Molecular Characterization of Ostertagia mossi and Ostertagia dikmansi from White-Tailed Deer (Odocoileus virginianus) Confirms they are the Same Species.

To examine whether Ostertagia mossi and Ostertagia dikmansi from white-tailed deer (Odocoileus virginianus) are separate species, we obtained DNA sequences for the cytochrome C oxidase subunit I and internal transcribed spacer 2 gene targets for phylogenetic analyses. Neither target revealed separation between morphotypes, confirming they are the same species and providing new data on Ostertagia morphotypes.

Clinging to the top: natal dispersal tracks climate gradient in a trailing-edge population of a migratory songbird.

Purpose: Trailing-edge populations at the low-latitude, receding edge of a shifting range face high extinction risk from climate change unless they are able to track optimal environmental conditions through dispersal.

Methods: We fit dispersal models to the locations of 3165 individually-marked black-throated blue warblers (Setophaga caerulescens) in the southern Appalachian Mountains in North Carolina, USA from 2002 to 2023. Black-throated blue warbler breeding abundance in this population has remained relatively stable at colder and wetter areas at higher elevations but has declined at warmer and drier areas at lower elevations.