Skip to main content
U.S. flag

An official website of the United States government

Latitudinal variation in reproductive strategies by the migratory Louisiana Waterthrush

January 1, 2011

We evaluated hypotheses that seek to explain breeding strategies of the Louisiana Waterthrush (Parkesia motacilla) that vary across a latitudinal gradient. On the basis of data from 418 nests of color-banded individuals in southwestern Pennsylvania and 700 km south in the Georgia Piedmont, we found that clutch size in replacement nests and probability of renesting were significantly greater in Pennsylvania (clutch size 4.4; renesting probability 0.66) than in Georgia (clutch size 3.8; renesting probability 0.54). Contrasts of the remaining measures of breeding were not statistically significant, and, in particular, mean daily nest survival in the two study areas was nearly identical (0.974 in Pennsylvania; 0.975 in Georgia). An individual-based model of fecundity (i.e., number of fledged young per adult female), predicted that approximately half of the females in both Pennsylvania and Georgia fledge at least one young, and mean values for fecundity in Pennsylvania and Georgia were 2.28 and 1.91, respectively. On the basis of greater support for the food-limitation hypothesis than for the season-length hypothesis, the trade-off between breeding in a region with more food but making a longer migration may be greater for waterthrushes breeding farther north than for those breeding farther south. ?? The Cooper Ornithological Society 2011.

Publication Year 2011
Title Latitudinal variation in reproductive strategies by the migratory Louisiana Waterthrush
DOI 10.1525/cond.2011.090212
Authors B.J. Mattsson, S.C. Latta, R.J. Cooper, R.S. Mulvihill
Publication Type Article
Publication Subtype Journal Article
Series Title Condor
Index ID 70032668
Record Source USGS Publications Warehouse