Sunday, January 11, 2009

Mobbing Crows

As I went out to replace the yard-bird water-dish (I bring it in at night so I won’t have a frozen block to deal with first thing in the morning) and fill it up with clean water, I heard an owl. Its “who who whoooo” was slightly higher pitched than I’ve heard in the past…I assumed I’d just learned the difference in a male and a female’s call; the male has a higher voice. I wonder if that’s because he’s the smaller of the two.

At any rate, I was still in my jammies and it was almost up to twenty degrees outside…so I didn’t spend time looking for him…until about an hour later when I heard a bunch of crows going nuts.

Okay, I haven’t heard many crows of late, and I know from experience when I hear many of them together, there is often an owl or a hawk at the center of their attention. I grabbed my binos and headed out to the enclosed front porch. I saw 22 American Crows amassed on a couple branches in the same part of a leafless tree; two Black-billed Magpies had joined them. While their bodies were not all facing in the same direction, they were all looking in the same direction; at a nearby evergreen tree.

I’m getting better about looking for what doesn’t fit…I scanned the tree; nothing on the outer branches. I began the rather difficult task of peering deep into this very dense tree, starting a bit low and slowly looking for lumps and bumps that were in places they didn’t belong; a thickening of the trunk, a mass on the topside of an inside limb. And there he was; a Great Horned Owl.

The above video sounds exactly like what I heard...but my owl was safely snuggled deep within the evergreen tree and the 24 large, mobbing birds screamed from a nearby bare-branched tree. They all eventually left and I presume the owl enjoyed a nap.

It didn’t help that when I found him, all I could see were his belly feathers…no tell-tale face or ears. But as I watched, trying to determine if this was a bunch of twigs or leaves playing tricks on my eyes…he scratched! Ha, I spy!!!

His movement set off another round of raucous cawing, as well as a strange rattle-sound I’ve never heard before. Of course I headed to Cornell’s site, where I discovered a different crow-call. Wild! You can hear the sound here.

I was tickled pink, invited a neighbor to come see the pretty boy as I headed off to work and just generally reveled in my accomplishment. I found the bird because I paid attention to the early morning call, the behavior of mobbing crows and how to find a bird hiding deep within a very dense tree; and I learned all that in books…reading about birds and bird behavior.

I wish I’d had time to grab my camera too; but I was already late to work! I’ve included a photo of a couple American Crows mobbing a Bald Eagle. Read more about mobbing behavior here.

Photo from Wikipedia

9 comments:

Kitt said...

Cool find! I'd be chuffed, too. Most people wouldn't notice anything different. They'd just hear crows being noisy and not consider that the noise is really communication that might reveal something interesting.

Is that your photo? Nice shot!

(I know exactly what squirrel's "Cat! Cat! Cat!" chatter sounds like, and for some reason robins often join them in raising the alarm. Always fun to spot the object of their attention.)

Beverly said...

Nope, neither the video clip nor the photo is mine. I mentioned the photo is from Wikipedia...I included the photo of the eagle because it was the only one I could find showing mobbing behavior. The video shows a couple owls in a bare tree really being hassled by the crows...but the sound was identical.

I've discovered that paying attention to that sound or the sudden departure of feeding birds usually means a predator is in the area. I have gotten a couple of photos that way, but mine aren't usually too good; I don't have a long lens... [sigh]

Thanks for popping in; I learned a new word, thanks to you! I'd never heard 'chuffed'.

lkw said...

Ooh, how great to see an owl! And the crows mobbing just make the experience more interesting.

It's always so fascinating to realize how being more observant (and a better listener) can help us 'see' more things...

Debbie said...

Interesting about the mobbing behavior. I see the birds at my feeder fly off when the Stellar's Jay comes around. And thinking about it, I've seen crows chasing hawks. But how weird that the crows would behave like that if the GHO was sitting there minding his own business. I wonder if the crows have a nest nearby.

Used to have GHOs at my old house, but haven't heard any here in the mountains. Went on a full moon snowshoe hike last night and I tried to listen out for owls, but I didn't hear any. Lucky you!

Beverly said...

A full-moon snow-shoe hike? What fun! Good for you...

Well, perhaps the owl was out and about when the crows found him and 'chased' him deep into the tree where he could rest without them actually reaching him.

I know that the crows predate owl (and other birds') young just as the owl hunts the crows nests. I think the mobbing, which sometimes attracts a bunch of different species, little songbirds included, in a full-out ALLERT.

Bosque Bill said...

Crows mobbing owls is one of those natural phenomenon that I find disturbing. Maybe because there seems to be 10 zillion crows and very few owls. Late last spring I witnessed this behavior, but the Great-horned Owl didn't seem to be enjoying itself in its rather exposed nest.

I know one is not supposed to intervene in nature, but I tried to chase the crows away with limited success. The next time I passed that owl nest there was no sign of the owl, in fact that was the last time I saw it there. I only hope that is because it was the end of the fledging season and not due to the darn crows.

Beverly said...

From my October post regarding Great Horned Owls, my research showed:

“Although mammalian prey typically comprise more than three quarters of the [GRHO] diet, more than fifty species of birds have been recorded as prey. In addition to hunting small songbirds, water birds (especially coots and ducks), can be important prey; as well as grouse, herons, Canada Geese, swans, hawks (including Red-tailed) and other owls. It is a serious predator on nestling Ospreys and the reintroduction of Peregrine Falcons has been hampered in some areas by owls killing both adult and nestlings.

And:

The Great Horned Owl is a regular victim of harassment from flocks of American Crows, as well as other smaller birds. Crows congregate from long distances to mob owls, and may continue shrieking and diving at them for hours. The antagonism of the crows may be well earned, however, as the owl is probably the most important predator of crows and their nestlings.”

While I’m aware cows hunt nestlings, even those of the GRHO…somehow I have the idea the bigger bird doesn’t get hurt much by crows, huh? I dunno…but it is hard to watch. Most of the video clips I could find make the crow out to be the bad guy; and I'm with you, had the owl I watched not have been so deep in the tree (and quite safe), I might have tried to scare off the crows, too!

Thanks for popping in…I’ve missed ya!

Blackbird said...

I came across your post googling mobbing crow call. I have learned to recognise the European Crow (Corvus corone) call when mobbing a Kestrel, it sounds exactly like you described and like in the recording, a rattle! Cool post.

Beverly said...

Wow, Blackbird...what kind words! I appreciate your comment AND I love your bug blog!!! Too cool!

Thanks for stopping by!