greater margin than any other study in Kansas. Additionally, fourth-order selection was not evident within this study system, contrary to studies within surrounding areas. Our findings join a growing body of literature that suggests containment of woody encroachment as a high priority for managers to maintain or expand prairie grouse habitat in many different environments. This containment is especially critical on Fort Riley because of its constrained environment, and further woody encroachment could lead to loss of habitat that is inescapable by the Greater Prairie-chicken population on Fort Riley. Spatially-explicit evaluations of habitat availability are increasingly important as more areas within the Greater Prairie-chicken range become constrained by urbanization, agricultural expansion, and intensive management practices.

Understanding how livestock grazing strategies of native warm season grasses (NWSG) can impact facultative grassland bird nesting can provide insight for conservation efforts. We compared pre and post treatment effects of rotational grazing (ROT) and patch-burn grazing (PBG) for facultative grassland bird species nest success and nest-site selection on NWSG pastures at three Mid-South research sites. We established 14, 9.7 ha NWSG pastures and randomly assigned each to either ROT or PBG and monitored avian nest-site selection and nest success, 2014–2016. We collected nesting and vegetation data in 2014, before treatment implementation, as an experimental pre-treatment. We implemented treatments across all research sites in spring 2015. We used a step-wise model selection framework to estimate treatment effect for ROT or PBG on avian nest daily survival rate (DSR) and resource selection function (RSF) at the temporal scale and within-field variables. Daily survival rates were 0.93% (SE = 0.006) for field sparrow (Spizella pusilla), 0.96% (SE = 0.008) for red-winged blackbird (Agelaius phoeniceus), and 0.92% (SE = 0.01) for indigo bunting (Passerina cyanea). Model support for PBG treatment and vegetation height were indicated as negative and positive influences for field sparrow DSR, respectively. Red-winged blackbirds’ DSR were negatively influenced by ROT while vegetation height positively affected DSR, and DSR for indigo bunting did not differ among treatments. Combined RSF models indicated nest-site selection for all species was positively related to vegetation height and only weakly associated with other within-field variables. We provide evidence that ROT and/or PBG effects vary by species for DSR for these three facultative grassland birds, and vegetation characteristics affected their nest-site selection in the Mid-South USA. A lack of disturbance in Mid-South grasslands can lead to higher successional stages (i.e., mix shrub-grassland), but some combination of ROT, PBG, and unburned/ungrazed areas can provide adequate nesting habitat on small pasture lands (∼1.8 –7.8 ha) for various facultative grassland birds and potentially offer the opportunity to simultaneously maintain livestock production and grassland bird nesting habitat.

Vertebrate embryos require access to water; however, many species nest in terrestrial habitats that vary considerably in moisture content. Oviparous, non‐avian reptiles have served as models to understand how environmental factors, like moisture availability, influence development because eggs are often exposed to prevailing environments in the absence of parental care. Though much research demonstrates the importance of water absorption by eggs, many ecological factors that influence moisture availability in natural nests have received little attention. For example, the type of substrate in which nests are constructed is understudied. We experimentally incubated eggs of the brown anole lizard (Anolis sagrei) in 2 naturally occurring nest substrates that were treated with varying amounts of water to determine how natural substrates influence development at different moisture concentrations. One substrate consisted of sand and crushed seashells and the other was mostly organic material (i.e. decayed plant material). Both are common nesting substrates at our field site. When controlling for water uptake by eggs, we found that egg survival and hatchling phenotypes were similar between substrates; however, embryos developed more quickly in the sand/shell substrate than the organic substrate, indicating substrate‐specific effects on embryo physiology. These results demonstrate that different natural substrates can result in similar developmental outcomes if the water available to eggs is comparable; however, some aspects of development, like developmental rate, are affected by the type of substrate, independent of water availability. Further study is required to determine how natural substrates influence embryo physiology independent of water content. [ABSTRACT FROM AUTHOR]

We documented nests built by Woolly‐necked Storks, a large waterbird, being preferentially reused by Dusky Eagle‐Owls, a large raptor, with nest sites located close to irrigation canals in Haryana, India. This novel commensal relationship observed in an agricultural landscape underscores the need to expand tropical ecology investigations to outside of protected forested reserves. [ABSTRACT FROM AUTHOR]

Understanding species' responses to temperature via behavior, and the factors affecting the extent of behavioral responses, is a critical and timely endeavor given the rapid pace at which the climate is changing. The young of altricial songbirds are particularly sensitive to temperature, and parents may modulate temperatures at nests via selection of nest sites, albeit to a largely unknown extent. We examined whether sagebrush-obligate songbirds, that reproduce within an open ecosystem with wide temperature fluctuations and span a range of body sizes, selected their nest sites on the basis of temperature. We further investigated whether nest predation risk and ambient conditions modulated temperature-based choices. We placed temperature loggers at nest sites and in unused but available nest niches and nest shrubs along a known predation-risk gradient and used nearby weather stations to determine ambient temperatures. The two smaller-bodied birds, Brewer's Sparrow (Spizella breweri) and Sagebrush Sparrow (Artemisiospiza nevadensis), selected nest shrubs and niches that were warmer and less variable relative to unused sites whereas the larger bodied species, Sage Thrashers (Oreoscoptes montanus), did not. Brewer's Sparrows and Sage Thrashers dampened selection for warmer nest sites when temperatures experienced during the nest-site prospecting period were warmer. None of the three species altered nest-site selection with respect to temperature in response to ambient temperature variability or our index of nest predation risk. The microhabitat characteristics that most influenced temperatures at nests varied across species. Our results suggest that songbirds can modulate temperatures at nests to some extent, and such responses can vary depending on the conditions experienced prior to nest initiation. Responses also varied across species, likely reflecting different physiological tolerances. The extent to which breeding birds will be able to continue to proximately influence temperature via nest-site choices likely will depend on the extent and rate of future climatic shifts. [ABSTRACT FROM AUTHOR]

Most bird species that nest in tree cavities globally occur in diverse assemblages in little‐studied tropical and subtropical forests which have high rates of habitat loss. Conservation of these communities will require an understanding of how species traits, such as body size, influence nest‐site selection. We examined patterns of nest‐site selection of secondary cavity‐nesting birds at the nest patch, tree and cavity scale, and investigated how these patterns are influenced by body size. Using conditional logistic regression, we compared characteristics of 155 nest tree cavities paired with 155 unused tree cavities in quebracho Schinopsis balansae forests in Chaco National Park, Argentina (2016–2018). The odds of a cavity being used for nesting increased with its depth and height above ground, decreased with entrance size, and were greater for dead trees than live. Small‐bodied (13–90 g) species used floor diameters in proportion to availability, but medium‐ (150–200 g) and large‐bodied (400–700 g) species selected cavities with larger floors. Model selection indicated that characteristics at the nest patch scale (canopy cover, tree density) had little effect on nest‐site selection when cavity‐scale variables were included. Cavity floor diameter, entrance size, cavity height and tree diameter (but not cavity depth) increased with body mass, and larger bird species more often used live trees. Two tree species proved to be key for the community: large and medium‐sized birds used almost exclusively large live Schinopsis balansae, whereas small birds used live and dead Prosopis spp. in a proportion greater than its availability. Small birds could be differentiated according to species‐specific cavity characteristics, but medium and large species overlapped considerably with one another. Although body mass explained much of the overall variation in tree and cavity characteristics between small and medium/large species, several small‐bodied species consistently used cavities outside of the expected characteristics for their body size, suggesting that other natural history traits may play important roles in nest‐site selection by small‐bodied birds. To retain the full suite of secondary cavity‐nesters in species‐rich tropical and subtropical forests, it is necessary to conserve a diversity of trees and cavities that meet the full range of nesting requirements of these trait‐diverse communities. [ABSTRACT FROM AUTHOR]

Studies on nest-site selection can reveal aspects of habitat requirements of the target species, and can be useful to infer about how habitat changes can affect local populations. The Helmeted Manakin, Antilophia galeata, is a piprid that inhabits mainly the humid gallery forests that occur along watercourses of the savanna-like Cerrado biome from central South America, and like most tropical forest understory passerines, it is poorly known under a nest-site selection perspective. Here we provide nest-site selection assessment based on nine variables for a population of the Helmeted Manakin from southeast Brazil. We found that females strongly selected Miconia nervosa (Melastomataceae) as a nesting plant species. Further, we demonstrated that the presence of nests was positively associated with canopy cover and with the occurrence of the endangered jussara palm trees, Euterpe edulis. These results suggest that the Helmeted Manakin is specialized in reproducing in mature and well-preserved gallery forest tracts. Gallery forests are narrow stripes of riparian vegetation from the endangered Cerrado domain, and here we showed that even in these linear habitats, the Helmeted Manakin can seek for specific portions for nesting. This is one of the few studies reporting nest-site specialization in a Neotropical forest-dwelling passerine. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Field Ornithology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract The selection of a nest site is crucial for successful reproduction of birds. Animals which re‐use or occupy nest sites constructed by other species often have limited choice. Little is known about the criteria of nest‐stealing species to choose suitable nesting sites and habitats. Here, we analyze breeding‐site selection of an obligatory “nest‐cleptoparasite”, the Amur Falcon Falco amurensis. We collected data on nest sites at Muraviovka Park in the Russian Far East, where the species breeds exclusively in nests of the Eurasian Magpie Pica pica. We sampled 117 Eurasian Magpie nests, 38 of which were occupied by Amur Falcons. Nest‐specific variables were assessed, and a recently developed habitat classification map was used to derive landscape metrics. We found that Amur Falcons chose a wide range of nesting sites, but significantly preferred nests with a domed roof. Breeding pairs of Eurasian Hobby Falco subbuteo and Eurasian Magpie were often found to breed near the nest in about the same distance as neighboring Amur Falcon pairs. Additionally, the occurrence of the species was positively associated with bare soil cover, forest cover, and shrub patches within their home range and negatively with the distance to wetlands. Areas of wetlands and fallow land might be used for foraging since Amur Falcons mostly depend on an insect diet. Additionally, we found that rarely burned habitats were preferred. Overall, the effect of landscape variables on the choice of actual nest sites appeared to be rather small. We used different classification methods to predict the probability of occurrence, of which the Random forest method showed the highest accuracy. The areas determined as suitable habitat showed a high concordance with the actual nest locations. We conclude that Amur Falcons prefer to occupy newly built (domed) nests to ensure high nest quality, as well as nests surrounded by available feeding habitats.

Abstract Raptor species conservation should consider a landscape perspective in order to include habitat requirements associated to large home ranges around nesting sites. Landscape analysis can help to better understand raptor habitat requirements and the degree of tolerance to habitat changes at different scales. We used a landscape ecology perspective to determine the nesting habitat selection of endemic and endangered Cuban Black Hawk, and using ecological niche modeling, we obtained the potential distribution of nests to evaluate the effectiveness of protected areas (PAs) for raptor conservation. Nesting habitat selection was related to breeding success at a landscape scale using data from 27 different nesting sites during 2012–2013 breeding seasons. The potential nesting areas distribution was compared with current officially PAs design in the central region of Cuba. All nests were located in mangrove swamp. Pairs chose nesting sites with low soil–vegetation moisture and low soil reflectance. At the landscape level, they selected low shape complexity of patches and few patches of coastal vegetation around nesting sites which contained similar mangrove patch size and shape. The potential distribution of nests increased close to the coastline. The model predicted a suitable narrow area of 556 km2, and the most favorable nesting area represented 2% of this total. 33% of nests were located within officially natural protected areas while 27% were close to or inside highly threatened areas. A 16% of high to medium suitable nesting habitat overlaps with urban areas. Currently, PAs contain 23% of the nesting area distribution. Our study shows landscape ecology and nest‐site selection approach is crucial to evaluate the persistence of Cuban Black Hawk, as environmental variables and human activity can be related to its productivity. This approach can be applied in conservation strategies of island raptors.

Nest‐site characteristics are thought to play an important role in reproductive performance in birds (e.g., influencing reproductive success and predation risk). Nest‐site characteristics such as concealment may be particularly critical at high elevation where nests are exposed to challenging environmental conditions. In this study, we conducted both conventional and phylogenetically controlled analyses to investigate whether nest concealment affected several reproductive traits across 21 sympatric bird species living on Tibet Plateau (3,400 m altitude). Qualitatively equivalent results were reached in analyses, regardless of phylogenetic controls. We found that clutch size, incubation period, nestling period, and nest success were strongly and positively associated with nest concealment across species. Our study addressed such a high‐elevation bird community that is lacking in the previous studies. This study adds to theory that while there are a few exceptions, overall evidence supports a positive effect of nest concealment on reproductive performance across coexisting alpine species. [ABSTRACT FROM AUTHOR]

Many species of the family Picidae, such as the woodpeckers, excavate the tree-cavities where they nest. Frequently the cavities are used during a single breeding season and subsequently abandoned, which allows their use by non-excavator species for nesting or roosting. Here we analyze the role of woodpeckers as providers of nesting and refuge places in two urban parks in the city of Madrid. The environmental characteristics of the woodpecker nest-sites were also studied. Prior to the breeding season 75 trees bearing woodpecker-excavated cavities and 142 control trees (i.e. without woodpecker cavities) were located, georeferenced and characterized by a set of variables relative to the tree and its environment. During the breeding season the cavities were monitored with an endoscopic camera to verify occupation and user identity. Additionally, 71 non-excavated tree-cavities were monitored to measure their occupancy and make comparisons with those excavated by woodpeckers. Woodpeckers showed a strong preference for trees of the genus Populus: 54 of 75 (72%) woodpecker-cavities were in poplars, which comprised only 7–10% of available trees. The excavated cavities were found mainly in the trunk of the trees, north oriented and away from paths. The occupancy rate by bird species was higher, although not significantly, for excavated cavities than for natural cavities (36.0% and 23.9% respectively). The richness and composition of cavity-user species also differed between types of tree-cavities. This work shows the importance of woodpeckers as providers of nesting and refuge places for other cavity-user birds and highlights their role as ecosystem engineers in urban parks. Finally, we consider that these results can guide biodiversity conservation efforts in urban planning. [ABSTRACT FROM AUTHOR]

Background: Interspecific interactions within ecological networks can influence animal fitness and behaviour, including nest-site selection of birds and ants. Previous studies revealed that nesting birds and ants may benefit from cohabitation, with interspecific attraction through their nest-site choice, but mutual interactions have not yet been tested. We explored a previously undescribed ecological link between ground-nesting birds and ants raising their own broods (larvae and pupae) within the birds' nests in a temperate primeval forest of lowland Europe. We tested whether the occurrence of ant broods within bird nests resulted from a mutual or one-sided interspecific attraction that operated through nest-site choice and was modified by weather conditions. Results: We found a non-random occupation of bird nests by ants raising their own broods within them, which indicated interspecific attraction driven solely by the ants. The birds' preference to nest near tussocks of vegetation showed little overlap with the most frequent placement of ant colonies among fallen deciduous tree-leaves, dead wood and moss. Additionally, birds did not appear to select forest localities with high densities of ant colonies. The occurrence of ant broods within bird nests was also unrelated to bird nest placement near to specific habitat features. The attractiveness of bird nests to ants appeared to increase with the thermal activity of the birds warming their nests, and also during cool and wet weather when the occurrence of ant broods within bird nests was most frequent. Ants often remained in the nests after the birds had vacated them, with only a slight reduction in the probability of ant brood occurrence over time. Conclusions: The natural patterns of bird nest colonisation by ants support the hypothesis of ants' attraction to warm nests of birds to raise their broods under advantageous thermal conditions. Similar relationships may occur between other warm-blooded, nest-building vertebrates and nest-dwelling invertebrates, which depend on ambient temperatures. The findings advance our understanding of these poorly recognised interspecific interactions, and can inform future studies of ecological networks. [ABSTRACT FROM AUTHOR]

Site fidelity after successful nesting and site shift after nest predation (win–stay, lose–shift) is a well-documented adaptation to spatially heterogeneous and temporally auto-correlated predation risk. However, site shift even after a successful nesting (win–shift) may become a better tactic than site fidelity (win–stay), if a successful nest site becomes more risky until the next nesting opportunity, and if new low-risk nest sites regularly appear. Correspondingly, selecting a new non-used nest site may become a better tactic than selecting one previously used successfully by a conspecific. I studied this dynamic by focusing on nest cavities that may be available for many years, and using nest boxes to allow an experimental design. At localities where Boreal Owls (Aegolius funereus) had nested successfully, a dyad of nest boxes was made available each year, one box in the original nest tree and one in a new tree for the season, each containing either old nest material from the successful nesting or new wood shavings. Boreal owls were more likely to select the box in the new tree when more years had elapsed since the successful nesting and since a box was installed in the original nest tree, independent of box content. The pattern of selection differed between young and old individuals for males, but not females. Young males based their selection of nest tree mainly on box content, while old males based it on time elapsed since the successful nesting in the original nest tree and how long a box had been present there. The probability of depredation of Boreal Owl nests by Pine Marten (Martes martes) has previously been found to increase with cavity age and number of nesting seasons elapsed since the previous successful nesting. This pattern of nest predation thus predicted the pattern of nest site selection found. [ABSTRACT FROM AUTHOR]

Breeding biology data are crucial for avian life history theory, but this information is unavailable for nearly half of the current living tropical bird species. Predation is the main driver of nest survival among tropical birds, and spatial and temporal factors may affect nest predation risk and survival. In this study, we describe the breeding biology of the Rusty-backed Antwren (Formicivora rufa), a bird that inhabits a coastal sandy plain in southeastern Brazil, and examine the effects of date and microhabitat features on nest survival. We found 47 nests over 2 breeding seasons. The nesting season lasted 7–8 months. The mean (± SD) nest-building time was 7.3 ± 1.1 d, the mean incubation period was 16 ± 1.9 d, and nestlings remained in the nest for 10 ± 0.8 d for a full nesting cycle that lasted for ∼26 d. Clutches invariably had 2 eggs and egg-laying occurred over 2 consecutive days. Males and females were both observed building nests, incubating eggs, and feeding nestlings and fledglings. We also report a nestling with a depigmented body, which may represent albinism. Most nests were depredated (68.1%, n = 32). Nest survival was constant throughout the breeding seasons and did not vary with microhabitat features (nest height above the ground, and vertical and horizontal distances between nest and shrub edges). The nesting biology of the Rusty-backed Antwren fits the general pattern typical of antbirds, and micro-spatial or temporal features cannot predict nest survival in our study population. [ABSTRACT FROM AUTHOR]

Copyright of Avian Conservation & Ecology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Background Floods and other extreme events have disastrous effects on wetland breeding birds. However, such events and their consequences are difficult to study due to their rarity and unpredictable occurrence. Methods Here we compared nest-sites chosen by Reed Parrotbills (Paradoxornis heudei) during June‒August 2016 in Yongnianwa Wetlands, Hebei Province, China, before and after an extreme flooding event. Results Twenty-three nests were identified before and 13 new nests after the flood. There was no significant difference in most nest-site characteristics, such as distance from the road, height of the reeds in which nests were built, or nest volume before or after the flood. However, nests after the flood were located significantly higher in the vegetation compared to before the flood (mean ± SE: 1.17 ± 0.13 m vs. 0.75 ± 0.26 m, p

Effective coordination of group actions underlies the success of group‐living organisms. Making decisions collectively is a crucial step in executing behaviours affecting the whole group. In social insects, decision‐making is typically achieved in a self‐organised manner and incorporates a quorum process, which can improve decision accuracy and be tailored to different conditions. Studies of the nest‐selection process in different social insect species have revealed remarkable consistency in the mode of decision‐making despite marked differences in life history and colony size. However, an often‐overlooked aspect of this decision process is how it might be influenced by diversity in behavioural propensity among colony members. Higher diversity can improve collective processes, but could also represent a cost if certain classes of individual do not contribute to the cooperative activity. Many ant species exhibit caste polymorphism, with different worker castes specialised to different functions. These castes could thus enhance or erode the collective decision process depending on whether they contribute to this process or not. In this study, we explore the process of colony emigration and nest‐site choice in the small carpenter ant Camponotus yamaokai, a species with two distinct worker castes. We show that this species is likely to use a quorum decision process facilitated by navigation with chemical trails. Both major and minor castes contributed to the collective decision and emigration process. However, although major workers comprised 24% of the colony on average, they were 5.5 times less likely than expected to be involved in assessing new nests and 4.6 times less likely than expected to contribute to brood transport. This may represent a previously unrecognised cost to the colony in the emigration process. In addition, we document the first observations of sequential brood transfer during emigration behaviour and speculate upon the function of this behaviour. [ABSTRACT FROM AUTHOR]