One of the small learnings I try to impart on my students is that science is
not a bunch of facts, but a process and a way to look at the world. Today,
while getting a late lunch at my favorite taco wagon I had an opportunity
for some improvised science.

After I had placed my order, I surveyed the area for birds as I always do.
There were 3 crows in a tree close to the parking area, and 5 others
scattered in the distance on light poles, tree tops and buildings. Mario
the cook opened the back door and was going to dump a pile of tortillas in
the trash. I asked if I could use them for an experiment and he was
amenable. I took the tortillas to the center of the gravel parking area and
shredded them into a pile. I looked up and I had the complete attention of
the 3 local crows, since I did not have binoculars I couldn't tell if the
distant crows were watching or not. As I walked away I started the stopwatch
on my phone. At 15 seconds I turned around as I reached my car and the 3
local crows were on the pile and eating. 45 seconds there were 5 crows, 1
minute 9 crows. 1:30 12 crows 2 gulls, 2 minutes 13 crows 5 gulls. At this
point there was not any visible food left. 2:30 17 crows 2 gulls 3:00 14
crows 3 gulls, and my burrito order was up. At 5:40 minutes as I walked back
to my car with my burrito in hand, in the local area trees and parking lot
there were 22 crows, 9 gulls. As I got to my car I realized that ALL of
them were looking at me! I had a brief Alfred Hitchcock "Birds" moment but
ducked into my car and with a wave drove off as the majority of the birds
took to flight scattering in several directions.

Years ago my students did a more refined experiment using frs radios to
track when particular birds left their perches. It is common to see both
crows and gulls perched on building ledges, light posts and other high spots
around town. It seems clear that these birds watch each other and form a
visual network which can span several blocks or more. There is some visual
cue which alerts perched birds that something worth investigating is
happening and they respond quickly. Today, the crow network was working
perfectly.

Rob Sandelin
Naturalist, Writer, Teacher
Snohomish County