Eagles Fighting Over Carp

I spent the weekend at The National Eagle Center in Wabasha, MN as a Swarovski Field Tek for a new company called Big River Optics who sells binoculars and spotting scopes through the Center.  I'll be there next Saturday and the following weekend (when we have a Birds and Beers) answering questions about digiscoping, binoculars and scopes.  Also, if you have Swarovski binoculars or a scope and would like a pro cleaning (similar to what they would do at the Swarovski headquarters) or if you need a minor eye cup adjustment, I'll be there to do that too.  Stop in and say, "Hi!"  It's not a bad way to spend the weekend--along the Upper Mississippi River watching bald eagles (like the above immature) float by.

We did get to watch some eagles squabble over a carp, right across the river from the Eagle Center.  An immature bald eagle got a huge carp and an adult came in to take over.  Other immatures came in to see if they could snatch a few morsels or the fish.

The adult was very intimidating to the younger birds.  As it would chase off one immature eagle, another would try to sneak in to claim the fish.

The immature eagle on the right almost had the fish when the adult charged it.

I love the eagle on the gound on the left.  It's as if the bird is say, "Oh crap, this just got real, I'm gettin' out of the way!"

The adult appears to have won the stand off with that particular immature.

Alas, the adult's charge was full on and it tried too late to put on the brakes.  It slid right off the ice and into the water.  Above, it's just about to go in.

It managed to turn around and get out quickly.  I missed that shot and this picture of it getting out is blurry.  Still, not a bad behavior capture for something on the other side of a river from where I was standing.

The adult was the overall winner of the carp.  A few of the immature were able to sneak in and get a few tidbits, but the adult ate the most.  It didn't have an easy time of it.  Below is a video and in the first part, an immature slams it from above.  You'll know when it's about to happen because the birds on the right look up and see it coming.  And watch how the eagles run around on the ice...it's hard to take them as majestic when they run like that.

[youtube]http://www.youtube.com/watch?v=g1FTyksKEJE[/youtube]

 

 

 

 

 

Birdchick Podcast 03-07-2011

Here are links to topics we covered:

Kabuki, the cockatiel you might hear in the background of the podcast.

New Species of storm petrel

Yorkshire home for bank nesting birds (like kingfishers)

Eagle with a "beak job"

Birds Eye Android App

Join the ABA!

National Eagle Center

Birds and Beers

You can subscribe to this podcast on iTunes.

[audio src="http://media.blubrry.com/birdchick/p/birdchick.com/wp/podcast/birdchick-podcast-8.mp3"]

What's An Uptown Owl Eating?

I mentioned earlier that there's a great horned owl pair nesting near my apartment in the Uptown area of Minneapolis. I love that we have such a large bird that is able to hide really well in such an urban area. Also, the distance that this owl is from my home, makes for a nice walk and a good incentive to get out and keep exercising in freezing weather so my biking muscles don't completely atrophy. I digiscoped this photo from the first day I saw the pair nesting, I don't always take my scope and camera.  One, walking through urban neighborhoods with that equipment makes home owners uneasy and can lead to police calls.  Two, I don't want to aim my scope every day at the owls and the nest to draw further attention and make them uneasy.

As I neared the area for the nest, I scanned the trees for the male. Some crows found him, they were cawing like crazy, but I didn't see him. When the crows saw me, the they took off. I got to point where I found an area in the snow covered in owl poop and pellets (I took the above photo with my phone since I didn't have my camera). Owls (like many predatory birds) cannot digest everything they eat and will regurgitate a pellet of fur and bones of what they couldn't digest from their prey. Owl pellets are fun to dissect because the bones give clues to what they've been eating. You generally do not find bones in hawk pellets because they tend to rip meat off of bones rather than swallow it whole and they have stronger digestive acids and the bones can break down.

Like Indiana Jones at an artifact, I carefully dislodged the large pellets from the snow. It suddenly occurred to me that where you see owl pellets and poop, the owl is generally overhead--at least, that's what I often tell people and have only found that to be true a couple of times.  I looked up and was so mad I didn't have my camera.  There was the male, directly over my head, about 20 feet up.  He stared down at me and was totally giving me the hairy eyeball...or would that be the feathery eyeball in a bird's case?  I quickly gathered the pellets and went on my way.  The owl never moved and is clearly accustomed to human activity.

Here are the pellets that I picked up.  I set a lime beside them to give an idea of size.  Two pellets were very dark and one was light gray.  I suspected right away that the pellet with the light gray fur was from a gray squirrel, since most of the mammal tracks in the snow around the nest are squirrel...and the female owl appears to be using an old squirrel nest for her nest.

The bones in these pellets are considerably larger than what you find from a pellet that you purchase.  Those are usually from zoos and wildlife rehab centers where the birds pretty much eat mice all day. This particular prey item was so large that the great horned owl couldn't swallow it hole and broke apart bones.  I think that's a rib bone up there and compared to the lime, that's a good size animal.

There were several pieces of vertebrae in the darker pellets.  I circled it in the above photo.  I puzzled over how to tell a rabbit spine from a squirrel spine.  I tried to crowd source that information on Twitter and got the following gems from the following Twitter users:

@ADruglis suggested: "Use a mass spectrometer to measure the ratio of calcium to disapproval in the bone."

Nice Disapproving Rabbits ref!

@ODN_Editor offered: "Any Easter egg shells mixed in? That's a dead giveaway."

Thanks.

@UppieSand said: "easy. Squirrels actually have them. Jk ;)"

Since Twitter was proving humorous rather than helpful, I went back to study the pellets.  I determined already that the lighter gray pellet was gray squirrel, I took to examining the fur of the dark pellet.

The fur was multicolored, dark, then brownish, then dark.  That was familiar...where have I seen that fur before?  Then it hit me: eastern cottontail.  I puzzled for a moment that it might be gray squirrel, the tail can have that color, but a raptor isn't really interested in eating squirrel tail.  It's mostly fur and bone--very little meat, why bother?

What was most interesting to me about all three pellets was that there were no small mammal remains in there, no mice, no voles, it was all big stuff.  I'll be curious to see if we can find other prey items in future pellets.  In the meantime, Uptown rabbits and squirrels, beware.

 

Birdchick Podcast 03-04-2011

  The latest Birdchick Podcast is out.  Below are links to some of the things we talked about:

6 Terrifying Ways Crows Are Smarter Than You

Cats Killing 79% of Catbird Fledglings

One Woman Blocks Rookery from chainsaws

Jeff Foiles Duck Hunting Scandal

Herpetologists vs Ornithologists

ABA President's Message Will you answer our challenge issued in the podcast?

You can join the American Birding Association here.

 

Have any questions for the podcast or suggestions? Email me at sharon at birdchick dot com

  You can subscribe to this podcast on iTunes  

[audio src="http://media.blubrry.com/birdchick/p/birdchick.com/wp/podcast/birdchick-podcast-7.mp3"]

Great Horned Owl Nest In My Hood

I debated about whether or not to blog this, it's an owl nest and some people can get their undies in a bunch when someone talks about them publicly. Some birds seem to attain a cult status and people get particularly prickly about them. Owls are definitely a cult status bird, even garnering their own set of fan boys and fan girls (and owls are cool, I can see why).

I have a great horned owl nesting within walking distance from my home. I have mixed feelings about blogging it. On the one hand, I get the wisdom of keeping nests on the down lo. On the other hand, I live in a very urban area and these birds have chosen to nest in a particularly high traffic spot. I think they knew what they were getting into. There are all sorts of people well aware of the nest and happy to walk up to any stranger and say, "Hey, there's owl right there!"

I'm not going to reveal the exact location, but that still won't stop some complainers. Last winter, a birding organization received an email asking that something be done about me because I had revealed a northern hawk owl perching location in my blog, it wasn't even nesting. I thought it was funny that an organization that I'm not associated with got such an email (what are they gonna do, fire me). It's no secret you can find northern hawk owls at Sax Zim Bog and I had gotten the location from a website promoting where to find the owls.  Ah well, haters gotta hate, as the young kids say these days.

Here's the male keeping watch near the nest, even though it looks like his eyes are closed, those little slits are open and he's keeping an eye on me with my scope.

So, what should you do if you find an owl nest? I think keeping the exact location hidden from the local birding listservs, Twitter, Facebook and FourSquare is a good idea.  But when you find something so cool, there can be a huge temptation to share it.  Be cautious with how many people you tell.   Locations should be shared to some groups--say for instance a place like The Raptor Center. If orphaned great horned owl chicks end up in their clinic, they try to find surrogate nests for the chicks. You could also submit it to Nestwatch a website trying to document bird nesting throughout the US. If someone is keeping track of breeding birds for an overall study or atlas, that would be a good idea too.  These could be safe ways of documenting the nesting process, a fun project for you, but won't bring hoards of people to the nest site.

I'm sure I'll be walking by and checking these birds out throughout the spring. I have an idea of when incubation started so hopefully some owl chick photos will come along.  I'll be curious to note the number of people, especially those walking their dogs who will walk past it without realizing it's there.

I'll also be curious to see how the nest holds up.  Great horned owls do not build a nest, but take over old hawk, crow or squirrel nests.  I'm pretty sure that meatball of leaves the female owl is hunkered on is an old squirrel nest. She had lots of squirrel nests to choose from, some more secluded than others. It's interesting she chose one in a well traveled. Here's hoping that this turns out to be a big win for urban great horned owl nesting this spring.

 

Birds and Beers

I just added some new dates for Birds and Beers and one is next week to happen after the Richard Crossley appearance with Minneapolis Audubon. You can check out his field guide and we can all go for a beer and discuss it afterwards. Perhaps Mr. Crossley will join us? There's also a Birds and Beers in Nelson, WI (right across the river from Wabasha) later this month.  Drive along the river and watch for eagles and then have some beer and cheese (noms!). I went ahead and set the date for an April Birds and Beers too, for our annual Woodcock Tailgate Party.  Check the Birds and Beers tab for all the dates and locations.

To get the most up to date announcement for Birds and Beers events, "Like" it on Facebook.