Crow Coughing Up A Pellet

I periodically do segments on our local All Things Considered broadcast in the Twin Cities. I offered to show them the winter crow roost and the host Tom and his producer Sam were interested. You can listen here and they brought along a videographer who got some terrific footage of the crows, be sure to check it out.

We had to reschedule the recording at least once because of the cold weather. We are having the sort of winter that Ned Stark would be proud of up here and I didn't want to take them out to see the roost in sub zero weather. Yeah, I know birders are hardy and we can take it, but I find with newbies and casual birders that they really don't have as much fun and I'm not into sadomasochist birding for everyone (just a select few). I like to do it when it works with everyone's schedule and comfort level.

We finally found a day when it was in the 30s and it was a great time.

I joked with producer Sam by asking if that is how he keeps his microphone warm in winter. He said that this was for wind protection but it looks like a piece of Muppet more than a microphone.

I know crows are pretty common birds, but I do really enjoy their winter roost--thousands of crows coming in and swirling around at dusk, it's beautiful spectacle. Not quite a murmuration, but definitely lovely in its own way. And I love taking non birders out and see them be just as awed as I am (if not more so).

As we did the interview, I tried my hand at digiscoping the crows with my iPhone. I can get some arty shots, but it's still can't quite capture the majesty of the roost. However, as I was grabbing footage, I managed to get a shot of a crow coughing up a pellet--just like an owl or hawk would. Watch the crow on the far right:

https://www.youtube.com/watch?v=bGrIpbUqkIA

Several bird species cough up pellets, just not as regularly as birds of prey. I've seen gulls, shorebirds, robins and even a scissor-tailed flycatcher do it. In theory, any bird will cough up parts of food they cannot digest from scales, exoskeletons or even berry husks. But you don't often see other birds do it. Was fun to capture the footage.

Uptown Great Horneds Still Around

The Crossley Birds and Beers was a blast. He was a fun interview and a blast after his talk--I think we closed the bar. If you would like to find out if Richard Crossley is coming to your town, check his site.

The great horneds near my home continue to incubate. It had been awhile since I took my scope and camera to the owls so I took them out yesterday. Even for a week day, several people passed beneath.  The keep an eye on the passers by but otherwise stay still.

Once again, the male was right over the main walkway. In this photo he's looking down  on a dad and his toddler son who had no idea they were walking right under a very large owl. This also leads me to wonder yet again--how many owls do I walk past on a regular basis.  I'm willing to bet that the number is very high.

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.

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.