Organisms that reproduce in temperate regions have limited time to produce offspring successfully, and this constraint is expected to be more pronounced in areas with short growing seasons. Information concerning how reproductive ecology of endotherms might be influenced by growing season length (GSL) is rare, and species that breed over a broad geographic range provide an opportunity to study the effects of time constraints on reproductive strategies. We analyzed data from a temperate-breeding bird, the lesser scaup Aythya affinis; hereafter scaup, collected at eight sites across a broad gradient of GSL to evaluate three hypotheses related to reproductive compensation in response to varying time constraints. Clutch initiation date in scaup was unaffected by GSL and was unrelated to latitude; spring thaw dates had a marginal impact on timing of breeding. Clutch size declined during the nesting season, as is reported frequently in bird species, but was also unaffected by GSL. Scaup do not appear to compensate for shorter growing seasons by more rapidly reducing clutch size. This study demonstrates that this species is remarkably consistent in terms of timing of breeding and clutch size, regardless of growing season characteristics. Such inflexibility could make this species particularly sensitive to environmental changes that affect resource availabilities.
The Middlefield Granite is a small elliptical body, roughly three miles long and one and a half miles wide, enclosed in a series of eugeosynclinal metasediments and located in the Chester quadrangle in west central Massachusetts The purpose of the study was to map and describe the Middlefield Granite and to determine through field and petrographic studies as much as possible about the history, origin, mode of formation of the rock, and its relation (time and space) to the surrounding country rocks.A geologic map of the granite and surrounding rocks, based on the author's field investigations, is presented.As a result of the petrographic examination of granite thin sections, the minerals present are described, with estimated modes tabulated: plagioclase, averaging An12 , (38.7%); perthitic microcline (24.0%); quartz (24.1%); biotite (6.0%); muscovite (4.0%); epidote (2.5%); and other accessories (0.8%).
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.