The numerous willow warblers, having journeyed anything up to 3000 to 4000 miles, seem eager to make the most of things by producing two broods
of young during their stay here, whereas the garden warblers, also numerous this year, stick at one.
One-third of the broods
arrived with dark, developed eggs in both years, with a mean laboratory duration before spawning of 3.6 [+ or -] 0.5 (SE) days for brown eggs and 8.2 [+ or -] 0.9 (SE) days for orange eggs.
To consider differences in breeding productivity estimates between moved and resident birds, we compared estimates of breeding success, 1) overall breeding success expressed by chicks per female and 2) brood
size (chicks counted in relation to broods
observed) using Poisson regression.
marginatus offspring that were in nonparasitized broods
, that were nest mates of parasites, and that were parasites.
In this study, the annual brood
production and colony population development of the Yigilca local honeybee colonies in their natural habitat were determined and compared with the other commonly used honeybee hybrids to expose adaptation to local ecological conditions.
As is the case in other House Sparrow populations (Summers-Smith, 1988), nesting mortality is common at our field site, with 34% of otherwise successful clutches containing at least one unhatched egg (Stewart and Westneat, 2013) and at least one nestling dying in 42% of otherwise successful broods
, such that the average clutch size is 4.8 [+ or -] 0.09 while the average brood
size is only 3.5 [+ or -] 0.13.
Evidence of second broods
(Table 1) is summarized below for two females in 2010 and one pair in 2011.
don't overlap much in any particular grove of trees.
Manipulated offspring of the first-brood stay and help to raise the second brood
. Alternatively, first-brood offspring can resist manipulation and leave.
II's emergence after 17 years of slumber was supposed to be an event.
But not all broods
are created equal and "Brood
II" is a big one.