San Diego Christmas Bird Count – land bird shortage?
Now that I have received and compiled
all of the data for the 66th San Diego Christmas Bird Count, the
final count stands at 216. Having already presented the highlights (https://groups.io/g/SanDiegoRegionBirding/message/9114),
I wanted to dig into the data a bit and see if it reflected the general feeling
that land bird numbers were down this year. In short, this answer is not really, most
numbers of migratory land birds were in fact stable. A few were notably down, however. I’ve not gone into any
intensive analyses or even corrected for observer effort, but simply compared 2018 numbers for
select species to the 10-year average from 2008 to 2017. (My, how things have
changed from the 1950s and 60s…) Below is a list of notable counts – high or
low, or for select species, average. Take this all with a large shaker of salt…
Greater White-fronted Goose – A new
high count this year with 27.
Ross’s Goose – A new high count this
year with 3. (Note this species was reported initially as Snow Goose.)
Canvasback – Fourteen is a good count
for recent years.
Ring-necked Duck – Just one reported
in each of the last 3 years, with average of 14.
Nearly all waterfowl numbers were
below 10-year averages, with Lesser Scaup and Northern Pintail at about
California Quail – Just three, and
while barely hanging on inside count circle, this species is a far cry from
when it reached triple digits as late as the early 1990s.
Pacific Loon – News from up north
suggests this species is perhaps in decline, and we registered just 59, with a
10-yr average of 320.
Black-vented Shearwater – Averaging
72, we only saw 4, although this species can simply move en masse offshore and
outside the circle.
Double-crested Cormorant – About half normal.
American White Pelican – A new high
count this year with 97.
Yellow-crowned Night-Heron – A new
high count of 11.
White-tailed Kite – Although historically
down, our count of 11 this year was equal to recent average.
American Avocet – Just 33, a near low,
with average 105.
Snowy Plover – Some good news, 232 was
well above average of 194.
Ruddy Turnstone – Apparently in
decline, we had 18 (half normal) while Black Turnstone remains stable.
Dunlin – About one-third recent
average, with 103 on count day.
Short-billed Dowitcher – We counted 166,
about 25% average.
Red Phalarope – Missed some years, we
saw 45, average is 184.
Cassin’s Auklet – I guess I didn’t
realize how big of a deal this was at the compilation: our 6 on count day was
the first observation since 1990!
Heermann’s Gull – Recent multi-year
breeding failure may have cause our recent steady decline since 2015. We
observed 178 this year, with 10-year average of 545.
Eurasian Collared-Dove – Thankfully
stable at 124.
Great Horned Owl – The first miss for
this species since 2002, but hopefully due to lack of effort.
Allen’s Hummingbird – Assuming the
majority of Selasphorus hummingbirds
reported were Allen’s, 232 would be a new high count for this species in San
Scissor-tailed Flycatcher- For two
years in a row (new in 2017) we’ve recorded two individuals – having a known
Loggerhead Shrike – This species is
just hanging on with 3 (a far cry from the long-term average of 41, recent
years’ average just 4.3), but generally in decline nationally.
White-breasted Nuthatch – An invasion
year, with 15 being a very good count. Average is 2.8, and the high is 20.
Cactus Wren – Happy to report above
average numbers with 13 inside the circle.
Blue-gray Gnatcatcher – A large count
from the east edge of the circle along the Otay River pushed our total to 113,
a new high count. Average is 37.
Ruby-crowned Kinglet – Above average numbers:
218 vs 166.
American Robin, American Pipit, and
Cedar Waxwing all above average.
Orange-crowned Warbler – At average: 272
Nashville Warbler – Three was a new
Yellow Warbler – Above average: 12 vs
Palm Warbler – None known in days
prior to count, and not found on the count, one made count week when found on
December 16th in Manzanita Canyon. A shocking miss on count day,
given what seemed to be the best fall on record for this species along the
coast in southern California.
Yellow-rumped Warbler – This species
was essentially at average: 3380 vs 3468.
Black-throated Gray – With 14 on count
day, we set a new high count. Average is 7.
Townsend’s Warbler – With 77, we were
at about 75% average.
Wilson’s Warbler – Average year, with 6
compared to 6.6.
Chipping Sparrow – Average year, with 34
compared to 33.6.
Lark Sparrow – Average year, with 7
compared to 8.8.
Dark-eyed Junco – Juncos were above
average with 49 observed, compared to 34.
White-crowned Sparrows – Plentiful as
always, apparently, with 1599 seen compared to recent years 1756.
Golden-crowned Sparrow – An average
year is 8.9, we had 13.
Savannah, Song Sparrow, California
Towhee – all about 75% average.
Summer Tanager – Essentially average,
with 6 vs 6.5.
Western Tanager – A notable uptick,
with 32 (a new high!), compared to average of 14 and past high of 25 (in 2014).
Brewer’s Blackbirds – Seemingly down,
and actually down, 103 was half average.
Brown-headed Cowbird – An average
year: 103 vs 104.
Bullock’s Orioles – Nearly a high
(20), we saw 17, which was above average (9.9).
And last but not least…
Scaly-breasted Munia – Continuing to
grow, we set a new high count with 89 this year. In 2017: 62. In 2016: 33.
And notable counts of non-countable exotics:
Red-masked Parakeet – While common in
parts of the county, 7 in the count circle was a new high.
Black-throated Magpie-Jay – While some
historically argued (surely no one still is?) that this species should be added
to the State List, with a 2018 count of 8 and a historic high of 17, not doing
so was the right decision.
Pin-tailed Whydah – Perhaps one to
watch? New for the count, with just 3, but this species is popping up at a
small number of parks in San Diego, and is already seemingly established in
some parts of Los Angeles and Orange counties. This species presumably
parasitizes munias, so its expansion with Scaly-breasted Munia makes sense.
Thanks again to all of the
participants who make this long-term dataset more valuable each year.
Happy New Year,
San Clemente Island
Source: SanDiegoRegionBirding Latest Reports