Why is this important?
Bird populations are indicators of the complexity and general
biological health of our local ecosystem. Numerous species are adapted
to particular areas and habitats. If an area becomes less suited
for a species, the number will decrease; if more suited, numbers
will increase.
What is the measure?
Audubon Society chapters annually conduct a winter bird count.
Teams of birdwatchers select the same date, as near as possible,
and survey the same locations each year to tally the types of species
and numbers. The total bird count reflects on both local and regional
habitats as most species do have some form of migration. Birds will
migrate either up or down the Sierra slope, and some migrate long
distances to other regions of the Western Hemisphere. The survey
is not an exact count of every bird, but it is a sampling procedure
of bird populations.
How are we doing?
The annual count shows a variation of 1,000 to 2,000 each year
from The Central Sierra Audubon Chapter long-term database on nearly
20,000 birds counted in one day. The average for the last five years
is 19,565 birds. This information suggests relative stability in
bird populations.
The total eagle counts from Lake Don Pedro show change from year
to year. Some of this variation is due to sampling problems from
counting birds in small populations. We are witness to Bald Eagles
recovering from near extinction as they repopulate our region.
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