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Natural history information is one of the major knowledge gaps in Neotropical ornithology. Several range-restricted and threatened species in the region are still poorly known, hindering the design of effective conservation programs. Here, we used direct observations collected at 7 localities throughout the Tropical Andes to describe habitat use and foraging ecology of the Yellow-headed Brushfinch (Atlapetes flaviceps), a species of conservation concern and endemic to Colombia. Our observational records (n = 174) indicate that this species mainly occurs in secondary forests and landscape mosaics that include patches of native vegetation and agricultural areas, but it seems to be frequently associated with the presence of regenerating vegetation in early successional stages. We found that the species' diet was mainly composed of fruits and invertebrates, although other items are occasionally included. Although our data suggest the possibility of an association between habitat type and the activity recorded, as well as temporal variation in foraging behavior, this requires more research. Our observations support the idea of this species being tolerant to human-altered habitats, but this needs to be confirmed by measuring habitat-specific productivity and survival. The results presented here not only increase knowledge of this poorly known endemic but can be useful for the subsequent implementation of management strategies aimed at increasing the availability of high-quality habitat. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Applied Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The tropical Andes are characterized by extreme topographic and climatic complexity, which has likely contributed to their outstanding current species diversity, composed of many range‐restricted species. However, little is known about how the distribution and abundance of highly mobile organisms, like long‐distance migratory birds, varies across different land covers, elevations, and climatic conditions within the Andes. We conducted 1,606 distance‐sampling point counts across the Colombian Andes, spanning elevations from 253 to 3,708 m, a range of precipitation regimes and representative land covers. We then employed a novel application of a multispecies hierarchical modeling approach to evaluate how elevation, local land cover, aboveground woody biomass, cloud cover, precipitation, and seasonality in precipitation shape the abundance of the migratory land bird community in the Andes. We detected 1,824 individuals of 29 species of migratory land birds, six of which were considered incidental in our study region. We modeled the abundance of the remaining 23 species, while considering observer and time of day effects on detectability. We found that both elevation and land cover had an overriding influence on the abundance of migratory species across the Andes, with strong evidence for a mid‐elevation peak in abundance, and species‐specific responses to both variables. As a community, migratory birds had the highest mean abundance in shade coffee plantations, secondary forest, and mature forest. Aboveground woody biomass did not affect the abundance of all species as a group, but a few showed strong responses to this variable. Contrary to predictions of a positive correlation between abundance and precipitation, we found no evidence for community‐level responses to precipitation, aside for a weak tendency for birds to select areas with intermediate levels of precipitation. This novel use of a multispecies model sheds new light on the mechanisms shaping the winter distribution of migratory birds and highlights the importance of elevation and land cover types over climatic variables in the context of the Colombian Andes. [ABSTRACT FROM AUTHOR]

Temporal variation in the connectivity of populations of migratory animals has not been widely documented, despite having important repercussions for population ecology and conservation. Because the long-distance movements of migratory animals link ecologically distinct and geographically distant areas of the world, changes in the abundance and migratory patterns of species may reflect differential drivers of demographic trends acting over various spatial scales. Using stable hydrogen isotope analyses (δ2H) of feathers from historical museum specimens and contemporary samples obtained in the field, we provide evidence for an approximately 600 km northward shift over 45 years in the breeding origin of a species of songbird of major conservation concern (blackpoll warbler, Setophaga striata) wintering in the foothills of the eastern Andes of Colombia. Our finding mirrors predictions of range shifts for boreal-breeding species under warming climate scenarios and habitat loss in the temperate zone, and underscores likely drivers of widespread declines in populations of migratory birds. Our work also highlights the value of natural history collections to document the effects of global change on biodiversity. [ABSTRACT FROM AUTHOR]

For migratory landbird species, large expanses of open water or inhospitable areas provide unique challenges during migration. Research on the strategies that species use to navigate barriers can yield insights into the factors shaping the evolution of migration and facilitate the identification of critical staging areas prior to barrier crossing. One such barrier, the Caribbean Sea, has received little study but must be negotiated by 50 migratory landbirds as they fly from South America to North America in spring. Recent discoveries from the gray-cheeked thrush Catharus minimus, which undertakes non-stop flights >3000 km across the Caribbean Sea, raises the possibility that the breadth of potential strategies has been unappreciated thus far. We calculated fuel load and potential flight range in 9985 individuals of 16 species captured over 10 years at two stopover sites in northern Colombia to 1) evaluate the likely migratory strategy of these species as they depart northern Colombia in spring, and 2) evaluate the influence of family, diet, morphology and migratory distance on potential flight range. We found considerable variation in flight ranges and therefore strategies for crossing the Caribbean Sea/Gulf of Mexico barrier complex. In addition to gray-cheeked thrush, non-stop flights >2500 km were possible in yellow-billed cuckoo Coccyzus americanus, yellow warbler Setophaga petechia and northern waterthrush Parkesia noveboracensis. The remaining species were either capable of over-water flights to the Yucatan Peninsula/Cuba (>1800 km) or shorter flights to middle Central America (>1000 km) and likely required one or more stopovers to reach North America. Predicted flight ranges were influenced by morphology but not by distance, diet or taxonomic group, providing a novel insight into the evolution of migratory strategies. Our study confirms the vital role northern Colombia performs in providing energy for migratory birds and highlights the Caribbean as a key migratory barrier for many species. [ABSTRACT FROM AUTHOR]

Migration theory has largely overlooked the role of overwintering grounds and yet many migratory animals spend most of the annual cycle there. High winter site familiarity could confer considerable advantages on animals preparing for subsequent migration phases, enabling them to maximize migration speed and minimise the use of unknown stopover sites. Despite this, quantitative studies of the magnitude of fuel stores attained at such sites are lacking. To evaluate the energetic contribution of an overwintering site to spring migration, we used manual and automated telemetry to estimate departure date, departure fuel load, flight range and breeding destination of blackpoll warblers (Setophaga striata) wintering in Colombia. Relative to overwinter mass, warblers increased body mass (a surrogate for fuel stores) by an average of 59% prior to departure from the overwintering site. Flight range (mean 2710 km, range 2110–3380 km, N = 16) and detections at automated telemetry stations in North America suggest movements to Cuba/southeastern US, before refuelling and then continuing towards breeding grounds in eastern Canada (total duration ∼ 30 days). Total migration length was ∼ 5350 km and energy acquired at the overwintering site was sufficient to cover 39–63% (mean = 50%), demonstrating the major contribution tropical wintering grounds can make to migration. It follows that varying the extent of fuelling prior to departing overwintering sites may provide animals with a mechanism for balancing their exposure to risk during migration, while simultaneously allowing for flexibility in migratory schedules in a changing world. • Optimal migration theory has largely overlooked the function of wintering sites. • Extensive fuelling at such sites could maximize migration speed and reduce risk. • Blackpoll warblers stored enough energy at a tropical wintering site to fly 2710 km. • Mean flight range was equivalent to 50% of the total migratory journey. • Wintering sites can have an intrinsic role in shaping migratory strategies. [ABSTRACT FROM AUTHOR]

The effect of habitat choice on fuelling behaviour and the organization of migration in birds has rarely been examined, despite the potential impact of widespread anthropogenic transformation of stopover regions. High energetic requirements in migrating birds mean that resource abundance, through its influence on fuel deposition rates (FDR), is expected to be the main determinant of stopover and migration strategy. We examined the spring stopover of Tennessee Warblers (Oreothlypis peregrina) in northern Colombia, evaluating how diet, FDR, stopover duration, departure mass and estimated flight range varied between two commonly used stopover habitats: shade coffee plantations and pre-montane forests. Diet included insects in both habitats, but fruit was only consumed in pre-montane forest, where FDR was highest (FDR forest = 2.4% LBM/day; coffee = 0.5% LBM/day). Three different estimates of stopover duration suggested longer stays in coffee but lengthier durations did not result in equivalent departure mass between habitats, such that estimated flight range was twice as long for birds departing forest (2000 km) relative to coffee (1088 km). We conclude that stopover performance differed between habitats, likely influencing the subsequent temporal and spatial organization of spring migration. On the basis of flight ranges, stopovers in shade coffee may also increase the risks of trans-Caribbean flights, suggesting a mechanism by which stopover habitat could directly influence survival. Given that fruit consumption in forest probably explains these differences, we recommend the identification of appropriate fruiting trees for Neotropical agroforestry systems that can tolerate a variety of conditions and increase the quality of these anthropogenic habitats for migratory and other frugivorous birds. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Field Ornithology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article presents a study on geographic origins and the timing of fall migration of veery in Sierra Nevada de Santa Marta, northern Colombia. The study analyses stable hydrogen isotopes (δD) in feathers and values expected from feathers' δD in the long-term isoscape. Result shows that most of the veery originated from the southwest or the northeast regions. Moreover, a chain migration was suggested as there is no correlation found between the δD and timing of arrival.

Body mass is one of the most important phenotypic attributes in animal ecology and life history. This trait is widely used in the fields of ecology and macroevolution, since it influences physiology, morphological functions, and a myriad of ecological and social interactions. In this data set, our aim was to gather a comprehensive bird and mammal body mass data set from northern South America. We report body mass, discriminated by sex, for 42,022 individual birds and 7,441 mammals representing 1,317 bird species (69% of Colombia's avifauna) and 270 mammal species (51% of Colombian mammals) from the Neotropics. The data were sourced from vouchers collected between 1942 and 2020 and from individuals captured and released at banding stations over the last two decades for birds (2000–2020) and the last decade for mammals (2010–2020), by 10 research groups and institutions in Colombia. This data set fills gaps identified in other similar databases, as it focuses on northern South America, a highly diverse Neotropical region often underrepresented in morphological data sets. We provide wide taxonomic coverage for studies interested in information both at regional and local scales. There are no copyright restrictions; the present data paper should be appropriately cited when data are used for publication. The authors would appreciate learning about research projects, teaching exercises, and other uses given to this data set and are open to contribute in further collaborations using these data. [ABSTRACT FROM AUTHOR]

Temporal variation in the connectivity of populations of migratory animals has not been widely documented, despite having important repercussions for population ecology and conservation. Because the long-distance movements of migratory animals link ecologically distinct and geographically distant areas of the world, changes in the abundance and migratory patterns of species may reflect differential drivers of demographic trends acting over various spatial scales. Using stable hydrogen isotope analyses ( δ 2 ) wintering in the foothills of the eastern Andes of Colombia. Our finding mirrors predictions of range shifts for boreal-breeding species under warming climate scenarios and habitat loss in the temperate zone, and underscores likely drivers of widespread declines in populations of migratory birds. Our work also highlights the value of natural history collections to document the effects of global change on biodiversity.Setophaga striata ) wintering in the foothills of the eastern Andes of Colombia. Our finding mirrors predictions of range shifts for boreal-breeding species under warming climate scenarios and habitat loss in the temperate zone, and underscores likely drivers of widespread declines in populations of migratory birds. Our work also highlights the value of natural history collections to document the effects of global change on biodiversity.