Monday, April 16, 2012

Why Osprey Are Cool

I don’t get to see too many Osprey here at the RMRP, but when I do I’m always amazed…and a little worried for them. They’re tenacious and strong like the rest of us, but they don’t seem to adapt as well to temporary captivity as some of the other birds. The Humans appear to feel the same way about Osprey—amazed and anxious. I can usually tell when an Osprey is admitted just by the change in energy among the Humans, that feeling of awe and concern that surrounds them. But the concern pays off--we have a good track record with Osprey.

Arthur Morris / Birds as Art
So why are Ospreys so awesome? What makes us all so excited to be in their presence? It’s a combination of their cool adaptations and their quirky personalities. Let’s start with the cool adaptations.

First I guess you need to know that Ospreys are fish-eating birds. They live near water and eat fish almost exclusively, so their neat adaptations are all related to fish-catching. To catch a fish, they fly or hover over the water from pretty high up (30-100 feet), spot their prey, then plunge in feet-first, submerging themselves completely in the pursuit of sushi. Then they fly out of the water to a safe place where they can eat the fish. Sounds simple, right? Wrong. If I, a Great Horned Owl, were to try to plunge into the water and catch a fish, I simply could not do it (not to mention I wouldn’t want to do it—water is…wet). Here are some of the traits that help Osprey get their dinner, and get it with such style!

From the top down:

See how lanky they are?

  • The flying/hovering thing: Ospreys have long, narrow, strong wings that enable them to fly in place so they can take their time scouting out the water and fish.
  • Their nares (nostrils) are also long and narrow, and capable of closing when the bird dives in. You can imagine how handy that must be when hitting the water at speed! 
  • Those long, narrow wings are critical for getting back out of the water--they're designed that way so they're extra-powerful as they try to swim/fly to the surface and break out of the heavy water with a heavy fish in their talons (now, try putting a bandage on an Osprey with a broken wing and see how long it stays on...)
  • Their feet--the fish-catching tools themselves--are very different from most other raptors:
    • Their toes are all the same length (as opposed to, say, Sharp-Shinned Hawks, who have a reaaaallly long middle toe) for more uniform grabbing of the slippery fish.
    • Their talons are uniformly rounded instead of edged like most raptors, and extra-hook shaped. 
    • One of their front toes can switch around to be a back toe (so, two in the front, two in the back, instead of three in the front and one in the back). As an Owl, I should mention that Owls can do that trick, too!
    • The feet are covered in rough spicules, like really course sand paper, that help them grip the slimy, wiggling fish.
    • Their tarsi (leg bones) are longer than other raptors so they can extend their legs far in front of their faces when diving in feet-first.
  • Their feathers are particularly rigid and strong. If I hit the water like that, I'd destroy my feathers.

So, pretty cool, right? Can you see why we get excited to see them? 

The quirky personality that I mentioned is just that--quirky. They're high-strung and finnicky, they take a lot of persuasion to eat when in rehabilitation, and they make the silliest noises and expressions. And they smell funny. And they prefer to be roommates with Turkey Vultures. I'm not kidding. They get along famously. Honestly, it's kind of hard to take Osprey seriously...and then you remember how incredibly skilled and perfect they are in their natural environment, and suddenly it's easy to be in awe again.

Let's see, what other cool stuff did that last Osprey we rehabbed tell me...oh yes--they live on every single continent except Antarctica! They're like the Peregrine Falcon in that regard. Except, while the Peregrine Falcon has many distinct subspecies and variations, there's really only one Osprey. There are a couple of "variations" out there, but they're a bit too vague for uncontested subspecies classification. What that means is that the Osprey does what it does really well. So well that it has never needed to be tweaked for different regions. c/o NASA
The Osprey has had one hiccup in its success story, at least in North America: DDT. Osprey populations were affected the same way that Bald Eagles and Peregrine Falcons were, and, like the Bald Eagle and Peregrine Falcon, has since recovered. 

A little bit of natural history: Osprey live near waterways, are migratory, primarily dine on freshwater fish (and are therefore good indicators of ecosystem health), mate for life, build big, ugly, ungainly stick nests (rather like a certain Owl I know...cough...), and lay 2-5 eggs. 

Caught in baling twine Thompson Photography 2008
They're picky about their nesting locations, and to help out with the Human encroachment on viable Osprey-nesting land, Humans have been building artificial nesting platforms all around the world, and the Osprey appear to like them just fine (the one at Willox and Shields here in town is a good example). Also, I don't know why it is, but Osprey have an affinity for that orange baling twine that farmers use to bale their hay. They use it in their nests, then get tangled in it and need help. Great Horned Owls don't seem to have this problem...just Osprey. But it's a big problem for them, so on behalf of the non-blogging Osprey I ask you to please take in your baling twine each season, cut it up and throw it away.

So, now that you know all about why Osprey are cool, watch this video on YouTube and see one in action! I especially like the flounder-hunting scene, when the Osprey extends his feet so they're exactly in front of his face--perfection. 

More locally, the Osprey are back in Fort Collins, home from their winter migration. They're on their nests and probably incubating eggs, so keep an eye out for chicks in the next couple months! That's it for now. Next installment will falcon. Yes. The American Kestrel! The guy with the Twitter account will just love that. Maybe I'll convince him to write it for me so I don't have to hear him talk about himself all day? 

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