Hooded Warbler Habitat Selection
Male and female hooded warblers separate into different habitats in the non-breeding season. In the Yucatan Peninsula in Mexico long-running studies revealed that males occupy forest habitat while females are in the treefall gaps, forest edges, and other adjacent shrubby habitats.
The key difference between the male and female habitats is the orientation of the vegetation. Males like their plant stems to be up and down while the females prefer their stems to be at an angle.
So ingrained is this preference that laboratory studies of hand-raised hooded warblers revealed that strips of black crepe paper arranged vertically were preferred by males whereas oblique arrangements were preferred by females.
But what would happen if the vegetation structure changed? In 1988, Hurricane Gilbert slammed into the study area and snapped off many a tree top.
In areas that had previously been the provenance of males, and had suffered significant changes to the vertical structure of the forest, females moved in. In areas that were relatively untouched the males remained.
This article summarizes the information in this scientific paper:
Morton, Eugene S., Van der Voort, M. and Greenberg, Russell S. 1993. How a warbler chooses its habitat: Field support for laboratory experiments. Animal Behaviour, 46: 47-53