scholarly journals Migratory connectivity of barn swallows in South Africa to their Palaearctic breeding grounds

2018 ◽  
Vol 24 (11) ◽  
pp. 1699-1708
Author(s):  
Marc S. Burman ◽  
Leslie G. Underhill ◽  
Res Altwegg ◽  
Birgit Erni ◽  
Magdalena Remisiewicz ◽  
...  
2011 ◽  
Vol 279 (1733) ◽  
pp. 1485-1490 ◽  
Author(s):  
Res Altwegg ◽  
Kristin Broms ◽  
Birgit Erni ◽  
Phoebe Barnard ◽  
Guy F. Midgley ◽  
...  

Many migratory bird species, including the barn swallow ( Hirundo rustica ), have advanced their arrival date at Northern Hemisphere breeding grounds, showing a clear biotic response to recent climate change. Earlier arrival helps maintain their synchrony with earlier springs, but little is known about the associated changes in phenology at their non-breeding grounds. Here, we examine the phenology of barn swallows in South Africa, where a large proportion of the northern European breeding population spends its non-breeding season. Using novel analytical methods based on bird atlas data, we show that swallows first arrive in the northern parts of the country and gradually appear further south. On their north-bound journey, they leave South Africa rapidly, resulting in mean stopover durations of 140 days in the south and 180 days in the north. We found that swallows are now leaving northern parts of South Africa 8 days earlier than they did 20 years ago, and so shortened their stay in areas where they previously stayed the longest. By contrast, they did not shorten their stopover in other parts of South Africa, leading to a more synchronized departure across the country. Departure was related to environmental variability, measured through the Southern Oscillation Index. Our results suggest that these birds gain their extended breeding season in Europe partly by leaving South Africa earlier, and thus add to scarce evidence for phenology shifts in the Southern Hemisphere.


The Condor ◽  
2021 ◽  
Author(s):  
Clark S Rushing ◽  
Aimee M Van Tatenhove ◽  
Andrew Sharp ◽  
Viviana Ruiz-Gutierrez ◽  
Mary C Freeman ◽  
...  

Abstract Archival geolocators have transformed the study of small, migratory organisms but analysis of data from these devices requires bias correction because tags are only recovered from individuals that survive and are re-captured at their tagging location. We show that integrating geolocator recovery data and mark–resight data enables unbiased estimates of both migratory connectivity between breeding and nonbreeding populations and region-specific survival probabilities for wintering locations. Using simulations, we first demonstrate that an integrated Bayesian model returns unbiased estimates of transition probabilities between seasonal ranges. We also used simulations to determine how different sampling designs influence the estimability of transition probabilities. We then parameterized the model with tracking data and mark–resight data from declining Painted Bunting (Passerina ciris) populations breeding in the eastern United States, hypothesized to be threatened by the illegal pet trade in parts of their Caribbean, nonbreeding range. Consistent with this hypothesis, we found that male buntings wintering in Cuba were 20% less likely to return to the breeding grounds than birds wintering elsewhere in their range. Improving inferences from archival tags through proper data collection and further development of integrated models will advance our understanding of the full annual cycle ecology of migratory species.


The Condor ◽  
2007 ◽  
Vol 109 (2) ◽  
pp. 268-275 ◽  
Author(s):  
Carola Sanpera ◽  
Xavier Ruiz ◽  
Rocío Moreno ◽  
Lluís Jover ◽  
Susan Waldron

Abstract To better understand migratory connectivity between breeding and nonbreeding populations, we analyzed mercury (Hg) and stable isotope signatures of nitrogen (δ15N), carbon (δ13C), and sulfur (δ34S) in Audouin's Gulls (Larus audouinii) breeding in two different colonies, the Ebro Delta (northeastern Spain) and the Chafarinas Islands (southwestern Mediterranean). Although abundant information is available on the biology and trophic ecology of this gull's breeding populations, little is known about migration patterns, distribution in winter, or conditions faced during the nonbreeding period. Analyses were carried out on first primary feathers, grown during the summer while gulls are on the breeding grounds, and mantle feathers, grown during the winter. Different isotopic signatures (δ15N, δ13C, and δ34S) in summer (primary) feathers from each area agree with the observed differences in diet between the two colonies. In winter (mantle) feathers, isotopic signatures did not differ, consistent with a common wintering ground and common diet, although the lack of isotopic basemaps in marine systems precludes assignment to a geographical area of reference. Future research is needed to relate isotopic signatures and Hg values in mantle feathers to trophic ecology in wintering areas. Results for Hg indicate that the excretory role played by primary feathers precludes their use as indicators of trophic ecology.


2017 ◽  
Vol 28 (3) ◽  
pp. 462-474 ◽  
Author(s):  
GUILLERMO FANDOS ◽  
JOSÉ LUIS TELLERÍA

SummaryBecause migrant birds occur in different parts of the world in different seasons, their numbers may be limited by the size of the smallest area they inhabit during the year. In addition, restricted ranges make populations more susceptible to local perturbations such that range size is frequently considered a correlate of species vulnerability. Despite this, little is known about the balance between seasonal ranges in the migrant populations of partially migratory species. These migrants are difficult to segregate from sedentary conspecifics in winter grounds and thus the extent of their ranges is difficult to assess. Here, we studied the extent of potential breeding and wintering ranges of 10 partial migratory passerines moving to winter in the Iberian Peninsula and the Maghreb. After testing migratory connectivity of the individual species, we used niche modelling to calculate the extent of potential breeding and wintering ranges in 1,113 pairs of ring recoveries linking individuals between breeding and wintering localities. The results indicate that most species show migratory connectivity and that all of them show range compression in winter relative to the breeding range, with scores ranging between 19% and 58% (mean 37%) of breeding ranges. We discuss the importance of non-breeding grounds for conserving migratory passerines in the Western Mediterranean Basin, an area under pressure from climate change and agricultural intensification.


2021 ◽  
Vol 50 (SuplEsp) ◽  
pp. 31-40
Author(s):  
Susana Caballero ◽  
Debbie Steel ◽  
Logan Pallin ◽  
Natalia Botero ◽  
Fernando Felix ◽  
...  

We analysed 114 DNA samples collected in different locations within the stock G breeding grounds, including Ecuador and the northern and southern Pacific of Colombia. We genotyped 15 microsatellite loci, sexed all samples, and performed genotype comparisons. Genotype comparisons were done using a DNA register of previously genotyped individuals from the Colombian breeding ground and the Antarctic Peninsula feeding Area. We confirmed connectivity between feeding grounds in Antarctic Peninsula and breeding grounds in Colombia and Ecuador using microsatellite loci. We found recaptures within each sampling location in the same year, but we also found a few recaptures in the same locations between years both in breeding and feeding grounds. Interestingly, we found recaptures between breeding and feeding grounds using samples collected 20 years apart, providing some information about longevity in this stock. Further comparisons with other data sets (Brazil, North Pacific) are needed to understand the migratory connectivity of this stock.


The Condor ◽  
2019 ◽  
Vol 121 (3) ◽  
Author(s):  
Ellis L Smith ◽  
Matthew W Reudink ◽  
Peter P Marra ◽  
Ann E Mckellar ◽  
Steven L Van Wilgenburg

ABSTRACT Populations of Vaux’s Swift (Chaetura vauxi), like those of many aerial insectivores, are rapidly declining. Determining when and where populations are limited across the annual cycle is important for their conservation. Establishing the linkages between wintering and breeding sites and the strength of the connections between them is a necessary first step. In this study, we analyzed 3 stable isotopes (δ13C, δ15N, δ2H) from feathers collected during spring migration from Vaux’s Swifts that perished during a stopover on Vancouver Island, British Columbia, Canada. We previously analyzed claw tissue (grown during winter) from the same individuals, revealing that the swifts likely wintered in 2 or 3 locations/habitats. Here, we used stable isotope analysis of flight feathers presumed to have been grown on, or near, the breeding grounds to determine the likely previous breeding locations and presumed destinations for the swifts. Stable isotope values (δ13C, δ15N, δ2H) showed no meaningful variation between age classes, sexes, or with body size. Surprisingly, ~26% of the birds sampled had feather isotope values that were not consistent with growth on their breeding grounds. For the remaining birds, assigned breeding origins appeared most consistent with molt origins on Vancouver Island. Overall, migratory connectivity of this population was relatively weak (rM = 0.07). However, the degree of connectivity depended on how many winter clusters were analyzed; the 2-cluster solution suggested no significant connectivity, but the 3-cluster solution suggested weak connectivity. It is still unclear whether low migratory connectivity observed for Vaux’s Swift and other aerial insectivores may make their populations more or less vulnerable to habitat loss; therefore, further efforts should be directed to assessing whether aerial insectivores may be habitat limited throughout the annual cycle.


2018 ◽  
Vol 5 (1) ◽  
pp. 1-16 ◽  
Author(s):  
Tara Leah Imlay ◽  
Keith A. Hobson ◽  
Amélie Roberto-Charron ◽  
Marty L. Leonard

Abstract Conservation efforts directed at population declines for migratory animals must consider threats occurring at different stages often separated by vast distances. Furthermore, connectivity between populations and fidelity of individuals to specific habitats during the annual cycle are also important considerations. Avian aerial insectivores are experiencing steep population declines in North America, and those declines may be driven, in part, by conditions on the wintering grounds. Here, using geolocators (2 species; 4 individuals) and stable isotope (δ2H, δ13C and δ15N) measurements of feathers (3 species; 841 individuals), we identified approximate winter areas, and assessed migratory connectivity and among-year winter habitat fidelity for three aerial insectivores (Bank Swallow Riparia riparia, Barn Swallow Hirundo rustica and Cliff Swallow Petrochelidon pyrrhonota) that breed in northeastern North America. All three species of swallows are declining in this region. Our results, largely from the stable isotope analysis, suggest that these species likely winter throughout the Cerrado, La Plata Basin, and the Pampas, in South America. These most likely areas were similar among years (2013-2016) for Bank and Cliff Swallows, but varied for Barn Swallows (2014-2016). We found weak migratory connectivity for all three species, and, with one exception, weak habitat fidelity among years for individuals. For individual Barn Swallows captured in two or more years, we found high repeatability in δ13C values, suggesting some fidelity to similar habitats among years. The most likely wintering areas for these species coincide with large areas of South America experiencing high rates of land-use change.


2015 ◽  
Vol 2 (5) ◽  
pp. 150004 ◽  
Author(s):  
Graham D. Fairhurst ◽  
Lisha L. Berzins ◽  
David W. Bradley ◽  
Andrew J. Laughlin ◽  
Andrea Romano ◽  
...  

Despite benefits of using light-sensitive geolocators to track animal movements and describe patterns of migratory connectivity, concerns have been raised about negative effects of these devices, particularly in small species of aerial insectivore. Geolocators may act as handicaps that increase energetic expenditure, which could explain reported effects of geolocators on survival. We tested this ‘Energetic Expenditure Hypothesis’ in 12 populations of tree swallows ( Tachycineta bicolor ) and barn swallows ( Hirundo rustica ) from North America and Europe, using measurements of corticosterone from feathers (CORT f ) grown after deployment of geolocators as a measure of physiology relevant to energetics. Contrary to predictions, neither among- (both species) nor within-individual (tree swallows only) levels of CORT f differed with respect to instrumentation. Thus, to the extent that CORT f reflects energetic expenditure, geolocators apparently were not a strong handicap for birds that returned post-deployment. While this physiological evidence suggests that information about migration obtained from returning geolocator-equipped swallows is unbiased with regard to levels of stress, we cannot discount the possibility that corticosterone played a role in reported effects of geolocators on survival in birds, and suggest that future studies relate corticosterone to antecedent factors, such as reproductive history, and to downstream fitness costs.


Author(s):  
Theadora A. Block ◽  
Bruce E. Lyon ◽  
Zachary Mikalonis ◽  
Alexis S. Chaine ◽  
Daizaburo Shizuka

AbstractResearching the complete life cycles of migratory animals is essential for understanding conservation and population dynamics. Many studies focus on the breeding season, but surviving winter is equally important. Living in groups during winter can play a vital role as social connections within groups can provide many benefits such as protection from predators and increased access to resources. However, it is often unknown how social connections change across seasons in migratory animals. We focus on social connections in a migratory bird and ask whether social connections in winter continue during breeding. Golden-crowned sparrows have distinct, stable winter communities which include both site and group fidelity across years: birds almost always rejoin the same social community each year. If these birds have social connectivity across migration, we would expect individuals that associate in winter would also associate together on their breeding grounds. Our small-scale GPS tagging study combined with intensive social behavior data revealed that sparrows in the same tightly-knit winter community migrated to highly disparate locations during summer, showing that social connections in winter do not continue in summer. This suggests that golden-crowned sparrows have entirely separate social structures across seasons and that long-term social memories allow them to reform stable groups each winter.


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