Osprey Cam Web Log 2005

Growing Chicks

The chicks are almost 3 weeks old now, and as the wonderful photos in the Gallery illustrate, their down has become darker and woolier. Osprey expert Alan Poole calls this the chicks' reptilian stage, saying it's when "they are black, scaly, and often crouch at danger, reminiscent of their reptilian ancestors."

We can see the chicks crouching for protection in several photos including this one; this posture is usually brought on by a parent calling out for them to stay low.

At about 2 weeks old, feathers begin to replace an osprey chick's down. According to Poole, "First to appear are rusty-golden pinfeathers on the head and neck. Darker body feathers follow slightly later, and primaries, secondaries and rectrices (outer feathers of the wing and tail) emerge at about 20-25 days."

When the chicks are about 30 days old, their growth will begin to slow and they will already be at about 70-80% their full-grown body weight. As for fledging, last year our chicks fledged when they were a little less than 2 months old.

If you'd like to seem some excellent close-up photos of the reptilian stage and the incoming pin feathers, check out these Maurice River osprey gallery photos.

Looking at our own Gallery, it's interesting to note that the less-than-12-hours difference in the chicks' births did seem to matter when it came to size and development. In several shots we can see that one chick reached the reptilian stage before the other did, and that chick also seemed to have a bit of a size advantage. Apparently in the world of an osprey chick, 12 hours is a long time.

Also noticeable in the Gallery is that the parents have been adding big sticks to the perimeter of the nest, now that the chicks are becoming more mobile. This behavior is much like human parents putting up a gate over the entrance to the stairs to keep the young from taking a tumble.

Also in the Gallery we can see an excellent example of the way in which the chicks relieve themselves -- based on the photo, it's clear that the birds get an amazing arc in their efforts to clear the nest.

All in all, the family seems to be doing well. The chicks often have bulging crops, so the father osprey appears to be up to the challenge of providing fish for the family, and the mother osprey appears skilled at protecting the young. They seem to be a solid family group, and we feel hopeful for their success in the coming weeks.

Our Gallery has many more great shots, so be sure to take a few minutes to look at the recently added photos and observe the emerging personalities of our two young raptors.

Technical note: Just a quick reminder for those cam watchers who might be new to the site -- if you'd like to know the weather at the Refuge, click on the "Refuge Weather" link in the lower left-hand side of the cam box. And if you'd like a detailed forecast, click on the graphic that pops up and you'll be taken to a full weather page.

Until next time,
Lisa - webmaster

Catching Up

First, thanks to all those cam watchers who sent me their wishes for a great vacation, and also thanks to all those who sent in photos from the cams during the last week. I received lots of great shots, and we'll be updating the Galleries in the coming week as we get caught up now that I'm back.

But before we get back into the osprey chicks and our departing eagle family, I wanted to share two photos I took while on vacation in the Outer Banks of North Carolina. The first is a shot of one of the sunrises we were treated to each morning and the second is a shot of one of the dolphins that was feeding off our beach. By the way, if you've never been to the Outer Banks and if you love the ocean, you really must visit at least once. It's an amazing place for nature lovers. Click on the thumbnails below.

Thanks again to everyone for keeping us up-to-date with our photos. The next web log will be about the rapidly growing osprey chicks.

Until next time,
Lisa - webmaster

Osprey Observations

First a personal note: I'll be going on vacation to the Outer Banks of North Carolina from June 18-25. During that time, we will not have any Gallery updates or new Web Log posts, but please feel free to continue sending Gallery submissions and questions, as I'll be checking in occasionally. We'll get caught up completely when I return.

Also, our cam technician will be keeping a close eye on the equipment, but with one less person on duty, we might not be as speedy to notice a problem, so we ask for your patience if any technical glitches occur.

On Friday, we'll do a Gallery update, and we'll be posting some interesting photos we've received over the last few days. In one photo we could just make out the bulging crop on the little chick, showing it's well fed. Also we saw the female shading the young from the hot sun (the weather is finally cooling down on Thursday). And we saw one shot where it looked like the female came incredibly close to whitewashing the camera lens -- she really had it in her sights. :-)

Another photo worth highlighting is the shot to the right, which relates to a question we received from a cam watcher who wanted to know why the ospreys cock their heads while looking skyward.

As some might remember from the Eagle Cam Web Log, we mentioned that unlike humans, raptors have two foveae (or centers of focus) in each eye, and these two foveae let them see both forwards and to the side at the same time.

The deep fovea has a line of sight that points forwards and about 45 degrees to the left or right of the head axis, and the shallow fovea has a line of sight that points forward but only covers about 15 degrees to the left or right. Of the two centers of focus, the deep fovea has the higher acuity.

Raptors have large eyes for their headsize, and it limits their eyeball movement (check out this photo of an imitation osprey skull, which shows how much of the skull is taken up by the eye sockets). So when an osprey wants to get a good look at a distant airborne threat, it has to cock its head at an angle to expose the target to the deep fovea of its eye, which offers maximum keenness. Researchers have observed that the more distant the object, the more likely the raptor will spend time looking at it sideways.

The greatest threat to our cam ospreys is from the air, so when a bird passes overhead, the osprey parents normally want to have a good look at it to decide if it's friend or foe. A few years ago, the osprey parents got an eyeful as a bald eagle made a dive at the platform. People in the Visitor Center saw it from the observation window, and we got questions from cam watchers asking if the birds were all right as they looked highly agitated. Fortunately, the eagle left without making contact with the ospreys, but it showed that any parent on the platform is wise to closely examine objects overhead. So keep those eyes to the skies. :-)

See you after June 25,
Lisa - webmaster

The Little Family

We had planned to update the Gallery this weekend, but I've been having email problems, and the emails sent to me earlier today just arrived late this afternoon -- in a very large mass mailing. I've called our tech people to let them know the email server seems to be slow in forwarding them, so hopefully it will get fixed soon. In the meantime, there will be a slight delay in updating the Gallery.

All seems well on the nest as both chicks have been observed feeding. Dad seems to be bringing in the meals, although that doesn't stop Mom from calling after him occasionally.

Thinking back on the hatching we recently witnessed, it reminded me of a chapter in a book I read called, "The Loon: Voice of the Wilderness." In the following passage, author Joan Dunning describes the hatching of a loon chick, and it provides a vivid picture of what our osprey family must have experienced:

"In the moonlight of a warm night in mid-July, the male loon, which is on the nest, stretches his neck forward, opens his bill slightly, and calls the long wail to his mate...In the nest, within one of the downy pouches where he warms the eggs, the male has felt the smallest movement -- hardly there, but undeniable. It is the first pecking...He calls again. The calls resound in the mountains, but his mate is already nearby, cutting a V across the glassy surface of the water.

They speak in soft tones, kwukking...There is the sense that something is to be done, but there is nothing do to but wait. Again the pecking...an insistent, dull tapping from within one of the eggs, a complaint against the dark incurving walls of the shell that limits space. Peck...tap...peck from out of the stillness of twenty-nine days there suddenly arises an urgency, a need for room. The little chick needs to stretch its neck out straight, needs to extend its tiny wings, needs to uncurl its little legs. It is ready to join this world of moonlight and stars, this world of lake water and breezes and blue sky and trees. It needs to breathe.

The big loon hoists himself to one side on the nest, and there, from a small hole on the side of one of the eggs, protrudes a tiny beak. More struggle, more pecking...and resting and pecking...It is so much work for little muscles being used for the first time. Peck...rest...peck...and then finally a side of the shell falls away and there, wet and tired and wavering, is a very small black chick with a little white breast.

The father loon kwuks softly, expressing the bond between himself and this new bit of life before him in the nest. His mate hears the gentle tone and knows there is a chick. But the little chick, for that night, will know nothing more than the warmth to be found beneath a loon's breast."

Welcome to the two additions in our new little family.

Until next time,
Lisa - webmaster

Two-Chick Brood

As we announced earlier in the day, we now have two chicks in our Osprey Cam 2005 nest. The second egg (of the three-egg brood) hatched late Friday afternoon and the third appeared to have hatched during our camera's daily "down time" -- somewhere between 11pm on Friday night and 3am on Saturday morning. One of our loyal cam watchers caught this photo at around 3:30am, and you can see two broken eggshells, showing that the last egg has hatched.

If both chicks make it, it will be advantageous that they were born within 12 hours of each other, as neither chick will have a noticeable size advantage, thus decreasing any potential aggression between the two. Also, it will be easier for the father osprey to feed two rather than three chicks, so food shouldn't be an issue between the siblings.

As we watched the nest today, we saw the mother osprey doing some occasional feeding but also spending a lot of time covering the chicks. Right now the chicks can't regulate their own body temperatures, and the Washington DC area is currently going through an early humid summer heat wave, so the mother osprey has been shading them from the elements. Sometimes we can also see her panting to keep herself cool as she sits out in the sun all day to protect the little ones.

Looking back now at the parents' actions during the last two days, we can see signs that the parents knew what was coming. A mother bird can feel movement and hear chirping before hatching, and it's obvious the father osprey was informed that chicks might be coming. In the last two days, he suddenly started spending more time at the platform with the female, while she in turn started eating from the fish he brought, and behaving more like a homebody.

The chicks will grow rather quickly now and will become easier to see in the nest. But at this point, they're well hidden much of the time due to their size, and also due to the fact that nature camouflages the chicks by giving them earth-toned colors and a white stripe that runs down their back. When they lay low in the nest, the stripe often makes them look like just another stick.

We're very happy that we have a chance at a successful nest this year. And we offer thanks to all those who were keeping watch as we waited for the hatching. Best of luck to the new osprey family.

Technical Note: Just a small camera tip -- sometimes cam watchers might notice that the 30-second refresh does not bring up a different photo. Assuming the cam is working properly, the failure to refresh can sometimes occur because the new image is not ready on the server when the web page refreshes. If that happens, and you see two consecutive photos with the same timestamp, you might try holding down the CTRL key while clicking the Refresh button on your browser toolbar. This will force the browser to get the newest image, and you might be able to bring up the new image you just missed. Note that this will not help if the camera is malfunctioning or we're having major server problems. But if it's a simple case of the browser and the image refresh being out of sync for one cycle, then the CTRL+Refresh will sometimes bring up a missing photo.

Until next time,
Lisa - webmaster

Welcome New Chick

Late this afternoon, we were rewarded with the appearance of the first visible chick of our Osprey Cam 2005 season!

Over the last day or so, we had seen the father osprey hanging around the nest quite a bit and the mother checking the eggs on and off. This afternoon, it suddenly appeared that one of the eggs had something beside it and it looked like that "something" was moving.

Not long after, we saw a little head pop up. And now we can see the broken shell being moved around the nest. Welcome little chick!

We hope he is healthy and starts to gain his strength. Saturday and Sunday are the likely hatching days for the third egg, so we might be treated to more action soon.

Since we now know that at least one of the eggs was fertile, it seems more likely that the first egg did hatch back on June 5, but the chick did not survive very long, and the eggshell and chick were quickly removed by the parents or buried under nesting material.

We'll try to update the Gallery over the weekend to show all the activity leading up to the hatching.

Still Waiting

We thought we had some possible hatching today, but no sign of a chick. Unfortunately, the osprey pair has a lot of material in the nest so when pieces of it move in the wind or poke up, it can look like a chick. As you can see in this evening's shot, we have two whole eggs.

June 8 and 9 are the first two likely hatching dates for the second egg, so Wednesday and Thursday might bring some hatching activity.

As an aid in what to look for: Below are two photos of a chick in last year's nest. You can see how it stands out a bit. Click on the thumbnail below.

But the very best clue that there is a chick is in watching the female. If she's looking under herself a lot or staying on the nest with her food and feeding it to something in the nest, then we have a chick.

While watching the couple today, we did see some interesting scenes. First there was the stick shuffle, where one of them almost poked the others eye out with a branch. Careful with those sharp objects. :-)

We also saw an exchange where the male osprey came with a fish and wasn't sharing it, so the female decided to help herself. We've seen the male feeding on the end of the platform quite a bit, so it seems that he's a capable fisherman, but we're not sure about how willing he is to share his prizes. :-)

Until next time,
Lisa - webmaster

Two Eggs

At this point, we're pretty sure we now have two remaining eggs (out of a total of three). Also, we're positive there is no chick. Today, the female showed no signs of feeding or caring for a chick.

She spent a good bit of time covering the eggs today because it is very hot here, especially when you're sitting out in the sun.

We are now hoping that the remaining two eggs will hatch sometime in the next week. We don't know what happened to the third egg, but the only possibilities at this point are a predator (from the air) or the chick hatching but not surviving. The parents have been rather good about either staying with the eggs or being nearby, so a predator seems the less likely scenario of the two. But we'll likely never know.

Thanks to those who sent in photos today as we tried to catch a glimpse of the third egg, which unfortunately we never did.

Technical Note: As most have probably noticed, we went to a 30-second refresh time on the Osprey Cam today so we could see more of the nest activity. In order to make that change, we had to change the Eagle Cam to a 3-minute refresh so we could stay within our bandwidth limits for both cams. We will continue to follow the Eagle Cam until we're sure the youngest eaglet has fledged and is independent.

Until next time,
Lisa - webmaster

Missing Egg

We wanted to provide an update of the day's action for our cam watchers. At around 4:30am, we can confirm that we had three eggs, but it seems that sometime after that we lost sight of one of them.

Throughout the afternoon, we did not see three eggs in the nest -- only two. That means one of several things: The egg is there but buried under nesting material; the egg hatched but the chick did not make it; the egg hatched but the chick cannot be seen in the nest so far.

We doubt that a predator got to the egg, because the female has been doing a good job of staying with the eggs in the evening and we did not see the parents away from the nest for long periods in the morning.

The mother osprey has not been acting as though she has a chick in the nest, so we're not sure what we have at this point. We'll have to continue to watch the nest closely tonight and tomorrow to see if we can tell more.

We want to thank all those who sent us photos throughout the day and helped us keep an eye on the eggs. We'll update the Gallery later tomorrow.

Until next time,
Lisa - webmaster

Brood Dynamics

As we mentioned on the cam page, assuming the osprey eggs follow the average incubation period of 38-39 days and assuming the eggs are all fertile, we expect hatching around the following days:

1st egg - June 5 or 6
2nd egg - June 8 or 9
3rd egg - June 11 or 12

Also, today we saw a little cat and mouse game played by the couple. Seems one wanted the sod-like material near the eggs and the other didn't. So back and forth they went. It made for an interesting series of photos.

Now that we're close to hatching time, a couple of our cam watchers wanted to know if we would see any chick aggression in the osprey nest or if the chicks would coexist like the eaglets did.

In the past four years that we've run our live Osprey Cam, we haven't had a three-chick brood for a sustained period of time. In 2001 and 2002, we had one chick fledge each year, and in 2003, we had two chicks fledge. Then in 2004, we had three eggs hatch, but the youngest chick only lived about three days and seemed to die of natural causes. The two remaining chicks then fledged successfully.

The topic of chick survival (or brood reduction) in osprey nests is an interesting one. Back in 1978, biologist R.J. O'Conner reported his theory that brood reduction in osprey nests might occur in three ways: fratricide (chick kills chick), infanticide (parent kills chick by selectively feeding individuals instead of all the chicks) or suicide (chick voluntarily stops trying to eat).

When most people think of fratricide, they imagine one chick pecking another chick to death or pushing a chick out of the nest. But fratricide can take more subtle forms, such as the oldest chick preventing the youngest from getting adequate nourishment.

The firstborn in an osprey nest has the advantage because raptor eggs hatch asynchronously, so the first chick is bigger. When that size advantage is coupled with aggression (which is likely in areas with inadequate food), the oldest chick can often keep the younger chicks from eating by pecking them and intimidating them into submission. Often the mother will feed those that are closest to her and most persistent; this is especially true if food is not plentiful. Basically it's survival of the biggest and the most aggressive when food is at a premium.

Last year on our Osprey Cam, we did not see a blatant act of aggression from the older chicks toward the younger chick that died, and we did not notice clear acts of aggression between chicks in our other cam nests from past years. We've been told by our biologist that the raptor nests at and around Blackwater Refuge do not seem to exhibit a great deal of fratricide. While sibling rivalry is common, it does not seem to lead to death or starvation. This follows the other popular theory that when fratricide occurs it is often the result of a food shortage -- something that is not a problem at Blackwater and around other parts of the Chesapeake Bay.

But this was not always true. Two Chesapeake Bay osprey studies -- one done in 1975 and one done in 1985 -- showed that aggression in ospreys nests had increased as the health of the Bay decreased. In the mid-80s, the Chesapeake Bay was going through a health emergency, and its fish and shellfish stocks were dropping dramatically. Below is a chart that shows how chick aggression and family dynamics changed as the health of the Bay changed:

Chick aggression became prevalent when the Bay's resources began to decline. The two brood deaths were attributed to malnutrition, as the osprey females had gone from feeding all their young sequentially, to feeding the bigger and most aggressive of the chicks.

As for the males, during the 1985 study they were having to spend more time away from the nest to find food, and the food they delivered was smaller in size. Even when some males delivered a large amount of food, it appeared that not all the chicks were getting fed equally as the female and the dominant young consumed most of the food and fish remains were left uneaten in the nest.

The Chesapeake Bay situation seemed to indicate a clear correlation between food supply and chick aggression, and other notable studies have backed this theory up. But as is often the case in nature, there always seems to be a few exceptions to every theory, and several studies have found chick aggression appearing even in areas with an adequate food supply.

One such exception appeared in a 1991 study of New Jersey ospreys, where the biologists concluded that while the local food supply was sufficient, a contributing factor to brood reduction was the hunting ability of the male ospreys. More experienced males would forage more successfully, and with greater vigor, than less experienced males. Thus the biologists concluded that even though there was plenty of fish in local waters, the weight differences among the chicks and the witnessed chick aggression was likely affected by the skill and experience of the males in providing for their families. In particular, the younger fathers had a difficult time struggling to meet the needs of a three-chick nest.

Our osprey pair this year is a new couple to us and are not the same ospreys that we've had in previous years on the cam nest. This year's pair laid their eggs rather late, which made us speculate that they might be an inexperienced couple. If their eggs hatch, it will be interesting to observe how they handle their brood and the coming parental challenges.

Until next time,
Lisa - webmaster

[Referenced Studies:

McLean, P.K. 1986. The feeding ecology of the Chesapeake Bay Ospreys and the growth and behavior of their young. The Wilson Bulletin 103(1): 105-111, 1991.

O'Conner, R.J. 1978. Brood reduction in birds: selection for fratricide, infanticide and suicide. Anim. Behav. 26:79-96.

Steidl, Robert J. 1991. Growth and brood reduction of Mid-Atlantic Coast Ospreys. The Auk 108:363-370.

Stinson, C.H. 1977. Growth and behavior of young Ospreys Pandion haliaetus. Oikos 28:299-303.]