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Transposable elements (TE) play critical roles in shaping genome evolution. Highly repetitive TE sequences are also a major source of assembly gaps making it difficult to fully understand the impact of these elements on host genomes. The increased capacity of long-read sequencing technologies to span highly repetitive regions promises to provide new insights into patterns of TE activity across diverse taxa. Here we report the generation of highly contiguous reference genomes using PacBio long-read and Omni-C technologies for three species of Passerellidae sparrow. We compared these assemblies to three chromosome-level sparrow assemblies and nine other sparrow assemblies generated using a variety of short- and long-read technologies. All long-read based assemblies were longer (range: 1.12 to 1.41 Gb) than short-read assemblies (0.91 to 1.08 Gb) and assembly length was strongly correlated with the amount of repeat content. Repeat content for Bell's sparrow (31.2% of genome) was the highest level ever reported within the order Passeriformes, which comprises over half of avian diversity. The highest levels of repeat content (79.2% to 93.7%) were found on the W chromosome relative to other regions of the genome. Finally, we show that proliferation of different TE classes varied even among species with similar levels of repeat content. These patterns support a dynamic model of TE expansion and contraction even in a clade where TEs were once thought to be fairly depauperate and static. Our work highlights how the resolution of difficult-to-assemble regions of the genome with new sequencing technologies promises to transform our understanding of avian genome evolution.

Explaining the evolution of sex differences in cooperation remains a major challenge. Comparative studies highlight that offspring of the more philopatric sex tend to be more cooperative within their family groups than those of the more dispersive sex but we do not understand why. The leading "Philopatry hypothesis" proposes that the more philopatric sex cooperates more because their higher likelihood of natal breeding increases the direct fitness benefits of natal cooperation. However, the "Dispersal trade-off hypothesis" proposes that the more dispersive sex cooperates less because preparations for dispersal, such as extra-territorial prospecting, trade-off against natal cooperation. Here, we test both hypotheses in cooperatively breeding white-browed sparrow weavers (Plocepasser mahali), using a novel high-resolution automated radio-tracking method. First, we show that males are the more dispersive sex (a rare reversal of the typical avian sex difference in dispersal) and that, consistent with the predictions of both hypotheses, females contribute substantially more than males to cooperative care while within the natal group. However, the Philopatry hypothesis cannot readily explain this female-biased cooperation, as females are not more likely than males to breed within their natal group. Instead, our radio-tracking findings support the Dispersal trade-off hypothesis: males conduct pre-dispersal extra-territorial prospecting forays at higher rates than females and prospecting appears to trade-off against natal cooperation. Our findings thus highlight that the evolution of sex differences in cooperation could be widely attributable to trade-offs between cooperation and dispersal; a potentially general explanation that does not demand that cooperation yields direct fitness benefits. Why do the more philopatric sex tend to be more cooperative within family groups than the more dispersive sex? This study uses radio tracking of white-browed sparrow weavers to reveal that sex differences in cooperation can be attributable to sex differences in the direct costs of cooperation, arising from a trade-off between cooperation and dispersal. [ABSTRACT FROM AUTHOR]

To address the problems of weak search ability, easily falling into local optimal solutions and poor path quality of sparrow search algorithm in AGV path planning, a multi-strategy improved sparrow search algorithm (MISSA) is proposed in this paper. MISSA improves the global search ability by improving the discoverer position update operator and introducing the sine cosine algorithm; adopts the adaptive number of vigilantes and adaptive adjustment step size to improve the convergence speed; introduces the Levy flight variation strategy to reduce the probability of falling into any local optimal solution; optimizes the boundary handling mechanism to prevent the loss of population diversity at a later stage; finally, uses the large-scale neighborhood search strategy and path smoothing mechanism for path optimization to further improve the path quality. The superiority-seeking ability of MISSA was verified by 12 standard test functions, and then 30 simulation experiments were conducted in grid maps with two specifications of 20×20 and 30×30. The experimental results showed that, by using MISSA, the path length was reduced by 44.1% and 63.1%, the number of turns was reduced by 68.4% and 78.4%, and the risk degree was reduced by 61.3% and 77.2%, which verifies the superiority of MISSA in path planning. Finally, MISSA was ported to the QBot2e mobile robot for physical verification to prove its feasibility in practical applications. [ABSTRACT FROM AUTHOR]

Environmental pollution from heavy metals such as zinc (Zn), lead (Pb), and cadmium (Cd) poses serious risks to human health and ecosystems. This study examines the bioaccumulation of these metals in the livers of house sparrows (Passer domesticus) in Meknes, Morocco, using them as bioindicators of pollution. Fifty adult sparrows were collected from five areas: The Industrial Zone (IZ), Town Centre (TC), Sidi Said Bus Station (SS), Fes-Meknes Main Road (MR), and a Rural Site (Ref). Liver samples were analysed with Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). The highest Zn concentrations were found at IZ (111.43 µg/g) and Ref (90.66 µg/g), Pb at TC (4.17 µg/g), and Cd at IZ and TC (0.70 µg/g and 0.71 µg/g). Statistical analyses revealed significant correlations between metal levels. Clustering techniques identified three distinct contamination profiles. These results highlight house sparrows as reliable bioindicators for monitoring heavy metal pollution. [ABSTRACT FROM AUTHOR]

Artificial intelligence (AI) has become an instrument used in all domains with good results. The water resources management field is not an exception. Therefore, in this article, we propose two machine learning (ML) techniques—an echo state network (ESN) and sparrow search algorithm–echo state network (SSA-ESN)—for monthly modeling of the water discharge of one of the biggest rivers in Romania for three periods (S, S1, and S2). In both models, R2 was over 0.989 on the test and training sets and the mean absolute error (MAE) varied between 4.4826 and 7.6038. The performance of the SSA-ESN was similar, but the ESN had the shortest run time. The influence of anomalies on the models' quality was assessed by running the algorithms on a series without the aberrant values, which were detected by the seasonal hybrid extreme studentized deviate (S-H-ESD) test. The results indicate that removing the anomalies significantly improved both models' performance, but the run time was increased. [ABSTRACT FROM AUTHOR]

Optimal migration theory predicts birds will follow migration strategies that minimize time, energy, or predation risk, and these strategies employ specific and conflicting behaviours. Many behaviours driving songbird strategies are relatively well known, however gaps remain, especially for spring migration. Here, we describe the behaviours of a short-distance migrant, the Ipswich Sparrow (Passerculus sandwichensis princeps Maynard, 1872), during spring migration. We determined the start and end dates of migration, migratory duration, travel speed, distance per night, and stopover location and duration. We also examined whether behaviours differed by sex and age. Sparrows migrated between March and June, and took an average of 29.1 days at a speed of 7.2 ± 9.4 m/s (SD) to fly ∼1574 km to their breeding grounds. Sparrows flew approximately 100 km/night and made stopovers of >7 days adjacent to ecological barriers. Males migrated before females, and behaviour did not differ with age. Overall, Ipswich Sparrows had a relatively slow travel speed and covered short distances each night consistent with efforts to minimize energy costs or predation risk. They had prolonged stopovers suggesting that they were also trying to minimize time. More work is required to determine which strategy sparrows may be using during spring migration. [ABSTRACT FROM AUTHOR]

With the development of technology, the working processes of rolling equipment have become more and more complex, and the traditional rolling model encounters difficulties in meeting current demands for accuracy. To reduce the thickness error of the rolling system, we propose a high-precision rolling force prediction method based on SSA–Bilstm–Attention, which reduces the thickness error of the rolling system by predicting the high-precision rolling force. Firstly, a mechanical model is established, and the parameters involved are analyzed to extract suitable parameters as inputs to the network to reduce the feature loss of the network inputs. Secondly, an improved sparrow search algorithm is used to search for the hyperparameters of the network to obtain better training results. Finally, the attention mechanism is introduced to increase the network's training accuracy. A stochastic small-batch gradient descent method is used to improve the training speed of the network. In addition, this paper establishes a web-based host computer, which provides an effective data source for the experimental analysis. The experimental results show that the optimized model has a mean square error of 1.22%, which is more accurate than other models, and has good generalization ability. The experiments confirm the method's effectiveness in improving the thickness accuracy of the rolling system and provide a new optimization scheme for the industry. [ABSTRACT FROM AUTHOR]

Mercury (Hg) concentrations and their associated toxicological effects in terrestrial ecosystems of the Gulf of Mexico are largely unknown. Compounding this uncertainty, a large input of organic matter from the 2010 Deepwater Horizon oil spill may have altered Hg cycling and bioaccumulation dynamics. To test this idea, we quantified blood concentrations of total mercury (THg) in Seaside Sparrows (Ammospiza maritima) and Marsh Rice Rats (Oryzomys palustris) in marshes west and east of the Mississippi River in 2015 and 2016. We also tested for a difference in THg concentrations between oiled and non-oiled sites. To address the potential confounding effect of diet variation on Hg transfer, we used stable nitrogen (δ15N) and carbon (δ13C) isotope values as proxies of trophic position and the source of primary production, respectively. Our results revealed that five to six years after the spill, THg concentrations were not higher in sites oiled by the spill compared to non-oiled sites. In both species, THg was higher at sites east of the Mississippi River compared to control and oiled sites, located west. In Seaside Sparrows but not in Marsh Rice Rats, THg increased with δ15N values, suggesting Hg trophic biomagnification. Overall, even in sites with the most elevated THg, concentrations were generally low. In Seaside Sparrows, THg concentrations were also lower than previously reported in this and other closely related passerines, with only 7% of tested birds exceeding the lowest observed effect concentration associated with toxic effects across bird species (0.2 µg/g ww). The factors associated with geographic heterogeneity in Hg exposure remain uncertain. Clarification could inform risk assessment and future restoration and management actions in a region facing vast anthropogenic changes. [ABSTRACT FROM AUTHOR]

We propose an experimental paradigm to examine acoustic features responsible for song preference and recognition in songbirds. Song preference in female songbirds is often influenced by early song experience. That is why several Estrildid species, including our subject species, the Java sparrow (Padda oryzivora), are known to show an imprinted preference for their father's songs. After confirming that Java sparrow females preferred their father's song compared to nonimprinted through song playbacks (first step), we repeated the playback tests in the same subjects using synthesized stimuli (second step). To create synthesized stimuli, we removed all the complex frequency modulations and subharmonics from song notes that we used for the first step playback tests to see the effect of spectrometric features on song recognition. The results indicated that females showed higher rate of calling towards synthesized father song stimuli, suggesting that the macroscopic patterns would play more important roles in song recognition than the microscopic acoustic features. Although we looked at spectrometric features and father-imprinted song preference in this study, similar testing can be applied in many ways to test preference for local dialects or subspecies-specific songs. [ABSTRACT FROM AUTHOR]

To evaluate reservoir porosity accurately, a method based on the bidirectional temporal convolutional network (BiTCN), bidirectional long short-term memory network (BiLSTM), and attention mechanism (AM) optimized by the improved sparrow search algorithm (ISSA) is proposed. Firstly, the sparrow search algorithm improved by a phased control step size strategy and dynamic random Cauchy mutation is introduced. Secondly, the superiority of the ISSA is confirmed by the test functions of Congress on Evolutionary Computation in 2022 (CEC-2022). Furthermore, the experimental findings are assessed using the Wilcoxon test, which provides additional evidence of the ISSA's superiority against the competing algorithms. Finally, the BiTCN-BiLSTM-AM is optimized by the ISSA, and the ISSA-BiTCN-BiLSTM-AM was applied to reservoir porosity construction in the Midlands basin. The results showed that the RMSE and MAE of the proposed model were 0.4293 and 0.5696, respectively, which verified the effectiveness and success rate of reservoir parameter construction by addressing the shortcomings in the capabilities shown by conventional interpretation procedures. [ABSTRACT FROM AUTHOR]

In order to balance power supply and demand, which is crucial for the safe and effective functioning of power systems, short-term power load forecasting is a crucial component of power system planning and operation. This paper aims to address the issue of low prediction accuracy resulting from power load volatility and nonlinearity. It suggests optimizing the number of hidden layer nodes, number of iterations, and learning rate of bi-directional long- and short-term memory networks using the improved sparrow search algorithm, and predicting the actual load data using the load prediction model. Using actual power load data from Wuxi, Jiangsu Province, China, as a dataset, the model makes predictions. The results indicate that the model is effective because the enhanced sparrow algorithm optimizes the bi-directional long- and short-term memory network model for predicting the power load data with a relative error of only 2%, which is higher than the prediction accuracy of the other models proposed in the paper. [ABSTRACT FROM AUTHOR]

A tool wear prediction method based on the improved sparrow search algorithm (ISSA) optimized XGBoost model is proposed to enhance the tool wear prediction performance under different machining conditions. The recursive feature elimination (RFE) algorithm is applied to adaptively identify the most representative features from cutting forces and torque signals. The XGBoost model is utilized to establish the tool wear prediction model, with ISSA optimizing its hyperparameters. The experimental results demonstrate that the RFE algorithm reduces the feature dimension by 94.22% and improves the model's precision by 10.64%. The proposed ISSA-XGBoost model has high recognition accuracy, with a classification accuracy of 93.62%. Comparative analyses with prediction models optimized using particle swarm optimization (PSO), grey wolf optimization (GWO), and sparrow search algorithm (SSA), the ISSA-XGBoost model achieves the improvements of 4.26%, 10.64%, and 8.51%, respectively, allowing it to efficiently identify the tool wear state at various spindle speeds. [ABSTRACT FROM AUTHOR]

Increased urbanisation influences the morphometric traits of various species, often resulting in urban individuals being smaller than their non-urban counterparts. Urbanisation can affect fundamental eco-evolutionary patterns and impact species' ability to adapt to and occupy rapidly changing environments through morphological changes. We investigated the morphometric responses of two passerine species, the non-native house sparrow (Passer domesticus) and its native congener, the Cape sparrow (Passer melanurus), along gradients of spatial and temporal urbanisation in South Africa over a 52-year period. The house sparrow was significantly heavier, larger and in better condition with increasing urban infrastructure and lower urban vegetation cover, while the Cape sparrow showed opposing trends along these gradients. Temporally, the house sparrow's body mass increased consistently over the 52-year study period, suggesting changes in morphology were concomitant with increasing urbanisation over time. This study demonstrates distinct differences in the morphological responses of the non-native house sparrow and the native Cape sparrow to increasing urban development. These morphological responses may also underpin community-level changes caused by urbanisation, enhancing the capabilities of non-native species to thrive over their native counterparts in these environments. [ABSTRACT FROM AUTHOR]

Only a few decades after its introduction to the United States in the mid-nineteenth century, the house sparrow was considered a pest that drove away native birds. Its downfall is representative of a story familiar to scholars of animals and technology who have studied the methods used to control or exclude unwanted species from both rural and urban areas. The case of the house sparrow, however, differs in a crucial respect: the birds made their homes in bird boxes, built technologies designed to attract avian species and bring them closer to humans. This article documents how bird boxes were used as tools to regulate avian life in the late nineteenth and early twentieth centuries in the United States and argues that they should be seen as a technology that mediates and regulates our relationship with nature by promoting or controlling certain aspects of living organisms. [ABSTRACT FROM AUTHOR]

The cover image for this issue of Technology and Culture depicts how bird boxes became contested technologies in the United States. The early twentieth-century image shows a pair of house sparrows (Passer domesticus)— an introduced species—taking over a bird box intended for native birds. But the claim that sparrows seized bird boxes and other nesting places to the detriment of American birds was controversial. Since their mid-nineteenth-century introduction to the United States, sparrows have had both supporters and detractors who used bird boxes as tools to aid or suppress the birds. This essay argues that this image and others like it constitute a form of "biological propaganda" that supported the professionalization of ornithology in the United States. Natural history illustrations are not value neutral but show animals and technology in such a way as to support their creator's specific view of nature and what "belongs" in it. [ABSTRACT FROM AUTHOR]

Determining space use for species is fundamental to understanding their ecology, and tracking animals can reveal insights into their spatial ecology on home ranges and territories. Recent technological advances have led to GPS-tracking devices light enough for birds as small as ~30 g, creating novel opportunities to remotely monitor fine-scale movements and space use for these smaller species. We tested whether miniaturized GPS tags can allow us to understand space use of migratory birds away from their capture sites and sought to understand both pre-breeding space use as well as territory and habitat use on the breeding grounds. We used GPS tags to characterize home ranges on the breeding grounds for a migratory songbird with limited available breeding information, the Golden-crowned Sparrow (Zonotrichia atricapilla). Using GPS points from 23 individuals across 26 tags (three birds tagged twice), we found home ranges in Alaska and British Columbia were on average 44.1 ha (95% kernel density estimate). In addition, estimates of territory sizes based on field observations (mean 2.1 ha, 95% minimum convex polygon [MCP]) were three times smaller than 95% MCPs created using GPS tags (mean 6.5 ha). Home ranges included a variety of land cover classes, with shrubland particularly dominant (64–100% of home range cover for all but one bird). Three birds tracked twice returned to the same breeding area each year, supporting high breeding site fidelity for this species. We found reverse spring migration for five birds that flew up to 154 km past breeding destinations before returning. GPS-tracking technology allowed for critical ecological insights into this migratory species that breeds in very remote locations. [ABSTRACT FROM AUTHOR]

Global warming has become an undeniable fact, and the frequent occurrence of extremely hot weather is a serious challenge to the survival of animals. As one of the most active components of the ecosystem, birds are sensitive to the constant changes in the climate and environment. To investigate the physiological responses of Eurasian tree sparrows (Passer montanus) to acute heat stress, various thermogenic parameters of the birds, which included resting metabolic rate (RMR), body mass, body temperature, water intake, and liver cellular metabolic capacity, were measured after exposure to 42°C for different times. The antioxidant response of Eurasian tree sparrows to heat stress was investigated by measuring the lipid oxidation indexes and related antioxidant oxidase activities in the serum and liver. Body temperature and water intake were significantly increased after 2 h of heat stress and lasted until the end of the heat stress (12 h). In contrast, RMR was significantly decreased after 2 h of heat stress. At the cellular level, liver COX activity was significantly increased during heat stress from 2 h to 6 h. Additionally, there was a significant increase in MDA content and superoxide dismutase (SOD) and catalase (CAT) activity levels in the serum. The glutathione peroxidase (GSH-PX) activity in the liver was significantly decreased after 2 h of heat stress. Our results indicated that heat production decreased while heat dissipation increased in Eurasian tree sparrows exposed to acute heat stress. At the same time, the internal antioxidant defense system of the birds was activated to counteract the damage caused by high temperatures. Therefore, it was reasonable to speculate that Eurasian tree sparrows might be resistant to high temperatures to the extent that they can maintain normal life activities through the regulation of thermogenic and antioxidant systems under acute heat stress. [ABSTRACT FROM AUTHOR]

Recent research has shown that songbirds that reside at low altitudes can ascend to ∼6000 m above sea level during migratory flight. Since migratory flight is aerobically demanding, whether migratory songbirds exhibit plasticity in breathing to maintain oxygen uptake in low-oxygen environments is unknown. This study investigated whether the hypoxic ventilatory response of sparrows was altered between resident house sparrows (Passer domesticus (Linneaus, 1758)) and migratory song sparrows (Melospiza melodia (A. Wilson, 1810)), and Lincoln's sparrows (Melospiza lincolnii (Audubon, 1834)) or seasonally (long daylight versus short daylight length) within a species. Breathing responses were assessed by stepwise reductions in inspired O2 tension, 21, 16, 12, 9, 7, and 5 kPa during long and short days. Ventilation increased in hypoxia in all species, although song sparrows and Lincoln's sparrows exhibited greater increases in ventilation in severe hypoxia compared to house sparrows. All species became more sensitive to hypoxia during short days compared to long days (increased breathing frequency and total ventilation), with reduced pulmonary oxygen extraction. Although all sparrows had similar ventilatory responses in moderate hypoxia, our findings suggest that migratory sparrows breathe more effectively in severe hypoxia compared to house sparrows, which would be important for maintaining oxygen uptake during migratory flights. [ABSTRACT FROM AUTHOR]

The harlequin ladybird (Harmonia axyridis) shows a high level of colour polymorphism. Particular forms differ in their colour combination, pattern and abundance.Two species of wild‐caught passerines native to Central Europe were offered various forms of ladybirds, differing in their colour pattern and abundance in nature. We predicted that those forms that are more abundant in the wild are better protected, as they are more familiar to predators.Forms novemdecimsignata and spectabilis, which represent 97% of individuals in the wild population, significantly differ in their visual appearance (mostly orange vs. mostly black). The form axyridis is very rare in the wild, and suturalis and aninkae do not occur in the wild and were derived from laboratory breedingsAs predators, we used great tits (Parus major), which are very aversive towards ladybirds, and tree sparrows (Passer montanus), which are quite willing to attack and even eat ladybirds.We compared bird responses to particular ladybird colour forms and included a brown‐painted control to test the effect of conspicuous colours.We showed that both species of birds attacked all conspicuous forms of the ladybird equally and usually very rarely. The brown‐painted novemdecimsignata form was attacked more frequently compared with the conspicuous forms, showing that the visual appearance prevents birds from attacking any conspicuous colour combination. Sparrows tended to eat the attacked ladybirds of forms novemdecimsignata, spectabilis and brown painted. The rare axyridis form and laboratory forms were very well protected from the attack, very likely due to neophobia.We may conclude that despite the outstanding polymorphism of H. axyridis, its protection against avian predators is very effective as long as the red‐and‐black pattern is preserved. [ABSTRACT FROM AUTHOR]

Animals' learned vocalizations often show high levels of intraspecific variation, and different variants may play different roles in attracting mates and settling territorial disputes. In any animal population with variable vocalizations, certain acoustic variants may be common and others rare. The responses of animals to local versus nonlocal sounds have been well characterized in prior investigations, but few investigations have explored the reactions of animals to songs that are present at different frequencies of occurrence within a population. Using an experimental approach to investigate a breeding population of Savannah sparrows, Passerculus sandwichensis , we tested the responses of territorial male songbirds to playback of locally common songs, locally rare songs and heterospecific songs. Male sparrows showed strong responses to conspecific song but weak responses to heterospecific song. Males showed their strongest responses to locally common songs and weaker responses to locally rare songs. Birds did not appear to discriminate between playback songs based on whether they were of the same song type as their own. We suggest that male Savannah sparrows perceive locally rare songs as weaker threats than locally common songs, similar to birds' reactions to foreign dialects. This could be due to low familiarity with locally rare songs, reduced female preference for locally rare songs, decreased success with territory defence for males singing locally rare songs or other perceived differences between locally rare and locally common songs. Overall, our results suggest that different song types elicit different responses from territorial songbirds, even songs that are found within the same population with different frequencies of occurrence. • Many animals show small-scale geographical variation in vocalizations. • Responses to locally common or locally rare vocalizations are seldom explored. • We used playback to test birds' responses to locally common and locally rare songs. • Savannah sparrows responded more strongly to locally common songs. • We suggest locally common songs are perceived as a stronger threat. [ABSTRACT FROM AUTHOR]

Many biological studies rely on accurate sex determination of individuals to investigate sex-specific differences in wild populations. Numerous species can be reliably sexed in the field using external characteristics such as plumage color and ornamentation or in the hand using breeding characteristics such as a brood patch (female) or cloacal protuberance (male). However, plumage differences may not be present year-round and breeding characteristics are not present outside of the breeding season. This is a problem for researchers as they may not be able to reliably sex individuals in the field outside of the breeding season. However, monochromatic species often exhibit sex differences in morphometrics including wing chord length and tarsus length. Recent studies have found that the Eastern (leucophrys) and Puget Sound (pugetensis) subspecies of the White-crowned Sparrow (Zonotrichia leucophrys) can be reliably sexed using wing chord length. The Gambel's (gambelii) subspecies was last studied in 1985 and the Nuttall's (nuttalli) subspecies has not been tested. We combined wing chord length, tarsus length, and sex data from adult Gambel's and Nuttall's White-crowned Sparrows to determine if these subspecies could be reliably sexed using wing chord length and/or tarsus length. We also determined if the migratory Gambel's subspecies and resident Nuttall's subspecies varied morphologically. We found that the Gambel's and Nuttall's subspecies could be reliably sexed using wing chord length outside overlapping ranges of 74–78 and 69–77 mm, respectively. We also found that the Gambel's subspecies had longer wing chord lengths and shorter tarsus lengths than the Nuttall's subspecies. Our findings provide a useful tool for sex determination in Gambel's, but not Nuttall's, White-crowned Sparrows. Further, our findings show that migratory and resident individuals within the same species vary morphologically, which may relate to the different selective pressures they face. [ABSTRACT FROM AUTHOR]

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This study investigated cadmium in urban sparrows from various Meknes zones with differing industrial and traffic intensities, compared to a rural site. Forty sparrows from industrial regions and ten from rural were analysed post-capture. Cadmium extraction used acid mineralisation, quantified via ICP. Findings revealed higher cadmium in sparrows' kidneys from industrial zones than the rural site, with an average of 1.25 µg/g wet weight, indicating urban and industrial impacts on metal accumulation. The kidneys showed notable vulnerability to cadmium. Statistical data highlighted significant concentration differences between zones. This research emphasises the need for environmental monitoring and pollution strategies in urban areas for safeguarding health. [ABSTRACT FROM AUTHOR]

Semi-empirical quantum chemical approaches are known to compromise accuracy for the feasibility of calculations on huge molecules. However, the need for ultrafast calculations in interactive quantum mechanical studies, high-throughput virtual screening, and data-driven machine learning has shifted the emphasis toward calculation runtimes recently. This comes with new constraints for the software implementation as many fast calculations would suffer from a large overhead of the manual setup and other procedures that are comparatively fast when studying a single molecular structure, but which become prohibitively slow for high-throughput demands. In this work, we discuss the effect of various well-established semi-empirical approximations on calculation speed and relate this to data transfer rates from the raw-data source computer to the results of the visualization front end. For the former, we consider desktop computers, local high performance computing, and remote cloud services in order to elucidate the effect on interactive calculations, for web and cloud interfaces in local applications, and in world-wide interactive virtual sessions. The models discussed in this work have been implemented into our open-source software SCINE Sparrow. [ABSTRACT FROM AUTHOR]

Animal culture evolves alongside genomes, and the two modes of inheritance—culture and genes—interact in myriad ways. For example, stable geographic variation in culture can act as a reproductive barrier, thereby facilitating genetic divergence between "cultural populations." White-crowned sparrows (Zonotrichia leucophrys) are a well-established model species for bird song learning and cultural evolution, as they have distinct, geographically discrete, and culturally transmitted song types (i.e., song dialects). In this study, we tested the hypothesis that divergence between culturally transmitted songs drives genetic divergence within Nuttall's white-crowned sparrows (Z. l. nuttalli). In accordance with sexual selection theory, we hypothesized that cultural divergence between mating signals both preceded and generated genetic divergence. We characterized the population structure and song variation in the subspecies and found two genetically differentiated populations whose boundary coincides with a major song boundary at Monterey Bay, California. We then conducted a song playback experiment that demonstrated males discriminate between songs based on their degree of divergence from their local dialect. These results support the idea that discrimination against non-local songs is driving genetic divergence between the northern and southern populations. Altogether, this study provides evidence that culturally transmitted bird songs can act as the foundation for speciation by sexual selection. [ABSTRACT FROM AUTHOR]

Eco‐phylogeographic approaches to comparative population genetic analyses allow for the inclusion of intrinsic influences as drivers of intraspecific genetic structure. This insight into microevolutionary processes, including changes within a species or lineage, provides better mechanistic understanding of species‐specific interactions and enables predictions of evolutionary responses to environmental change. In this study, we used single nucleotide polymorphisms (SNPs) identified from reduced representation sequencing to compare neutral population structure, isolation by distance (IBD), genetic diversity and effective population size (Ne) across three closely related and co‐distributed saltmarsh sparrow species differing along a specialization gradient—Nelson's (Ammospiza nelsoni subvirgata), saltmarsh (A. caudacuta) and seaside sparrows (A. maritima maritima). Using an eco‐phylogeographic lens within a conservation management context, we tested predictions about species' degree of evolutionary history and ecological specialization to tidal marshes, habitat, current distribution and population status on population genetic metrics. Population structure differed among the species consistent with their current distribution and habitat factors, rather than degree of ecological specialization: seaside sparrows were panmictic, saltmarsh sparrows showed hierarchical structure and Nelson's sparrows were differentiated into multiple, genetically distinct populations. Neutral population genetic theory and demographic/evolutionary history predicted patterns of genetic diversity and Ne rather than degree of ecological specialization. Patterns of population variation and evolutionary distinctiveness (Shapely metric) suggest different conservation measures for long‐term persistence and evolutionary potential in each species. Our findings contribute to a broader understanding of the complex factors influencing genetic variation, beyond specialist‐generalist status and support the role of an eco‐phylogeographic approach in population and conservation genetics. [ABSTRACT FROM AUTHOR]

Simple Summary: The Worthen sparrow (WS) is an endemic species of the Mexican rangelands that is considered endangered. The objective of this study was to document the building materials for nest building of this obligate grassland bird species. After completing the breeding season from 2013–2016, 207 empty nests were collected to analyze the construction materials used in their assembly. The findings revealed that Muhlembergia torrey was a key component of the WS's nest. The study was conducted within a well-managed beef cattle operation in northeastern Mexico. Each nest was weighed and dissected to obtain the plant and animal material used to build the nests. The number of materials present per nest and relative frequency were determined. Twenty-one building materials were used. Over the years, Muhlenbergia torreyi represented 85.5% of the total biomass of the nests, and Aristida longiseta, Bouteloua gracilis, Brickellia canescens, Purshia mexicana and Cirsium ehrenbergii constituted 2.45, 2.80, 2.44, 1.34 and 1.11% of the total biomass, respectively. The above-mentioned grasses represented 95.62% of the total biomass. Material of animal origin was horse and cow hair, which represented 0.84 and 0.58% of the total biomass, respectively. It was concluded that, at the study site, Muhlenbergia torreyi was a key nest-building material for the Worthen sparrow nest. [ABSTRACT FROM AUTHOR]

Noise from oil and gas development is pervasive across many landscapes and creates a novel soundscape that wildlife must adapt to or avoid. In response to anthropogenic noise, many wildlife species alter their vocalizations. Some adjusted vocalizations may promote effective communication in the presence of noise by improving detection and preserving information about the sender's status. However, if adjusted vocalizations fail to improve communication in noise, both missed detections and misinterpretations of vocalizations could impact the fitness of individuals and ultimately contribute to population declines. Baird's sparrow is a species at risk in Canada that adjusts its songs in response to oil well drilling noise by altering whole-song elements such as decreasing the peak frequency of songs (Curry et al., 2017, Bioacoustics, 27 (2), 105–130). We examined the efficacy of these adjusted songs in the mixed-grass prairies of southern Alberta, Canada during the Baird's sparrow breeding season (May–July 2018 and 2019) using a repeated measures study design (N = 69 dyads) in which we simulated territorial intrusions by broadcasting adjusted songs and unadjusted songs in the presence and absence of oil well drilling noise recordings. We found that focal male behaviour was mainly mediated by noise treatment when compared to song treatment. In noisy trials, males sang less, called more and performed more flybys, regardless of song treatment type. However, in noisy trials, males displayed longer song latency in response to unadjusted songs compared to adjusted songs. The results of our novel study suggest that the presence of oil well drilling noise elicits more aggressive territorial defence behaviour in Baird's sparrows or hinders the ability of individuals to locate or assess rivals. Additionally, our results suggest that adjusted songs only partially restore effective communication in noise. • Focal male behaviour was mainly influenced by the presence or absence of noise. • Noise may have caused increased aggression or impaired detection in focal males. • Focal males did not generally discriminate between adjusted and unadjusted songs. • Adjusted songs may partially improve acoustic detection in noise. • Unadjusted songs may experience partial acoustic masking in noise. [ABSTRACT FROM AUTHOR]

Global contamination of environments with lead (Pb) poses threats to many ecosystems and populations. While exposure to Pb is toxic at high concentrations, recent literature has shown that lower concentrations can also cause sublethal, deleterious effects. However, there remains relatively little causal investigation of how exposure to lower concentrations of environmental Pb affects ecologically important behaviors. Behaviors often represent first-line responses of an organism and its internal physiological, molecular, and genetic responses to a changing environment. Hence, better understanding how behaviors are influenced by pollutants such as Pb generates crucial information on how species are coping with the effects of pollution more broadly. To better understand the effects of sublethal Pb on behavior, we chronically exposed adult wild-caught, captive house sparrows (Passer domesticus) to Pb-exposed drinking water and quantified a suite of behavioral outcomes: takeoff flight performance, activity in a novel environment, and in-hand struggling and breathing rate while being handled by an experimenter. Compared to controls (un-exposed drinking water), sparrows exposed to environmentally relevant concentrations of Pb exhibited decreases in takeoff flight performance and reduced movements in a novel environment following 9–10 weeks of exposure. We interpret this suite of results to be consistent with Pb influencing fundamental neuro-muscular abilities, making it more difficult for exposed birds to mount faster movements and activities. It is likely that suppression of takeoff flight and reduced movements would increase the predation risk of similar birds in the wild; hence, we also conclude that the effects we observed could influence fitness outcomes for individuals and populations altering ecological interactions within more naturalistic settings. [ABSTRACT FROM AUTHOR]

Phenotypic plasticity facilitates organismal invasion of novel environments, and the resultant phenotypic change may later be modified by genetic change, so called 'plasticity first.' Herein, we quantify gene expression plasticity and regulatory adaptation in a wild bird (Eurasian Tree Sparrow) from its original lowland (ancestral stage), experimentally implemented hypoxia acclimation (plastic stage), and colonized highland (colonized stage). Using a group of co-expressed genes from the cardiac and flight muscles, respectively, we demonstrate that gene expression plasticity to hypoxia tolerance is more often reversed than reinforced at the colonized stage. By correlating gene expression change with muscle phenotypes, we show that colonized tree sparrows reduce maladaptive plasticity that largely associated with decreased hypoxia tolerance. Conversely, adaptive plasticity that is congruent with increased hypoxia tolerance is often reinforced in the colonized tree sparrows. Genes displaying large levels of reinforcement or reversion plasticity (i.e. 200% of original level) show greater genetic divergence between ancestral and colonized populations. Overall, our work demonstrates that gene expression plasticity at the initial stage of high-elevation colonization can be reversed or reinforced through selection-driven adaptive modification. [ABSTRACT FROM AUTHOR]

Industrial chemical contamination is known to have immuno-toxic effects on birds. It may also interfere with natural stressful conditions to further disrupt the immune responses, but these possible interactive effects are still poorly documented in free-living birds. Using the phytohaemagglutinin skin-swelling test, we assessed how the T-cell mediated immune response varied according to the perceived risk of predation in hybrid sparrows, Passer domesticus × Passer hispaniolensis, originating from two sites differentially impacted by industrial chemical contamination, in southern Tunisia. Results showed that T-cell mediated immune response decreased with increasing perceived risk of predation, but the extent of this predator-associated immunosuppression was weaker in birds from the contaminated site compared to those from the control site. The immune response of birds living in the contaminated site was so weak that it could not be further weakened by a predator-related stress. Overall, these results support the idea that chemical contamination interferes with natural environmental stressors, such as predators, thus entailing profound disruption of the immune responses, with possible deleterious repercussions on the ability of birds to cope with diseases. [ABSTRACT FROM AUTHOR]

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In white-throated sparrows, two alternative morphs differing in plumage and behavior segregate with a large chromosomal rearrangement. As with sex chromosomes such as the mammalian Y, the rearranged version of chromosome two (ZAL2m) is in a near-constant state of heterozygosity, offering opportunities to investigate both degenerative and selective processes during the early evolutionary stages of supergenes. Here, we generated, synthesized, and analyzed extensive genome-scale data to better understand the forces shaping the evolution of the ZAL2 and ZAL2m chromosomes in this species. We found that features of ZAL2m are consistent with substantially reduced recombination and low levels of degeneration. We also found evidence that selective sweeps took place both on ZAL2m and its standard counterpart, ZAL2, after the rearrangement event. Signatures of positive selection were associated with allelic bias in gene expression, suggesting that antagonistic selection has operated on gene regulation. Finally, we discovered a region exhibiting long-range haplotypes inside the rearrangement on ZAL2m. These haplotypes appear to have been maintained by balancing selection, retaining genetic diversity within the supergene. Together, our analyses illuminate mechanisms contributing to the evolution of a young chromosomal polymorphism, revealing complex selective processes acting concurrently with genetic degeneration to drive the evolution of supergenes.

The trill elements of many bird species' songs have been hypothesized as honest signals of performance. However, the breadth of receiver responses to variation in the signaller's trill performance is unknown. We exposed wild male Lincoln's sparrows (Melospiza lincolnii) to two song treatments, one with low- and another with high-performance trills. We found no effect of treatment on measures of agonistic behaviour and song length. However, relative to the subjects' trills following the high-performance treatment, those following the low-performance treatment were elevated in performance due to trill types with high frequency bandwidth in the third trill of songs. Treatment also affected trill duration through its syllable count in a manner that varied by the song's trill number. Thus, the performance of a signal to which a receiver is exposed drives plasticity in his own performance in sequence-specific manner. Males may showcase their own performance in the presence of lower-performing rivals. [ABSTRACT FROM AUTHOR]

The federally endangered Cape Sable seaside sparrow (Ammospiza maritima mirabilis) is endemic to the Greater Everglades ecosystem in southern Florida, inhabiting fragmented marl prairies in six individual subpopulations. The subspecies is threatened by loss of breeding habitat from fire and water management. Genetic information is severely limited for the subspecies but could help inform decisions regarding subpopulation protections and potential translocations for genetic rescue. To provide genetic data and inform management efforts, feather samples were collected across five subpopulations (designated A–E) and protocols were tested to optimize DNA extraction yields. We assessed four mitochondrial DNA markers (N = 36–69) and 12 nuclear microsatellite loci (N = 55) in 108 sparrows. Mitochondrial DNA sequences revealed low haplotype diversity, with NADH dehydrogenase-2 haplotypes matching to most other extant subspecies and to the Atlantic coast subspecies. Nuclear diversity was low compared to other subspecies, but similar across subpopulations. Samples grouped as one population when analyzed by Principal Component Analysis, Bayesian modelling and genetic distance metrics. Limited genetic emigration was detected from one putative migrant. Relatedness was significantly different for sparrows in the most geographically distant subpopulation (A), likely reflecting high self-recruitment and natal site fidelity (P = 0.003). The low to moderate effective population size (NE = 202.4; NE:NC = 0.06) and generation time estimates indicated that unique genetic variation could be lost quickly during stochastic events. The sample sizes were limited, which reduced the power to comprehensively address recent population size reductions and any subsequent loss of genetic diversity. [ABSTRACT FROM AUTHOR]

The white-crowned sparrow, Zonotrichia leucophrys, is a passerine bird with a wide distribution and it is extensively adapted to environmental changes. It has historically acted as a model species in studies on avian ecology, physiology and behaviour. Here, we present a high-quality chromosome-level genome of Zonotrichia leucophrys using PacBio and OmniC sequencing data. Gene models were constructed by combining RNA-seq and Iso-seq data from liver, hypothalamus, and ovary. In total a 1,123,996,003 bp genome was generated, including 31 chromosomes assembled in complete scaffolds along with other, unplaced scaffolds. This high-quality genome assembly offers an important genomic resource for the research community using the white-crowned sparrow as a model for understanding avian genome biology and development, and provides a genomic basis for future studies, both fundamental and applied. [ABSTRACT FROM AUTHOR]

Seasonally breeding birds express variations of traits (phenotypic flexibility) throughout their life history stages that represent adaptations to environmental conditions. Changes of body condition during migration have been well studied, whereas alterations of skeletal and cardiac muscles, body mass, and fat scores have yet to be characterized throughout the spring or fall migratory stages. Additionally, we examined flexible patterns of muscle, body mass, and fat score in migrant white-crowned sparrows (Zonotrichia leucophrys gambelii) in comparison with those in a resident subspecies (Zonotrichia leucophrys nuttalli) during the stages they share to evaluate the influence of different life histories. Migrants showed hypertrophy of the pectoralis muscle fiber area on the wintering grounds in late prealternate molt, yet increased pectoralis muscle mass was not detected until birds readied for spring departure. While pectoralis profile and fat scores enlarged at predeparture in spring and fall, pectoralis, cardiac, and body masses were greater only in spring stages, suggesting seasonal differences for migratory preparation. Gastrocnemius mass showed little change throughout all stages, whereas gastrocnemius fiber area declined steadily but rebounded in fall on the wintering grounds, where migrants become more sedentary. In general, residents are heavier birds with larger leg structures, while migrants sport longer wings and greater heart mass. Phenotypic flexibility was most prominent among residents with peaks of pectoralis, gastrocnemius, and body masses during the winter stage, when local weather is most severe. Thus, the subspecies express specific patterns of phenotypic flexibility with peaks coinciding with the stages of heightened energy demands: the winter stage for residents and the spring stages for migrants. [ABSTRACT FROM AUTHOR]

Cases of parasitism of the Shiny Cowbird (Molothrus bonariensis) on the Rufous-collared Sparrow (Zonotrichia capensis) have only been reported in urban areas below 2817 masl in Ecuador. Between January and March 2022, in the city of Quito, Ecuador, at 3040 masl, we registered parasitism by the Shiny Cowbird using the Rufous-collared Sparrow as a host. We observed the fledgling Shiny Cowbird insistently begging to be fed by adult Rufous-collared Sparrows over a period of 58 days, until the fledgling abandoned parental care. This report represents an extension of 223 m in the altitudinal range of parasitism between these two species, and contributes to information on the expansion and colonization of the Shiny Cowbird in high Andean areas. Our record of a longer duration of parental care of the fledgling has implications for the parasite-host relationship, requiring greater energy expenditure by small hosts. [ABSTRACT FROM AUTHOR]

Combating the current biodiversity crisis requires the accurate documentation of population responses to human‐induced ecological change. However, our ability to pinpoint population responses to human activities is often limited to the analysis of populations studied well after the fact. Museum collections preserve a record of population responses to anthropogenic change that can provide critical baseline data on patterns of genetic diversity, connectivity, and population structure prior to the onset of human perturbation. Here, we leverage a spatially replicated time series of specimens to document population genomic responses to the destruction of nearly 90% of coastal habitats occupied by the Savannah sparrow (Passerculus sandwichensis) in California. We sequenced 219 sparrows collected from 1889 to 2017 across the state of California using an exome capture approach. Spatial–temporal analyses of genetic diversity found that the amount of habitat lost was not predictive of genetic diversity loss. Sparrow populations from southern California historically exhibited lower levels of genetic diversity and experienced the most significant temporal declines in genetic diversity. Despite experiencing the greatest levels of habitat loss, we found that genetic diversity in the San Francisco Bay area remained relatively high. This was potentially related to an observed increase in gene flow into the Bay Area from other populations. While gene flow may have minimized genetic diversity declines, we also found that immigration from inland freshwater‐adapted populations into tidal marsh populations led to the erosion of divergence at loci associated with tidal marsh adaptation. Shifting patterns of gene flow through time in response to habitat loss may thus contribute to negative fitness consequences and outbreeding depression. Together, our results underscore the importance of tracing the genomic trajectories of multiple populations over time to address issues of fundamental conservation concern. [ABSTRACT FROM AUTHOR]

Abiotic stressors can be major sources of selection, resulting in diverse demographic responses operating via multiple direct and indirect mechanisms. However, unusual weather events are notoriously difficult to study due to their spatial and temporal unpredictability. A severe drought affected the Flint Hills of Kansas in 2018, occurring during the ongoing population‐level studies of three species of declining grassland songbirds: Eastern Meadowlarks (Sturnella magna), Grasshopper Sparrows (Ammodramus savannarum), and Dickcissels (Spiza americana). We compared nest survival, nest initiation date, and potential behavioral drivers of reproductive differences (i.e., nest orientation, investment) between the 2018 drought year and 2–6 years of average‐to‐wet years. Nest initiation in the drought year was concentrated early in the season, suggesting that birds did not renest or attempt second broods. The two species that build domed nests shifted the orientation of nest entrances away from early morning sun and toward the direction of prevailing winds in the drought year. Multiple nest‐level metrics of investment and success were similar in drought and nondrought years. These results suggest that demographic changes during droughts can reflect both direct responses and may also involve biotically mediated trophic consequences. [ABSTRACT FROM AUTHOR]

Migratory animals may trade-off between investing energy in immune defense versus investing in energy reserves needed for seasonal migration. However, these trade-offs are often masked by other sources of variation and may not be detected through observational field studies of free-living animals. Moreover, observational studies can rarely distinguish the costs of pathogenic infection from those of mounting an immune response. To disentangle such effects, we conducted an immune challenge experiment. We captured song sparrows (Melospiza melodia) and white-throated sparrows (Zonotrichia albicollis) in autumn migratory condition, challenged the sparrows with non-infectious antigens that induce an acute-phase immune response, then monitored body composition and migratory restlessness behavior. For both species, body mass was higher the day after exposure to keyhole limpet hemocyanin (KLH) compared to controls. White-throated sparrows, but not song sparrows, increased lean mass 1 week after exposure to lipopolysaccharide (LPS), suggesting that effects of immune upregulation on body composition may be long-lasting and specific to certain combinations of hosts and antigens. White-throated sparrows exposed to KLH increased nocturnal migratory restlessness (Zugunruhe) for the week following exposure. These findings suggest that short-term activation of the acute immune response does not constrain migratory physiology in these songbirds. [ABSTRACT FROM AUTHOR]

Divergence in the acoustic structure of mate-attraction signals between closely related taxa can contribute to reproductive isolation and speciation, and acoustic differences are often useful for identifying otherwise similar taxa from recordings. The Brewer’s Sparrow (Spizella breweri) is a migratory oscine songbird with 2 recently diverged subspecies. The nominate subspecies (S. b. breweri) primarily breeds in sagebrush (Artemisia spp.) shrublands in the western United States and southwestern Canada, whereas the Timberline Sparrow (S. b. taverneri) breeds in alpine shrubs and conifer krummholz near treeline in mountain ranges from east-central Alaska to northwestern Montana. Quantitative comparison of the acoustic structure of Brewer’s Sparrow mate-attraction songs is needed to help resolve the outstanding debate regarding the taxonomic status of S. b. taverneri and improve subspecific identification from song recordings. I compared the acoustic structure of 181 short song types from 180 male S. b. breweri and 22 short song types from 20 male S. b. taverneri recorded from across each subspecies’ breeding range. Despite extreme variation in acoustic structure of short songs among individuals, 19 acoustic variables differed between subspecies. Short song types of S. b. taverneri averaged 19.3%–22.1% lower maximum frequency, 4.9%–15.9% higher minimum frequency, 36.7%–42.6% narrower frequency bandwidth, and 12.9%–26.0% lower aggregate entropy (a measure of sound complexity) than those of S. b. breweri across acoustic elements (song, section, syllable, and note). Random forest classification analysis identified 10 acoustic variables important for distinguishing between short songs of the 2 subspecies and correctly classified 89.2% (95% CI 84.1% to 93.1%) of songs overall. Principal component scores representing overall acoustic structure showed an abrupt change near the breeding boundary between S. b. breweri and S. b. taverneri but overlapped sufficiently that they did not meet an established “75%–99% rule” for reciprocal diagnosability of subspecies. An easy-to-measure logistic regression threshold based on song bandwidth and mean note bandwidth accurately classified >90% of short songs to subspecies. Additional recordings of S. b. taverneri are needed to improve our understanding of geographic variation in the song of that subspecies. Data on responses of males and females to songs of the other subspecies would inform whether acoustic differences are sufficient to impede mate recognition and attraction in areas of potential breeding overlap. [ABSTRACT FROM AUTHOR]

The inheritance of structural characteristics and individual note parameters is often studied in oscine passerines. However, other song features, such as the temporal characteristics of song, are less well studied. Inheritance of these features could be influenced by a range of factors, including social inheritance, mechanical constraints, genetic relatedness and the developmental environment. Using archived song data, we examined patterns of inheritance of temporal song features, relating to song duration, song tempo and internote intervals, in a laboratory population of Java sparrows, Padda oryzivora , some of which had been cross fostered. Overall, we found strong evidence for cultural inheritance of temporal song features, that is, temporal song features were learned from the social father. We found that song duration was, at most, weakly socially inherited and constrained by a correlation between song tempo and number of notes. Internote gap durations were also influenced by other song features, in particular the duration of the preceding and following notes, although social learning was still apparent when controlling for these features. Across all measures, we found no evidence that temporal song features were affected by genetic relatedness or the developmental environment. Our findings, and those in other species, suggest that temporal song features are likely to be inherited through a combination of the learning of song structure and spectral structure of notes, and specific learning of temporal song features during development. • Many temporal features of Java sparrow song are socially inherited. • Gap durations are affected by a range of song characteristics. • No evidence that genetics or the developmental environment affect temporal features. • Social learning may drive song divergence and affect gene flow between populations. [ABSTRACT FROM AUTHOR]

Urbanization is rapidly changing habitats of wild birds around the world. Food availability is one of the important factors leading to phenotypic differences between urban and rural bird populations. Comparing the physiological plasticity responses of urban and rural bird populations to different food conditions can reveal the mechanism of bird adaptation to urban environment. In this study, we hypothesized that the glycogenolysis, glycogenesis and gluconeogenesis of urban birds have been adjusted to cope with food shortage in urban areas. To test this, we designed a food quantity-controlled experiment to compare the effects of different food quantities (daily 1 g, 3 g, 5 g, 7 g per bird) on the activities of glycogen phosphorylase (GP), glycogen synthase (GS) and phosphoenolpyruvate carboxylase (PEPCK) in plasma of Tree sparrows (Passer montanus) from urban and rural areas of Beijing. The activities of GP and PEPCK in plasma of Tree sparrows from both urban and rural areas increased with the food quantity decrease. Only the activity of PEPCK was significantly different between urban and rural sparrows. The PEPCK activities of urban sparrows were significantly higher than those of rural sparrows in 1 and 3 g treatments. These results indicate that Tree sparrows from urban areas have greater gluconeogenesis plasticity than rural sparrows, which supports our hypothesis that gluconeogenesis plasticity of urban birds has been adjusted in response to urban environment. [ABSTRACT FROM AUTHOR]

When evaluating avian reproduction, life history theory examines the trade‐offs between parental effort, the number and size of offspring, and the rate of nestling development. The growth rates and body sizes of developing birds vary geographically and can diverge with both latitude and migratory strategy. In terms of offspring size, growth rate can deviate in nestlings of the same or similar species due to the correlated influences of weather events, predation pressure, food availability, number of nestmates and parental provisioning. Furthermore, a longer photoperiod for species nesting at higher latitudes increases the duration over which a nestling can be fed each day, and increased nestling provisioning has been positively correlated with growth rate. Whether the amount of time a bird is fed during development drives this variation in growth rate and morphology is unknown. By removing supplemental environmental stressors (e.g. weather, predation) and standardizing feeding rate and environment, we explored the influence of daily duration of nestling provisioning on dark‐eyed junco Junco hyemalis nestlings. We hand‐reared 65 chicks of a sedentary junco subspecies J. h. carolinensis under both their natural photoperiod and the longer photoperiod of a closely related migratory subspecies J. h. hyemalis and compared growth rate, mass, morphology and the amount of food consumed. Average growth rate, fasted mass, wing length and total daily food consumption were all greater in birds hand‐reared under the longer, more northern photoperiod treatment. These findings suggest that increased daily photoperiod at higher latitudes may allow for greater total food provisioning and thus may play a role in the ability of parents in compressed breeding seasons to produce high quality offspring. This points to a trade‐off between provisioning effort and nestling growth rate in lower latitude (shorter photoperiod) populations and points to an important role of developmental plasticity on growth rate and morphology. [ABSTRACT FROM AUTHOR]

Malaria parasites (genus Plasmodium) are important agents of infectious disease in birds and multiple factors, including warming temperatures and environmental contamination, may act to increase their geographic and host ranges. Here, we examined the role of geographical variation and environmental mercury exposure in malaria parasite infection dynamics in an imperiled songbird species with high mercury exposition, the Saltmarsh Sparrow (Ammospiza caudacutus). Using polymerase chain reaction (PCR) methods, we screened 280 Saltmarsh Sparrows from across their breeding range for malaria parasite infection. We detected malaria parasites in 17% of sampled birds and a total of 6 Plasmodium lineages. Prevalence of infection and diversity of parasite lineages varied across the breeding range of the Saltmarsh Sparrow and increased at more northern latitudes. Although mercury is a known immunosuppressant and has been documented to alter an individual's susceptibility to pathogens, we did not find a significant difference in blood mercury levels between infected and not infected birds, perhaps due to sampling methods and/or small sample sizes. As a specialist of coastal wetlands, the Saltmarsh Sparrow is an excellent indicator species for ecological health, and the patterns of malaria parasite infection with host distribution and mercury suggest that birds at northern latitudes are at greater risk of disease and should be priorities for conservation, habitat, and pathogen monitoring. [ABSTRACT FROM AUTHOR]