Well, we are now six weeks into 2018 and the question still seems to be
are Black-capped Chickadee numbers down in numbers as they were during
the Christmas Bird Count? And a lot of us are looking at our feeders
and the answer seems to be yes indeed.
So using eBird data for all of Vermont from 2008 to 2018 for the first
six weeks of the year we can get an overall view, but it is not really
possible to sort out specifically data from feeders.
I pulled out from eBird the "frequency" and "average count" data for
each of the first six weeks of the year for those 11 years plus for all
years combined as far back as they go, averaged them for each year and
the combined "all years", and compared the years.
"Frequency" is the percent of all eBird checklists submitted during the
period that had at least one Black-capped Chickadee. This measures notes
how common or not the species is in the landscapes being birded,
including feeders reported to eBird. "Average Count" is the average
numbers of birds reported on the checklists having at least one
chickadee. This corresponds with comments such as "there were a lot of
chickadees in the woods today" or "haven't seen as many chickadees at my
feeder as I saw last year.
The average 'frequencies" for the six week period range from 43% to 64%,
for the 11 years.
The average "average counts" for the six week period range from 4.7 to
7.5 birds per checklist.
Ranking the years from highest "frequency of observation" to lowest,
this year is the 4th highest at 58% of all checklists submitted. I.e.,
Chickadees are being reported more frequently than in most years.
Ranking the years from highest "average count" to lowest, this year is
dead last at 4.7 birds per observation. I.e. the number of Chickadees
on checklists is the lowest during this time period for any year since
sometime before 2008.
The data for all years combined for Vermont for these six weeks of the
year are: "frequency" of 55%, three percent lower than this year's
frequency; and "average count" 6.1, which is substantially higher than
this year's 4.7.
Compared with the previous two years, this year the birds are being seen
more often, but significantly fewer in numbers when seen.
Good luck with your Great Backyard Bird Counts!
On 2/15/2018 6:42 PM, Pamela Coleman wrote:
> None up the road in Mt Tabor either - seems like when the temps soar the birds disappear :-( Sure hope colder temps bring them back for the GBBC!!
> From: Ruth <[log in to unmask]>
> To: [log in to unmask]
> Sent: Thursday, February 15, 2018 5:08 PM
> Subject: [VTBIRD] NO BIRDS! and chickadees
> Unbelievably, I have seen NO birds at my feeders or suet today. From dawn till I left the house at 9 a.m. - NO BIRDS! Not a junco in sight. I looked around for predators, but saw none. Now as dusk approaches... still not a bird at my feeders. Is this happening any were else today - Thurs.?
> I have just read the summary report of this year's CBirdCounts https://vtecostudies.org/blog/cbc-roundup-the-118th-christmas-bird-count-by-the-numbers/ EVERYONE, reported low numbers of chickadees. This goes along with fewer birds at feeders during the fall... and who knows what the GBBC will turn up. Has anyone speculated what has happened to the chickadees? Die off? moved south? hiding? This is very disconcerting to me.
> Ruth Stewart
> E. Dorset, VT