(photo courtesy of Chuck Noble)
The Tejon Ranch Conservancy is dedicated to the citizen
science movement that was pioneered by Audubon more than a century ago. We have two long-running annual citizen
science bird counts that we conduct on Tejon Ranch, the Christmas Bird Count
and the Breeding Bird Blitz. The Christmas Bird Count provides information on bird species
wintering on Tejon Ranch, whereas the Breeding Bird Blitz is intended to
provide information on breeding species, although we often see many migrants as
well. The Conservancy’s Breeding Bird Blitz is conducted during the late
spring in mid to late May. We use the
same 15-mile diameter count circle established for the
Christmas Bird Count. This allows us to collect data in
the same locations throughout the year. Teams
are sent to both the San Joaquin Valley and Antelope Valley sides of the
Ranch. Both counts provide vital
information about bird populations and trends during the winter and breeding
seasons.
Photo 1: Adult long-eared owl captured through the binoculars of our Conservation
Science Director, Dr. Mike White.
The inaugural Breeding Bird Blitz was
conducted in 2009 and it has been conducted every year since. We counted 112 species that first year (Table
1). Even though we have never reached
that magic number of 112 again, we have continued to add new species to our overall
Breeding Bird Blitz species list (Table 2).
Some of these species have also been new to our overall Tejon Ranch bird
species list. Since 2009 we have detected a total of 171 species during the Breeding Bird Blitz. Please visit our website to view the species lists for each year the count has been conducted.
Table 1. Total number
of species counted each year during the Tejon Ranch
Conservancy Breeding Bird
Blitz.
Table 2.
Number of species new to the Breeding Bird Blitz species list for each count
year.
As our dataset increases each year, we can begin to pull out
patterns from the data. We are beginning
to see that in the spring we often find more species in the canyons of the
Antelope Valley, rather than on the San Joaquin Valley side of the Ranch (Table
3). This is an expected trend as both
spring migrants and breeding birds are coming from the south and funneling into
the resource rich canyons after crossing the desert. Spring migrants feed and rest before making
their way over the Tehachapi Mountains and continuing northward to their breeding
grounds. After refueling in the desert
canyons it is easy for birds to zoom over the mountains without needing to
settle into the canyons on the San Joaquin Valley side of the Ranch. Breeding birds find in these canyons the
resources they need to settle in and establish territories to nest. But even though these trends are expected, it
is exciting to see them displayed in the data, validating both our hypotheses
and the importance of these canyons for both migrating and breeding birds.
Table 3. The number
of bird species observed during the Breeding Bird Blitz in the
Antelope Valley
versus the San Joaquin Valley.
We conducted our 7th Breeding Bird Blitz on May
16. Thirteen volunteers joined us for a
beautiful day of birding. Three teams
tallied a total of 99 species, adding 4 new species to the overall Breeding
Bird Blitz species list. New species
included: long-eared owl, Western screech-owl, Virginia’s warbler, and black-throated
sparrow. Owl families were the theme of
the day as one team watched a nesting pair of adult long-eared owls and their
two fledgling owlets, and observed an adult burrowing owl feeding a chick. Another team observed a group of the Sage
Sparrows (Mojave race) in a location where we have never seen them before. The team found it interesting that the
sparrows were in a group, rather than separated into breeding pairs. Perhaps they were a group that was just
passing through, on their way to other breeding grounds. Virginia’s Warbler was just added to the
Ranch bird species list the weekend before the Breeding Bird Blitz. It is simple observations such as these that
make birding such a fun activity. What
are these birds up to? Why have we only
just found the Virginia’s warbler? Do
they often pass through undetected or have a few strayed off path this
year? Do the long-eared owls always nest
in this spot and we have only just stumbled upon them this year? Are the sage sparrows starting to breed on
the Ranch or are they passing through on their way to some other far off place? So much mystery is encompassed in such small
beings. Let’s keep questioning and
learning!
Photo 2: Adult long-eared owl and one of its owlets (photos courtesy of Chris Gardner).
