Migratory species can experience limiting factors at different locations and during different periods of their annual cycle. In migratory birds, these factors may even occur in different hemispheres. Therefore, identifying the distribution of populations throughout their annual cycle (i.e., migratory connectivity) can reveal the complex ecological and evolutionary relationships that link species and ecosystems across the globe and illuminate where and how limiting factors influence population trends. A growing body of literature continues to identify species that exhibit weak connectivity wherein individuals from distinct breeding areas co-occur during the nonbreeding period. A detailed account of a broadly distributed species exhibiting strong migratory connectivity in which nonbreeding isolation of populations is associated with differential population trends remains undescribed. Here, we present a range-wide assessment of the nonbreeding distribution and migratory connectivity of two broadly dispersed Nearctic-Neotropical migratory songbirds. We used geolocators to track the movements of 70 warblers from sites spanning their breeding distribution in eastern North America and identified links between breeding populations and nonbreeding areas. Unlike blue-winged warblers (), breeding populations of golden-winged warblers () exhibited strong migratory connectivity, which was associated with historical trends in breeding populations: stable for populations that winter in Central America and declining for those that winter in northern South America.

No abstract

No abstract

No abstract

No abstract

We used Anabat acoustical monitoring devices to examine bat activity in intact canopy forests, complex canopy forests with gaps, forests subjected to diameter-limit harvests, recent deferment harvests, clearcuts and unmanaged forested riparian areas in the Allegheny Mountains of West Virginia in the summer of 1999. We detected eight species of bats, including the endangered Indiana bat (Myotis sodalis). Most bat activity was concentrated in forested riparian areas. Among upland habitats, activity of silver-haired bats (Lasionycteris noctivagans) and hoary bats (Lasiurus cinereus) was higher in open, less cluttered vegetative types such as recent deferment harvests and clearcuts. Our results suggest that bat species in the central Appalachians partially segregate themselves among vegetative conditions based on differences in body morphology and echolocation call characteristics. From the standpoint of conserving bat foraging habitat for the maximum number of species in the central Appalachians, special emphasis should be placed on protecting forested riparian areas. North. J. Appl. For. 21(3):154 –159.

No abstract

Concerns over declining songbird populations have led to investigations of the effects of various silvicultural practices on breeding songbirds. Few studies published, however, have examined both songbird populations and avian nest success among harvesting treatments, particularly in forested landscapes. We conducted a study in the Monongahela National Forest of West Virginia during the summers of 1993 to 1996 to compare breeding-bird abundance and daily nest survival rates among different sivicultural treatments: a two-age treatment (a type of deferred removal in which 37-49 mature trees/ha remain after a harvest until the next rotation), clearcutting treatments 15 years after harvest, unharvested forest surrounding the harvested stands, and unharvested stands not adjacent to cuts. Abundance and daily nest-survival rates did not differ among treatments ( p Ͼ 0.05) for four of the five species for which the most nests were found: Wood Thrush ( Hylocichla mustelina ), Rose-breasted Grosbeak ( Pheucticus ludovicianus ), Acadian Flycatcher ( Empidonax virescens ), Veery ( Catharus fuscescens ), Red-eyed Vireo ( Vireo olivaceus ). Parasitism rates were low (6%), and most parasitized nests were associated with the two-age harvest treatment. A source-sink model for the Wood Thrush revealed that all treatments were likely population sources for this species. Thus, it appears that 15 years after harvest, cuts placed within otherwise extensively forested areas do not result in the type of edge effects (population sinks) observed in areas fragmented by agriculture in the midwestern United States. Further, because neither nest success nor avian abundance was lower in the two-age than clearcut harvests, we conclude that two-age management is a viable conservation alternative to clearcutting in large forested landscapes where Brown-headed Cowbird ( Molothrus ater ) parasitism is not a concern.Abundancia de Aves Canoras y Tasas de Supervivencia de Nidos de Aves en Bosques Fragmentados por Diferentes Tratamientos Silviculturales Resumen: La preocupación sobre la declinación de poblaciones de aves canoras ha conducido a investigaciones sobre los efectos de varias prácticas silviculturales sobre la reproducción de aves canoras. Sin embargo, pocos estudios han examinado tanto las poblaciones de aves como el éxito de nidos de aves entre tratamientos de cosecha, particularmente en paisajes boscosos. Realizamos un estudio en el Parque Nacional Monongahela en Virginia Occidental durante los veranos de 1993 a 1996 para comparar la abundancia de aves reproductoras y las tasas diarias de supervivencia de nidos entre diferentes tratamientos silviculturales (tratamiento de dos edades [un tipo de remoción diferida en el que permanecen 37-49 árboles maduros/ha después de una cosecha hasta la siguiente rotación] y tratamientos de tala total 15 años después de la cosecha, bosque no cosechado alrededor de los áreas cosechadas y áreas sin cosechar no adyacentes a áreas con cortes). La abundancia y las tasas diarias de supervivencia de nidos no d...