Determinants of local and migratory movements of Great Lakes double-crested cormorants

Abstract

Determinants of local and migratory movements of Great Lakes Determinants of local and migratory movements of Great Lakes double-crested cormorants

Distribution, relative abundance, and prey demand by double-crested cormorants on Manitoulin Island lakes vs. Lake Huron Coast

“…Regional movements of individuals in other species of cormorants matched this spatial scale (Frere et al, 2008). Mean home range size of satellite collared cormorants in the Laurentian Great Lakes basin was 1937 km 2 (Guillaumet et al, 2011). There were no clear colony effects on home range size demonstrating the limits of colony-scale variables on regional distributions of foraging cormorants in the Great Lakes.…”

“…There were no clear colony effects on home range size demonstrating the limits of colony-scale variables on regional distributions of foraging cormorants in the Great Lakes. The only pattern was consistent differences among individuals in home range size (Guillaumet et al, 2011). In most studies, movements included areas inland from the main body of water presumably to other aquatic ecosystems.…”

“…Nesting colonies on Lake Huron are abundant, distributed throughout the coastal zone, and in close proximity to inland lakes for numbers of colonies (Dorr et al, 2010b;Ridgway et al, 2006). If Great Lake colonies are near inland lake or river ecosystems then foraging cormorants could easily integrate these aquatic ecosystems into their foraging distribution at regional scales (e.g., Guillaumet et al, 2011). This has important implications for understanding the carrying capacity of the Great Lakes cormorant population.…”

Relative demand by double-crested cormorants and anglers for fish production from lakes on Manitoulin Island, Lake Huron

“…Seasonal patterns of consumption differed among these regions but aggregate prey demand over a season was similar between the North Channel and large lakes on Manitoulin Is (1.2 kg•ha −1 •yr −1 ; Ridgway and Middel, 2011). Because within basin movements of cormorants are extensive in the Great Lakes (Guillaumet et al, 2011), foraging on inland lakes that are in close proximity to the Lake Huron coast is likely occurring in other areas (e.g., Dorr et al, 2010). Patterns detected in this study may occur in other locations given site differences in lake productivity and stress imposed by cormorants and anglers.…”

Towards optimized population control efficiency in space and time: A modelling framework adapted to a colonial waterbird

“…We assume that the selection of a new breeding colony (dispersal) occurs between the end of the reproduction period and fall migration, at a period when cormorants frequently visit other colonies (Guillaumet et al, 2011).…”