ZOO-ology column: To float or not to float, ask any chickadee
Nov. 6, 2011 at 5:06 a.m.
By Judie Farnsworth
When you visit The Texas Zoo and Riverside Park, the adventure begins as soon as you open your car door.
The trees and plantings are host to many bird species.
"Chicka-dee-dee-dee," is a familiar greeting. Look up for tiny bursts of gray, black and white energy.
There are seven species of chickadees in North America, but the Carolina chickadee is the species seen here. These agile little spunksters are commonly found in mixed flocks that can include species like woodpeckers, tufted titmouse and kinglets. A definite pecking order exists within the mixed flock and another within each individual species. Chickadees have quite a structured society.
Rank may be determined by strength and age. Dominant birds get the best food, perches, territories and mates. It's not always obvious to the casual observer, but just like a pride of lions, they have rules. If chickadees are waiting near your feeder while another is chowing down - the diner is probably top bird.
Chickadees are monogamous. The goal is to become the dominant or alpha breeding pair. An average flock, six to 12 birds, normally has one alpha male and female. Occasionally there may be two high ranking older pairs.
Not all birds may breed. They must be paired and successfully establish and defend a breeding territory. Unsuccessful birds may leave the area or become inconspicuous, non-territorial birds called summer floaters.
After spending the summer as a floater in the vicinity of a flock, it may have an "in" before a first year bird, when the winter flock forms.
Breeding territories are not needed in the fall/winter and larger feeding territories are developed.
Established pairs, a few younger birds and maybe a floater or two form a looser flock.
Birds that don't join a flock become winter floaters that drift between several flocks. There are rules and a separate hierarchy among floaters. Pairing between floaters is a huge no-no.
Vacancies in the flock occur as birds die or are killed.
Established pairs are set in their relationships and one won't run off to grab a higher vacant spot.
Instead, a floater takes the place of a deceased bird and the higher ranked floater has priority.
If the deceased was a lower ranked bird, the floater may pass and wait for a more significant vacancy.
The second-ranked floater may then decide to move in - or not.
Should both alpha birds in a flock die, the next pair in rank may move up to first and on down the line. Birds entering into low ranks always have the chance for an upgrade.
The best floater scenario is a winter floater taking the place of a deceased alpha bird. The floater, however, should "keep its toes crossed" that its acquired mate survives the winter and they are able to breed. Should its mate die, a floater can't replace it - remember - two floaters can't pair up. Unless there's an unattached, second ranking established bird to move up with the floater - sorry Charlie, you're a floater again.
If you're not a chickadee, all the exceptions, buts and possibilities may be baffling. This is a much simplified peek into a complex niche. Suffice it to say there's ever so much more going on around us than we can possibly imagine.
Judie Farnsworth is a longtime volunteer at the Texas Zoo specializing in educational programs.