A Murder of Crows

I "pish" when I walk in the woods.  The sibilance captures the attention of birds drawing them out of their hiding places.  At least that's I think when I'm doing it.

I was impatient this sunny afternoon.  The only birds I'd seen or heard on my walk were chickadees bouncing like ping-pong balls, from seed-laden ragweed stalks to leafless Box Elder trees.   A small flock of Purple Finches seemed to follow them.

I was distracted by the noise of more than 100 crows sitting in the recently harvested corn field between the Chippewa River State Trail and the river.  I stopped to watch.  What were they doing?

The noise made me think:  Great-horned Owl.  Was this a mass "mobbing?"

No, I didn't see an owl, or a Red-tailed Hawk, another popular target of mobbing crows.

Could it be something to do with the corn?   Perhaps one of the wagons used during the harvest tipped and spilled.  The longer I watched the crows, the more I realized that wasn't it.

What changed my mind was the arrival of several Bald Eagles soaring overhead.  I watched as the eagles circled the field and strafed the noisy "murder" of crows, dispersing them to the tree line at the edge of the field.  Then the eagles landed in the middle of whatever it was that attracted them all and bent over to feed.   It had to be animal remains - the only food interest both species share.   Then I remembered, it's bow season.  Maybe this is where a hunter field dressed his deer.

Swamp Sparrow

As I headed back to my car, absent-mindedly "pishing" as I walked, I stopped to look at a spring-fed marsh.  All of a sudden, a sparrow popped-up and landed on the barbed wire that separates the marsh from the trail.  The little brown bird cocked its tail, puffed itself up, and then, like a jack-in-the-box, dropped back down, disappearing in the cattails.  A Swamp Sparrow.

According to the Atlas of the Breeding Birds of Wisconsin, this sparrow is common throughout the Badger State, and while most migrate in September and October, some spend the winter here.

Another reason for me to keep pishing when I walk by the marsh.

Crows and "Mobbing"

I drove around looking for eagles today.  No, I didn't go to the river.  I headed south and east for a spin through the coulees.

Several Bald Eagles.  No goldens.  Lots of Horned Larks looking for weed seeds along roadsides recently scraped by snowplows.

When I spotted larks, I switched to "electronic mode" in my Prius, rolled down my window and crept up on them.  How close could I get before they'd fly?  Usually - not close enough to get a good photo.

I was playing this "game of stealth" when I heard the raucous "caaawww, caaawww" up the road.  I looked up and spotted a half dozen crows, "mobbing" a Red-tailed Hawk.

American Crow "mobbing" a Red-tailed Hawk

in Maxville, Wisconsin

They screamed.  They dive-bombed.  They did whatever it takes to drive a red-tail away.  Some "mobbers" add defecating and vomiting to the list of "whatever it takes."

Usually, noise is all they need.  Like a police whistle,  "noise" can motivate predators to move on.  Causing a ruckus can also alert other potential prey to the presence of the predator - and invite them to join in on the harassing.

As long as they keep a safe distance, the "mobbers" are seldom at risk.  It's more of an exclamation point at the end of the sentence "we see you, we want you to leave, now!"

Crows, gulls and passerines as small as chickadees will "mob" raptors to defend themselves and protect their nests.  

But red-tails don't prey on crows, and they're not nesting this time of year.  So why spend the energy?

Maybe they're teaching their offspring to recognize predators.  Maybe they're trying to get the predator to drop his meal.  Or maybe they're just having fun.