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A key step in generating effective recovery strategies for species at risk is to identify habitat used under a variety of geographic settings. In part attributable to habitat loss and degradation, the Blanding's turtle (Emydoidea blandingii) is considered at risk across most of its range. Because little information for this species exists for the many islands of Georgian Bay, the world's largest freshwater archipelago, we conducted an intensive study on the habitat use of 12 turtles (6 males, 6 females) on a protected island. We used a combination of radio tracking and GPS loggers to determine habitat use during the active seasons of 2011 and 2012. We used aerial imagery to quantify available habitat and used compositional analyses to determine habitat selection. Both sexes used vernal pools and wet forest to move between habitat patches. Females used inland wetlands early in the year and coastal wetlands during the nesting season, whereas males maintained extensive use of inland wetlands during ...

Studies of sea turtle epibiosis have focused on the diversity and ecology of facultative commensalisms and less attention has been given to parasitic associations, in which the epibiont species derives nutrients from the tissue of the host turtle. We present the first description and quantitative survey of the parasitic isopods Excorallana costata, Excorallana bicornis and Excorallana oculata on loggerhead (N = 79) and hawksbill turtles (N = 23), and E. costata on olive ridley turtles (N = 9), nesting on Praia do Forte, Bahia, Brazil during the 2009–2010 season. Excorallana costata was the most common isopod species (N = 651), followed by E. bicornis (N = 77) and E. oculata (N = 20). Patterns include: (1) E. costata exhibited a higher frequency and intensity of parasitism than E. bicornis and E. oculata and (2) loggerheads hosted parasitic isopods at a higher frequency and intensity than hawksbills and olive ridleys. We also detected temporal shifts in the occurrence and intensity of parasitism across the nesting season, which strongly suggests that turtles were parasitized by all three isopod species during their internesting periods. Because parasitic isopods were observed only rarely prior to the 2009–2010 turtle-nesting season and have continued to be common in subsequent seasons, it is important to gain a better understanding of the basic biology of these interactions, the reasons for their recent emergence, and the potential biological impacts on turtle, as well as isopod, populations.

Northern bobwhites (Colinus virginianus) represent a valuable resource for upland game-bird hunters and the rural economies they support; however, bobwhite populations are declining across the United States. As ground-nesting birds, bobwhites are highly susceptible to mammalian predation during the breeding season. We placed global positioning collars on 6 coyotes (Canis latrans), 4 bobcats (Lynx rufus), and 11 raccoons (Procyon lotor) in Texas, USA, during the nesting season of bobwhites (April–August of 2009–2011) to assess their habitat selection and use, as well as determine the relative frequency with which they may encounter bobwhite nests. Overall, nightly encounter rate of predators with known bobwhite nest sites was low. Coyotes encountered nest sites 3 times more frequently than male raccoons and 7 times more frequently than bobcats. Female raccoons did not come within 50 m of any nest locations. The higher encounter rate of coyotes with bobwhite nest sites was associated with the similarity of habitat preference of coyotes and bobwhites for grasslands and grass–shrub habitats and the wide-ranging nocturnal paths of coyotes. Bobcats and raccoons had shorter nightly paths and mainly used habitats providing a greater degree of cover than is typically suitable for nesting bobwhites. Male raccoons were more mobile than females and made greater use of the grass–shrub habitat, and thus were more likely to encounter quail nests. Despite having lower individual encounter rates with bobwhite nest sites than did coyotes, male raccoons remain important predators of quail nests because they have the behavioral ability to attain greater population densities than those of the more territorial coyotes and bobcats. © 2014 The Wildlife Society.

Nest predation can threaten marine turtle nesting success, and having to address dissimilar predator species complicates nest protection efforts. On Florida's Keewaydin Island predation by raccoons Procyon lotor and invasive feral swine Sus scrofa are disparate, significant threats to marine turtle nests. Using 6 years of nesting data (mostly for loggerhead marine turtles Caretta caretta) we examined the impacts of swine predation on nests and the benefits of swine eradication, caging nests to protect them from raccoon predation, and the effects of nest caging on swine predation. Nest predation by swine began in mid nesting season 2007, after which swine quickly annihilated all remaining marine turtle nests. During 2005–2010 raccoon predation rates for caged nests (0.7–20.4%) were significantly lower than for uncaged nests (5.6–68.8%) in every year except 2009, when little raccoon predation occurred. The proportions of eggs lost from raccoon-predated nests did not differ between caged and uncaged nests. Caging did not prevent destruction by swine but median survival time for caged nests was 11.5 days longer than for uncaged nests, indicating that caged eggs in nests have a greater chance of hatching before being predated by swine. The financial cost of the eradication of swine greatly outweighed the value of hatchlings lost to swine predation in 2007.

To improve conservation strategies for threatened sea turtles, more knowledge on their ecology, behavior, and how they cope with severe and changing weather conditions is needed. Satellite and animal motion datalogging tags were used to study the inter-nesting behavior of two female loggerhead turtles in the Gulf of Mexico, which regularly has hurricanes and tropical storms during nesting season. We contrast the behavioral patterns and swimming energetics of these two turtles, the first tracked in calm weather and the second tracked before, during and after a tropical storm. Turtle 1 was highly active and swam at the surface or submerged 95% of the time during the entire inter-nesting period, with a high estimated specific oxygen consumption rate (0.95 ml min-1 kg-0.83). Turtle 2 was inactive for most of the first 9 days of the inter-nesting period, during which she rested at the bottom (80% of the time) with low estimated oxygen consumption (0.62 ml min-1 kg-0.83). Midway through the internesting period, turtle 2 encountered a tropical storm and became highly active (swimming 88% of the time during and 95% after the storm). Her oxygen consumption increased significantly to 0.97 ml min-1 kg-0.83 during and 0.98 ml min-1 kg-0.83 after the storm. However, despite the tropical storm, turtle 2 returned to the nesting beach, where she successfully re-nested 75 m from her previous nest. Thus, the tropical storm had a minor effect on this female's individual nesting success, even though the storm caused 90% loss nests at Casey Key.

International audience; Wild bees are declining in intensively farmed regions worldwide, threatening pollination services to flowering crops and wild plants. To halt bee declines, it is essential that conservation actions are based on a mechanistic understanding of how bee species utilize landscapes. We aimed at teasing apart how foraging resources in the landscape through the nesting season affected nesting and reproduction of a solitary bee in a farmland region. We investigated how availability of floral resources and potentially resource-rich habitats surrounding nests affected nest provisioning and reproduction in the solitary polylectic bee Osmia bicornis. The study was performed in 18 landscape sectors dominated by agriculture, but varying in agricultural intensity in terms of proportion of organic crop fields and seminatural permanent pastures. Pasture-rich sectors contained more oak (Quercus robur), which pollen analysis showed to be favored forage in early season. More oaks ≤100 m from nests led to higher proportions of oak pollen in nest provisions and increased speed of nest construction in early season, but this effect tapered off as flowering decreased. Late-season pollen foraging was dominated by buttercup (Ranunculus spp.), common in various noncrop habitats. Foraging trips were longer with more oaks and increased further through the season. The opposite was found for buttercup. Oak and buttercup interacted to explain the number of offspring; buttercup had a positive effect only when the number of oaks was above the mean for the studied sectors. The results show that quality of complex and pasture-rich landscapes for O. bicornis depends on preserving existing and generating new oak trees. Lignose plants are key early-season forage resources in agricultural landscapes. Increasing habitat hetero-geneity with trees and shrubs and promoting suitable late-flowering forbs can benefit O. bicornis and other wild bees active in spring and early summer, something which existing agri-environment schemes seldom target.

Ecologists have long recognized the influence that environmental conditions have on abundance and range extent of animal species. We used the northern bobwhite (Colinus virginianus; hereafter bobwhite) as a model species for studying how microclimates serve as refuge against severe weather conditions. This species serves as an indicator or umbrella species for other sensitive ground-nesting, grassland obligate species. We conducted a mensurative field experiment in the rolling plains of Texas, USA, a semi-arid ecosystem on the southwestern periphery of bobwhite range, to determine whether native bunch grasses, apparently suitable for bobwhite nesting, could reduce ambient temperature below levels harmful for eggs. During the nesting season, we compared temperature and relative humidity readings at daily heat maxima (i.e., the 3 h during each day with highest temperatures) during the nesting season over the course of two years at 63 suitable nest sites paired with 63 random locations (n= 126) using two sensors at ∼10 and ∼60 cm above ground level. Mean temperature at nest height was 2.3% cooler at nest sites (35.99 °C ± 0.07 SE) compared to random locations (36.81 °C ± 0.07 SE); at ambient height, nest sites were slightly cooler (32.78 °C ± 0.06 SE) than random location (32.99 °C ± 0.06 SE). Mean relative humidity at nest sites was greater at nest height (34.53% ± 0.112 SE) and ambient height (36.22% ± 0.10 SE) compared to random locations at nest (33.35% ± 0.12 SE) and ambient height (35.75% ± 0.10 SE). Based on these results, cover at sites that appear visually suitable for nesting by bobwhites and other ground nesting birds provided adequate thermal refuge in the rolling plains by maintaining cooler, moister microclimates than surrounding non-nesting locations. Post-hoc analyses of data revealed that habitat conditions surrounding suitable nest sites strongly influenced thermal suitability of the substrate. Given that eggs of bobwhites and probably other species would experience lethal temperatures without these thermal refuges in the context of proper habitat condition, nesting vegetation is a critical component of niche space for bobwhites and other ground nesting birds in semi-arid regions. Many contemporary land uses, however, degrade or destroy bunch grasses and grassland systems, and thus decrease landscape inhabitability. Conservationists working with obligate grassland species that require bunch grasses in semi-arid regions should develop land management strategies that maximize the availability of these thermal refuges across space and time.

Understanding high-use areas for highly migratory species and their movements within these areas may provide insight into behaviors such as foraging and mating. In the Western Atlantic, the leatherback sea turtle, Dermochelys coriacea, has a broad geographic range extending from nesting beaches at low latitudes to foraging areas off the coast of Eastern Canada. Biotelemetry has revealed much about the movements and habitats of leatherbacks. However, the timing and location of leatherback mating behavior remains unclear. We conducted spatial analyses of the movements of reproductive female leatherbacks prior to their first seasonal nesting events. Using kernel density estimates, high-use areas for seven female turtles originally tagged in Canadian waters were revealed from 50% volume contours depicting pre-nesting movements (120 days prior to confirmed nesting events) and inferred mating behavior (45 days prior to confirmed nesting events). All individuals initially remained offshore within a relatively small range of latitude (10–15° N) before transiting to and residing in coastal waters adjacent to nesting beaches in Colombia (n = 2), Trinidad (n = 3), Guyana (n = 1), and French Guiana (n = 1). Comparison of these movement patterns to those of mature male leatherbacks (n = 12) revealed similarities. Male and female residency within this offshore high-use area may be indicative of prey exploitation prior to the energetically costly nesting season. While the offshore residency period of three males and one female extended into the interval in which mating is expected to occur, most males and females transited to coastal waters where they resided throughout this period. High-use areas determined through kernel density analysis support and corroborate previous telemetry work indicating that mature male leatherbacks exhibit seasonal residency adjacent nesting beaches for the early portion of the nesting season, presumably to exploit mating opportunities. Fine-scale analyses of fisheries interactions in both coastal and offshore waters and estimation of accompanying mortality rates is required to evaluate fishery threats to this population during the pre-nesting interval.

Nest counts are often used as indices for nesting female abundance in marine turtle monitoring, but accurately interpreting nest count trends requires context on the scale of demographic connectivity and estimates of reproductive parameters. Weak nest site fidelity (NSF) relative to the scale of tagging effort may bias parameter estimates. The reproductive ecology of Northern Recovery Unit (NRU) loggerhead turtles (Caretta caretta) was assessed through subpopulation-scale genetic capture-recapture via clutch sampling from approximately 1000 km of coastline from Georgia to Maryland, USA (30.75–38.06°N and 75.24–81.45°W). Of 20,682 clutches recorded from 2010 to 2012, 20,222 sampled clutches were assigned to 5684 unique females through microsatellite genotyping. Approximately 73% of females detected laying multiple clutches deposited them within a 20-km span, suggesting the possibility of demographic structuring across NRU rookeries that warrants further investigation. Estimated clutch frequencies (ECF) generated from open robust design modeling were 4.28 (4.02–4.54) in 2010, 4.63 (4.45–4.80) in 2011, and 4.57 (4.28–4.77) in 2012, and were significantly higher than observed clutch frequencies. ECF generated from single-island data were biased low by 23–50% relative to those from regional genetic tagging. Among females that nested at least once on a physical tagging beach, 54% also nested elsewhere, with 81% of these “permanently” emigrating during the nesting season. This pattern of relatively strong NSF, but distributed across multiple nearby islands, confounded modeling of detection in single-island datasets and highlights the need for regional coverage for generating robust estimates of demographic parameters for marine turtles.

The marine habitat use of olive ridley sea turtles (Lepidochelys olivacea) from northeastern Brazil was analyzed via stable isotope analysis (SIA). Blood (red blood cells and serum), epidermis and scute samples from 46 nesting females were collected for SIA of carbon (δ 13C) and nitrogen (δ 15N) to infer the habitats used at distinct time windows. Such approach is possible because each tissue reflects consumer’s diet at different time scales due to different tissue turnover time. Prey representative of both neritic and oceanic realms was used as endpoints. Differences in the residence time of δ 13C and δ 15N among samples indicated a shift from oceanic feeding grounds to neritic habitats before nesting or effects of prolonged fasting on stable isotope values. However, two individuals seemed to have used neritic feeding habitats for longer timespans before the nesting period. Stable isotope mixing models demonstrated high individual variability, suggesting the variable use of non-breeding grounds. Moreover, serum indicated that olive ridleys might feed during the nesting season, most likely opportunistically on discards from trawl fisheries. Finally, through correlations of stable isotope values among tissues, this study provides equations for the conversion and adequate comparison between values from different tissues. Therefore, the habitats used by olive ridley sea turtles from Brazil are vast, encompassing both oceanic and neritic habitats, where they encounter pelagic longline and trawl fisheries, respectively. The high individual variability in the population results in turtles experiencing distinct and variable threats during their annual cycle.

Egg fertilization rate is a defining event in the life history of oviparous species. However, for many terrestrial oviparous species, this parameter is only estimated after hatching and emergence of hatchlings, by studying evidence of embryonic development in unhatched eggs. We compared the accuracy of this method with a second technique based on the careful excavation of sea turtle nests within the first 96 hours of oviposition and calculating the proportion of alive eggs, where a clear white spot is externally visible in the shell. Both methods underestimate the fertility rate but we are not aware of any other alternative on-invasive technique. The study was conducted in a nesting population of loggerhead turtles (Caretta caretta) at Boa Vista Island (Republic of Cabo Verde). We found significant differences in the estimation of fertilization rate between both techniques. When inspecting eggs after hatching, researchers significantly overestimated the number of unfertilized eggs and this calculation was not correlated with the estimation based on examination of eggs soon after oviposition. The first estimate was not correlated with hatching success or hatchling phenotype. There was no relationship between the number of viable embryos at oviposition and the hatching success and the hatchling’s phenotype. The absence of embryo or its early death had no effect on survival of developing embryos within a nest. Fertilization rate in loggerheads did not show spatial or temporal variation during nesting season. We suggest the implementation in sea turtle nesting monitoring programs of annual less-invasive estimation of egg fertilization rate based on the excavation of a sample of representative nests immediately after the formation of the white spot in the shell of developing embryos When inspecting eggs after hatching, researchers significantly overestimated the number of unfertilized eggs and this calculation was not correlated with the estimation based on examination of eggs soon after oviposition. The first estimate was not correlated with hatching success or hatchling phenotype. There was no relationship between the number of viable embryos at oviposition and the hatching success and the hatchling’s phenotype. The absence of embryo or its early death had no effect on survival of developing embryos within a nest. Fertilization rate in loggerheads did not show spatial or temporal variation during nesting season. We suggest the implementation in sea turtle nesting monitoring programs of annual less-invasive estimation of egg fertilization rate based on the excavation of a sample of representative nests immediately after the formation of the white spot in the shell of developing embryos.

Publisher Summary This chapter explains the adverse effects of persistent organic pollutants (POPs) exposure on wild birds that alter reproductive performance, cause terata and other defects. Wild birds are sentinels of environmental safety because they share our environment and many are high trophic feeders. During the nesting season, many birds deal with the dynamics of climate, and temporal changes in the kinds and supply of feedstuffs available. Reproductive disruptions in birds can affect all stages of reproduction. Some of the defects caused by POPs are skeletal defects, soft-tissue defects involving the nervous system, eggshell thinning and productivity, and teratogenic endocrine disruption. Skeletal defects in birds can affect mobility, feeding and possibly durability in combat and defense. The PCBs, PCDDs and PCDFs are known to cause neurologic terata in wild birds. These POPs have been associated with brain asymmetry in some species. Eggshell thinning and desiccation can be a cause of reduced reproductive performance. Birds have many different mating strategies dependent on male and female behaviors. These behaviors are endocrine driven and the timing of onset of the events is important. Endocrine disruptions can alter the ability to respond to stress and changes in metabolic demands and reproductive successes. Reproductive success of birds relies on many integrated processes ranging from courtship to fledging success. Disruption at any one these multiple processes can have a significant negative impact on the survival of the species.

Extant estuarine and freshwater animals show a variety of adaptations to marine life, which could reflect transitional stages in a gradual evolution from freshwater to the sea. Our aim was to identify the temporal and spatial environment associated with pig-nosed turtles Carettochelys insculpta coastal nesting in the Kikori Region, Papua New Guinea (PNG). We also related the use of coastal areas with size within and among different populations of C. insculpta and species of the superfamily Trionychoidea. Throughout its range, C. insculpta nests during the drier months when suitable sandbanks are exposed. In PNG, rainfall in the drier season dilutes salinities and C. insculpta nests in coastal sandbanks. In Australia, high salinities prevail in the river mouths during the nesting season and no coastal use is observed. Trends toward a larger body size in coastal areas suggest that size is an important factor to explore coastal environments. It is unlikely that female C. insculpta with less than 50 cm (curve carapace length) would be able to cope with the Kikori coastal environment. Expanding this trend to its superfamily Trionychoidea, only species larger than 37 cm (leathery carapace length) explore coastal environments. As the Australian coast is not suitable for nesting, the selection for larger body sizes was probably relieved. Of course, the reverse could be true, but our study provides an example of the caution required when placing evolutionary interpretations on life-history traits whose manifestation is studied only within a restricted portion of a species range.

We investigated the relationship between red-cockaded woodpecker (Picoides borealis) reproductive success and microhabitat characteristics in a southeastern loblolly (Pinus taeda) and shortleaf (P. echinata) pine forest. From 1997 to 1999, we recorded reproductive success parameters of 41 red-cockaded woodpecker groups at the Bienville National Forest, Mississippi. Microhabitat characteristics were measured for each group during the nesting season. Logistic regression identified understory vegetation height and small nesting season home range size as predictors of red-cockaded woodpecker nest attempts. Linear regression models identified several variables as predictors of red-cockaded woodpecker reproductive success including group density, reduced hardwood component, small nesting season home range size, and shorter foraging distances. Red-cockaded woodpecker reproductive success was correlated with habitat and behavioral characteristics that emphasize high quality habitat. By providing high quality foraging habitat during the nesting season, red-cockaded woodpeckers can successfully reproduce within small home ranges.

Predation is one of the major causes of crocodilian egg mortality. Many studies have suggested that opening nests, handling eggs, and capturing attending females may increase predation rates, but the influence of such activities on nest predation has not been quantified. For that reason, we studied the impacts of different research activities on nests of wild Spectacled Caimans (Caiman crocodilus crocodilus) from a flooded forest (varzea) in the Piagacu-Purus Sustainable Development Reserve, Central Amazonia. During the 2010 nesting season, predation on eggs in disturbed nests was generally higher than in nests without research activities found in the same area. However, natural predation rates in similar habitat were not significantly different, suggesting that predation rates on disturbed nests, though elevated, remain within the broad range found in undisturbed nests. We conclude that the benefits in knowledge gained from research activities will generally out-weigh the small increase in nest ...

As seabird nesting colonies have become concentrated on fewer managed islands, available nesting habitat for open-ground nesters such as Common Terns (Sterna hirundo) has rapidly become overgrown by guanofertilized vegetation, leading managers to try various methods of vegetation control to open usable nesting habitat. Two of these methods, burning and synthetic weed barrier treatments, were tested in the summers of 2009 and 2010 to assess their ability to open and maintain Common Tern nesting habitat on two nearshore seabird nesting islands in Maine. Treatments were applied to overgrown habitat pre-nesting, and vegetation regrowth and Common Tern nest and fledging success were monitored in treated plots, untreated vegetation plots and occupied Common Tern nesting habitat. Burned areas did not remain open for the full nesting season, but regrew shortly after egg-laying, creating unsuitable vegetation structure and leading to near-complete nest failure in these plots. However, vegetation characte...

Freshwater turtles are appropriate organisms for studying maternal investment in offspring because, unlike most long-lived vertebrates, turtles show high fecundities and most provide no parental care. We studied reproductive patterns of two emydine freshwater turtle species, the Texas river cooter (Pseudemys texana) and the red-eared slider (Trachemys scripta elegans) at Spring Lake, Hays County, Texas during the 2009 nesting season. Forty-six percent of all nesting Texas river cooters and 25% of all nesting red-eared sliders nested twice, with some Texas river cooters nesting more than twice. Mean egg mass, egg length, and egg width decreased in subsequent clutches in Texas river cooters. However, there was an insufficient sample size of subsequent clutches (n = 6) to draw conclusions for red-eared sliders. Red-eared sliders did not show a positive relationship between clutch size and body size. We found that in both species there was a positive relationship between egg width and egg mass in relation to maternal body size. However, only Texas river cooters showed a positive relationship between clutch size and maternal size, while only red-eared sliders showed a positive relationship between egg length and maternal size. By comparing reproductive parameters of these two coexisting populations, we concluded that the members of these two species allocate resources differently for reproduction.

Herbivorous turtle, Chelonia mydas, inhabiting the south China Sea and breeding in Peninsular Malaysia, and Natator depressus, a carnivorous turtle inhabiting the Great Barrier Reef and breeding at Curtis Island in Queensland, Australia, differ both in diet and life history. Analysis of plasma metabolites levels and six sex steroid hormones during the peak of their nesting season in both species showed hormonal and metabolite variations. When compared with results from other studies progesterone levels were the highest whereas dihydrotestosterone was the plasma steroid hormone present at the lowest concentration in both C. mydas and N. depressus plasma. Interestingly, oestrone was observed at relatively high concentrations in comparison to oestradiol levels recorded in previous studies suggesting that it plays a significant role in nesting turtles. Also, hormonal correlations between the studied species indicate unique physiological interactions during nesting. Pearson correlation analysis showed that in N. depressus the time of oviposition was associated with elevations in both plasma corticosterone and oestrone levels. Therefore, we conclude that corticosterone and oestrone may influence nesting behaviour and physiology in N. depressus. To summarise, these two nesting turtle species can be distinguished based on the hormonal profile of oestrone, progesterone, and testosterone using discriminant analysis.

Count data are often used to assess relative population size and population trends with sufficient power and confidence for wildlife population studies, including those for nesting sea turtles. Although access to sea turtles while nesting is relatively simple compared to many other migratory marine animals, optimal surveys tagging every individual through the nesting season are often not feasible due to time, financial and other logistic constraints. Partial survey counts can then be used to estimate population abundance. Several models have previously been published describing the seasonal shape in abundance for nesting turtles, but none have compared different model fits using a numerical approach and all have limited general application as they describe only 1 location or 1 species. We compared 22 non-parametric and parametric modelling approaches for 9 populations of sea turtles comprising 3 different species: green sea turtles Chelonia mydas, loggerhead sea turtles Caretta caretta and leatherback sea turtles Dermochelys coriacea. Although models showed marked differences in the shape of their fit, all models provided reasonable estimates of annual nesting abundance, with mean errors less than 8% for 50% data coverage and mostly 8 to 10% for 20% random coverage. Of the 3 models that produced significantly lower mean absolute error, we recommend using generalized additive models to estimate annual abundance due to their ease of fitting, flexibility across populations and seasonal shapes and their good predictive ability.

Understanding geospatial linkages is critical to the development of appropriate management and conservation strategies for migratory species. Stable isotope analysis is a powerful tool that is performed routinely across taxa to unravel migratory connectivity. Marine turtles are a highly migratory and widely distributed taxon, but are largely studied at breeding areas. Isotopic values of several slow turnover rate tissues have been used to identify often distant foraging areas. However, as more isotopic data from various tissues become available, the relationships between tissues need to be calculated to permit meta-analyses to elucidate isotopic patterns across broader spatiotemporal scales. We used several commonly collected tissues (blood, skin, fresh eggs and unhatched eggs) collected simultaneously from loggerhead turtles (Caretta caretta) to develop a common currency for stable isotope analysis studies conducted on the nesting beach. We found highly significant relationships between the tissue signatures (r 2 ranged from 0.83 to 0.96) and developed equations to convert isotopic values from one tissue to another. We examined inter- and intra-clutch isotopic variability and found that a single sampling event over the 4-month nesting season adequately defined the loggerhead female foraging area. Consequently, we propose using unhatched eggs as a common currency in stable isotope studies of nesting loggerheads. Unhatched eggs represent a noninvasive and nondestructive method that enables more extensive (both numerically and spatially) sampling. Given similar physiologies, analogous relationships might be derived in other sea turtle species.

Normal reference ranges of biochemical parameters are considered important for assessing and monitoring the health status of sea turtles. For this study, plasma biochemistry determinations were analyzed in normal adult nesting and foraging hawksbill turtles (Eretmochelys imbricata). Blood samples were collected in March–April during (nesting season) and December–November (foraging season). Differences in plasma biochemistry values, except for creatinine and lipase, were statistically different (P

Knowledge of the mechanisms influencing phenology can provide insights into the adaptability of species to climate change. Here, we investigated the factors influencing multidecadal trends in the nesting phenology of the leatherback turtle Dermochelys coriacea at Playa Grande, Costa Rica, in the eastern Pacific Ocean and at Sandy Point, US Virgin Islands, in the western Atlantic Ocean. Between 1993 and 2013, the median nesting date (MND) at Playa Grande occurred later, at a rate of ~0.3 d yr-1. In contrast, between 1982 and 2010, the MND at Sandy Point occurred earlier, at a rate of ~0.17 d yr-1. The opposing trends in the MND of each population were not explained by variation in the multivariate El Niño-Southern Oscillation index, North Atlantic Oscillation index, or Atlantic Multidecadal Oscillation index; however, the MND at Playa Grande was significantly correlated with nesting population size. We propose that changes in demography, linked to the population decline at Playa Grande, and the population recovery at Sandy Point may explain the contrasting trends in MNDs. If the observed trends in MND continue into the future, the nesting season at Playa Grande will coincide with increasingly adverse conditions for hatching success, exacerbating the already detrimental effects of climate change. Alternatively, shifts in the nesting phenology may make the Atlantic populations more resilient to climate change. Our findings highlight the increasing need for conservation efforts for eastern Pacific leatherback turtles to consider climate change mitigation practices, Funding for the project at Playa Grande was provided by the Earthwatch Institute, The Betz Chair Endowment of Drexel University, The Schrey Chair Endowment of Indiana University-Purdue University Fort Wayne, and The Leatherback Trust. Funding for the project at Sandy Point was provided by the USFWS — Division of Refuges, the National Marine Fisheries Service — Southwest Science Center, West Indies Marine Animal Research and Conservation Service, USFWS Section 6 appropriations administered through the Virgin Islands Department of Planning and Natural Resources, and the EarthWatch Institute

The social behavior of turtles during the nesting season can be attributed to a series of functions such as reducing predation, increasing hatchling survivorship, and information exchange between nesting females. However, the mechanism(s) used to remain in a group during the different phases of nesting behavior has yet to be explained. The objective of this study is to document the sounds produced by Giant South American River Turtle, Podocnemis expansa, during the nesting period, and identify how acoustic mechanisms might facilitate social behavior and group aggregation during this period. From September 2009 to October 2011, the sound repertoire of P. expansa was identified during the nesting period, which begins with the migration of the turtles from the flooded forests to the nesting beaches and terminates when the hatchlings emerge and the females migrate with the hatchlings to the flooded forests. Sounds were recorded when the turtles were active in different behavioral patterns (1) migra...

We studied Greater Roadrunners' (Geococcyx californianus) habitat use during spring and summer of 2011 in the Red Rolling Plains of west Texas. We captured 10 roadrunners (one male and nine females) and fitted each with a 10-g backpack style radio-transmitter. Roadrunners were relocated 2–4 times per week from February–August. We used these data to build a logistic regression model to better understand the vegetative and topographic features important to roadrunners during the nesting season. The initial data set consisted of 30 random and 30 used locations. The best model showed both percent rock and percent litter to be higher at used locations and correctly classified 88% of the sites. Evaluation of the model with an additional 30 random and 30 used locations maintained significance of both the model and variables and correctly classified 83% of sites. Both variables were associated with the location's mesa ridge slopes. Litter dominated locations under shrubs on the ridge tops and slopes and ...

The decline in population and range of lesser prairie-chickens (Tympanuchus pallidicinctus) throughout the central and southern Great Plains has raised concerns considering their candidate status under the United States Endangered Species Act. Baseline ecological data for lesser prairie-chickens are limited, especially for the shinnery oak-grassland communities of Texas. This information is imperative because lesser prairie-chickens in shinnery oak grasslands occur at the extreme southwestern edge of their distribution. This geographic region is characterized by hot, arid climates, less fragmentation, and less anthropogenic development than within the remaining core distribution of the species. Thus, large expanses of open rangeland with less anthropogenic development and a climate that is classified as extreme for ground nesting birds may subsequently influence nest ecology, nest survival, and nest site selection differently comparedto therest ofthe distributionofthespecies. Weinvestigated thenestingecologyof50radio-tagged lesser prairie-chicken hens from 2008 to 2011 in the shinnery oak-grassland communities in west Texas and found a substantial amount of inter-annual variation in incubation start date and percent of females incubating nests. Prairie-chickens were less likely to nest near unimproved roads and utility poles and in areas with more bare ground and litter. In contrast, hens selected areas dominated by grasses and shrubs and close to stock tanks to nest. Candidate models including visual obstruction best explained daily nest survival; a 5% increase in visual obstruction improved nest survival probability by 10%. The model-averaged probability of a nest surviving the incubation period was 0.43 (SE ¼0.006; 95% CI: 0.23, 0.56). Our findings indicate that lesser prairie-chicken reproduction during our study period was dynamic and was correlated with seasonal weather patterns that ultimately promoted greater grass growth earlier in the nesting season that provided visual obstruction from predators. 2014 The Wildlife Society.

Average age and size at first reproduction are important demographic parameters used in the management and conservation of populations. For sea turtles, absolute values for these parameters are still ambiguous, as most species are slow-growing, late-maturing migrants which are rarely encountered during the first 1 to 2 decades of their lives. Additionally, growth is signif- icantly influenced by a variety of intrinsic and extrinsic factors which make it difficult to describe agesize relationships. Extensive notching (mutilation-tagging) of South African loggerhead tur- tles was used to determine age and size at reproduction (putative first nesting season), and thus to identify the trigger for sexual maturation. To date, 137 clearly identified notched adult females have been encountered at the nesting beach. A Gaussian and log-normal distribution were fitted to the age distribution data but only the Gaussian distribution can be used to safely estimate age at first observation, as the right part ('older ages') of the distribution is still unknown. The esti- mated age at first observation was corrected for the possibility that a female was not encountered during her first nesting season. Results indicate an average age of 36.2 ± SD 7.71 yr (95% CI 28.2 to 44.3 yr) with a straight carapace length (SCLmin) of 83.7 ± 4.15 cm (95% CI 83.0 to 84.4 cm). It was concluded that size is a more important threshold for the initiation of the maturation process than age and that the onset of sexual maturity is dependent on intrinsic and extrinsic factors.

Despite being widespread and abundant, little is known about the breeding ecology and natural history of the Eastern Wood-Pewee (Contopus virens), in part because nests are often high in the canopy, difficult to view, and adults are monomorphic. We monitored nests of Eastern Wood-Pewees and recorded the feeding rate of nestlings by adults as part of a larger study on breeding demography of Eastern Wood-Pewees across a gradient of savanna, woodland, and forest in the Missouri Ozarks in 2010–2011. We monitored 287 nests between 26 May and 22 August and conducted feeding rate observations for 54 nests with nestlings. There was an 88-day nesting season with peaks of nest activity on 24 June and 22 July. We recorded 19 cases of double brooding and nine cases of within-season nest reuse. Seasonal fecundity was 2.2 fledglings per territory. The frequency of parental feeding visits increased with nestling age. These are additional observations of nest reuse, nesting cycle lengths, and breeding season len...

Ocean temperature is a key determinant of the distribution and phenology of marine life, particularly poikilotherms. We examined effects of ocean temperature on nesting phenology and fecundity for Loggerhead Sea Turtles (Caretta caretta) in the northern Gulf of Mexico using long-term nesting survey data from northwest Florida. The first clutch of the year was deposited earlier when sea surface temperature in months prior to the nesting season was warmer and this resulted in a longer nesting season. Nest abundance and clutch size were associated with the monthly mean temperature just prior to the nesting season, with higher fecundity occurring in warmer years. Higher nest success was associated with higher February temperature and lower May temperature. Median nest date was not associated with monthly temperature prior to the nesting season. Our results provide further details about the impacts of the thermal environment on Loggerhead Sea Turtle life history and suggest that altered ocean temperat...

The primary objectives of this study were to understand how canopy cover and nest temperatures affect hatchling sex ratios and locomotor performance (i.e., swimming sprint speed and righting response) of Chrysemys picta marginata nests. Seventeen nests were monitored with temperature data-loggers during the 2009 nesting season and found to contain 100% male-biased clutches with a mean nest temperature range of 20.0–24.0°C during the thermosensitive period (TSP). The percentage of canopy cover over each nest was inversely and significantly correlated with mean nest temperatures experienced during the TSP. Mean nest temperatures (MNT) did not have a statistical effect on either measure of locomotor performance; however, there was an observed trend toward increased performance with increased MNT.

Summary Road mortality is a major component of human impacts on wildlife populations, and the pervasiveness of roads on the landscape presents a substantial challenge for managing those impacts. The feasibility of methods to reduce road mortality depends on the degree to which this threat is spatially or temporally concentrated, which can be based on habitat, human activities or species' ecology. Diamondback terrapins Malaclemys terrapin are a species of conservation concern across their range, and road mortality is a major threat contributing to local population declines. We used intensive road surveys of the 8·7-km Downing-Musgrove Causeway to Jekyll Island, Georgia, USA, over 2 years to determine whether road activity and mortality was diffused or concentrated spatially (hot spots) or temporally (hot moments) in order to guide efficient management. In 2009 and 2010, we documented 636 terrapin crossings that were temporally and spatially condensed. Temporally, there was a 70–80% chance of a terrapin occurring on the road within a 3-h period around the diurnal high tide and within the first 30 days of the ˜75 day nesting season. Over the two nesting seasons, 52% of terrapin occurrences on the road occurred within the 3-h period around high tide. Spatially, 30% of terrapins were observed crossing in three hot spots that composed less than 10% of the length of the entire causeway, and the percentage of unvegetated high marsh was negatively associated with the number of terrapins that occurred on a section of road. Synthesis and applications. Our results demonstrate that hot spots and hot moments can be identified for species at finer scales than those found by other studies and are related, strongly or weakly, to specific temporal processes or habitat features. We found patterns of road mortality, like most threats, can be diffused or concentrated; therefore, complementary management tools that focus on hot spots or moments and also address the more diffused component of road mortality will be required to reduce this threat for at-risk wildlife.

The use and potential consequence of alien plant parts in the construction of open-cup leaf nests by Nearctic-breeding forest songbirds has not been investigated. We dissected 19 leaf nests constructed by Veeries (Catharus fuscescens) over two breeding seasons in a temperate broadleaf forest infested with alien plants. Our objectives were: (1) confirm the architectural approach used by Veeries to construct nests, (2) determine if Veeries used alien plant parts in nest construction, (3) determine if nest success was related to the use of alien material, (4) determine the use of alien plants relative to native plants, and (5) test for an association of alien plant mass with the progression of the nesting season. Our results showed that Veeries constructed three separate nest layers: (1) a platform for support, (2) an inner cup, and (3) nest lining. Veeries incorporated parts from six alien plant species in their nests representing 22% of the 27 species used. All nests contained alien plant parts bu...

The number of nesting leatherback turtles (Dermochelys coriacea) in the eastern Pacific Ocean has declined dramatically since the late 1980s. This decline has been attributed to egg poaching and interactions with fisheries. However, it is not clear how much of the decline should also be ascribed to variability in the physical characteristics of the ocean. We used data on individually marked turtles that nest at Playa Grande, Costa Rica, to address whether climatic variability affects survival and inter-breeding interval. Because some turtles might nest undetected, we used capture–recapture models to model survival probability accounting for a detection failure. In addition, as the probability of reproduction is constrained by past nesting events, we formulated a new parameterization to estimate inter-breeding intervals and contrast hypotheses on the role of climatic covariates on reproductive frequency. Average annual survival for the period 1993–2011 was low (0.78) and varied over time ranging from 0.49 to 0.99 with a negative temporal trend mainly due to the high mortality values registered after 2004. Survival probability was not associated with the Multivariate ENSO Index of the South Pacific Ocean (MEI) but this index explained 24% of the temporal variability in the reproductive frequency. The probability of a turtle to permanently leave after the first encounter was 26%. This high proportion of transients might be associated with a high mortality cost of the first reproduction or with a long-distance nesting dispersal after the first nesting season. Although current data do not allow separating these two hypotheses, low encounter rate at other locations and high investment in reproduction, supports the first hypothesis. The low and variable annual survival probability has largely contributed to the decline of this leatherback population. The lack of correlation between survival probability and the most important climatic driver of oceanic processes in the Pacific discards a climate-related decline and point to anthropogenic sources of mortality as the main causes responsible for the observed population decline.

Red fox (Vulpes vulpes) management has been conducted on Masonboro Island Reserve, a component of the North Carolina National Estuarine Research Reserve, North Carolina, USA, since 2013 to reduce depredation on loggerhead sea turtle (Caretta caretta) and green sea turtle (Chelonia mydas) nests. Depredation rates have varied among years indicating either an influx of red fox onto the island post cull or other mesocarnivores preying on sea turtle nests. We investigated the presence of red fox and other mesocarnivores on Masonboro Island Reserve after a culling event in 2016 to characterize mesocarnivore behavior and interactions during the turtle nesting season. We systematically placed 17 Moultrie® panoramic 150 passive infrared cameras every 0.80 km along the base of the dunes on the shoreline of Masonboro Island Reserve during May–October 2016. Of 81,509 pictures taken by the cameras, we observed 2 red fox and 1 Virginia opossum (Didelphis virginianus). There was 1 documented mammalian depredation event on turtle nests in 2016 and the number of false crawls (where females return to the ocean without laying eggs) was lower than the previous 5 years. Given that we only recorded 3 pictures on 2 different nights of mesocarnivores, our results may indicate that the 2016 cull was successful. Mesocarnivores, especially red fox and raccoons (Procyon lotor), on the mainland may temporarily shift their home range during the onset of the turtle nesting season to procure food for their offspring. By early fall, most mammal offspring disperse and likely recolonize the island annually, suggesting management efforts to reduce mammalian predators should continue. Human and domestic dog (Canis familiaris) presence on the island is abundant and also may influence turtle nest success.

Recent technological developments in video surveillance help shed light on the behavior and ecology of nesting birds. There is little information regarding breeding ecology of white-tipped doves (Leptotilaverreauxi), an elusive gamebird in southern Texas. Our objective was to describe parental attendance during the nesting season. We located nests in citrus groves and remnant woodlands. We used video camera systems to monitor parental behavior at the nest. We sampled video to establish time budgets for 13 nests, including 9 that reached the nestling stage. White-tipped doves take part in continual nest attendance, except for brief periods when the parents switch nesting duties. Female white-tipped doves attend the nest during the night and into the morning hours, when the male relieves her. The female forages throughout the day and returns in the evening, trading places with the male. White-tipped dove parental behavior was consistent with other columbid species.

Year-round behavioral observations and surveys were used to investigate the temporal dynamics of life history events and associated variation in behavioral activities of the endangered, island-endemic Hawaiian Duck (Anas wyvilliana) on Kaua‘i, Hawai‘i, USA. Although breeding activity occurred throughout the year, backdated brood observations (n = 67) revealed that birds initiated 94% of nests during the 9-month period from September through May, their peak nesting season. A greater proportion of females (n = 149) were paired during the peak nesting season (75%) than the off-peak season (48%). Behavioral patterns (n = 984; 329 hr) differed between seasons for males but not for females. Males allocated more time to vigilance and less time to foraging during the peak nesting season than the off-peak season. Activity budgets also differed between sexes, but only during the peak nesting season. During this period, females spent more time foraging than males, whereas males allocated more time to vigilance, locomotion, and social activities. Current management objectives for the Hawaiian Duck aim to provide resources for multiple life history stages concurrently throughout the year, and although this approach is largely appropriate, our results suggest refinements in the timing of certain activities (e.g., managing nesting habitat to be available during September-May).

Anas fulvigula (Mottled Duck) has experienced long-term population declines due to habitat loss and other anthropogenic factors. Our objectives were to (1) generate annual survival and recovery estimates, while examining the influence of age and sex, and (2) examine the influence of rainfall and drought on reproductive success. We followed the Brownie approach using the RMark package in R to analyze 4967 bandings and 705 recoveries from 2004–2015. We examined linear and curvilinear relationships between precipitation variables and a reproductive index. Hatch-year (HY) males had the highest annual recovery probability, while after-hatch-year (AHY) females had the lowest. Annual survival varied predominately by sex but also with age. Hatch-year females had the lowest estimate of survival, while after-hatch-year males had the highest. Total rainfall during peak nesting season showed a weak negative relationship with our reproductive success index (β = -0.0085, 95% CI: -0.0240, 0.0070), and was our only competitive model besides the null. Annual survival and recovery estimates were similar to other studies on Mottled Ducks. Our reproductive success analysis was inconclusive in that either there is no effect of precipitation or the measures we used for the reproduction index or the predictor variables were inadequate.

The painted turtle (Chrysemys picta) is widely distributed from coast to coast in North America with each of four subspecies generally occupying different regions. In the southwestern USA and northern Mexico, where C. p. bellii is the expected native race, populations are small and widelyscattered. Introduced populations of other painted turtle subspecies are reported from various locations in the USA. We discovered a small but dense introduced population of C. p. marginata on the Colorado Plateau in northern Arizona, a region with few, if any, turtles due to aridity and an elevated topography with little surface water. The turtles were in a remote pond constructed to provide cattle with water. Chrysemys p. marginata occur naturally east of the Mississippi River, over 2,000 km away. The nearest native population of C. p. bellii in Arizona is over 160 km away. We observed nesting females, juveniles, and the presence of shelled eggs in females via Xradiography confirming a self-sustaining population. The body sizes and nesting season we observed were consistent with data for those variables from native populations of the taxon. It is unknown exactly how the turtles came to be established in such a remote location, but it is unlikely that they will spread due to the scarcity of perennial water sources in the semi-arid region. Due to increasing drought frequency and duration in the region, small populations like this one, introduced into a novel environment, may be bellwethers for monitoring the effects of climate change.

Satellite-based remote sensing has essentially been absent from processes evaluating compliance with environmental policy. Through a case study of the observance of sea turtle light ordinances in Florida, this study seeks to demonstrate that remotely sensed data can be beneficial in evaluation of environmental policy compliance. As a means to increase the successful sea turtle nesting rate, 21 counties and several other municipalities adapted policies prohibiting the lighting of beaches during sea turtle nesting season from May to October. Using visible/infrared imager radiometer suite (VIIRS) nighttime lights satellite imagery to determine mean radiance values and diamond plots of difference images of nighttime lights radiance values, this study confirms compliance with these light ordinances while emphasizing the benefits of remote sensing techniques in the process.

Sea turtles have iteroparous reproduction, migrating periodically from foraging habitat to nesting grounds where they generally lay several clutches at regular intervals throughout a nesting season. The total length of the nesting season depends ultimately on environmental conditions that are conducive to the production of viable hatchlings, and varies from 3 to 4 months to year-round nesting. As with many migratory marine species, the ease of monitoring marine turtles on their nesting beaches opposed to on their foraging grounds, has resulted in a focus of research on breeding females for population studies and provides a useful albeit limited population index. To explore the precision of monitoring regimes to sample nesting turtle populations, we developed theoretical models for 3 1/2-month and 9-month nesting populations. We used individual-based models for tagged animals and parametric and non-parametric models to estimate annual nest abundance for track count data. These simulation models show that seasonality substantially influenced both the length and temporal position of optimal sampling regimes, showing a five to sevenfold greater effort in monitoring required for longer nesting seasons in order to encounter between 83 and 90% of the annual population. The implications for trend detection and inter-annual and inter-species variations are discussed.

Many environmental variables that affect incubating turtle eggs in the nest may also affect hatchling development, following hatchling emergence. However, these effects may be subtle and are largely unexamined. In this study, we analyzed the effect of sand moisture content during incubation on the postemergence growth rates of loggerhead sea turtles (Caretta caretta) in southeastern Florida. We divided 10 clutches in halves, reburied them, and exposed them to 1 of 2 treatments. At emergence, 7 clutches met minimum criteria for inclusion in the study. One halfclutch received only ambient rainfall (“dry” treatment) while the other half-clutch received ambient rainfall plus daily watering (“wet” treatment). Data loggers were used to record incubation temperatures in both groups. Hatchlings were captured at emergence and laboratoryreared over a period of ∼ 3 mo. Mass, straight carapace length (SCL), and straight carapace width (SCW) were measured weekly to track growth. Initial measurements were larger for turtles from the wet nests in all metrics. Turtles from wet nests grew more in SCW than turtles from dry nests. Turtle growth from the 2 treatments did not differ in SCL or mass measurements. Larger initial sizes and faster SCW growth may enable the turtles to more quickly achieve a refuge size from their gape-limited predators. Moisture availability during nesting season is projected to decrease based on climate change models. If that change materializes, it could negatively affect hatchling sizes and neonate growth rates, survival, and hence the recovery of this imperiled species.

The availability of small, lightweight tracking devices enhances our ability to study birds during mobile phases of their lives. Tree Swallows Tachycineta bicolor, a model species of wild songbird, are well-studied during their breeding season; but our understanding of their biology at other times of the year, when they are not tied to the fixed location of a nest, is more limited. We developed a lightweight radio tag with no battery (solar nanotag) to study the movements of small animals, and we deployed it to explore the behavior of Tree Swallows after the end of their summer breeding season. We tagged 32 breeding adult swallows and 36 juveniles and monitored their presence and absence at the breeding site during the post-fledging period. Although our observations are based on very small sample sizes, the tags revealed previously unknown patterns in Tree Swallow behavior during the post-breeding season. Some Tree Swallow fledglings continued to visit the site repeatedly in the months following the nesting season, with the latest detection occurring on September 30th; by contrast, all adults had permanently departed by the end of July. These results inform future hypotheses about post-breeding movements in Tree Swallows. But, more generally, the detection of tagged swallows on their distant wintering grounds, seven months after tagging, indicates the potential of studying small passerine movements throughout their entire lifetimes, and suggests a rich array of applications for these "Life Tags" to study the movements of small animals world-wide.

Botany Bay Plantation Wildlife Management Area is one of only four known natural nesting sites for least terns ( Sternula antillarum ) on the South Carolina coast, and more than 20,000 people visit the 3-mile stretch of beach each nesting season since it opened to the public in 2008. We developed a simulation model for the adaptive management of human disturbance on nesting habitat for least terns, which is described using the ODD (Overview, Design Concepts, and Details) protocol. The simulation uses the Questions and Decisions (QnD) system framework, an object-oriented modeling approach that emphasizes interactions among key ecological and social components. The model is designed to explore the potential results of management actions and identify key indicators for future monitoring. Initial model parameters were developed from existing literature, expert opinion and on-site ecological observations as few baseline data were available for the recently opened site. In addition, substantial uncertainty surrounded the nesting behavior of least terns related to productivity levels, responses to human disturbance, and overwash tides. In order to test model assumptions and performance, parameters are assigned stochastic probability distributions made explicit to wildlife managers and can be updated as additional monitoring data become available. Simulation results suggest that Botany Bay colonies are at significant risk of collapse. Monte Carlo simulations of the model ( n = 500) show that current management practices result in a median productivity of 0.08 fledglings per breeding adult, well below the minimum productivity threshold of 0.13 needed to encourage site fidelity. But closing one particular section of beach during the nesting season would result in a global median productivity of 0.26. A sensitivity analysis identified one variable in particular as important to monitor for reducing uncertainty in model results: the duration of tern defense response from human disturbance and the variation of this response among spatial units. These simulation results are intended to initiate an ongoing and adaptive monitoring program for improving colony productivity at the site.

Conservation strategies for declining species often are based on limited knowledge about how fecundity and survival may change across a species' range, and what factors may be limiting for a given population. Incomplete understanding of how a species' demography varies across a range of conditions may lead to inappropriate management decisions. Our objective was to compare demographic data from northern and southern extremes of the breeding range of Golden-winged Warblers (Vermivora chrysoptera). Specifically, we compared minimum estimates of annual adult survival, daily nest survival, fecundity, and population growth (lambda) for Tennessee and Ontario breeding populations. Tennessee nest survival decreased throughout the nesting season and as daily minimum temperature increased, but the constant survival model was equally supported (model averaged daily survival rate, DSR = 0.972 [0.01 SE]). Ontario nest survival also decreased throughout the nesting season, but not as a function of temperatur...

A small population of Mugger crocodiles occurs in the southeastern part of Iran, in Sistan & Baluchestan Province, at the westernmost global range of the species. The peak nesting season is May and consequently the eggs hatch in July, but the nesting season can be extended. In four nests found in the wild, 24, 26, 21 and 13 eggs were counted. A 2.2 m long female, which fell in an overflow pond, laid 21 eggs on a concrete surface exposed to the air. A female kept in captivity laid 18 and 25 eggs in two consecutive years. The mean size for the eggs in the last three nests was calculated as 75.7 x 47.7 mm and 91.27 g in weight. The mean total length and weight for 19 hatchlings was 30.47 cm (29.2–33.9 cm) and 84.3 g (66.2 to 90.3 g) respectively. Based on the number of observed hatchlings compared with the clutch size, it seems that hatchlings have a high mortality rate in the early stages after hatching as a result of natural threats.

Impacts on sea turtle populations from fisheries bycatch, climate change, habitat destruction and poaching have been widely discussed, but little is known about boat strikes as a potential threat to sea turtles. Here we present data on Pacific green turtles (Chelonia mydas) that suffered boat strikes in the Galapagos Marine Reserve at nesting beaches at Isabela Island and from foraging sites at San Cristobal Island from 2008 to 2011. Tourism in Galapagos has increased to more than 180,000 visitors a year and the boat traffic within the Marine Reserve poses a significant risk to sea turtles. Boat strikes were most frequent at foraging sites close to Puerto Baquerizo Moreno, a commercial and tourism port, where incidence varied between 16 and 20%. Incidence at nesting beaches was much lower with 3.7% of 4198 turtles showing injuries resulting from boat strikes. However, at the nesting beaches most of the impacts (59%) had occurred during the same nesting season while only 5% of the sea turtles observed at the foraging sites suffered their injuries during the study period. No data on survival rates from boat strike exist, however it is clear that many turtles die from the trauma caused by the impact. This report focuses on only the survivors; therefore the results represent a minimum estimate. Our study clearly shows that the overall threat from boat strikes has an important effect on the Galapagos green turtle population. Conservation management including speed limits in key turtle habitats are needed to improve their survival in the Galapagos Marine Reserve.

Studies of nesting success can be valuable in assessing the status of raptor populations, but differing monitoring protocols can present unique challenges when comparing populations of different species across time or geographic areas. We used large datasets from long-term studies of 3 raptor species to compare estimates of apparent nest success (ANS, the ratio of successful to total number of nesting attempts), Mayfield nesting success, and the logistic-exposure model of nest survival. Golden eagles (Aquila chrysaetos), prairie falcons (Falco mexicanus), and American kestrels (F. sparverius) differ in their breeding biology and the methods often used to monitor their reproduction. Mayfield and logistic-exposure models generated similar estimates of nesting success with similar levels of precision. Apparent nest success overestimated nesting success and was particularly sensitive to inclusion of nesting attempts discovered late in the nesting season. Thus, the ANS estimator is inappropriate when exact point estimates are required, especially when most raptor pairs cannot be located before or soon after laying eggs. However, ANS may be sufficient to assess long-term trends of species in which nesting attempts are highly detectable.

Resighting of adult Sooty Terns Onychoprion fuscatus that had been ringed on Bird Island, Seychelles, as chicks in 2002 indicated that birds of higher body mass at fledging had higher post-fledging survival than lighter birds. Resighting of birds that had been ringed at the same time, but at different developmental stages, suggested that birds that fledged from eggs laid late had lower post-fledging survival than chicks that fledged from eggs laid at the peak of the nesting season. These findings are discussed in relation to factors that influence chick survival within the colony and post-fledging survival in the marine environment, along with their implications for the commercial harvest of Sooty Tern eggs in Seychelles.

The Snowy Plover (Charadrius nivosus) is unique in being a determinate layer of an odd modal clutch size and in having a variable mating system in which female brood desertion occurs regularly. These traits make determining Snowy Plover offspring sex ratios important not only for long-term population stability, as the species is of conservation concern, but also for application to sex allocation theory. In this study, we determined Snowy Plover offspring sex ratios, examined differential costs of producing male and female offspring, and evaluated sex ratio variation in relation to maternal condition, habitat condition, and time during the nesting season on saline lakes of the Southern High Plains of Texas. Examination of 245 chicks from 118 clutches during 1999–2000 and 2008–2009 showed that male offspring were more costly to produce than female offspring; however, offspring sex ratio did not differ from parity, but was slightly male-biased in most years. The probability of producing a male offspring was greater both earlier and later in the breeding season than in the middle. As the availability of saline lake surface water and the subsequent availability of food vary unpredictably throughout the breeding season, depending on precipitation events, we suggest that sex ratio adjustment in unpredictable environments may not be straightforward and may follow nonlinear models and/or vary annually The effects such changes in sex ratios may have on population growth and stability remain unknown.

Intensive agriculture, as is typical of corn and soybean production, may be responsible for declines in the abundance and diversity of farmland birds. In Quebec, the transition to intensive crops is evidenced by marked increases of corn and soybean fields. From 2008 to 2010, we used satellite telemetry to study use of corn (Zea mays) and soybean (Glycine max) fields, other farmlands, wetlands, urban areas, and other habitats by 10 female Peregrine Falcons (Falco peregrinus) of the anatum—tundrius complex, a taxon of “special concern” in Canada. We monitored females during the nesting season, from hatching of eggs to independence of young, but before the young dispersed away from the nest site. Adult females were less likely to use corn and soybean fields than the “other farmlands” and “other habitats” categories during the nestling stage and the first month after young fledged. Once young fledged, other farmlands and urban areas were more likely to be used than the “other habitats” category when...