I live on two acres with trees surrounded by open cultivated fields, which
creates something of an island for the more sedentary birds. I can sort of
see the population cycles

Every winter, we have a covey of California Quail that roost overnight in
the conifers. Last summer, a nest of 13 quail was hatched on the property
by what appeared to be 4 adults. After they hatched, it was impossible to
count the little ones. The group always had a sentry and the little ones
stay out of sight. Now that winter has begun, the covey is more visible.
There seem to be 8 this year. At the beginning of winter, there are usually
5 to 12 quail. (I have counted more in some winters.) By the end of
winter, there are usually 5 to 7 quail. They seem to have a surprisingly
high winter survival rate, with most of the mortality coming between
hatching and winter, but perhaps some quail from other areas converge on the
property during winter to keep the numbers up.

The House Sparrows usually start the winter with a flock of 15 to 30 birds
and seem to end it with about 8 to 15.

Kelly Cassidy