WINTER
(December - January - February)
If a heron survives migration, it will spend the winter
attending to the solitary pursuits of food gathering, feather care and rest.
Cold temperatures in their northern range and the concentration of birds
on southern grounds intensify competition for food.
Male birds claim and defend winter feeding territories,
which vary in size depending on food availability.
Females and immature birds scatter and range widely for food.
They do not expend energy attempting to hold foraging sites for their exclusive
use.
Most birds have a "preen gland" by the base of their tails that
produces an oil they spread on their feathers to maintain and waterproof
them. Herons, by contrast, grow specialized "powder feathers"
on the breast and pelvic regions that crumble into a fine, waxy talc they
use to dress and clean their feathers
Winter behaviors narrow to expressions of self-maintenance.
Little social interaction occurs. Occasionally a small group of herons will
roost together, but when morning dawns, they disperse and individually look
for food. As days lengthen and winter tilts toward spring, the herons spend
more time together. The added sunlight of late winter prompts subtle hormonal
changes. A partial molt initiated in January produces the characteristic
breeding plumage before migration begins. Soon the impulse to move north
and repeat the cycles of pair formation and family rearing will prompt their
departure.
