Because American redstarts
return to the same site to breed each year, arriving later may make it harder for them remain to remain in synch with their breeding cycle," Studds said.
Consequences of dominance-mediated habitat segregation in American Redstarts
during the nonbreeding season.
Red-bellied Woodpeckers have also been recorded depredating mostly single nests of the American Redstart
(Setophaga ruticilla; Watt 1980), Acadian Flycatcher (Empidonax virescens; Trail 1991), Indigo Bunting (Passerina cyanea; Hazler et al.
Male American Redstarts
, after correcting for multiple tests, were the only group for which arrival dates were significantly related to any climate variable with males arriving earlier in warmer years (reverse stepwise regression, P = 0.
Spatial foraging differences in American Redstarts
along the shoreline of northern Lake Huron during spring migration.
Sexual habitat segregation by American Redstarts
wintering in Jamaica: importance of resource seasonality.
For example, Robinson and Holmes (1984) found that American Redstarts
and Red-eyed Vireos (Vireo olivaceus) took more flights in white ash (Fraxinus americana) than other tree species because white ash had lower vegetation density and more evenly distributed leaves than other trees.
The sex ratio among American Redstarts
(Setophaga ruticilla) in Jamaica, for example, varied from 50:50 at only two of six study sites along a gradient from natural to agricultural habitats (Johnson et al.
striata), and two American Redstarts
Differences in relative abundance of American Redstarts
(Setophaga ruticilla) and Blackburnian Warblers (Dendroica fusca) approached significance (P = 0.
are sexually dichromatic and yearling males exhibit delayed plumage maturation, suggesting strong sexual selection on plumage coloration.
Additionally, unpaired male American Redstarts
(Setophaga ruticilla) had significantly higher and less variable song rates than paired male counterparts (Staicer et al.
2006) explored the utility of song rates in ascertaining mating status in American Redstarts
(Setophaga ruticilla), but their data were from a single locality.
Our work on stopover and breeding ecology of landbird migrants (Smith and Moore 2003, 2005a, b) in Michigan's eastern Upper Peninsula provided an opportunity to examine the patterns of American Redstarts
(Setophaga ruticilla) passing through and arriving at a northerly stopover and breeding site, and to assess arrival timing in response to annual variation in environmental conditions.
Clustering during breeding may have (1) a predator deterrence effect through mobbing and alarm calls (Perry and Andersen 2003), (2) a means of competitive exclusion of American Redstarts
(Setophaga ruticilla) (Sherry and Holmes 1988), or (3) may be in response to female pursuit of extra-pair copulations and formation of hidden leks (Tarof et al.