July 03, 2006
Fishing Ospreys
Nest Update: First, a reminder that we have started our Name the Osprey Chicks Competition. Be sure to visit the contest page for details on entering. The contest will end on July 14.
As our cam watchers can see, we have a new cam installed at the platform. The view is a bit different because we straightened out the camera, and we can now see the whole nest box. This will be a good view when the chicks start flying and landing in a short time. A cam watcher asked about a first flight -- flight normally occurs at around 50-55 days of age. For the oldest chick, that would be as early as July 10.
The tree service worker who visited the nest said the camera was covered in poop, which you can see from this photo. We were lucky we could see as well as we did. He also said there was a lot of poop at the base of the nest, and the weeds were really tall thanks to all the natural fertilizer. :-)
We know it's likely that the birds will hit the cam again -- especially since I've already seen several incidents since the new cam went up where an osprey's rear was pointing at it -- but all we can do is cross our fingers and hope that they miss the lens itself. Normally poop is not this big a problem at our Osprey Cam, but this year we have so many bodies in the nest that the amount of flying guano has greatly multiplied.
Our bookstore manager -- who has good access to our live TV monitor at the Visitor Center -- says that even though the youngest chick is occasionally getting pecked by an older bully, it is still feeding well, and as we can see, the youngest is definitely growing. The tree service worker said he couldn't believe that it was the same chick he saw the last time he was at the nest. Now that the youngest's feathers are starting to come in, in a short while it will be hard to pick the youngest out from the pack.
As you can see from our Gallery update, the chicks are spending a lot of time exercising and strengthening their wings. Our bookstore manager says that when one of the chicks stands up and begins pumping its wings, it's every bird for himself. The other chicks have to duck to avoid getting slapped by all the wing flapping in the crowded nest. Also we've noticed that once a chick exercises its wings, it seems to encourage the other chicks to do the same. Apparently it's rather infectious behavior.
We saw a few more photos of chicks taking the fish and trying to feed themselves. It's hard to tell if the chicks have been successful in tearing off any fish bits, but mom always comes back over and takes the food away again. I guess she's trying to make sure no one is hogging the meal. Also, we have seen Mom going out and catching a meal herself even though Dad is bringing in a reasonable amount of fish.
Another activity we're seeing a lot more of is preening. As the chicks grow, they lose their down and develop feathers that grow out in protective sheaths, which they pull at as the feathers develop. You can see a close-up of those sheaths here, along with the business end of the osprey -- its sharp, piercing talons. Once the chicks have their feathers in, they must then clean them and waterproof them. They do this by taking oil from a gland at the base of their tail and rubbing it on their feathers. They can also pull their feathers through their beaks to "zip" the feathers back into a tidy alignment if the feathers become ruffled or unkempt.
We mentioned in the last log post that we wondered if the father osprey might have been temporarily waterlogged by all the rain we received last week. Recently we did hear that another osprey had to be pulled from the water near a bridge that is on the way to the Refuge. The osprey was dried out and later released.
While ospreys can waterproof their feathers with oil, that doesn't mean that they are immune to heavy amounts of moisture. If they sit in water or are in heavy rain for too long, they can become so waterlogged that it is difficult to fly.
Flying is crucial to the ospreys' survival because their main form of feeding is to dive for fresh fish. To catch a meal, ospreys use their excellent eyesight to spot fish from the air, then they plummet from as high as 200 feet, extending their feet in front of them right before they penetrate the water and drive their sharp talons into the slippery prey. An osprey's plumage is dense and oily to keep it from getting soaked after each dive, and the feathers on their legs are short and stiff so the legs will dry out quickly. (You can see a good close-up of osprey legs in this photo.)
We have a slide show on our site which shows how an osprey goes about diving for its food. Our chicks must learn this behavior before the summer is out and before they migrate to Central or South America -- on their own -- for the winter. The chick that excels at this skill will have the best likelihood of surviving to breeding age, which is about two to three years old.
Websites:
Finally I wanted to mention a couple new osprey websites. First, here is an Osprey Cam in Minnesota where they currently have three chicks (we helped them a bit with their set up). Also here is an Osprey Cam in Virginia -- the cam is not live but they have a good photo archive of the current nest. By the way, the Blackwater River they mention on their site is a different river than ours here at the Refuge in Maryland.
Thanks again to all those who have been sending in images to our Gallery. Your images help many of our cam watchers follow the action that they might otherwise miss. And you also help us build a valuable record of the osprey family's nesting season. If you're new to our cam and wonder how others send in their photos, you can find instructions for doing so here.
Until next time,
Lisa - webmaster
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