Local weather affects body condition of three North American songbird
species on the Texas coast
Abstract
Body condition is a frequently used physiological indicator of avian
health and is affected by an array of environmental variables. Although
a number of studies have investigated the specific effects of individual
weather variables on body condition in birds, few have analyzed the
effects of both temperature and precipitation within the context of an
extreme weather event such as hurricanes. In this study we examined the
relationship between breeding season body condition and daily maximum
temperature, daily minimum temperature, and monthly total precipitation
for three passerine bird species at the Welder Wildlife Refuge near
Rockport, Texas. We also evaluated yearly changes in body condition over
a twelve-year period for northern cardinals (Cardinalis cardinalis),
painted buntings (Passerina ciris), and white-eyed vireos (Vireo
griseus), focusing on the extreme precipitation event of Hurricane
Harvey which caused heavy localized flooding. We found that body
condition declined with average daily minimum and maximum temperatures,
while precipitation had varied, species-specific effects in the three
species analyzed. Our results also suggest that northern cardinals
experienced a notable reduction in average body condition in the two
years following Hurricane Harvey. Taken together, we conclude that
short-term precipitation and temperature drivers can be important
correlates of body condition in songbirds and that severe weather events
may reduce body condition in some bird species.