A land manager's guide to conserving habitat for forest birds in ...

Female American Redstart — Photo: Nick Bartok
to forage on. Yet, these are not the only factors affecting
productivity. Food availability within a woodlot can have a
substantial influence on the nesting success of forest birds.
Habitats with poor food resources will result in reductions in the
growth of young, their survival, the number of nesting attempts,
and the number of young that survive until they are independent.
Food can vary annually due to natural variation in insect
populations; but it is also highly dependent on vegetation
structure and the landscape features.
For most species, once the young have fledged from the nest,
they are dependent on the parents for food and protection for
two to three weeks. This is a time when many young die. The
first few days, young cannot fly and stay relatively close to the
nest site. Thereafter, they move further away, often into more
protected areas with dense, low trees and shrubs, and begin to
forage for themselves. By the end of the third week they are
totally independent.
Finally, at the end of the breeding season, in August or
September, adults gradually replace all their old feathers with
new ones. This process is called molting. They also build up fat
reserves for their fall migration back to the wintering grounds.
Prothonotary Warbler at nest cavity —
Photo: Mark Peck
Habitat Selection
Wildlife needs a place to live. For humans, this place is called
home, but for wildlife, this place is called habitat. Habitat includes
food, water, shelter, and space. When all parts blend together an
individual not only survives, but thrives. The quality of the habitat
for a bird is based on how well it can provide food, water, cover,
and nest sites. Not all habitats are equal, and each bird species has
a unique set of requirements. Some, habitat specialists, are very
specific in their requirements, like the Prothonotary Warbler which
requires cavities in large, living trees or snags (standing dead trees)
in flooded woodlands for its nest site. Other species, like the
American Robin, can adapt easily to changes in the environment,
and are called habitat generalists. This species can nest in the
canopy of a large tree in a forest, in the eaves trough of your house,
or virtually anywhere in between.
Usually, the more varied the habitat conditions, the greater the
variety of wildlife or biodiversity that habitat will support. This
diversity is intimately linked to the structure, age, and
composition of the forests. Vertical structure, an important feature
of a habitat, is the extent to which plants are layered within a
stand. This arrangement of plant growth forms (trees, vines,
shrubs, herbs, etc.) combined with the distribution of trees of
different species, age, height, diameter, and crown characteristics
determines the vertical structure of the forest.
Prothonotary Warbler nesting habitat —
Photo: Al Woodliffe
Forest Birds in Ontario 17