Category: Icteridae

Factors affecting how male and female bobolinks apportion parental investments

Bobolink (Dolichonyx oryzivorus) Science Article 7 abstract Male and female Bobolinks (Dolichonyx oryzivorus) adjust the amount of time spent brooding and provisioning nestlings at primary nests in light of prevailing weather conditions and food availability. Males brood nestlings less and feed them more (mg/h) when food is scarce, regardless of weather conditions. Primary (i.e., first-mated) […]

Does the avian ophthalmic nerve carry magnetic navigationalinformation?

Bobolink (Dolichonyx oryzivorus) Science Article 3 abstract The bobolink (Dolichonyx oryzivorus) uses the earth’s magnetic field as one source of directional information for its migratory orientation. However, the location and structure of the magnetoreceptors that transduce the magnetic information to the nervous system are unknown. Because treatment with a strong magnetic pulse results in a […]

Photoperiodism and the annual testicular cycle of the bobolink (dolichonyx oryzivorus), a trans equatorial migrant, as compared with two temperate zone migrants

Bobolink (Dolichonyx oryzivorus) Science Article 5 abstract It is now quite generally accepted that seasonal changes in day-length play animportant role in the temporal regulation of several annual cyclic phenomena inmany birds of the northern hemisphere. Best known is the effect of photoperiodson the annual cycle of the testes, but evidence is accumulating that there […]

Spatial responses of bobolinks (dolichonyx oryzivorus)near different types of edges in northern iowa

Bobolink (Dolichonyx oryzivorus) Science Article 2 abstract Habitat edges are well-studied components of fragmented landscapes, yet factorsmediating edge effects remain unclear. We report how different types of edges surroundingpatches may affect spatial distributions of Bobolink (Dolichonyx oryzivorus), a declining, area-sensitive songbird that breeds in grasslands. We expected Bobolinks to be less abundant near edges, and […]