Saturday, January 22, 2011

The Snowstorm, Feathers In the Snow, Junco and Sparrow Anti-raptor Moves

This is the bottom half of today's post.
I'm working on the top half. Up soon.

Snowstorm at night.

The snow storm during the day. Ordinarily the snow doesn't catch on the glass but in this case there was quite a wind driving the flakes. They hit the door and melted.

And if I looked carefully this is what I saw. Individually droplets capturing a bit of the view.

I was blithely walking to the bird bath with a bucket of water, and nearly had a mini-heart attack. Dove feathers in the snow. The first concrete sign of a raptor and likely a Cooper's. Why a raptor and not a cat? No tracks on the trajectory of several tufts of feathers going across the snow.

My first thought, I do dearly hope it isn't Doorstep Dove. Not that I didn't hope it wasn't Friend too but the previous day I'd seen Doorstep out in the feeding area totally alone. Usually a sign there is a Cooper's around and someone isn't paying attention. But you don't get to be a four or five year old Mourning Dove by being dumb. After several hours of wondering, Doorstep and Friend showed up on the bird bath at dusk for their last warming of the day and I admit to a sigh of relief.

The next day, after putting the leavings of Silver's Nutri-berries outside, I looked out and there were 32 Mourning Doves making short work of them. I don't see her here, but amongst the flock there was a dove who looked a little worse for wear. Though not bare any where, thank goodness in the cold, she was missing several patches of feathers including part of her tail. Whether she belonged to the feathers above, I don't know, but she'd managed to survive a close call and was happily pecking away.

I realized while staring out the patio door, (staring is a good pastime, you think of things), that what I have out there are a number of game trails. Note one of the "game" heading toward the sunflower seed feeder from the right.

But more that that, why do all the trails merge in the area of the goody stump? Does just about everyone check out the goodie stump on the way to the feeders just in case there might be an exotic tidbit before the indulge in the same old seed? For the most part, the "food" is the seed area. And it isn't that they're having a drink as you'll note the trails run past the water bowl. Most of the trails apex at the goody stump and then follow my large path towards the house. Cover? Okay there is a single animal trail that meanders from the multi-trail apex to beneath the bird feeder. That's a crow walking through the snow. They do have a tendency to break their own paths. I don't know why they do that yet.

Speaking of the crows, most days there are several episodes of crow calls and or ground visits in the back yard. Today there were none. The weather is downright frigid, with below zero temps on and off. I can't imagine all the crows are frozen solid so if they haven't visited here, have they gone somewhere else? Perhaps a little winter vacation until things become less inclement? Another question I haven't the answer for. Yet.

Of course if you look back up at the full shot, there are two well worn paths which start at the foot of the two Maples nearest the feeders and go to the feeders those belong to the squirrels.
Yesterday's squirrel count was 6 by the way.

In fact all the trails start at cover and converge. The Cottontail Rabbits come from under the Spruce trees or from under the hedge or travel close up to the perimeter of the house. (Yes I know the above line isn't in bold or as large as the others. Blogger doesn't care and it doesn't want it to change. Very strange.)

Speaking of cover, there has been a Cooper's Hawk in the neighborhood and so the birds are being very nervous and wary.

First I noted that the Junco's have an interesting rapid retreat. If startled when in anti-predator mode they take to the air and all appear to be making a bee line for the Spruce trees but upon getting nearly there, they all zig zag in the air across each other's flight paths and then ZAP they disappear into the evergreen boughs. I'm thinking that the last minute maneuver to an attempt to loose the Cooper's focus so she isn't able to just easily follow one in and pick them off a branch having kept her eye on them and their straightforward trajectory into the boughs. It appears that a Coop can fly through a tree, even an evergreen tree, as if it doesn't even exist. It is their specialty. They go in at speed and grab their victim on the way through. If they aren't sure exactly where the prey is, the quick fly through doesn't work all that well.

The House Sparrows on the other hand when startled fly directly and as fast as their little wings can carry them in a tight group, back to their stick and snow igloo and dive into the recesses. They have a different flight adaptation from the Juncos because they hide in a dense pile of sticks the Coop is too big to enter.

Moonrise. Not just another light.


Karen Anne said...

Speaking of flying through trees, I've noticed that some of the birds who eat at the feeders on my deck will fly away through the deck vertical posts, as opposed to flying over the deck railing.

They must be very aware of where their wings are in order to do that without hitting the posts.

At least the blue jays do this, I forget off hand which others I've seen. Blue jays aren't predators on other birds, are they? So maybe all birds really know a lot about their wing positions even when they're moving them rapidly.

Donegal Browne said...

Hi Karen,

Interesting point. Jays have been known to predate the nests of smaller birds. Perhaps one of the reasons they have the knack of slipping through gaps.

Though I've begun to notice that these species that do predate the nests of smaller birds, and we might hold it against them if we've not been watching carefully, that they also do quite a bit of bird community service. For instance Jays are capable of breaking the ice in bird baths to get a drink. The smaller birds will watch for this and are then able to get a drink themselves. And as we all know they put up quite a racket when there are raptors around and the smaller birds all know their danger call. The same services goes for crows as well.

Thank goodness for bird bath warmers as there are still very few jays around and the Crows are just now making a come back in this area from West Nile Virus. Otherwise the little guys would be hard pressed to get a drink and have to eat snow. which isn't optimum or days without snow hard pressed for water at all in winter.