Journal of Avian Biology最新文献

{"title":"Preening for protection: a systematic review of the antimicrobial properties of uropygial secretions","authors":"Carlos Mora-Rubio,&nbsp;Luz García-Longoria,&nbsp;Alfonso Marzal","doi":"10.1111/jav.03425","DOIUrl":"10.1111/jav.03425","url":null,"abstract":"<p>Uropygial secretion might play a crucial role in avian defense by exhibiting antimicrobial properties that protect birds from various pathogens. Although there has been considerable research, the differences in methods and results have led to varying conclusions about how well it works as an antimicrobial. Despite extensive research, the differences in experimental methods and results have led to varying conclusions regarding its antimicrobial effectiveness. This review consolidates existing literature on the antimicrobial activity of uropygial secretion or related compounds against bacteria and fungi across different bird species. A comprehensive search identified 35 studies, showcasing a variety of techniques used to assess antimicrobial activity, including agar diffusion, colony-forming unit (CFU) counting, and flow cytometry. The findings reveal a diverse range of antimicrobial effects influenced by bird species, target microorganisms, and the methodologies employed. Notably, uropygial secretion appears to be more effective against gram-positive bacteria than gram-negative bacteria and fungi, although these latter groups have been less extensively studied. The review also underscores significant limitations in taxonomic representation, as research has primarily focused on a limited number of bird species while many others remain underrepresented. Additionally, gaps in standardization and the predominance of in vitro studies hinder our ability to draw comprehensive conclusions about the antimicrobial potential of the uropygial secretions under natural conditions. Future research should prioritize standardizing methodologies, broadening the taxonomic scope, and investigating the combined effects of individual compounds within the secretion, including symbiotic microorganisms. Addressing these gaps will enhance our understanding of the evolutionary and ecological significance of uropygial secretion and clarify its role in avian health and defense mechanisms.</p>","PeriodicalId":15278,"journal":{"name":"Journal of Avian Biology","volume":"2025 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jav.03425","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143689732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Host response to conspecific brood parasitism in colonial red-breasted mergansers Mergus serrator: positioning of parasitic eggs within the clutch","authors":"Emilie Knighton,&nbsp;Mohammadi Kaouass,&nbsp;Rodger Titman,&nbsp;Mark Mallory,&nbsp;Shawn Craik","doi":"10.1111/jav.03399","DOIUrl":"10.1111/jav.03399","url":null,"abstract":"<p>Brood parasitism can be costly to host fitness, which in turn may favour host strategies that decrease these costs. Duck (Anatinae) nests are often parasitized by eggs of other ducks, and one way that hosts can respond to potentially costly brood parasitism is to move parasitic eggs to the clutch periphery, where egg incubation temperatures can be suboptimal relative to the clutch centre. We explored whether red-breasted mergansers <i>Mergus serrator</i> use discriminatory egg incubation against parasitic eggs laid by conspecifics in a population where conspecific brood parasitism (CBP) is common. We used isoelectric focusing electrophoresis of egg albumen from entire clutches of 12 parasitized nests to identify parasitic eggs. A randomization test pooling identified parasitic eggs (n = 50) across nests revealed that hosts did not position parasitic eggs along the periphery of clutches or out of the central region more than was expected by chance, and this was the case for parasitic eggs laid both before and after the onset of incubation. Similarly, nest-level analyses showed that parasitic eggs were random in all but the smallest clutch, which contained one identified parasitic egg. Thus, parasitic eggs were not moved to the periphery of heavily parasitized clutches, where egg temperature gradients between central and peripheral regions of nests are expected to be greatest. Only four eggs (&lt; 0.5% of 1276 eggs) were found buried within nest bowls. Eggs that were removed from nests consisted of parasite and host eggs and were more likely along the periphery of clutches prior to their removal than was expected by chance. Our results indicate that discriminatory egg incubation of parasitic eggs is not a well-developed tactic for defending against CBP in red-breasted mergansers, though hosts may rely on certain cues to decide which eggs are to be removed from nests (e.g. addled eggs).</p>","PeriodicalId":15278,"journal":{"name":"Journal of Avian Biology","volume":"2025 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jav.03399","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143646281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flight muscle mitochondria are robust against endurance flight damage in blackpoll warblers Setophaga striata","authors":"Soren Z. Coulson,&nbsp;Catherine M. Ivy,&nbsp;James F. Staples,&nbsp;Christopher G. Guglielmo","doi":"10.1111/jav.03381","DOIUrl":"10.1111/jav.03381","url":null,"abstract":"<p>Migratory birds are physiologically challenged by intense exercise while fasting during flights that may last hours to days. Exercise-induced oxidative stress could compromise flight performance by inducing mitochondrial dysfunction in the flight muscle. Endurance flight is partially fuelled by the catabolism of lean tissues, but how this catabolism is partitioned between different organs and muscles has not been previously studied under controlled conditions. We hypothesized that simulated migratory flight would result in dysfunction of flight muscle mitochondria, and selective catabolism of lean tissues. We predicted that simulated migratory flight would cause reduced mitochondrial oxidative phosphorylation capacity while increasing emission of reactive oxygen species (ROS) and that lean tissue mass catabolism would preferentially occur in digestive organs not needed in flight. We measured mitochondrial function, muscle morphology and the wet masses of organs and muscles following 8-hour wind tunnel flights in blackpoll warblers <i>Setophaga striata</i>, which use multi-day nonstop flights as part of their migration strategy. In contrast to our predictions, we found that simulated migratory flight did not alter mitochondrial fatty acid oxidation capacity or ROS emission. However, flight and fasting increased whole-animal lean mass catabolism and were associated with reductions in the masses of liver, gizzard and proventriculus, but masses of tissues in the flight apparatus (pectoralis, heart, lungs) were unaffected. Pectoralis muscle fiber morphology was also unchanged over the tested flight duration. Our findings indicate that mitochondrial function in blackpoll warblers is robust against damage induced by simulated migratory flight, and energy deprivation is sufficient for organ catabolism.</p>","PeriodicalId":15278,"journal":{"name":"Journal of Avian Biology","volume":"2025 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jav.03381","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143646203","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Intrinsic factors influence a physiological measure in a forest bird community: adults and females have higher H/L ratios than juveniles and males","authors":"Finja Strehmann,&nbsp;Markus Vogelbacher,&nbsp;Clara Guckenbiehl,&nbsp;Yvonne R. Schumm,&nbsp;Juan F. Masello,&nbsp;Petra Quillfeldt,&nbsp;Nikolaus Korfhage,&nbsp;Hicham Bellafkir,&nbsp;Markus Mühling,&nbsp;Bernd Freisleben,&nbsp;Nina Farwig,&nbsp;Dana G. Schabo,&nbsp;Sascha Rösner","doi":"10.1111/jav.03269","DOIUrl":"10.1111/jav.03269","url":null,"abstract":"<p>Physiological parameters have the potential to serve as valuable early warning indicators for the conservation of animal populations. However, measuring physiological adaptations in wildlife is often challenging, due to intrinsic differences causing natural variations of physiological measures between individuals across species. This study is aimed at addressing this by investigating the influence of intrinsic factors, including sex, age, body condition, and the incubation of eggs on the H/L ratio of a forest bird community. As physiological measure, we used the heterophil to lymphocyte (H/L) ratio of individuals belonging to different species in the forest bird community, which was assessed using a novel deep learning approach based on convolutional neural networks (CNNs) applied to whole blood smear scans. Using phylogenetically controlled Bayesian analyses across the bird species, we found higher H/L ratios in adult birds than in juveniles and observed slightly higher H/L ratios in females than in males. While body condition had no effect on the H/L ratio, incubating birds tended to have higher H/L ratios than non-reproductive birds, regardless of their sex. Furthermore, we found a robust phylogenetic signal of the H/L ratio in the studied bird community. Our results reveal significant general patterns of the effect of intrinsic factors on the H/L ratio across a bird community.</p>","PeriodicalId":15278,"journal":{"name":"Journal of Avian Biology","volume":"2025 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jav.03269","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143632978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Associations between human non-motorised recreational activity on nest box occupation, exploratory behaviour and breeding success in a passerine bird","authors":"Utku Urhan,&nbsp;Kim Platjouw,&nbsp;Peter P. de Vries,&nbsp;Eva Serrano Davies,&nbsp;Kees van Oers","doi":"10.1111/jav.03281","DOIUrl":"10.1111/jav.03281","url":null,"abstract":"<p>Anthropomorphic activities have a large impact on ecosystems in many ways, one of which is how animals behave. Non-motorised nature recreation is a popular human activity of which the impacts on nature are largely unknown. These activities, which include hiking, biking, pet walking and horseback riding, tend to increase during the commencement of the breeding activity for most passerine forest birds in temperate zones. We here investigated whether variation in recreational activity associates with patterns of nest box occupation and reproductive success in a long-term study of personality-typed great tits <i>Parus major</i>. We measured human disturbance in the area by recording the frequency of non-motorised recreational activities by observations. We were particularly interested in the relationship between disturbance levels and nest box occupancy as well as the relationship between disturbance levels of occupied nest boxes and exploratory scores of the great tits that occupied them. We also investigated whether reproductive characteristics such as fledging success, clutch size, chick weight and tarsus length varied with disturbance levels at occupied nest boxes. We did not find a direct association between nest box occupation and disturbance. Habitat quality rather than disturbance explained the nest occupation. Furthermore, more exploratory individuals occupied boxes in less disturbed areas, independent of habitat quality. Fitness decreased with increasing disturbance independent of habitat quality. Chicks were heavier and had longer tarsi, and clutch sizes were bigger in less disturbed areas. In conclusion, we found breeding site choice of great tits to be independent of human activity, although there are clear fitness effects of human disturbance.</p>","PeriodicalId":15278,"journal":{"name":"Journal of Avian Biology","volume":"2025 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jav.03281","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595270","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Differential effects of foraging strategies on carotenoid-derived plumage color and individual quality in stripe-tailed yellow finches","authors":"Mariana de-Carvalho,&nbsp;Pedro Diniz,&nbsp;Osmindo R. Pires Júnior,&nbsp;Regina H. Macedo,&nbsp;Gabriela B. Nardoto","doi":"10.1111/jav.03337","DOIUrl":"10.1111/jav.03337","url":null,"abstract":"<p>Carotenoid-based plumage color is crucial in avian mate selection, often serving as an indicator of individual quality. To determine whether carotenoid-derived color can be a sign of individual condition and if there is a relationship between an individual's condition and color production, it is necessary to identify how carotenoids are acquired by individuals and subsequently used by the organism. Our objective was to determine how carotenoid pigments are used in the stripe-tailed yellow finch <i>Sicalis citrina</i>, a species wherein females exhibit a light yellowish ventral color while males are bright yellow. By using carbon and nitrogen stable isotope analyses we were able to determine if these carotenoid-derived colors are a signal of individual condition in terms of physiological stress and body condition. Females with low <i>δ</i>¹³C values (≈ −18‰) indicating the consumption of C₃ and C₄ seeds, exhibited colors shifted toward longer wavelengths and better body condition, and those with such color shifts also had higher carotenoid concentrations. In contrast, brighter females had higher <i>δ</i>¹⁵N values, indicating greater consumption of arthropods. Males with more saturated ventral patches had higher carotenoid concentrations, while those with colors shifted toward shorter wavelengths or lower H/L ratios, i.e. less stress, exhibited high <i>δ</i>¹⁵N values, suggesting that they supplement their diet with arthropods (<i>δ</i>¹⁵N ≈ 5‰). Our results show that the carotenoids dynamics in stripe-tailed yellow finches differ between sexes and highlight how food sources impact condition, stress, and ornamentation. Our study indicates that sexual dimorphism extends beyond plumage color to deeper physiological and ecological differences.</p>","PeriodicalId":15278,"journal":{"name":"Journal of Avian Biology","volume":"2025 2","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jav.03337","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sitting in the open: how nest microclimate influences incubation behavior in an open-cup nesting passerine","authors":"Kelly A. Williams,&nbsp;Jacob P. Sieg,&nbsp;Laura R. Dykstra,&nbsp;Cheryl R. Dykstra","doi":"10.1111/jav.03385","DOIUrl":"10.1111/jav.03385","url":null,"abstract":"<p>Incubating passerines modulate their behavior in response to local conditions and changing energetic demands, and nest microclimate can significantly influence female incubation behavior. We tested how ambient temperature affects incubation behavior, and how incubation behavior in turn influences in-nest temperature for an open-cup nesting passerine, the hooded warbler <i>Setophaga citrina</i>. We also examined how covariates of brown-headed cowbird <i>Molothrus ater</i> parasitism, clutch size, year, and females' experience influence female management of incubation behavior and in-nest temperatures. We used iButtons to measure nest microclimate and in-nest temperatures for incubating hooded warblers in southern Ohio, USA, and we used in-nest temperatures to estimate incubation behavior. Under warmer ambient conditions, females incubated for longer periods of time, with fewer (but longer) off-bouts, resulting in a higher proportion of time spent incubating. These data suggested that females under cooler circumstances leave the nest more to forage for themselves; while warmer conditions allowed females to stay on the nest longer for each on-bout, and for a greater proportion of the day. However, increasing variability of ambient temperatures caused females to take more off-bouts and on-bouts. Incubation behaviors directly influenced the realized in-nest temperatures: longer on-bouts and more incubation time overall generated higher and more stable in-nest temperatures. In contrast, longer off-bouts resulted in lower mean in-nest temperatures and less stable nest temperatures, resulting in lower hatching success. Our results linked the flexibility of incubation behavior in response to nest microclimate variation to in-nest temperatures and hatching success for an open-cup nesting species, contributing to a better understanding of how climate influences critical maternal behaviors.</p><p>Keywords: climate, incubation behavior, nest microclimate, parent–offspring conflict, reproductive rate, tradeoff</p>","PeriodicalId":15278,"journal":{"name":"Journal of Avian Biology","volume":"2025 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jav.03385","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143490017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Understanding complexity of the migratory phenotype in Palearctic–Indian migratory buntings: connecting molecular dots from laboratory studies","authors":"Vinod Kumar,&nbsp;Aakansha Sharma,&nbsp;Vatsala Tripathi,&nbsp;Amit Kumar Trivedi,&nbsp;Sanjay Kumar Bhardwaj,&nbsp;Sangeeta Rani","doi":"10.1111/jav.03343","DOIUrl":"10.1111/jav.03343","url":null,"abstract":"<p>Avian migration has been studied for a long time. Yet, very little is understood about the mechanisms underlying the preparation and departure of these migrants twice-a-year towards their destination. In recent years, some experimental evidence is accumulated from studies on the Palearctic-Indian migratory blackheaded buntings <i>Emberiza melanocephala</i> and redheaded buntings <i>Emberiza bruniceps</i>. These are obligate latitudinal migrant passerines, with yearly to-and-fro migrations between breeding grounds in west Asia/southeast Europe and overwintering areas in India. The migratory voyages are not isolated seasonal events; rather, they are part of the overall annual itinerary closely coupled to the reproduction. This review focuses mainly on the studies that have been carried out for more than four decades on these two buntings. We will outline first the characteristic traits of the anticipation, preparation, beginning and maintaining the migratory flight. The subsequent sections summarize briefly the molecular mechanisms underlying fat fuel accumulation, and changes associated with the phasing of the activity and rest periods within 24-h day during the nocturnal flight and daytime stopovers. In addition, we discuss mechanistic differences between the onward (to wintering areas, autumn migration) and return (to breeding grounds, spring migration) migrations. The two seasonal migrations differ in the context, physiological states that birds are in prior to each migration, and surrounding physical environment (photoperiod, temperature, food availability) that birds encounter during the migration period. The final section on perspectives presents an ecological and societal relevance of avian migration research.</p>","PeriodicalId":15278,"journal":{"name":"Journal of Avian Biology","volume":"2025 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jav.03343","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143490016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variation in wing and tail moult intensity in white-chinned petrels","authors":"Oluwadunsin E. Adekola,&nbsp;Peter G. Ryan","doi":"10.1111/jav.03327","DOIUrl":"10.1111/jav.03327","url":null,"abstract":"<p>The cost of moult is substantial, and the timing and intensity of flight feather moult can influence survival and fitness, especially in large, long-winged species such as many seabirds. We explore variation in wing and tail moult in &gt; 2400 white-chinned petrels <i>Procellaria aequinoctialis</i> killed in fisheries off southern Africa to assess how they integrate moult into their annual cycle and whether wing moult impacts their behaviour at sea. All petrels showed a simple descendent primary moult and one active moult centre, although moult of P2–3 sometimes started before P1. The Underhill–Zucchini moult model estimated that adult primary moult started after breeding on 7 May (± 8 days SD) and lasted 103 days (mean end date 20 August ± 10 days). Adult males started and finished moult 10 days before females. Immature petrels started primary moult earlier than adults, and their moult was probably more protracted as they moulted fewer primaries at once (1.9 ± 1.2) when compared to adults (2.3 ± 1.1), independent of sex. Adult moult was particularly intense in the inner primaries, growing up to six feathers at once, slowing to at most 3–4 outer primaries. The secondary moult started two weeks after the primary moult, once 3–4 primaries had been dropped. Secondary moult typically started with the innermost secondaries, plus inward waves from S1 and S5 in 2.7 ± 1.3 active moult centres (range 1–6), replacing 4.6 ± 2.7 (1–13) secondaries at once. Adults had more intense secondary moult (4.7 ± 2.8 growing feathers) than immatures (3.6 ± 2.3), with no difference between the sexes. However, photographs of non-moulting birds at sea show that 27% of birds do not replace all secondaries each year. The tail moult usually commenced at the start of the secondary moult and was highly variable, with 1–12 rectrices growing at once. Adults had more active centres (3.0 ± 1.4) than immatures (2.3 ± 1.0). Moult symmetry was greater among the primaries (84%) than either the secondaries (46%) or rectrices (68%). Although adult wing moult was intense, there was no marked reduction in flight activity among breeding adults fitted with leg-mounted activity loggers during the moult period. Our findings are largely in accord with previous studies of moult in petrels, but our large sample size reveals considerable variation among individuals, which is surprising given the high cost of moult. Future studies should attempt to investigate the factors determining this variation.</p>","PeriodicalId":15278,"journal":{"name":"Journal of Avian Biology","volume":"2025 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jav.03327","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143455912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Radar revelations: insect availability influences parental provisioning in breeding tree swallows Tachycineta bicolor","authors":"Victoria F. Simons,&nbsp;Carrie Ann Adams,&nbsp;Eli Bridge,&nbsp;Miguel F. Jimenez,&nbsp;Annika L. Abbott,&nbsp;Marissa E. Drake,&nbsp;Kyle G. Horton","doi":"10.1111/jav.03333","DOIUrl":"10.1111/jav.03333","url":null,"abstract":"<p>Airspace habitat is essential foraging space for tree swallows <i>Tachycineta bicolor</i>, which rely on flying insects as their main source of food. Insect availability can change quickly from hour-to-hour or day-to-day, however, it is unclear whether insectivores primarily respond to changing atmospheric dynamics, resource dynamics, or a combination. Rapidly changing conditions are common in high-elevation areas – an understudied portion of the tree swallow's breeding range. To explore the relationship between food availability and high-elevation weather conditions as related to female provisioning, we deployed a mobile radar unit to collect insect abundance data during the 2022 and 2023 summer breeding seasons at a high-elevation site in Colorado's Rocky Mountains. We monitored 41 active nest boxes using radio-frequency identification (RFID) technology to track female provisioning behavior. We deployed three models to assess 1) how strongly swallow provisioning rates correlated with insect traffic rates, 2) how well swallow provisioning rates were explained by insect traffic rates and weather conditions, and 3) how insect traffic rates were related to weather conditions. Although there remains substantial unexplained variation in tree swallow provisioning rates, we found a significant positive relationship with insect traffic rate, a negative relationship with precipitation, and curvilinear relationships with temperature and wind speed. Weather variables and time of day explained nearly 80% of the variation in insect traffic rate, and the strength of these relationships suggests weather conditions serve as a good proxy of airborne insect activity. This research presents a link between our vast airspace habitat and animal ecology, advancing our understanding of how flying organisms respond to rapidly changing conditions in aerial environments and how multiple factors contribute to variation in provisioning rates in an aerial insectivore.</p>","PeriodicalId":15278,"journal":{"name":"Journal of Avian Biology","volume":"2025 1","pages":""},"PeriodicalIF":1.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/jav.03333","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}