Breeding Behavior:
Mating System:
Black-capped Chickadees are monogamous(one partner). Most pair bonds remain
throught life but if a partner disappears they will take a new partner (possibly
a floater) for the next season. Chickadees have been known to "divorce"
their partner. The rank of the mate or possible mate may affect divorce.
Pair Bond and Formation:
The pair bond can form any time of the year but is most prevalent in
late summer, early fall as flock formation. In spring, floaters may replace
bird that have become died. Floaters can also replace mates that die during
the breeding season (Poole, et al . 1992).
Courtship:
Most chickadees first breed at age 1. Once a bird enters a breeding population
it tends to breed each year afterward. There is no obvious courtship in
Chickadees. The winter flocks break up and paired chickadees start feeding
together and do not join other chickadees. Territorial skirmishes begin
and nest selection starts. Wing-quivering and mate feeding have been obseverved
during this time. Mating then occurs (Stokes,1968).
Nest Activities:
Usually chickadees only has one brood. Two broods, the second started as
soon as first brood is fledged is rare. If a brood is lost a replacement
is started within a few days of loss.
Nest Site and Nest Building:
Chickadees use cavieties such as woodpecker holes or nest boxes for a nest
site. The nest are up to 20m off the ground, averaging 2-7m off the ground.
Both sexes excavate several sites by removing rotten wood, etc. before chosing
one site. The female selects the site of the nest but the male may help.
Once the site is chosen, the female builds the nest by herself in about
4-5 days. Foundations of the nest is made of materials such as moss and
is lined with soft material such as rabbit's fur. They do not reuse the
same nest twice. If a nest is lost to predation, the chickadees move the
site of their replacement nest a distance away.
Eggs:
Size, Shape, Color, Texture:
Their eggs are round-ovate, averaging 1.52cmlong x 1.22 cm wide. They are
smooth white eggs with fine reddish-brown spots concertrated at the larger
end. Egg laying begins 1-2 days after the nest is complete.
Egg Laying and Incubation:
One egg is laid a day in early morning until all the clutch laid. The average
clutch size is 6 eggs. The female incubates the eggs alone. The female has
develops one brood patch on her belly by the end of egg laying. Incubation
period is 12-13 days. Often during this period the female is feed by the
male. A soft verion of his Fee-bee song is given. When the female
receives the food she Wing-quivers (Wings are lowered, slighty opened and
rapidly quivered) (Stokes,1968).The pair may gather food together before
continuing incubation. The female sits on the eggs for 20-25 minutes and
leaves them for about 7-8 minutes.
Hatching:
Hatching can occur at any time of the day. All the eggs usually hatch within
12-30 hrs of each other. The eggshells are removed from the nest and taken
some distance away. They are either dropped or eaten. Chickadees are altritial(helpless)
at hatching. Naked, closed eyes, weighing about 1g. They give faint call
and gape for food on the day they hatch.
Growth and Development of Nestlings
By day 12 they have most of their contour feathers except for a bare belly.
By day 15 they resemble the adults except for they have shorter tail and
wings. Chicks are active at all times. Streching and preening themselves
starts around day 9-12. Start to look out the nest around day 13. Calls
gradually change from faint peeps to noisy call. Begging dees do not start
until the young have left the nest. The nestling stage lasts about 16 days.
Parental Care:
The young chickadees are feed from hatching thru when the juveniles disperce
2-3 weeks after they leave the nest. Both parents feed the young mostly
insects during this time. The nest is defended against predators by fully
spreading their wings and tai, leaning forward toward the predator, they
slowly raise and lower the wings, giving their "snake" display
and giving their high see call.
Fledgling Stage:
On about day 16 the young chickadees leave the nest. The adult may accompany
the young on their first flight. After the first few have left the nest,
the parent may give a soft Fee-bee call and take food to the nest
and then take it away. This is to encourge the remaining young to leave.
Once they leave the nest they do not come back but disperse in groups. When
they have been gone a week from the nest they are difficult to tell apart
from the adults. The young stay around the parents 3-4 weeks after leaving
the nest. The parents continue to feed the young but after a week or so
the young start to forage for themselves.
Juvenile / Immature Stage:
The young suddenly leave the area of the nest after 3-4 weeks. The young
move some distance from the parents and tend to join winter flocks as regular
members. Members of these flocks tend not to be related to each other. Some
will become winter floaters (Poole et al, 1992).
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