Category: Icteridae

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 […]

Preliminary Study in whether land management affects dialect formation in Bobolinks

Bobolink (Dolichonyx oryzivorus) Science Article 4 abstract Song dialects occur when individuals share similarity in song phrases at the group level. Most hypotheses regarding formation and maintenance of dialects attempt to explain how females select mates through preferences for local song types (Payne et al. 1981; Baker & Cunningham 1985; Rothstein & Fleischer 1987). Anastasia […]

Natural and induced magnetization in the bobolink, dolichonyx oryzivorus (aves: icteridae)

Bobolink (Dolichonyx oryzivorus) Science Article 1 abstract The magnetic characteristics of the heads from 28 bobolinks [Icteridae:Dolichonyx oryzivorus (L.)] were analysed using remanence magnetometers. Thenatural remanent magnetization of 12 freshly preserved heads averaged 3-20xl0~7electromagnetic units (e.m.u.) (le.m.u. = 103Am~’) and was oriented horizontallyfrom side to side. An electromagnet was used to induce magnetization with externalfield […]