Long-time CREW Trust volunteer naturalist Dick Brewer is a treasure-trove of information and brilliant citizen scientist. This week’s critter count includes a chicken turtle, almost 30 red-bellied woodpeckers and a great photo of two crested caracaras. Interested in making your own critter count during your next hike? Print out Dick’s BIRD ROOKERY SWAMP Wildlife Checklist and take it with you!
Bird Rookery Swamp
Wednesday, December 19 ~~ 7:05 AM – 1:00 PM
temperature: 54.0-76.0º ~~ RH 85.5-60.5%
sky: sun early, clouds late ~~ wind: calm at start, then 8-12 mph
Q: What are the differences between a bird call and a bird song?
A: A bird call tends to serve a specific function and is primarily
innate rather than learned. A bird song is almost always learned and
is often customized by individual males.
EXAMPLES OF CALLS
Alarm calls alert every bird within hearing range that danger is
present, and all innately understand what the call means and act
accordingly. The alarm call of one species can be recognized by birds
of many other species.
Location calls let mates or birds in a flock know where the others
are. For example, when a Barred Owl calls during the day, a mate often
answers, sometimes from a good distance away. Each then knows where
the other is. Location calls can also identify good feeding and
A chick’s “feed me” call triggers a parental response to find and
bring food to its offspring. As the chicks get older, begging behavior
complements the call for food.
EXAMPLES OF SONGS
Male birds tend to sing more than females, and unmated males sing more
than mated ones. Males use songs to attract mates and to identify and
defend territory. The song warns other males to stay out of its
territory, and it invites females to come in. Males can recognize the
songs of neighbors and usually don’t pay any attention to them, but
they sing furiously if they hear the song of a stranger who might
enter their territory.
In selecting a mate, females may use the size and complexity of the
song to determine a male’s potential fitness as a partner. More mature
males usually have more elaborate songs which may indicate to the
female that the male is a survivor with more breeding experience and
A majority of songbirds have at least two different songs. The extreme
singer is the male Brown Thrasher which is estimated to have over
3,000 song types.