Yup, certainly within a crows repetoire. This year I witnessed an American Kestrel try to take nestling Hairy Woodpeckers from their nest cavity. The young were old enough to be at the cavity entrance and their loud incessant calling/begging probably attracted the kestrel. The kestrel landed at the cavity entrance and stuck its head in the cavity hole to try and grab a chick. Luckily, the young must have hunkered down in the bottom of the cavity because the kestrel eventually flew off without a meal.

I also have seen evidence where ravens have pecked holes in a snag right at where the bottom of the cavity would be to extract the young. A fellow researcher has also observed that same behavior with crows at Chestnut-backed Chickadee nests.

BN

Crows will eat anything they can find. That's why during nesting season I plunk them with a bb gun whenever I can. That keeps them out of my yard anyway.

They regularly prey on fledgling swallows under a bridge by my house. They pluck them out of nests while on the wing, even while being mobbed by the parents.

It is illegal and wrong to plunk crows with any guns. Crows are predators and hold an essential part in all ecosystems. You may be killing crows and growing House sparrows, which would be deeply ironic.

Crows have coexisted successfully with other birds for millions of years. As nice as your intentions are, the other birds don't need your help, outside of not using pesticides.

elly, although I agree with you in theory, things change. For the first time ever, crows have lost their fear of me and are combing my yard, killing everything they can find. I live in the middle of a forest which means they are killing lizards, little snakes, frogs, baby rabbits and anything else that moves. Ferule cats aren't welcome here, either.
Plinking at crows with a weak BB gun to make them regain some fear may not be a bad idea. It is really for their own good and every other living thing in the yard.
I have had squirrels and raccoons lose their fear of me and it doesn't work out well at all.

Brown-headed Cowbirds have established themselves at every birdfeeder across the nation now. They are destroying every songbird nest they can find and enslaving the parent birds to raise their young. I will be killing them starting next spring. They have been growing in numbers on my property for the last few years and I have been negligent in protecting the birds from this silent killer.

I have not seen an immature White-eyed Vireo or Kentucky Warbler in 4 years now. I have over 20 pairs of Cardinals and I have looked hard to find 2 immatures this year.

Things change and we have to keep up with it. Nobody is talking about wiping them out, it is simply thinning out a few Cowbirds. I have a new saying to remind me of what I have to do.
"Everytime I rid my yard of a Cowbird, a nestful of beautiful baby songbirds get their wings."

Elly, did I say I was killing anything?

To keep crows and other trash birds away, avoid feeding cracked corn and scraps on the ground or using trays. If you put it out there, they will come.

After years of trash bird-free property, a month ago a flock of Starlings landed on my property, proceeded to feed their fledglings and began taking over. I quickly bought a pump pellet gun but they may have sensed all was not well and vanished, to a bird, the day I got it.
I have the gun lying on the kitchen table but not one has reappeared. With Starlings, you only get one shot and they remember, even if you miss. They have look-outs also that warn the flock of dangerous individuals and they will bookmark your yard as not safe.

I make an effort (read BB gun) to keep away Starlings and HOSP, but Brown Headed Cowbirds are such infrequent visitors, I can't bring myself to harm them.
I know what havoc they can bring to indigenious songbirds (here in Texas you can get a seasonal license to destroy as many as you can trap), but I'm still not comfortable killing them.
They evolved over thousands of years of following the great bison herds that were constantly on the move, so it was a definate advantageous survival technique to be able to reproduce without stopping to build a nest.
Since we're indirectly responsible for the demise of the eco system they evolved in, I have a problem with destroying them for doing what nature meant them to do.

We have been battling cowbirds for 40 years. The first time a cowbird landed on my feeder, my heart just filled with dread. I have put it off for 4 years and now the time has come.

We've heard people doing the blame game, passing the buck and blaming it all on mankind. All those things are ancient history. I am the reason that there are cowbirds on my feeders, I have allowed it. And, yes, if I don't do anything about it, mankind will be to blame. Me.

It's not a pleasant task, it is a necessary task. I have designed a feeder with only one perch on it. When a cowbird lands on it, I push a button and an electrical current surges through. It is very precise and very swift. Once again, nobody wanted this situation but, lack of action is just negligence on our parts.
When a person puts out a birdfeeder, they are now an active part of the ecology and with that comes responsibilities or one can really mess things up.

Let's not wait until it is necessary to make people purchase a permit to hang a birdfeeder. One would still have to sign an agreement to allow people to come in and rid the property of cowbirds. It is this serious of a problem.

One should study up on it. I believe it is the Kirkland's Warbler up north that was on the brink of extinction because of cowbirds. Through their program of trapping and disposing of the cowbirds, these warblers are making a comeback.

The same thing in Texas with the Black-capped Vireo and the Golden-cheeked Warbler. They have disposed of over 20,000 cowbirds and lowered the parasitism of these 2 birds by cowbirds from 90% in the eighties to 10% today.

And, now, the cowbirds have discovered birdfeeders and spread into suburbia.
Our songbirds are under attack. This is not a game, take it seriously.

Birdguy:

I was a volunteer at the Texas Extension Service in the mid 80's when the problem was recognized. I intially thought it was a good idea to implement Cowbird control.
But over the years, as we gather more information since trapping and disposal has began, it has become apparent that:

1. Cowbird parasitism probably is not responsible for continent-wide declines of many North American songbird species.

2. Cowbird populations are declining across the continent. Dispite recent range estensions into Florida and some local areas of increase, the Breeding Bird Survey from the Audobon Society show that cowbirds delined about 1% per year between 1966-1996. This dispels the widely held notion by the public, and even scientific community, that cowbirds are increasing.

I didn't mean to hijack this thread about crows in a debate over Cowbird control. I respect your choice to deal with problem in your backyard as you see fit. But, one has studied up on it....

Re: the OP's question, there is a pair of Bluebirds nesting in a Red Pine snag in my back yard. I have been watching their activity closely, and they are on their 3rd brood, which hatched a couple days ago.

There is a master birder who lives in a neighboring town and she is an expert on Bluebirds. She has helped me understand what is going on with this Bluebird pair. When we talked about what the possible risks to Bluebird fledglings, she has said that unfortunately, crows DO prey on the fledglings.

I have seen more Crows this year than previous years. Supposedly the West Nile virus has hit them pretty hard in previous years. I'm happy to see the Crow population increase, but hopefully it won't take too much a toll on the Bluebirds or other songbirds.

The original decline in populations of the Kirtland's Warbler was due to loss of the early successional jack pine habitat, through decades of fire suppression, these birds depend on. Fire opens the jack pine's cones causing seeds to come out and germinate after a fire. The young growth of pines that followed is what the Kirtland's Warbler depended on. Once the population of Kirtland's Warblers declined from loss of habitat, added pressures from parasitism of their nests by Brown-headed Cowbirds added to their declining population. So, the Kirtland's Warbler was not on the "brink of extinction" due to cowbirds, but originally was due to loss of habitat that cause their population decline in the first place.

In addition to cowbird parasitism the Black-capped Vireo experienced declining populations due to loss of habitat via urbanization, fire exlcusion, grazing, and brush control. The Golden-cheeked Warbler has suffered tremendous habitat loss of its Ashe juniper habitat due to the expansion of the cities of Austin, San Antonio, and Waco. Add to that parasitism by cowbirds, and you get the same story as for the Kirtland's Warbler.

These three species, both with normally limited distributions due to extremely narrow habitat requirements, make them susceptible to habitat loss and the added pressures that brings on their populations.

The moral here is that other causes, primarily loss of the species primary habitat, are the reasons for the initial decline of these species. Then, the impact of cowbird parasitism is enhanced because the species impacted have such low populations from habitat loss, they can't make up for the loss of parasitism by cowbirds. Thus, wildlife biologists and land managers institute cowbird removal programs within the species last remaining breeding habitats so that populations can more easily recover as new habitat is created to aid in recovery. One should study up on it.

And a final note (which has been mentioned on this and other forums) Brown-headed Cowbirds are a protected native species. Any killing of these birds, however deemed "right", is illegal without a permit. If you are going to write about killing them or other species besides starlings, house sparrows, and rock pigeons that are not protected, you should be prepared for people responding to your posts with less than sympathetic views.

BN

First of all, I have been studying Brown-headed Cowbirds since 1960. My father studied them for many years before that. They interested me because they were such strange birds. They were following the bison herds, and later cattle, so that they could eat the undigested seeds from the manure. That is how they got their name. People thought they were actually eating the manure. (See why they developed brown heads lol)

So, these birds have always let someone else gather their food for them and then raise their young for them. Taking advantage of cattle, feed lots, crop fields and, now, birdfeeders, is what they have always done.

Secondly, to say these other songbirds have other factors that contribute to their declining numbers doesn't underscore the fact that the cowbirds are one of the reasons for the decline.

Thirdly, although cowbird numbers may be slightly down in the wild doesn't mean that their numbers aren't increasing rapidly at backyard birdfeeders. There aren't many House Sparrows or Starlings out in the wild either.
Cowbirds will soon be undoing any benefit that comes from putting a birdfeeder out. In fact, birdfeeders are becoming the deathtraps for songbirds because the cowbirds can sit there, eat, and just follow songbirds straight back to their nests.

Fourthly, I did expect a lot of grief when I started this conversation. Same people who screamed and pointed fingers and did nothing about the House Sparrows and Starlings, either. Now, they can live with them.

"Everytime I zap a cowbird, a nestful of beautiful baby songbirds gets their wings".

Oh, so, shooing away the crows isn't all that bad. lol

I applaud birdguy for taking a stance on the brown-headed cowbird issue. There is no brown-headed cowbird issue where I am.

But there is a House Wren issue around here. The House Wren around here causes more damage to nesting small songbirds than the much maligned House Sparrow. However, the House Wren is native and hence protected, whereas the House Sparrow is non-native and not protected. What an irony! We ought to be more rational than blindly pigeonholing birds into native and non-native. I am with those who question whether the House Wren should be a protected species.

There are 50 million Brown-headed Cowbirds in North America. Each year they are responsible for the deaths of 100 million baby songbirds. Anyone that doesn't see that as a factor in songbird populations either lacks reference skills or is an attorney for the Brown-headed Cowbird. Believe me, the glove fits.
That is 100,000,000 baby songbirds, every year.

LOL, each of us seem to have our own problem birds

Yes, we all have our own problem birds, but predators are a faction in many species on the planet, and a necessary part. By the way, can't anyone just get a Magnum Nerf Gun? It works for pigeons around here when the hawks aren't around.

Well actually I am thinking about getting a supersoaker water gun to scare off the cats and squirrels that sit under, or climb on, my feeders, hoping to get birds or the birds' food for dinner; or my dog, who I caught chasing a bunny last night (it escaped - whew!) A harmless zap in the backside would be a good deterrent I would think. (Of course, this means you would have to catch them in the act and be close enough to be accurate.)