June 15, 2007
Osprey Nests on the Net
Here at Blackwater Refuge, our ospreys are spending a lazy summer hanging out until migration time arrives. Adults that don't produce chicks often migrate earlier than those that do, so we're not sure when ours will migrate, but it might be around mid to late August. Once they leave, the local bald eagles will probably start using the platform as a riverside perch again -- something they like to do when the ospreys aren't around to defend the nest.
We did see a funny scene at the nest recently where an osprey adult was playing with the sod/marsh-root ball that was in the nest. The bird kept moving it around with his feet. Possibly a form of osprey soccer. :-)
A couple cam watchers have asked why the ospreys stay at the nest if they don't have chicks. The fish hawks probably feel compelled to defend the nest from other ospreys and from the local bald eagles. Even if the ospreys don't have chicks this year, they want the nest for future use, and they want to be sure that no other bird takes it over. So for now, they put in appearances at the nest to let the neighborhood know that the nest hasn't been abandoned and it's not open for business.
Something I have noticed that is different is that without chicks, the osprey adults don't seem to eat at the nest as much. They're obviously still fishing and eating, so that means they're eating most of their meals elsewhere -- probably at a favorite nearby perch.
Other Local Ospreys:
In case you missed it, I posted a wonderful photo from our cam technician showing a three-chick nest located in the water near his home. We have a lot of osprey nests around the Blackwater area and in nearby towns -- this is one of the local nests that appears to be doing very well. In the close-up shot, you can see that the chicks are getting their pin feathers, and you can also see the white camouflage stripe that runs down their backs (this makes them look like another stick in the nest to an aerial predator). Also, note that osprey chicks have red eyes, rather than the yellow eyes of an adult. These birds are in what is called their "reptilian stage," but they will soon have a set of feathers that will make them look more like their parents.
Ospreys on the Web:
I also wanted to mention some news from other osprey websites that are seeing new chick action. First, we had some sad news from our friend Bob Montanaro down at Pelican Island National Wildlife Refuge in Florida. Bob is an incredibly talented photographer who follows the ospreys there each season via his website called Osprey Watch. At the nest he's been photographing, the middle chick (who had fledged) disappeared right before Tropical Storm Barry arrived. The fledgling was too young to be independent but it has not been seen since the storm, so it seems we did have one storm casualty among our Net ospreys. Fortunately the two remaining fledglings at the nest are doing well. Thanks to Bob for maintaining his wonderful osprey website.
On the Osprey Cam at Montezuma National Wildlife Refuge in upstate New York, we hear that one chick has definitely hatched and a second might have hatched. This nest was a little late in starting, but that is typical with nests north of us here in Maryland.
At the Puleston Osprey Cam, located at Wertheim National Wildlife Refuge in New York, they have two healthy chicks. They did have some intruder problems recently, but the parents seem to be keeping the chicks safe.
At the Osprey Cam at Woods Hole Oceanographic Institution in Massachusetts, they now have one chick. And not to insult the proud osprey parents, but this nest may qualify for the "Most Garbage Collected" award, as they seem to enjoy bringing large amounts of non-natural materials to their nest. That's not a problem unless they bring back something that can be harmful to the chick.
At the Connecticut Audubon Osprey Cam, the two chicks are doing well. Here's a photo showing that the parents brought a shell to the nest for decoration. And here's a shot showing an early attempt at flapping by one industrious chick. Well, he's either flapping or he's mooning us. :-)
Across the pond, we hear that EJ and Henry -- at the famous Loch Garten nest in Scotland -- now have their first chick. This is the nest where EJ laid a full second clutch after the first was destroyed. The first egg hatched in 33-34 days -- much shorter than the normal 38-40 day period. But then again, this couple doesn't seem to follow any rule books -- they just do their own thing. :-)
And at the Finland Osprey Cam they now have two chicks. In this photo from the Finland nest you can see the chick's egg tooth -- which is the device a chick uses to chip through the shell when it's hatching. The tooth is only for this purpose and will eventually fall off. And in this photo, you can see a feeding session where it looks like the father is on the lookout while mom feeds the chicks. Note that the mother is banded on her talon. Also note that she is using her nictitating membrane -- or transparent third eyelid -- while she feeds the chicks. Sometimes parents use this eyelid to cover their eyes so that they're protected from chicks that are jabbing at the food that the parents are offering.
Something else worth noticing in this shot is that the male osprey has coloring on his chest. Here at Blackwater, we know that most smaller birds with white chests are males. But in Europe, the males often have necklaces or brown/tan coloring on their chests -- just like the females. For example, here is a mating shot from another Finland Osprey Cam (the photo was from last year), and you can see the male has a very dark necklace.
I've never read a scientific reason for why European osprey males have necklaces and North American osprey males don't, so I'm not sure why it's this way. But it's good to remember that identifying a male osprey by his white chest might not work outside North America.
Until next time,
Lisa - webmaster
(contact)