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This article discusses a study on the lifespans of Neotropical forest landbirds, which has been a topic of interest for scientists for a long time. The study used a 45-year dataset from central Panama to determine the longevity of 47 species. The oldest recorded individual was an 18-year-old Rufous Motmot, and most species had a lifespan of at least 7 years. The study also explored the relationship between longevity and factors such as body mass, diet, and sociality. Surprisingly, there was no correlation between body mass and longevity, and some of the smallest species actually lived the longest. The study suggests that future research should involve larger-scale studies to obtain more accurate estimates of lifespan. [Extracted from the article]

Migration is a prevalent strategy among birds used to track seasonal resources throughout the year. Individual and population‐level migratory movements provide insight to life‐history variation, carry‐over effects, and impacts of climate change. Our understanding of how geographic variation in a species' breeding or wintering grounds can impact migration distances is limited. However, changes in migration distances can have important fitness consequences for individuals and conservation implications for populations, particularly if migratory connectivity is altered during the annual cycle. In this study, we use three decades of data from the United States Geological Survey Bird Banding Laboratory for six migratory species of Arctic and subarctic breeding geese. We employ a Bayesian hierarchical framework to test if the distance between breeding and wintering locations has changed over time, while accounting for the latitude of the breeding grounds. A model that included only a temporal trend estimated the average rate of change in migration distance, across all six species, at −3.0 km/year over the period 1990–2019. Five of the six species showed a significant decrease in migration distances. Including an interaction effect with breeding latitude revealed that the reduction in migration distance was strongest in the southernmost populations for four of the six species. For those species, migration distance in northern populations were all either relatively unchanged or increasing. This indicates that southern breeding populations of geese had a stronger association with the observed spatiotemporal changes in wintering ranges, potentially influenced by a combination of climatic and biotic factors (e.g. resource availability or competitive interactions) that uniquely impact these populations. Abundant, long‐term banding data shows promise for use in illuminating changes in migratory patterns under climate change, leading to improved management and conservation outcomes, from regional to continental scales. [ABSTRACT FROM AUTHOR]

A wide variety of attachment techniques have been used to track birds with electronic tags, with glue, tape, leg rings, neck collars and harnesses being the most common methods. In general, the choice of attachment method should strive to minimize tagging effects, but ensure that sufficient data are collected to address the research question at hand. The aim of our study was to develop and evaluate tag attachment methods to track Sandwich Terns Thalasseus sandvicensis during the last part of the incubation and the chick‐rearing period of one breeding season. Tag attachments had to stay on for the duration of the chick‐rearing period (5–6 weeks) and be non‐restraining and flexible, but strong enough to withstand the forces and submersion associated with their plunge‐diving foraging technique. We first experimentally tested the durability of flexible material under various environmental conditions with the aim of developing a self‐releasing harness. Then, in field studies, we compared three different attachment methods on terns during the breeding seasons, attaching tags to dorsal feathers using (1) tape, (2) glue or (3) a newly developed harness made specifically for short‐term deployments of one chick‐rearing period and constructed from degradable material. Assessment of the performance of attachment methods was based on retention time of the loggers and on annual survival rates of tagged individuals in comparison with non‐tagged individuals. The use of tape and glue led to premature loss of tags (median minimum retention time (range) of 3 (1–4) days and 15 (5–26) days, respectively), whereas the self‐releasing harness had a median minimum retention time of 42 (18–91) days, which is sufficient to track Sandwich Terns during the entire chick‐rearing period. The apparent annual survival of birds tagged using glue or tape did not differ from that observed in non‐tagged control birds. In contrast, birds fitted with the self‐releasing harnesses might have experienced a lower survival rate than control birds. Entanglement of birds in the harness material was incidentally observed in three cases, which may have contributed to the lower survival rates observed in this group. The risk of entanglement can potentially be mitigated with a leg‐loop harness instead of a full‐body harness. Our results highlight the necessity of careful consideration when selecting appropriate attachment methods. Specifically, there is a need to address whether the research questions and desired tracking duration justify the use of a harness and the higher impact that it entails, or whether a tape or glue‐mount is sufficient. More broadly, sharing field expertise in tag attachments across studies is essential to successful deployments while minimizing the impact on animals. [ABSTRACT FROM AUTHOR]

Waterbirds are particularly affected by the high hunting pressure they face in many regions, which in some cases is compromising conservation actions for threatened species. The marbled teal Marmaronetta angustirostris is one of the most endangered waterbirds in Europe. In order to restore its population, several conservation actions have recently been undertaken, including a population reinforcement programme in Spain using captive‐bred birds. With the aim of assessing the success of the reinforcement programme to establish a long‐term self‐sustaining population, we identified mortality causes of marbled teal, evaluated the survival of individual birds of the reinforcement programme and estimated the viability of the population under different management scenarios. We used data from wild and captive‐bred individuals tracked by GPS since 2018 (n = 42) and from a mark–recapture programme initiated in 2015 (n = 297). We recovered 15 dead birds or transmitters: 20% died of natural causes, 60% of non‐natural causes (including all anthropic causes) and 20% of unknown causes. Furthermore, the GPS tags of 24 birds unexpectedly stopped transmitting without any indication of malfunction, and for 66.7% of these disappeared birds, the cessation was suspected to be caused by illegal shooting. Survival during the hunting season was higher for males (31.3%) than for females (12.5%), and for the wild (50%) than for the captive‐bred birds (9.4%), probably due to differences in migration patterns to North Africa. Population viability models revealed that maintaining the breeding population at the current mortality rates is only possible with a permanent release programme of captive‐bred individuals, and that in order to establish a self‐sustaining population, non‐natural mortality would have to be reduced by at least 40%. We recommend management measures to reduce marbled teal mortality, such as limiting legal hunting to hours with clear visibility, prosecuting illegal shootings, controlling exotic predators and improving water management to reduce disease outbreaks. Some improvements can be implemented in captive‐breeding programmes, such as earlier release times and incorporating anti‐predator training. [ABSTRACT FROM AUTHOR]

Wintering birds serve as vital climate sentinels, yet they are often overlooked in studies of avian diversity change. Here, we provide a continental‐scale characterization of change in multifaceted wintering avifauna and examine the effects of climate change on these dynamics. We reveal a strong functional reorganization of wintering bird communities marked by a north–south gradient in functional diversity change, along with a superimposed mild east–west gradient in trait composition change. Assemblages in the northern United States saw contractions of the functional space and increases in functional evenness and originality, while the southern United States saw smaller contractions of the functional space and stasis in evenness and originality. Shifts in functional diversity were underlined by significant reshuffling in trait composition, particularly pronounced in the western and northern United States. Finally, we find strong contributions of climate change to this functional reorganization, underscoring the importance of wintering birds in tracking climate change impacts on biodiversity. [ABSTRACT FROM AUTHOR]

Summary: The presence of transient abnormal protein banding (M‐protein immune reconstitution) in serum immunofixation electrophoresis after autologous haematopoietic stem cell transplantation in patients with multiple myeloma has been reported. The purpose of this study was to investigate the impact of post‐transplant M‐protein immune reconstitution on the prognosis of patients with multiple myeloma. M‐protein immune reconstitution was observed in 25.9% (75/290) of patients. The CR rate and MRD negativity were higher in the M‐protein immune reconstitution group (85.3% vs. 69.3%, p = 0.013, 81.9% vs. 66.5%, p = 0.014). Although there were no significant differences between the groups, the overall median survival time was longer in the M‐protein immune reconstruction group (80 vs. 72 m, p = 0.076; not reached vs. 105 m, p = 0.312). Among patients in the cytogenetic high‐risk group, the occurrence of M‐protein immune reconstitution predicted better PFS and OS (80 vs. 31 m, p = 0.010; not reached vs. 91 m, p = 0.026). Additionally, in revised‐International Staging System stage III patients, PFS and OS were better in those who achieved M‐protein immune reconstitution (80 vs. 20 m, p = 0.025; 57 vs. 32 m, p = 0.103). The better prognosis of M‐protein immune reconstitution patients may be associated with the acquisition of a deeper response. In high‐risk patients, early acquisition of M‐protein immune reconstitution may suggest a better prognosis. [ABSTRACT FROM AUTHOR]

Natal dispersal distance (NDD) is critical in understanding and defining populations and their conservation. It is defined as the linear distance between the natal location and first reproductive ('effective NDD') or potential reproductive ('gross NDD') location. It is a measure of gene flow and the functional connectivity across generations between individuals breeding in the same or different geographies. NDD is difficult to record in large raptors. GPS‐satellite telemetry has facilitated its recording. Previous Scottish studies showed that gross and effective NDD were apparently equivalent, and an algorithm based on telemetric data could identify the territory settlement timing and location of birds originally tagged as nestlings. We analysed natal dispersal data from 39 Golden Eagles GPS‐tagged in Scotland to estimate NDD. Raw median estimates were 29.8 km for males (n = 22) and 58.6 km for females (n = 17), 38.1 km averaged across sexes. Males had significantly shorter NDD, as theoretically predicted. Our NDD estimates were shorter but not grossly dissimilar to those from the USA, where sex differences in NDD had not been confirmed. Respective sample sizes may underly the latter contrast in confirmation. We also showed that in the absence of data from sexed birds, NDD estimates can be different. Natal dispersal duration was not related to NDD, suggesting that time to prospect a territory opportunity was not associated with the selected territory's distance from the natal site. The previous status of the subsequent settled territory (occupied or vacant) was also not related to NDD. We conclude that sex differences in NDD are important in application to population demography and conservation. Although we found no support for two other potential drivers of NDD (natal dispersal duration and previous territory status), identifying additional influences on NDD is in its infancy in large raptors and deserves more study. [ABSTRACT FROM AUTHOR]

Seabird populations are declining across their global range due to a variety of threats, including shifting food webs from climate change. The impact of these threats is exacerbated in long‐lived species with low reproductive output and high investment in a few offspring, where juvenile survival is of substantial importance to populations. Changes to post‐fledging survival and recruitment of adults are difficult to detect, necessitating better information to forecast juvenile survival before fledglings take to sea. To achieve this goal, we test the hypothesis that there is an ideal mass range for fledglings, outside of which survival is limited, providing an early warning signal for future recruitment failures. Here we present a long‐term study of chick banding, weighing and resighting of wedge‐tailed shearwaters, Ardenna pacifica, a globally widespread but declining tropical/subtropical seabird in a sea‐surface warming hotspot across a span of 43 years. We provide data on 1615 fledgling birds banded most years between 1977 and 2020, with 111 resighted as adults. We found that fledglings weighing 380–470 g have the best chance to survive to adulthood and those weighing 330–540 g have a possible chance of survival. We detected a gradual decline in masses since data collection began, with chicks fledging, on average, 1.6 g lighter each year. This decline has been sharpest since 1996, with fledging masses decreasing at an average rate of 3.8 g annually. Should this 1.6 g decline continue, the average fledgling will cross out of the 'survivable' mass range by 2047/2048. We contextualise these findings with observed declines reported in some populations across the species South Pacific range, adding to the conversation about challenges to seabirds in regions experiencing rapid change. [ABSTRACT FROM AUTHOR]

Foraging outcomes dictate the nutritional resources available to an organism and may vary with intrinsic factors, like age. Thus, understanding how age affects foraging performance, alone or in interaction with extrinsic factors (like environmental quality), improves our understanding of aging processes in the wild. We examined how foraging traits, measured across five breeding seasons, change with age, environmental variation, and their interaction in Nazca boobies (Sula granti), a pelagic seabird in Galápagos. We evaluated the hypotheses that (1) foraging performance is better in middle‐aged birds than in young ones, and that (2) foraging performance is better in middle‐aged birds than in old ones. Furthermore, favorable environmental conditions will either (3) attenuate age differences in foraging performance (by relieving constraints on young, inexperienced and old, senescent age classes), or (4) accentuate age differences (if middle‐aged birds can exploit abundant resources better than other age classes can). Incubating birds tagged with GPS loggers (N = 815) provided data on foraging performance (e.g., total distance traveled, mass gained) to evaluate interactions between age and environmental variation (e.g., sea surface temperature). Poor environmental conditions associated with the cool phase of the El Niño‐Southern Oscillation increased foraging effort, including foraging distance and duration, for example. Across age classes, foraging boobies responded similarly to environmental variation except for female mass gain rate: age‐related declines in mass gain rate were reduced under favorable environmental conditions. Birds of different ages also searched in somewhat distinct areas in the poor conditions of 2016, but not in other years. In several foraging traits, including foraging duration and distance, female boobies showed predicted early‐life improvement and late‐life decline, following the established pattern for reproductive traits in this species. Thus, deficits in resource acquisition (this study) may contribute to the poor survival and reproductive outcomes previously observed in old Nazca boobies, particularly in females. [ABSTRACT FROM AUTHOR]

The history of the decline of the Ivory‐billed Woodpecker is long and complex, but the status of the species since 1944, when the last widely accepted sighting in continental North America occurred, is particularly controversial. Reports of Ivory‐billed Woodpeckers have continued, but none has reached the threshold of quality for general acceptance by ornithologists or the birdwatching public. In 2021, the U.S. Fish and Wildlife Service opened for public comment a proposal to declare the species extinct. Here, we present evidence suggesting the presence of the Ivory‐billed Woodpecker at our study site, based on a variety of data collected over a 10‐year search period, 2012–2022. These data are drawn from visual observations, ~70,000 h of recordings by 80–100 acoustic recording units, ~472,550 camera‐hours by as many as 34 trail cameras, and ~1089 h of video drawn from ~3265 drone flights. Using multiple lines of evidence, the data suggest intermittent but repeated presence of multiple individual birds with field marks and behaviors consistent with those of Ivory‐billed Woodpeckers. Data indicate repeated reuse of foraging sites and core habitat. Our findings, and the inferences drawn from them, suggest that not all is lost for the Ivory‐billed Woodpecker, and that it is clearly premature for the species to be declared extinct. [ABSTRACT FROM AUTHOR]

To investigate the effects of piscivorous colonial waterbird predation on juvenile salmonids (smolts) and to determine what proportion of all sources of smolt mortality was due to predation, we analyzed a data set describing fall Chinook Salmon Oncorhynchus tshawytscha that were marked with PIT tags in the Columbia River, USA. We used a state‐space Bayesian model that incorporated live detections of tagged fish and recoveries of tags from dead fish to jointly estimate predation and survival over multiple river reaches and years (2008–2019). By incorporating recoveries of tags on bird colonies, the model was also able to increase the precision and spatial extent of survival estimates compared with a more traditional capture–recapture model. Results indicated that the avian predation probability (proportion of available fish consumed) varied depending on the predator species, colony location, and the fish's rearing type. Estimates of cumulative predation probability ranged annually from 0.066 (95% credible interval = 0.049–0.089) to 0.283 (0.210–0.419), and predation accounted for 7.3% (4.3–11.9%) to 29.1% (19.7–40.2%) of all sources of smolt mortality during out‐migration to Bonneville Dam. Probabilities of predation on wild smolts were significantly higher than those for hatchery smolts in most river reaches and years. Predation probabilities were the highest for colonies of American white pelicans Pelecanus erythrorhynchos and double‐crested cormorants Nannopterum auritum, which were located near where wild smolts rear and congregate. Estimates of predation by Caspian terns Hydroprogne caspia, California gulls Larus californicus, and ring‐billed gulls L. delawarensis were often <0.03 of available smolts annually. Collectively, results indicated that the cumulative effects of predation on Chinook Salmon smolts were substantial in some but not all river reaches and years. Future models that consider biological and environmental factors influencing smolt susceptibility to avian predation may provide a more holistic understanding of the degree to which predation limits fish survival. [ABSTRACT FROM AUTHOR]

The timing of avian migration has evolved to exploit critical seasonal resources, yet plasticity within phenological responses may allow adjustments to interannual resource phenology. The diversity of migratory species and changes in underlying resources in response to climate change make it challenging to generalize these relationships.We use bird banding records during spring and fall migration from across North America to examine macroscale phenological responses to interannual fluctuations in temperature and long‐term annual trends in phenology.In total, we examine 19 species of North American wood warblers (family Parulidae), summarizing migration timing from 2,826,588 banded birds from 1961 to 2018 across 46 sites during spring and 124 sites during fall.During spring, warmer spring temperatures at banding locations translated to earlier median passage dates for 16 of 19 species, with an average 0.65‐day advancement in median passage for every 1°C increase in temperature, ranging from 0.25 to 1.26 days °C−1. During the fall, relationships were considerably weaker, with only 3 of 19 species showing a relationship with temperature. In those three cases, later departure dates were associated with warmer fall periods. Projecting these trends forward under climate scenarios of temperature change, we forecast continued spring advancements under shared socioeconomic pathways from 2041 to 2060 and 2081 to 2100 and more muted and variable shifts for fall.These results demonstrate the capacity of long‐distance migrants to respond to interannual fluctuations in temperatures, at least during the spring, and showcase the potential of North American bird banding data understanding phenological trends across a wide diversity of avian species. [ABSTRACT FROM AUTHOR]

Advances in spring migratory phenology comprise some of the most well‐documented evidence for the impacts of climate change on birds. Nevertheless, surprisingly little research has investigated whether birds are shifting their migratory phenology equally across sex and age classes—a question critical to understanding the potential for trophic mismatch. We used 60 years of bird banding data across North America—comprising over 4 million captures in total—to investigate both spring and fall migratory phenology for a total of 98 bird species across sex and age classes, with the exact numbers of species for each analysis depending on season‐specific data availability. Consistent with protandry, in spring (n = 89 species), adult males were the first to arrive and immature females were the last to arrive. In fall (n = 98), there was little difference between sexes, but adults tended to depart earlier than juveniles. Over 60 years, adult males advanced their phenology the fastest (−0.84 days per decade, 95 CrI = −1.22 to −0.47, n = 36), while adult and immature females advanced at a slower pace, causing the gap in male and female arrival times to widen over time. In the fall, there was no overall trend in phenology by age or sex (n = 57), driven in part by high interspecific variation related to breeding and molt strategies. Our results indicate consistent and predictable age‐ and sex‐based differences in the rates at which species' springtime phenology is shifting. The growing gap between male and female migratory arrival indicates sex‐based plasticity in adaptation to climate change that has strong potential to negatively impact current and future population trends. [ABSTRACT FROM AUTHOR]

Many populations of long‐distance migrant shorebirds are declining rapidly. Since the 1970s, the lesser yellowlegs (Tringa flavipes) has experienced a pronounced reduction in abundance of ~63%. The potential causes of the species' decline are complex and interrelated. Understanding the timing of migration, seasonal routes, and important stopover and non‐breeding locations used by this species will aid in directing conservation planning to address potential threats. During 2018–2022, we tracked 118 adult lesser yellowlegs using GPS satellite tags deployed on birds from five breeding and two migratory stopover locations spanning the boreal forest of North America from Alaska to Eastern Canada. Our objectives were to identify migratory routes, quantify migratory connectivity, and describe key stopover and non‐breeding locations. We also evaluated predictors of southbound migratory departure date and migration distance. Individuals tagged in Alaska and Central Canada followed similar southbound migratory routes, stopping to refuel in the Prairie Pothole Region of North America, whereas birds tagged in Eastern Canada completed multi‐day transoceanic flights covering distances of >4000 km across the Atlantic between North and South America. Upon reaching their non‐breeding locations, lesser yellowlegs populations overlapped, resulting in weak migratory connectivity. Sex and population origin were significantly associated with the timing of migratory departure from breeding locations, and body mass at the time of GPS‐tag deployment was the best predictor of southbound migratory distance. Our findings suggest that lesser yellowlegs travel long distances and traverse numerous political boundaries each year, and breeding location likely has the greatest influence on migratory routes and therefore the threats birds experience during migration. Further, the species' dependence on wetlands in agricultural landscapes during migration and the non‐breeding period may make them vulnerable to threats related to agricultural practices, such as pesticide exposure. [ABSTRACT FROM AUTHOR]

Experimental studies of biotic interactions in real field conditions are essential to understand the structure and functioning of ecological networks. The use of artificial caterpillars to mimic actual prey availability is generally seen as a standard approach to compare the activity and diversity of predators along environmental gradients. Yet, even with standardized material and procedures, biases may still affect data from multiple observers with different expertise. We used pictures of artificial caterpillars with or without various predation marks, in an online survey that was targeted for the participants of the project, to evaluate the reliability of predation marks identification made by non‐scientists and by scientists with and without experience in predation mark identification. Pictures of artificial caterpillars displayed typical marks left by birds, mammals, and arthropods, as well as non‐predation marks ('false positive'). In total 357 respondents scanned 7140 pictures of artificial caterpillars. Scientists were more confident and accurate in their observations than non‐scientists, but the differences in correct identifications among scientists and non‐scientists were low. Scientists with experience were also more accurate than scientists without experience, whereas there were no differences in self‐confidence among scientists with and without experience. Accuracy in predation mark identification did not differ among types of predators, but respondents were more keen to identify marks left by birds or mammals than marks left by arthropods. Our results have practical implications for the design of multi‐observer projects relying on artificial caterpillars as a proxy to assess predation intensity, in particular in the context of citizen science. [ABSTRACT FROM AUTHOR]

Selective hunting has various impacts that need to be considered for the conservation and management of harvested populations. The consequences of selective harvest have mostly been studied in trophy hunting and fishing, where selection of specific phenotypes is intentional. Recent studies, however, show that selection can also occur unintentionally. With at least 52 million birds harvested each year in Europe, it is particularly relevant to evaluate the selectivity of hunting on this taxon. Here, we considered 211,806 individuals belonging to 7 hunted bird species to study unintentional selectivity in harvest. Using linear mixed models, we compared morphological traits (mass, wing, and tarsus size) and body condition at the time of banding between birds that were subsequently recovered from hunting during the same year as their banding, and birds that were not recovered. We did not find any patterns showing systematic differences between recovery categories, among our model species, for the traits we studied. Moreover, when a difference existed between recovery categories, it was so small that its biological relevance can be challenged. Hunting of birds in Europe therefore does not show any form of strong selectivity on the morphological and physiological traits that we studied and should hence not lead to any change of these traits either by plastic or by evolutionary response. [ABSTRACT FROM AUTHOR]

American barn owls (Tyto furcata) often rely on nest box networks for breeding, especially within agricultural landscapes. Nest boxes are commonly installed for pest management purposes and require regular maintenance, such as removal of pellet debris and repairs, to remain functional and safe for breeding owls. Ideally, nest box maintenance should be conducted before the breeding season begins to minimize nest disturbance. The timing of the barn owl breeding season is especially important to understand in California, USA, which has a high diversity of ecoregions and expansive latitudinal range. Our objective was to describe the barn owl breeding season throughout California using nestling records to assist with data‐driven management recommendations. We queried 96 years of barn owl nestling banding records (n = 22,670) from the United States Geological Survey Bird Banding Lab to estimate egg laying dates across California and summarized 39 years of intake records (n = 1,741) from the California Raptor Center in the Central Valley. Our results suggest that barn owls typically begin to lay eggs in California in winter months; the median egg laying date for the state was 20 February. Based on these reports, planning for barn owl nest box maintenance to begin in fall (Sep–Nov) would align with the season that breeding activity and nest disturbance may be lowest, especially in the Central Valley and Southern Coast ecoregions. [ABSTRACT FROM AUTHOR]

1. Fine-scale tracking of animal movement is important to understand the proximate mechanisms of animal behaviour. The reverse-GPS system--ATLAS--uses inexpensive (~€25), lightweight (<1 g) and low-power (~0.4 mJ/transmission) tags. Six systems are now operational worldwide and have successfully tracked over 50 species in various landscape types. The growing use of ATLAS to track animal movement motivates further refinement of best-practice application and an assessment of its accuracy. 2. Here, we test the accuracy and precision of the largest ATLAS system, located in the Dutch Wadden Sea, using concurrent GPS measurements as a reference. This large-scale ATLAS system consists of 26 receivers and covers 1,326 km2 of intertidal region, with almost no physical obstacles for radio signals, providing a useful baseline for other systems. We compared ATLAS and GPS location estimates for a route (mobile test) and 16 fixed locations (stationary test) on the Griend mudflat. Precision was estimated using standard deviation during the stationary tests. We also give examples of tracked red knots Calidris canutus islandica to illustrate the use of the system in tracking small shorebirds (~120 g). 3. ATLAS-derived location estimates differed from GPS by a median of 4.2 m (stationary test) and 5.7 m (mobile test). Signals that were collected by more receiver stations were more accurate, although even three-receiver localisations were comparable with GPS localisations (~10 m difference). Receivers that detected 90% of the 1 Hz transmissions from our test tag were within 5 km of their furthest detection but height of both receiver and tag seemed to influence detection distance. The test tag (1 Hz) had a fix rate of >90% at 15 of 16 stationary sites. Tags on birds (1/6 Hz) on the Griend mudflat had a mean fix rate of 51%, yielding an average sampling rate of 0.085 Hz. Fix rates were higher in more central parts of the receiver array. 4. ATLAS provides accurate, regional-scale tracking with which hundreds of relatively small-bodied species can be tracked simultaneously for long periods of time. Future ATLAS users should consider the height of receivers, their spatial arrangement, density and the movement modes of their study species (e.g. ground-dwelling or flying). [ABSTRACT FROM AUTHOR]

Poultry litter is generated in large quantities throughout the southeastern United States and is an excellent nutrient source for increasing crop yields. However, surface applications result in nutrient losses to air, soil, and water. Subsurface banding poultry litter is a promising technology for reducing nutrient losses to surface and groundwater, but information is needed on optimum crop seeding distance from bands. This study evaluated edamame [Glycine max (L.) Merr. 'Edamame'] yield (residue, pod, and total plant), crop quality, and leaf greenness. Subsurface banded poultry litter and crop row distances (13, 25, and 38 cm) were compared with surface‐applied poultry litter (all received 168 kg ha−1 total N) under irrigated and nonirrigated conditions from 2019 to 2020. Both chlorophyll and edamame total yields were greatest (P ≤.05) under subsurface banding litter, relative to surface applications, regardless of distance. Overall, greatest total crop yields were observed for 13‐ and 25‐cm banding distances under irrigation and the 38‐cm distance, irrespective of irrigation, relative to surface applications. Residue nutritive value for the 13‐cm distance was greater under irrigation than dryland. Both systems provided high levels of nutritive residual mass, thus edamame could be used as a vegetable crop and a forage following harvest. Overall, subsurface banding poultry litter in conservation tillage systems is a viable replacement to surface applications for edamame production (vegetable and fodder), particularly in organic systems. Results can be used to develop nutrient management plans for organic edamame and other specialty crop production systems in the Mid‐South. Core Ideas: Subsurface banding resulted in greater leaf greenness and yield compared with surface litter.Edamame can serve as a multifunctional crop for use as an organic vegetable and fodder.Subsurface banding litter at all distances were optimum for organic total edamame yields. [ABSTRACT FROM AUTHOR]

Terrestrial insectivorous birds of tropical rainforests are sensitive to disturbance, such as fragmentation. To help answer this question, we quantified the light and thermal niches of these birds in what should be pristine Amazonia using sensors on both birds and their environment. [Extracted from the article]

Leg rings are frequently used to mark aquatic birds in order to identify individuals, and study population dynamics and migration patterns, with the proviso being that the rings should not affect the birds. The effects of tags and rings are of particular interest in diving birds because any change in body shape could impact swimming efficiency and costs, as water is almost a thousand times denser than air. We attached tri‐axial accelerometers to both ringed and unringed breeding Imperial Shags Leucocarbo atriceps to assess dive performance based on descent angle, descent rate, power stroke rate, power stroke peak acceleration amplitude and Vectorial Dynamic Body Acceleration (VeDBA) as a proxy for energy expenditure. Ringed birds, especially females, had a higher foot‐stroke amplitude than unringed animals. In addition, the overall efficiency of the ringed individuals, as expressed by the descent rate per unit VeDBA, was compromised (by 3.5% in females and 4.3% in males) compared with unringed birds. We conclude that leg rings change the diving performance of Imperial Shags, although the effect is small and may not affect reproductive success. However, given that birds are typically ringed for life, we urge researchers to be particularly careful about the potential cumulative effect of attaching leg rings to foot‐propelled diving species. [ABSTRACT FROM AUTHOR]

The use of biologging and tracking devices is widespread in avian behavioral and ecological studies. Carrying these devices rarely has major behavioral or fitness effects in the wild, yet it may still impact animals in more subtle ways, such as during high power demanding escape maneuvers. Here, we tested whether or not great tits (Parus major) carrying a backpack radio‐tag changed their body mass or flight behavior over time to compensate for the detrimental effect of carrying a tag. We tested 18 great tits, randomly assigned to a control (untagged) or one of two different types of a radio‐tag as used in previous studies in the wild (0.9 g or 1.2 g; ~5% or ~6–7% of body mass, respectively), and determined their upward escape‐flight performance 1, 7, 14, and 28 days after tagging. In between experiments, birds were housed in large free‐flight aviaries. For each escape‐flight, we used high‐speed 3D videography to determine flight paths, escape‐flight speed, wingbeat frequency, and actuator disk loading (ratio between the bird weight and aerodynamic thrust production capacity). Tagged birds flew upward with lower escape‐flight speeds, caused by an increased actuator disk loading. During the 28‐day period, all groups slightly increased their body mass and their in‐flight wingbeat frequency. In addition, during this period, all groups of birds increased their escape‐flight speed, but tagged birds did so at a lower rate than untagged birds. This suggests that birds may increase their escape‐flight performance through skill learning; however, tagged birds still remained slower than controls. Our findings suggest that tagging a songbird can have a prolonged effect on the performance of rapid flight maneuvers. Given the absence of tag effects on reproduction and survival in most songbird radio‐tagging studies, tagged birds in the wild might adjust their risk‐taking behavior to avoid performing rapid flight maneuvers. [ABSTRACT FROM AUTHOR]

Migratory animals experiencing substantial change in diet and habitat across the annual cycle may have corresponding shifts in host‐associated microbial diversity. Using automated telemetry and radio tags to recapture birds, we examined gut microbiota structure in the same population and often same individual of Kirtland's Warblers (Setophaga kirtlandii) initially sampled on their wintering grounds in The Bahamas and subsequently resampled within their breeding territories in Michigan, USA. Initial sampling occurred in March and April and resampling occurred in May, June and early July. The composition of the most abundant phyla and classes of the warblers' microbiota is similar to that of other migratory birds. However, we detected notable variation in abundance and diversity of numerous bacterial taxa, including a decrease in microbial richness and significant differences in microbial communities when comparing the microbiota of birds first captured in The Bahamas to that of birds recaptured in Michigan. This is observed at the individual and population level. Furthermore, we found that 22 bacterial genera exhibit heightened abundance within specific sampling periods and are probably associated with diet and environmental change. Finally, we described a small, species‐specific shared microbial profile that spans multiple time periods and environments within the migratory cycle. Our research highlights that the avian gut microbiota is dynamic over time, most significantly impacted by changing environments associated with migration. These results support the need for full annual cycle monitoring of migratory bird microbiota to improve understanding of seasonal host movement ecologies and response to recurrent physiological stressors. [ABSTRACT FROM AUTHOR]

Tagging wildlife with transmitters is one of the most widely used techniques for research and monitoring. Knowing the possible impact of attaching transmitters to an animal has always concerned researchers; however, most assessments have been directed at the effects of transmitters on behaviour and fitness, and fewer have addressed possible injuries to the individuals. The present study evaluated the physical status of birds tagged with transmitters mounted with a Garcelon‐type backpack harness, from five species of large and medium‐sized soaring raptors in western Europe. The study also assessed the factors determining their duration and outcomes. We sent a survey to the managers of projects involving tagged raptors over a 24‐year period, concerning tracking results and veterinary analyses. We obtained information on 659 birds, of which 196 included clinical evaluation from birds in hand. None of the birds showed marks, injuries or abrasions on their feathers or skin caused by the harness or the transmitter. Therefore, this deployment technique is recommended for soaring birds in general and for others in which the use of a backpack harness is chosen. The duration of the system on the bird depended on the traits of the transmitter, being greater in platform transmitter terminal (PTT) satellites. The device lasted longer in larger species and for a shorter time when tagging nestlings. We propose the need for nestlings to be fitted with harnesses corresponding to the size of their adult conspecifics, distinguishing between males and females. Otherwise, the differential growth between sexes could cause discomfort and more frequent removal attempts of the harness. Our results are especially useful for managers and ethics committees to assess bird welfare risks before issuing official permits. [ABSTRACT FROM AUTHOR]

The nestlings of many bird species have ornaments in their mouths, yet the within‐species function of these ornaments remains relatively little studied compared with adult ornaments. Here, we describe the pattern of variation in the tongue spots of Dunnock Prunella modularis nestlings and evaluate their potential influence on parental allocation. We observed that some nestlings hatch with a third tongue spot at the tip of the tongue, which then fades as nestlings age. The number of tongue spots present is inversely related to nestling weight, but the number of tongue spots present does not appear consistently to influence parental allocation. This suggests the need for further investigations into within‐species variation of mouth marks in nestling birds to pave the way to a better understanding of these intriguing ornaments. [ABSTRACT FROM AUTHOR]

Ringing is the most common technique used for individual marking of passerine birds, informing understanding of many aspects of their behaviour and ecology. Birds caught for ringing may also be substantially handled before release (e.g. to obtain biometric data, blood or feather samples), and all such procedures may affect the subsequent behaviour of a captured individual. Previous field studies that have assessed the potential effects of capturing and handling birds have nevertheless, to date, lacked an entirely independent unhandled control. In this study, we used individual acoustic monitoring to compare the apparent survival and re-encounter probabilities of male tree pipits Anthus trivialis that were captured with mist nets and intensively handled (measured, blood-sampled and ringed) with those of a control group of unhandled birds tracked solely by their vocalization. There were no differences between handled and unhandled birds in apparent survival rates, either in simple annual estimates, or in jointly estimated within- and between-breeding season survival estimates. Re-encounter probabilities in the latter analysis peaked at the start of the breeding season, when song activity would be expected to be greatest, but were higher for handled than unhandled birds in mid-to late May. Apart from demonstrating that tree pipits were not affected in the long-term by capture and associated handling, our study confirms that individual acoustic monitoring is a valuable non-intrusive method for long-term monitoring studies. [ABSTRACT FROM AUTHOR]

Emerging diseases of wildlife origin are increasingly spilling over into humans and domestic animals. Surveillance and risk assessments for transmission between these populations are informed by a mechanistic understanding of the pathogens in wildlife reservoirs. For avian influenza viruses (AIV), much observational and experimental work in wildlife has been conducted at local scales, yet fully understanding their spread and distribution requires assessing the mechanisms acting at both local, (e.g., intrinsic epidemic dynamics), and continental scales, (e.g., long‐distance migration). Here, we combined a large, continental‐scale data set on low pathogenic, Type A AIV in the United States with a novel network‐based application of bird banding/recovery data to investigate the migration‐based drivers of AIV and their relative importance compared to well‐characterized local drivers (e.g., demography, environmental persistence). We compared among regression models reflecting hypothesized ecological processes and evaluated their ability to predict AIV in space and time using within and out‐of‐sample validation. We found that predictors of AIV were associated with multiple mechanisms at local and continental scales. Hypotheses characterizing local epidemic dynamics were strongly supported, with age, the age‐specific aggregation of migratory birds in an area and temperature being the best predictors of infection. Hypotheses defining larger, network‐based features of the migration processes, such as clustering or between‐cluster mixing explained less variation but were also supported. Therefore, our results support a role for local processes in driving the continental distribution of AIV. [ABSTRACT FROM AUTHOR]

The Florida mottled duck (Anasfulvigula fulvigula) inhabits a relatively small range of approximately 90,000 km2 within peninsular Florida, USA, and is threatened by habitat loss and genetic introgression with feral mallards (Anas platyrhynchos). Moreover, the Florida mottled duck population status has not been assessed for more than a decade. We used band‐recovery and recapture data from 2000–2013 to examine geographic and demographic factors that influence the survival of Florida mottled ducks and to determine whether survival and harvest probabilities have changed over time. Mean survival probabilities were higher for birds banded in the southern portion of their Florida range than for those banded in the northern portion and higher for adult males than for adult females in both areas. Harvest probabilities increased in the northern extent of its range in Florida for adults and juveniles and remained relatively constant in the southern portion of its range during the study period. Mean harvest probabilities for adult males in both areas were higher than for adult females. Mean harvest probability for juvenile females was higher than that for juvenile males in the north but was similar between the sexes in the south. Our results suggest that mortality rates are generally greater in the northern portion of the Florida mottled duck range because of regional differences in habitat distribution and permanence and in how mottled ducks and humans use wetlands in these areas. We suggest increasing conservation efforts in the north portion of the Florida mottled duck range and improving inferences from leg banding by incorporating live recapture data. © 2020 The Wildlife Society. Mottled duck mortality rates are generally greater in the northern portion of the Florida mottled duck range. We suggest increasing conservation efforts in the northern portion of the Florida mottled duck range and improving inferences from leg banding by incorporating live recapture data. [ABSTRACT FROM AUTHOR]

Dispersal is a critical process influencing population dynamics and responses to global change. Long‐distance dispersal (LDD) can be especially important for gene flow and adaptability, although little is known about the factors influencing LDD because studying large‐scale movements is challenging and LDD tends to be observed less frequently than shorter‐distance dispersal (SDD).We sought to understand patterns of natal dispersal at a large scale, specifically aiming to understand the relative frequency of LDD compared to SDD and correlates of dispersal distances.We used bird banding and encounter data for American kestrels (Falco sparverius) to investigate the effects of sex, migration strategy, population density, weather, year and agricultural land cover on LDD frequency, LDD distance and SDD distance in North America from 1961 to 2015.Nearly half of all natal dispersal (48.9%) was LDD (classified as >30 km), and the likelihood of LDD was positively associated with the proportion of agricultural land cover around natal sites. Correlates of distance differed between LDD and SDD movements. LDD distance was positively correlated with latitude, a proxy for migration strategy, suggesting that migratory individuals disperse farther than residents. Distance of LDD in males was positively associated with maximum summer temperature. We did not find sex‐bias or an effect of population density in LDD distance or frequency. Within SDD, females tended to disperse farther than males, and distance was positively correlated with density. Sampling affected all responses, likely because local studies more frequently capture SDD within study areas.Our findings that LDD occurs at a relatively high frequency and is related to different proximate factors from SDD, including a lack of sex‐bias in LDD, suggest that LDD may be more common than previously reported, and LDD and SDD may be distinct processes rather than two outcomes originating from a single dispersal distribution. To our knowledge, this is the first evidence that LDD and SDD may be separate processes in an avian species, and suggests that environmental change may have different outcomes on the two processes. [ABSTRACT FROM AUTHOR]

Resident populations of Canada geese (Branta canadensis) are of particular management interest throughout the eastern United States given increased human‐wildlife conflicts due to regional increases in the Atlantic Flyway Resident Population. Within Virginia, USA, growth rates of resident goose populations have been reduced through extended harvest seasons and increased bag limits. Our objective was to investigate spatiotemporal patterns in survival rates and harvest rates of resident geese in Virginia over the past 25 years. We estimated annual survival, recovery, and harvest rates using mark‐recapture data from 1990–2015 for individuals that were banded as resident birds during summer throughout the state. We tested for differences in annual survival probability and harvest rates of resident geese banded and recovered in 3 distinct goose hunt zones: the Atlantic, Southern James Bay, and Western hunt zones, each of which had different hunting regulations. We also tested for differences in survival and harvest rates between individuals banded in rural or urban sampling locations, and between age classes (i.e., after hatch‐year or hatch‐year). In general, survival rates of resident geese over the past 25 years in Virginia are declining. Differences in survival among the 3 goose hunt zones also suggests that current harvest management strategies have reduced survival rates of resident geese. Upon closer examination, we found differences in survival among zones, with resident geese in the Atlantic and Southern James Bay hunt zones showing more negative declines compared to resident geese in the Western zone. Resident geese banded in rural areas had higher survival than urban‐banded geese. We also investigated the effects of sampling effort on survival estimates and found no difference in survival estimates among groups when using 75%, 50%, 25%, or 5% of the data randomly sampled from the full data set, suggesting that banding efforts of resident geese could be reduced and continue to inform adaptive management strategies for these populations throughout Virginia. © 2020 The Wildlife Society. Using 25 years of mark‐recapture data from resident Canada geese in Virginia, on average, survival rates are declining and harvest rates are increasing. These trends indicate that hunting regulations across the state are effective and are aiding in the achievement of established management goals for resident geese in Virginia. We were able to detect observed trends in survival and harvest rates despite using much‐reduced data sets, suggesting the potential to reallocate resources for banding of resident geese to other population reduction methods. [ABSTRACT FROM AUTHOR]

Many large raptors exploit or rely on anabatic and orographic winds which provide vertical lift, to supplement or provide the energy fuelling flight. Airspace is therefore a critical habitat for such large raptors and its use is subject to the underlying terrestrial topography, because particular topographical features are more likely to provide wind‐energetic lift. Accordingly, ridges and/or 'rugged topography' are common preferred features in habitat use by large raptors. Our study aimed to provide a simple model of space use for a large raptor, the Golden Eagle Aquila chrysaetos, based on thousands of GPS telemetry records during juvenile dispersal of 92 birds tagged as nestlings between 2007 and 2016 across upland Scotland. Model development was based on the hypothesis that four topographical variables would be influential: slope, aspect, altitude and distance from ridge. The telemetry dataset was divided into training and two testing components. The first testing set was derived by a temporal split resulting in approximately equal sample size on records and some temporal overlap in individuals' records with training data. The second testing set involved no individuals from the training set. Aspect was removed early in training model development because it was not influential. The model found that young Golden Eagles preferred, or used according to availability, space above slopes greater than 10°, at an altitude of ≥ 300 m, and within 300 m of a ridge. The test data were highly correlated with those from the training data in the model variables, and performance as regard to expected preferences from the model was improved in both test datasets, indicating the model was robust. Given the apparent universal nature of large raptor dependence on topography, that topography is relatively immutable according to time and use, and that topographical data are readily available, we commend our approach to other habitat preference studies of Golden Eagles and other large raptors elsewhere. [ABSTRACT FROM AUTHOR]

In Focus: Reneerkens, J., Versluijs, T. S. L., Piersma, T., Alves, J. A., Boorman, M., Corse, C., ... Lok, T. (2020). Low fitness at low latitudes: wintering in the tropics increases migratory delays and mortality rates in an Arctic breeding shorebird. Journal of Animal Ecology, 89, 691–703. A central question in migratory ecology has been to understand the fitness consequences of individual variation in migration distance among different species and populations. Reneerkens et al. (2020) investigated the demographic consequences of long‐distance migration for Sanderlings Calidris alba, an Arctic‐breeding species of sandpiper. Their study population has a remarkable geographic distribution with a breeding range that is concentrated in northeast Greenland and Ellesmere Island, Canada but a nonbreeding range that extends across 85° of latitude from Scotland to Namibia. The authors report on unexpected patterns of latitudinal variation in three demographic parameters: timing of passage on northward migration, probability of juvenile migration and apparent survival of adults. Sanderlings travelling 1,800–2,800 km to settle at north temperate sites during the nonbreeding season had earlier passage dates, and also higher probabilities of migration and apparent survival. In contrast, birds travelling 6,000–7,800 km to equatorial sites experienced later passage dates, delayed maturity and lower apparent survival. However, if Sanderlings migrated even farther and flew over 11,000 km to nonbreeding sites in Namibia, then their performance was restored to early passage dates and higher survival. Movement tracks from birds tagged with geolocators showed that birds wintering in Namibia make nonstop flights of 7,500 km that bypass West Africa during northward migration. Thus, all lines of evidence suggest that Sanderlings face adversity when spending the nonbreeding season at equatorial latitudes. Moreover, the central finding that components of fitness can have nonlinear relationships with migration distance is a novel discovery that leads to many additional questions. The new findings have broader implications for theoretical models of migration, and for understanding how different patterns of movements may arise or be maintained in migratory species. [ABSTRACT FROM AUTHOR]

Currently, the deployment of tracking devices is one of the most frequently used approaches to study movement ecology of birds. Recent miniaturization of light‐level geolocators enabled studying small bird species whose migratory patterns were widely unknown. However, geolocators may reduce vital rates in tagged birds and may bias obtained movement data.There is a need for a thorough assessment of the potential tag effects on small birds, as previous meta‐analyses did not evaluate unpublished data and impact of multiple life‐history traits, focused mainly on large species and the number of published studies tagging small birds has increased substantially.We quantitatively reviewed 549 records extracted from 74 published and 48 unpublished studies on over 7,800 tagged and 17,800 control individuals to examine the effects of geolocator tagging on small bird species (body mass <100 g). We calculated the effect of tagging on apparent survival, condition, phenology and breeding performance and identified the most important predictors of the magnitude of effect sizes.Even though the effects were not statistically significant in phylogenetically controlled models, we found a weak negative impact of geolocators on apparent survival. The negative effect on apparent survival was stronger with increasing relative load of the device and with geolocators attached using elastic harnesses. Moreover, tagging effects were stronger in smaller species.In conclusion, we found a weak effect on apparent survival of tagged birds and managed to pinpoint key aspects and drivers of tagging effects. We provide recommendations for establishing matched control group for proper effect size assessment in future studies and outline various aspects of tagging that need further investigation. Finally, our results encourage further use of geolocators on small bird species but the ethical aspects and scientific benefits should always be considered. [ABSTRACT FROM AUTHOR]

The recent boost in bird migration studies following the development of various tracking devices raised awareness of how detrimental attaching devices can be for animals. Such effects can occur during migration, but also immediately post‐release if the device impairs escape flight performance and, consequently, the bird's ability to evade predators.In this study, we investigated the effect of carrying a device on the escape flight speed and aerodynamic force production in a migratory passerine. We recorded upward‐directed escape flights of 15 male blackcaps. Each individual was tested without a tag, and when equipped with three different leg‐loop dummy tags with masses representing around 3%, 5%, and 7% of their body mass. The experiment was designed such that all individuals passed through all treatments in a randomized order.We found that two factors affected flight speed in roughly equal amounts: first, tagged escape flights had lower flight speeds compared to the control flights, irrespective of tag mass. Second, we found an effect of the total mass, that is, the sum of the masses of the individual bird and of the tag, with heavier birds being slower. In contrast, flight speed was not correlated with relative tag mass in percentage of body mass, the metric commonly used in ethical guidelines for tag attachment. Aerodynamic flight force production also depended on total mass, with heavier birds producing higher forces. But these flight forces did not differ between flights with or without a tag.We conclude that, when tagging birds, it is misleading to choose heavy individuals for tagging in order to minimize the tag mass as a percentage of body mass. This is particularly relevant in species for which body mass is not necessarily related to size, like migratory birds that accumulate large fat reserves. The lower escape speed in "tagged" flights could not be explained by differences in net flight force production, because these did not differ between flights with and without a tag. This suggests that the tag also affected pre‐flight take‐off dynamics, possibly due to a leg harness‐induced reduction in leg push‐off performance. [ABSTRACT FROM AUTHOR]

Abstract: Mist netting is the most commonly used method for catching birds for scientific ringing, but despite decades of use, there have been few attempts to quantify the associated potential risks to the individuals caught. Any incidence of mortality through capture and handling, however low, is of potential ethical concern and may also introduce biases into the data. We estimate the mortality rate associated with capture of previously ringed (recaptured) passerines from the British and Irish Ringing Scheme (c. 1.5 million records) caught using mist nets. The importance of species, age, mass, month, time, previous captures, and an index of predator occurrence was tested using generalized linear mixed‐effects models. The average mortality rate was 0.0011, most of which was reported to occur before the individuals had been extracted from the nets (c. 70% of incidents). Juveniles appeared to be at higher risk and the incidence of predation from mist nets was seasonal, with increased risk during the winter. Species differed in their reported mortality rates with the apparent risk being greatest for Chiffchaff Phylloscopus collybita (0.0029) and Bullfinch Pyrrhula pyrrhula (0.0027). To improve our understanding (and hence minimize risk in future), we recommend collecting more complete data on incidences of mortality, and also injuries; exercising increased care when the species we have identified as being at greater risk are likely to be captured, and ensuring there are robust procedures for the checking of nets (as most reported incidents of mortality occur before handling). We also recommend that all Ringing Schemes should collate and make available data on capture‐related mortality. Overall rates of mortality associated with capture, although, were low and support the use of mist netting as a safe capture technique, without undue bias from mortality, when used by appropriately trained individuals. [ABSTRACT FROM AUTHOR]

Identifying migratory connections across the annual cycle is important for studies of migrant ecology, evolution and conservation. While recent studies have demonstrated the utility of high-resolution SNP-based genetic markers for identifying population-specific migratory patterns, the accuracy of this approach relative to other intrinsic tagging techniques has not yet been assessed., Here, using a straightforward application of Bayes' Rule, we develop a method for combining inferences from high-resolution genetic markers, stable isotopes and habitat suitability models, to spatially infer the breeding origin of migrants captured anywhere along their migratory pathway. Using leave-one-out cross validation, we compare the accuracy of this combined approach with the accuracy attained using each source of data independently., Our results indicate that when each method is considered in isolation, the accuracy of genetic assignments far exceeded that of assignments based on stable isotopes or habitat suitability models. However, our joint assignment method consistently resulted in small, but informative increases in accuracy and did help to correct misassignments based on genetic data alone. We demonstrate the utility of the combined method by identifying previously undetectable patterns in the timing of migration in a North American migratory songbird, the Wilson's warbler., Overall, our results support the idea that while genetic data provides the most accurate method for tracking animals using intrinsic markers when each method is considered independently, there is value in combining all three methods. The resulting methods are provided as part of a new computationally efficient R-package, gaiah, allowing broad application of our statistical framework to other migratory animal systems. [ABSTRACT FROM AUTHOR]

Identifying the overlap of commercial fishing grounds and seabird habitat can suggest areas of high bycatch risk and inform management and mitigation measures. We used Bayesian state space modeling to describe the movements of 10 satellite-tagged Great Shearwaters and a bivariate kernel density technique to investigate spatial overlap with commercial fishing effort to predict areas of high bycatch in the Gulf of Maine. We then used contemporaneous fishery observer data to test the validity of our predictions, highlighting an area constituting 1% of the Gulf of Maine as having the highest bycatch risk that accounted for 50% of observed takes. Fishery observer data also provided insights into characteristics of the seabird-fishery interactions. Our results indicate that a relatively small number of satellite-tagged seabirds, when combined with fishery-dependent data, can lead to identifying high-bycatch areas, particular fishing practices that might increase risk, and fishing communities that could be targeted for education/mitigation. [ABSTRACT FROM AUTHOR]

Capturing and marking free-living birds permits the study of important aspects of their biology but may have undesirable effects. Bird welfare should be a primary concern, so it is necessary to evaluate and minimize any adverse effects of procedures used. We assess short-term effects associated with the capture, handling and tagging with backpack-mounted transmitters of Pin-tailed Pterocles alchata and Black-bellied Pterocles orientalis Sandgrouse, steppe birds of conservation concern. There was a significantly higher mortality (15%) during the first week after capture than during the following weeks (< 2.5%) in Pin-tailed Sandgrouse, but no significant temporal mortality pattern in Black-bellied Sandgrouse. In Pin-tailed Sandgrouse, mortality rate during the first week increased with increasing relative transmitter and harness weight regardless of season, and with increasing handling time during the breeding season. There were no significant differences in mortality rate between study areas, type of tag, sex or age or an effect of restraint time. These results suggest the use of lighter transmitters (< 3% of the bird's weight) and a reduction of handling time (< 20 min), particularly during the breeding season, as essential improvements in procedure to reduce the mortality risk associated with the capture, handling and tagging of these vulnerable species. [ABSTRACT FROM AUTHOR]

A major aim of bird ringing is to provide information about the migration and movements of bird populations. However, in comparison with demographic studies, little research has been devoted to improving quantitative inferences through large-scale spatial analyses. This represents a serious knowledge gap because robust information on geographical linkages of migratory populations throughout the annual cycle is necessary to understand the ecology and evolution of migrants and for the conservation and management of populations., Here, we review recent developments and emerging opportunities for the quantitative study of movements of bird populations based on marked birds. Large-scale spatial analyses of ringing data need to account for spatiotemporal variation in re-encounter probability and the complexity of movement processes, including variability among individuals and populations in migration direction and distance., We identify seven recent studies that used quantitative methods for large-scale spatial analyses of ringing and re-encounter data gathered by national ringing centres. In most cases, numbers ringed and recovered in a series of source and destination areas were used to derive estimates of the proportion of each source population travelling to each destination area. Where recovery data were sparse, precision was improved by incorporating information on re-encounter probabilities of similar species. When numbers ringed were not available, inferences could sometimes be drawn based on local recapture data from the source areas., Studies to date illustrate that analyses of these large-scale ringing data sets can provide robust quantitative inferences. Further work is needed to develop these modelling approaches and to test their sensitivity to key assumptions using both real and simulated data. Data for all birds that were marked, not only those re-encountered, are often inaccessible and should be computerised in parallel with analytical developments. Further, there is great potential for the formal combination of re-encounter data with information from additional data sources such as counts and detailed movement data from radiotracking or data loggers. Because data from bird ringing operations cover long periods of time and exist in large quantities, they hold great promise for inferring spatiotemporal migration patterns, including changes in relation to climate, land use change and other environmental drivers. [ABSTRACT FROM AUTHOR]

The migration route of Red-necked Phalarope populations breeding on North Atlantic islands has been subject to considerable speculation. Geolocator tags were fitted to nine Red-necked Phalaropes breeding in northern Scotland to assess whether they migrated to Palaearctic or Nearctic wintering grounds. Of four birds known to return, two had retained their tags, of which one was recaptured. This male Phalarope left Shetland on 1 August 2012 and crossed the Atlantic Ocean to the Labrador Sea off eastern Canada in 6 days, then moved south to reach Florida during September, crossed the Gulf of Mexico into the Pacific Ocean and reached an area between the Galapagos Islands and the South American coast by mid- October, where it remained until the end of April, returning by a similar route until the tag battery failed as the bird was crossing the Atlantic Ocean. The total migration of 22 000 km is approximately 60% longer than the previously assumed route to the western part of the Arabian Sea, and this first evidence of migration of a European breeding bird to the Pacific Ocean also helps to indicate the possible migratory route of the large autumn movements of Red-necked Phalaropes down the east coast of North America. [ABSTRACT FROM AUTHOR]

A better knowledge of chick survival rates is required to enable understanding of the population dynamics of gamebirds and to A better knowledge of chick survival rates ia required to enable understanding of the population dynamics of gamebirds and to develop management measures to conserve their populations. The Red-legged Partridge Alectoris rufa is a highly valued game species in Spain but its populations have declined in recent decades. A lack of appropriate monitoring methods has been a limitation in gaining information on the mortality of Red-legged Partridge chicks. We developed methods for the effective radiotagging of chicks in captivity and applied these methods in the field in northern Spain to estimate survival during the first 5 months of life. The most effective method for radiotagging captive chicks between 3 and 8 days old involved gluing small tags directly to the skin in the interscapular space using cyanoacrylate adhesive. Backpack harness tags attached with elastic bands were the most effective method of radiotagging 4-week-old chicks. Predation was the main cause of chick mortality identified during the field experiments. Survival between hatching and 5 months of age was estimated to be 16-21%. The lowest survival rates occurred during the first 7 days of life (62-70% cumulative survival) and this period seems to be a major determinant in the life history of the species. develop management measures to conserve their populations. The Red-legged Partridge Alectoris rufa is a highly valued game species in Spain but its populations have declined in recent decades. A lack of appropriate monitoring methods has been a limitation in gaining information on the mortality of Red-legged Partridge chicks. We developed methods for the effective radiotagging of chicks in captivity and applied these methods in the field in northern Spain to estimate survival during the first 5 months of life. The most effective method for radiotagging captive chicks between 3 and 8 days old involved gluing small tags directly to the skin in the interscapular space using cyanoacrylate adhesive. Backpack harness tags attached with elastic bands were the most effective method of radiotagging 4-week-old chicka. Predation was the main cause of chick mortality identified during the field experiments. Survival between hatching and 5 months of age was estimated to be 16-21%. The lowest survival rates occurred during the first 7 days of life (62-70% cumulative survival) and this period seems to be a major determinant in the life history of the species. [ABSTRACT FROM AUTHOR]

Growth bands are alternate dark/light bands perpendicular to the feather rachis. Previous studies indicate that pairs of dark/light bands are grown every 24h, with light bands being produced at night, and dark ones during the day. Thus, the dark:light width ratio could reflect the photoperiod under which a feather was grown. We tested this hypothesis by inducing feathers to grow under contrasting photoperiods, using red-legged partridges Alectoris rufa as a model species. We first validated the assumption that a pair of dark/light band is produced every day. Secondly, we show that dark/light width ratios remain close to 1:1, irrespective of the photoperiod under which feathers were grown. Dark:light width ratios of feathers grown in summer (15 light-hours: 9 darkness-hours) and winter solstices (9l: 15d) did not show any consistent pattern of variation within individuals. Thus, the dark/light banding patterns are not simply the product of light regimes and are not indicative of photoperiod. This finding, together with reports of 'aberrant' growth band patterns (e.g. two growth bands produced over 24 h instead of one) challenges our current knowledge of growth bands. We propose that the normal circadian periodicity of growth bands is primarily driven by circadian rhythms: band formation starts at a point of critically low physiological activity (e.g. during night resting), and thus every 24 h irrespective of photoperiod. Our experiment emphasises that our knowledge of growth bands is weaker than previously appreciated, and that the study of dark/light band patterns on feathers could shed new light on interesting phenomena such as unusual avian biological rhythms and the functioning of internal clocks. Detecting 'aberrant' banding patterns could therefore allow identifying bird species with unusual activity patterns or physiological rhythms. [ABSTRACT FROM AUTHOR]

We developed a method for predicting wood duck (Aix sponsa) harvest rates in eastern North America using waterfowl banding and recovery data, annual indices of hunter numbers, and harvest survey data from the United States and Canada. We predicted that under the current season length (60 days), if hunter numbers remain unchanged, increasing the wood duck bag limit from 2 to 3 would increase harvest of adult male wood ducks in the Atlantic and Mississippi flyways by 12.3%, causing an increase in harvest rate of 7.1% from 0.087 to 0.093. The Flyway Councils and the United States Fish and Wildlife Service can consider this information to predict the impacts of regulatory changes. [ABSTRACT FROM AUTHOR]

1. Survival estimation forms the basis of much ecological research, and usually requires data on marked animals. In population studies of territorial animals, however, data are often collected on animal territory occupancy without identification of individuals. Previously, these data could not be used to estimate demographic parameters such as survival. 2. We developed a hierarchical site-occupancy model for estimating survival from territory occupancy data without individual identification. We defined survival as the probability that an individual occupying a territory survives until the next reproductive period and settles in the same territory again. To evaluate our model, we used simulated data as well as real data from a long-term study on nightingales Luscinia megarhynchos, from which mark-recapture data and territory occupancy data were available. 3. When applied to simulated data sets on territory occupancy, with parameter settings that are typical for different monitoring programmes (i.e. 10 years duration, three or eight visits per season, and 55 or 200 territories surveyed), our model yielded unbiased estimates of survival if the probability of detecting an occupied territory during a single visit was p = 0·5 or p = 0·7. 4. When applied to the data on nightingale territory occupancy, estimates of survival from our model were very similar to the estimates obtained from a traditional mark-recapture model (Cormack–Jolly–Seber model) applied to the ringing data from the same nightingale population. 5. Synthesis and applications. Data collection for mark-recapture analysis is usually invasive and labour intensive, and suitable data are rarely available from large-scale monitoring programmes covering entire regions or countries. Applying our model to territory occupancy data from such monitoring programmes could make large amounts of data available for research on animal demography. [ABSTRACT FROM AUTHOR]