Bruce,

You witnessed an example of "anting", a well-described practice by corvids
of allowing ants to crawl all over them and under their feathers. The ants
are attacking the crow, and in doing so, excreting formic acid which kills
or at least inhibits bird lice. The crows were not eating the ants. They
will sometimes pick up ants and place them under their feathers for best
effect. You witnessed a common occurring but uncommonly seen event!


Thanks for your report.

Scott


""""""""""""""""""""""
" Scott Ray "
" Moxee, WA "
" scray at wolfenet.com "
""""""""""""""""""""""

-----Original Message-----
From: TWEETERS-owner at u.washington.edu
[mailto:TWEETERS-owner at u.washington.edu]On Behalf Of Bruce McKenzie
Sent: Monday, January 20, 2003 5:52 PM
To: Tweeters
Subject: Crows on an Anthill


At about 3:10PM this afternoon approximately fifteen crows converged on an
anthill across the street from our house. One of the crows is banded. Afraid
we did not get a good look at the bands as the crow was standing in grass
long enough to cover the bands. I did go ahead and report the crow, noting
my reservations at:

http://courses.washington.edu/vseminar/main.htm#8

The pecking order of the crows appeared to be in force. The first crows on
the anthill were quickly dispersed by three crows that showed up last. The
three crows then established a pecking order. It was a bit frenzied at the
beginning with several crows attempting to get onto the anthill. Several
times I saw the crows drop their wings and spread them a bit, like birds do
when they are "sunbathing." Along with this action the crows would do a lot
of hurried pecking on the anthill, apparently picking up ants. I highly
doubt this action was drawing out the ants. Instead I suspect this was just
a way to "defend" a territory while the crow was eating.

I haven't measured the anthill but estimate it is currently 16 to 18
inches high, about 30 inches in diameter. It did have a rather rectangular
shape with a flat top but collapsed a bit during the (late) Autumn rains and
is now rounded. While the anthill is not even close to the scale of the
anthills at the Finley National Wildlife Refuge near Monroe, Oregon, it did
remind me of those in general shape.

With the cold weather the last few days and the cloudy skies (no warming
sunlight to bring out the ants) I'm rather surprised the ants were drawing
attention to themselves. I did not see any ants on the surface or around the
anthill. The anthill construction started last spring so it may just be the
crows know it is there and came by for a snack. The way in which the crows
arrived (what caught my attention) made me think one or more knew where they
were going and why.

I have never seen any birds going after the ants on the anthill before. In
the past I have seen sparrows or jays land on the anthill but quickly jump
and/or fly away like they were being bit. Even the flickers keep about three
feet away while "drilling" for ants nearby. Been rather surprised that while
I have watched flickers "eye" the anthill I've never seen one approach it.

Bruce McKenzie
Kenmore, WA USA
mailto:bmsh.mckenzie at gte.net