Osprey Cam Web Log 2005

Nest Maintenance

We had a nice shot this evening of the female using her balled up talons to turn the eggs. Click on the thumbnail for a larger version.

Despite this dramatic photo, normally when the osprey parents are incubating the three eggs, it looks like they're spending almost all their time just sitting and eating. But one important activity that is ongoing is nest maintenance. The male is often bringing new materials to the nest and the female spends a good bit of time rearranging the nest to her liking.

We saw quite a few shots in the last week that showed the pair adding to the nest and redecorating in preparation for the coming family. Sometimes they work together to move the items around and sometimes the female will even use the material to cover the eggs.

Among the items that we've seen added include tree branches, sod, cornstalks, and what looked like a phragmite reed (an invasive plant in Chesapeake Bay wetlands). But the one item missing this year -- and something we saw last year -- is a bird wing.

Ospreys have a rather unusual habit of bringing the wings of other birds to their nest and using them as nesting material. Ospreys are normally strict fish-eaters (we've never seen them eat anything else at the Blackwater cam nest), and they don't eat carrion. In addition, ospreys have not been known to attack other birds unless provoked, yet somehow they find bird wings to bring back to their nests.

Acclaimed ornithologist Arthur Cleveland Bent reported that ospreys have been seen bringing the wings of ducks and gulls to their nests. And back in 1927, biologist Chester Lamb recounted that during a trip he made to isolated Natividad Island in California, he saw ospreys using bird wings extensively in their nests. Peregrine falcons had killed many black-vented shearwaters that inhabited the island, and Lamb reported that all the osprey nests examined were made partly of black-vented shearwater wings; and at one nest in particular, all except a part of the foundation was entirely made of the wings.

Last year, we saw photos of our cam ospreys adding a large bird wing to their home and then working together to reposition the unusual item. Where they got it from and why they liked having it in the nest still remains a birding mystery. :-)

A technical note: Due to the upcoming American holiday, some of us will be out of town. We ask for your patience if any technical glitches happen during the weekend as it might take a little longer for us to get them fixed.

Until next time,
Lisa - webmaster

Countdown to Hatching

The osprey parents continue to do a very dutiful job of incubating the three eggs, and they're a couple weeks away from payday. As we mentioned before, early June is when we would expect to see hatching. Eggs normally hatch about a day or two apart, so the hatching could spread out over several days.

For those who are watching both the Eagle and Osprey cams, the action at the Eagle Cam has diminished now that it looks like the oldest is out of the nest more, although the youngest is still mostly nest-bound.

Our plan at this point is to eventually put the Osprey Cam back to 30-second updates when we have chicks to watch, and at the same time extend the refresh time for the Eagle Cam. Note that we'll stick with the eaglets until they're gone.

Wallpaper

Changing to a slightly different topic: For those osprey fans who like desktop wallpaper, we saw a great photo on the Lake District Osprey Cam website (based in England). You can find the wallpaper here -- it's an amazing close-up of a young osprey in a nest with unhatched eggs. Note that the image beside the wallpaper links isn't the image that's on the wallpaper. Click the links to see the image.

Other Cam Sites

And onto yet another topic (this is a very eclectic post!): For those who enjoy seeing other types of cams, we want to post one more set of links for cams where there is currently nest action. Some of these are unique cams and are worth checking out:

Stork nest in Germany

Kestrel and Peregrine Falcon Cams from Italy

Xcel Energy Bird Cams (great horned owl, eagle, falcons)

Osprey Cam in Wilmington, North Carolina

Connecticut Audubon Osprey Cam

We'll update the Osprey Gallery on Wednesday. Thanks again to everyone who takes the time to send in their photos. Our Galleries are strong because of your wonderful contributions.

Until next time,
Lisa - webmaster

Egg Collecting

Awhile back we mentioned on the cam page that osprey eggs are highly regarded for their wide color variations. Noted ornithologist Arthur Cleveland Bent called osprey eggs “the handsomest of all the hawks’ eggs.”

Unfortunately Bent wasn't the only one who thought this, as through the years osprey nests have often been the target of egg collectors and egg thieves. This has mainly been a problem in the United Kingdom, where it was the fashion in Victorian days to collect eggs both as a hobby and as a form of nature study.

Eventually egg collecting got so out of hand that by 1916, ospreys were completely exterminated from the UK. After a 40-year absence, ospreys slowly started reappearing in Scotland in the 1950s, but collectors still continued to target the eggs to the point that between 1954 and 1990, 9.3% of osprey clutches were illegally taken in that country.

Authorities estimate that today there are over 300 hard-core collectors still operating in the United Kingdom -- people who get nothing but eggs and the thrill of the theft from their efforts, since the act is considered a crime and the eggs cannot be legally sold for profit. Thieves usually take the whole clutch and will take eggs at any stage of development, although freshly laid eggs are a favorite because it is easier to "blow" out the contents of the egg, which rot when left inside the shell.

Sometimes when an osprey nest is discovered in the UK, conservationists and wildlife authorities have to work mighty hard to keep the birds and their eggs safe -- even to the point of keeping the nest location a secret or surrounding the nests with barbed-wire and posting guards to keep the thieves at bay. (Read about an incident last year at a famous osprey nest in England).

Fortunately, all the hard work is paying off. Scotland's osprey population has grown to over 130 pairs, and hacking and natural migration is helping to reestablish the population in England.

Two locations in the UK -- that were among the first places where ospreys began their revival-- now have online Osprey Cams. Both Loch Garten in Scotland and the Lake District in England have great websites and live cams that follow the saga of their ospreys. Also, the Rutland ospreys in central England have a website following their activities, and the folks there have used satellite tracking to learn more about the migration habits of European ospreys.

We take our hats off to the determined people of the UK who have put up a noble fight to keep the raptors safe and to let the osprey parents do what they were meant to do -- raise little ospreys.

Until next time,
Lisa - webmaster

An Osprey Homecoming

We don't normally plug things in the web logs, but I wanted to alert our osprey fans to a special film that they will likely enjoy.

For those who followed our Osprey Cam and Web Log last year, you might remember that at that time we were treated to a video clip of Bucko, a southern Michigan osprey fledgling that was learning to fish. The clip was courtesy of Christi Vedejs from the website Ospreylovers.com.

During that time, Christi was working on an osprey documentary video that she has now finished. In fact, the documentary just aired on PBS in Michigan and it is also available on DVD through her media company, Earthluv Media. The documentary is titled "An Osprey Homecoming" and it tells the story of the Osprey Reintroduction Program of Southern Michigan. In 2002, one of the program's hacked ospreys returned to the Kensington Metropark in Michigan and started a family. Bucko was the product of that nesting season, making him the first native-born osprey chick known to hatch in southern Michigan in over 60 years.

The film, which was a finalist at the International Wildlife Film Festival, is wonderful to watch because not only do you get to see the behind-the-scenes activity of the hacking program, but you also get to see the family life of ospreys as the parents go from preparing the nest to watching their chicks learn to fish. There's even a scene where one male osprey has to chase off a menacing bald eagle.

The three chicks whose stories you follow are Bucko, Ossie, and Sam, who by the end of the story head off to Central or South America for the winter. That was a few years ago when the film was shot, so now in 2005, the folks at Kensington Metropark are waiting to see if the three young ospreys return to raise their own families. In fact, they're having a contest in Michigan for the first people to spot the banded ospreys (note that immature ospreys wait about two or three years before returning north to breed).

The documentary features excellent osprey photography and a charming soundtrack, as well as amazing shots of a sandhill crane family, a great blue heron family, and other local wildlife.

If you'd like to learn more about the documentary, watch a trailer, or visit their store, be sure to check out the Osprey Homecoming website:

Until next time,
Lisa - webmaster

Building Osprey Platforms

In the previous log post we mentioned that there are two common types of osprey platforms -- water platforms and land platforms.

Some people are surprised to learn that ospreys will raise a family in an artificial nest. Unlike eagles, ospreys are a little more flexible when it comes to choosing a nesting location. Also, as coastal development has greatly reduced the number of natural nesting sites available to ospreys, the raptors have been forced to be more creative when looking for a place to raise their families.

For some purists, the idea of artificial nests seems wrong, but the fact is that platforms have played a vital role in the comeback of the osprey since the banning of the pesticide DDT. Reviving osprey numbers would not have been accomplished so successfully had artificial nesting sites not been available on the crowded coasts. Osprey expert Alan Poole states that, "The great majority of coastal osprey nests today are on artificial sites. On the New England coast between New York and Boston, it's close to 100 percent." Since humans aren't going away anytime soon, it's ultimately good for the osprey as a species that they are so willing to accommodate our intrusion into their traditional home areas and are willing to nest on structures that we've designed.

Below are two sets of photos -- sent in by two of our talented cam watchers -- that illustrate the different styles of platforms that you can see at Blackwater Refuge. The first two photos show a water platform, which is relatively low, since land predators are not a factor out in the river. Click on the thumbnail photos for a larger version:

In the next two photos you can see views of our Osprey Cam land platform. As you can tell from the photos, this platform is very high in the air, as ospreys on land like being in the highest structure in the general area, so they can watch for predators from all directions. Note that the arm sticking off the platform in these photos is to hold our camera and wouldn't be needed on an average platform.

The only problem with ospreys nesting on human-made structures is that the raptors sometimes choose a nest site that was not meant for birds, such as on a chimney, on a utility pole, or on a channel marker. Sometimes these choices are so dangerous that they lead to the death of the parents or the chicks. To prevent this from happening, many individuals who live near osprey-friendly waters build their own osprey platforms to provide additional housing for the birds.

Ospreys are normally loyal to their nesting sites, so once an osprey pair adopts a platform, there's a good chance the ospreys will return each nesting season. Platform designs usually consist of a platform atop a pole or tripod. Sometimes platforms are also placed on topless trees. Any new platform should be in place by late January or early February -- before the nesting season begins (note that the start of the season can vary depending on where you live).

Below are several websites that provide tips and plans for building your own osprey platform. The staff and volunteers at Blackwater Refuge don't provide written plans nor do we build platforms off the Refuge property, but if you have a specific question about platforms and it's not answered on these websites, feel free to write us using our contact page.

Osprey Platform Links:

• Citizens United to Protect Maurice River
• Ospreys.com
• Roanoke Wildlife Rescue
• University of Minnesota Raptor Center
• Building Nesting Platforms for Ospreys -- Ontario Landowner Resource Centre PDF file (215KB)

Until next time,
Lisa - webmaster

Nest Predators

The osprey parents have displayed quite a turnaround in their egg monitoring skills, especially since those early days when they left the first egg uncovered at night and during the rainstorm. Now we hardly see them off the eggs, and even when they are apparently gone, it's highly likely that one of them is sitting on the camera arm, out of sight, but there to watch over the safety of the eggs.

But why is it so important that they stay with the eggs? First, there is incubation. The eggs must be kept at a certain temperature for the chick to develop properly. Also the eggs must be turned throughout the day (some sources say it's done once an hour) to keep the embryo from sticking to the inside wall of the eggshell.

Another major concern is predators. If the ospreys were to leave the eggs unattended for long periods, there are a host of animals that would be more than happy to relieve them of the burden of incubation. This is where the male osprey is especially important -- while both parents can incubate, the female does it the most, while the male mostly brings food and makes sure predators stay clear.

Common land predators that have been known to take or puncture osprey eggs include foxes, skunks, and raccoons. This is why ospreys often prefer water-based platforms -- because the threat of land predators is greatly reduced. Fortunately at our cam platform, land predators are not a major concern because the pole is so tall. But many folks who build their own osprey platforms often add sheet metal or a predator guard to the poles to keep animals off.

At our platform, the greatest threat is actually from the air. During the day, birds like crows, vultures, and even bald eagles would go after the eggs or chicks if they were left unattended. During the evening, nocturnal great horned owls pose a very real danger -- not only to the eggs and chicks, but in rare occasions, to the female herself. Osprey expert Alan Poole has discovered female osprey remains that possessed talon injuries, which he believed came from the fierce great horned owl -- perhaps the only animal that could pose a serious threat to a full-grown osprey.

Danger from these owls once extended to the eagle nest, too. Back in the winter and early spring, great horned owls were a threat to the eagle eggs and young chicks at the Eagle Cam nest; that was why you often saw one of the eagle parents standing watch over the sleeping eaglets when it was dark. Now the eaglets are big, so the owl is not a threat.

But there's no doubt that great horned owls are alive and well at Blackwater. Craig Koppie recently said that a few of the owls had even taken over old bald eagle nests at the Refuge, and the eagles didn't seem to challenge them. Owls have also been known to claim former osprey nests.

You can learn more about great horned owls here.

Until next time,
Lisa - webmaster

Osprey Clutch & Platform View

As of Sunday morning, we still have three eggs, so I'll go out on a limb and declare that three is our final total. It's a good average-size clutch, and even if all the eggs don't hatch (sometimes an egg never hatches), it seems likely we'll see some chick action, especially now that the parents have been doing a better incubating job.

Because our website server was in and out during the egg-laying process, we're not sure of the exact date when the second egg made its appearance, but based on when the first and third arrived, this is the likely timetable:

1st egg laid - 4/28
2nd egg laid - 5/1
3rd egg laid - 5/4

Normal incubation is around 35-43 days, but last year all the eggs hatched in around 38-39 days, so this means we will hopefully see hatching begin in the first week of June.

Also on another topic, we had a cam watcher write in to ask us if we could give some perspective as to where the Osprey Cam platform is at the Refuge. Unlike the Eagle Cam nest, the Osprey Cam nest is very visible to visitors -- in fact, the osprey platform is right off the Wildlife Drive, which is a paved road that snakes through some of the more scenic parts of Blackwater Refuge.

In the background of the Osprey Cam image, you can see the Visitor Center building off in the distance. The building is under renovation right now, which is why you sometimes see lights on in the evening. The marshy area in front of it is a freshwater impoundment that has varying amounts of water at different times of the year.

Even though there is water around the platform, the platform pole itself is in solid ground and leading up to it is an access road, which is accessible from the Wildlife Drive. Refuge staff use the access road to get to the platform to maintain the equipment. The platform is far enough back from the Wildlife Drive that the visitors on it don't bother the birds.

As for the area in front of the platform -- the area you can't see on the cam -- we can offer a video clip from last year that gives you a better idea of what that area looks like. Below is a MPEG video clip (5.5MB) that was taken last summer and shows one of the two osprey fledglings taking a beginner's flight. As the osprey flys away from the platform, you can get a view of the Blackwater River, which is directly in front of them.

The video is not especially high quality (I can say that -- I took it!), but it gives you an idea of what a beautiful view the ospreys have of the river. To download the clip, right-click on the link below and choose "Save Target As," then download the clip to play from your computer.

Osprey Fledgling Flight

Until next time,
Lisa - webmaster