| a stable-isotope approach to delineate geographical catchment areas of avian migration monitoring stations in north america. | migration monitoring stations (mmss) were established to provide information on population trends of north american passerines. however, apart from inferring general origins of birds, there has been no way to delineate geographical catchment areas sampled by mmss. the ability to resolve mms catchment areas would greatly enhance our ability to link and constrain population declines to specific geographical areas and thereby focus conservation efforts. here, we utilize stable-hydrogen (delta d) an ... | 2001 | 11355202 |
| fuel loads acquired at a stopover site influence the pace of intercontinental migration in a boreal songbird. | long-distance migratory organisms are under strong selection to migrate quickly. stopovers demand more time than flying and are used by individuals to refuel during migration, but the effect of fuel loads (fat) acquired at stopover sites on the subsequent pace of migration has not been quantified. we studied stopover behaviour of grey-cheeked thrush (catharus minimus) at a site in northern colombia and then tracked their migration using an intercontinental radio-telemetry array. tracking confirm ... | 2017 | 28611372 |
| when winners become losers: predicted nonlinear responses of arctic birds to increasing woody vegetation. | climate change is facilitating rapid changes in the composition and distribution of vegetation at northern latitudes, raising questions about the responses of wildlife that rely on arctic ecosystems. one widely observed change occurring in arctic tundra ecosystems is an increasing dominance of deciduous shrub vegetation. our goals were to examine the tolerance of arctic-nesting bird species to existing gradients of vegetation along the boreal forest-tundra ecotone, to predict the abundance of sp ... | 2016 | 27851768 |
| comparative phylogenetic histories of two louse genera found on catharus thrushes and other birds. | the louse genera brueelia (ischnocera) and myrsidea (amblycera) are broadly codistributed on songbirds (passeriformes), but differ in a variety of life history characteristics. we used mitochondrial and nuclear dna sequences to assess levels of genetic divergence and reconstruct phylogenies of these 2 genera, focusing especially on catharus thrushes in north america. we then qualitatively compared the phylogenies and levels of divergence within these 2 genera of codistributed parasites. neither ... | 2009 | 18821823 |
| assessing seasonal changes in animal diets with stable-isotope analysis of amino acids: a migratory boreal songbird switches diet over its annual cycle. | tools to study seasonal changes in animal diets are needed to address a wide range of ecological questions. this is especially true of migratory animals that experience distinct environments where diets may be substantially different. however, tracking diets of individuals that move vast distances has proven difficult. compound-specific isotope analysis has emerged as a valuable tool to study diets but has been little used to study dietary changes of migratory animals. using this technique, we q ... | 2018 | 29564539 |