March 30, 2006

Google Earth

sleep2.jpgNest Update: Well, Craig Koppie -- our eagle specialist -- is involved in an important litigation case at the Chesapeake Bay Field Office where he works, and they've asked Craig to stay near the office the rest of this week. Craig still plans to come recenter our Eagle Cam, but I'm going to stop predicting when he might come and just say he hopes to be here next week.

In the meantime, we have waited long enough to move the Osprey Cam to a 1-minute refresh, and since we're not sure exactly when Craig is coming, we plan to go ahead and put both cams at 1-minute refreshes as soon as we can -- hopefully on Friday.

We select the 1-minute refresh time for a couple reasons: 1) our satellite dish provider has placed a limit on the amount of traffic we can send via the dish, and 1-minute refreshes on both cams keep us under that limit and 2) many of our cam watchers who are still using a dial-up Internet connection have said that anything faster than a 30-second refresh causes problems for them, as they say the image doesn't have enough time to finish loading before the next image arrives. So a 1-minute refresh on both cams seems to be the best arrangement we can come up with to satisfy most people's needs. We appreciate your patience as we fine tune the cams in preparation for the ospreys coming nesting season.

For those who are wondering about the ospreys, we would expect to see osprey eggs around mid-April. Once we get closer to that time, I'll open the 2006 Osprey Cam Web Log on the website and we'll talk more about what to expect at the osprey nest. Things look promising with the couple. They're eating at the nest and building up the nest cup, adding sod and soft material in preparation for the eggs. So everything looks good there.

As for the flapping tape you sometimes see on the Osprey Cam -- our cam technician had planned to remove the loose tape before the season started, but a broken ankle grounded him, so he decided that we will remove the tape on the next maintenance trip up the platform. Fortunately, the tape doesn't often interfere with the image and it doesn't seem to bother the birds.

As for the eaglets, they're growing each and every day. In case you missed it, we updated the Gallery on Wednesday, so be sure to check out the photos. I noticed in the last day or two that we're starting to see pin feathers on the youngest and small tail feathers on the oldest. Very exciting to see their feathers coming in this way.


Special Treat

Here at Blackwater Refuge we truly appreciate our cam watchers who are not only very loyal, but also very patient as we work through our technical issues and various other adventures with the cameras and the birds. As a thank you, I wanted to offer a special treat.

Some of you may have heard of Google Earth -- it's a satellite imaging program that the search company Google offers for free on its website. It's an amazing program that lets you basically travel the globe and get an aerial view of countless sights using satellite images.

In order to give our cam watchers from around the world a better idea as to where we are located, I've put together a short Google Earth movie showing the Earth from a distance and then zooming in to Blackwater Refuge, which is located near the town of Cambridge on the Eastern Shore of Maryland. This area is also known as the Delmarva Peninsula, because the peninsula is comprised of Delaware and parts of Maryland and Virginia (Del-Mar-Va).

Our Refuge is very close to the Chesapeake Bay -- the largest estuary in the U.S. -- which splits the western and eastern shores of Maryland, so keep an eye out for that big blue landmark in the movie. In the clip, you will also see a box representing our Visitor Center on Key Wallace Drive. And at the end of the clip, you will see our Wildlife Drive, which looks like a thin white line running beside the waters of the Blackwater River in the area below the Visitor Center. The river that is emptying into the Refuge from above is the Little Blackwater River.

The movie is a 5.7 MB Windows Media Video file. You can right-click on the image below and choose "Save Target As" to download it to your computer to play. We hope you enjoy!

google.jpg

Until next time,
Lisa - webmaster
(contact)

Posted by Webmaster at 09:42 PM

March 28, 2006

Eagle Feather Stages

faceshotNest Update: The weather forecast is calling for milder temperatures later this week, so Thursday morning, Craig Koppie plans to climb our cam tree to check on the family and recenter our camera. Keep your fingers crossed that the weather cooperates. :-)

Also, some folks might have noticed that our site was down for several hours last night. Our web host installed a security patch that unexpectedly brought their whole network to its knees, but the glitch seems to be fixed now.

I'll update the Gallery tomorrow, but I wanted to point out a set of photos I somehow missed when they were first sent in: the photos show the youngest pecking at a fish in the nest. This was exciting to see as it indicates the eaglets are starting to learn to feed themselves. The parents will continue to tear off food for the chicks for a while, but slowly the eaglets will begin trying to pull off meat, and it's just another sign that they are becoming more independent. Thanks to all those who sent in the shots.

And speaking of our rapidly growing eaglets, some cam watchers had asked when they will eventually develop the coloring of their parents -- with the all-white head and tail. Young eagles will not develop the adult coloring until around 5-7 years of age. Sometimes it happens around 4 years of age, but it can be later, and it's always a gradual process rather than a sudden change.

Below are a series of photos illustrating how a bald eagle progresses from a fuzzy white chick to a fully grown white-headed raptor.

Click on the thumbnails below to see the photos. The photos will open in a separate web page because I left them extra large so you could see all the details:

eaglesr1 eaglesr2
eaglesr3 eaglesr4
eaglesr5 eaglesr6

In photo #1 we see two eaglets with their first coat of down right after their birth. In photo #2 we see an eaglet with its woollier second coat of down. In photo #3 we see an eaglet at the stage our chicks are at now -- with the dark feathers coming in and pushing out the down. In photo #4 we see one of the Maryland eaglets that was relocated to Vermont last year -- this bird was very close to fledging and had most of its feathers. In photo #5 we see a sub-adult eagle that is beginning to get its all-white head but still has an eye-stripe and mottled coloring on its body. And in photo #6 we see an adult bald eagle with the distinctive all-white head and tail.

Often a young bald eagle (photo #4) is mistaken for a golden eagle because of the young bird's size and coloring. You can read more about golden eagles on the Cornell All About Birds website.

And finally, we wanted to share another excellent eagle gallery link that one of our cam watchers sent in. Be sure to check out these amazing shots of what look like a very young mother bald eagle and her brood.

Until next time,
Lisa - webmaster
(contact)

Posted by Webmaster at 08:52 AM

March 25, 2006

Bird Cams

Nest Update: I spoke with our gift store manager, Peggy Tillier, the other day. She spends a good deal of time in the store near the Eagle Cam monitor, so she gets a good view of the eaglets on the live video. She reports that there is less aggressiveness now by the oldest eaglet, as the big sibling seems to have relaxed a lot in the bullying department. She also reports that the birds are stretching their wings a good deal and spending a lot of time napping -- which we can confirm based on our observations from the website.

talkSpeaking of our youngest, while the oldest was feeding this week, the littlest decided to make another trip to the edge. The youngest is quite the adventurer. As for the oldest, this week we saw it examining a stick in the nest. The scene reminded me of an episode we saw last year where the oldest decided to perform some nest redecorating on his own.

Just a reminder, we hope to have Craig Koppie here next week to check on the family and recenter the cam. Hopefully we will have a day of good weather that gives him an opening to visit.

Also, a couple cam watchers have asked about when we will move both cams to a 1-minute refresh. We would have done it by now, but since Craig might come to fix our view, we decided to leave the Eagle Cam on the shorter refresh a little longer since we hope our view will improve next week. After that, we'll leave the Eagle Cam on the 30-second update for a little while so our cam watchers can enjoy the new view, then we'll take both cams to a 1-minute refresh each. If Craig can't come next week, then we'll move the ospreys to a 1-minute refresh sooner.

The ospreys seem to be doing well, and they appear to be taking their time filling up the nest. We've seen a couple shots of them in a mating posture, although we would not expect eggs until around the middle of April. We will definitely have their cam on a shorter refresh by the time the eggs arrive.


Bird Cams

One of our cam watchers remembered that last year I posted a web log entry listing various bird cams around the Internet. The post was by no means a complete list of all the best cams, but I highlighted a sampling of some of the wonderful websites that show wild birds up close. Now that spring is here and the nesting birds are becoming active, I'll post the link to the list again. Take a moment to visit these sites and check out the nest action.


Request for Photographs

On to a different topic: As some of you may recall, we have recently renovated our Visitor Center at Blackwater Refuge. As part of our renovation process, we are adding new exhibits to our expanded floors and also creating new publications, and so we have a need for quality photographs of certain wildlife species. The photos do not have to be from Blackwater, but if they are from another locale, we would like the background to be indistinguishable -- meaning just water, trees, wetlands, or sky.

We cannot pay for the photos -- it would be a donation -- but the exhibit and publications will credit the photographers, and they can know that they have contributed to the enjoyment and education of all our future visitors. Visit our Photo page to read more about donating your photographs to this worthy cause.

Speaking of photos, I also want to thank everyone for sending in their cam photos for the galleries. We'll update the Eagle Cam Gallery next week and also open the Osprey Cam Gallery for the new season.

Until next time,
Lisa - webmaster
(contact)

Posted by Webmaster at 04:29 PM

March 21, 2006

For the Students

flappingNest Update: As a reminder, if the weather is good on March 23, Craig Koppie, our endangered species specialist, will be heading up the tree to check the family and the nest, and also to recenter the cam so we can see more of the family.

As for action at the nest, today we got to see a clear shot of the oldest eaglet's pin feathers starting to arrive. Very exciting news!

Also, some folks had asked about our Eagle Festival, which we held about ten days ago. It was a wonderful success, and we were very pleased with the turnout. The weather was good, and it seemed as though all had a good time.

I especially want to thank those folks who came a long distance to visit us. I know we had some visitors from Ohio, and we were thrilled that they were willing to make the long drive to see the refuge and our wonderful wildlife. Thanks again to everyone who came and everyone who asked about the day. :-)

Finally, in case anyone missed it, we posted a link to an absolutely amazing eagle gallery that includes some fantastic aerial battle photos. A cam watcher asked what kind of brown bird was trying to steal the adult eagle's meal -- it was an immature bald eagle.

For the Students

In the last couple months we've received several emails from teachers who told us they have students watching our Eagle Cam and now our Osprey Cam.

computer.gifWe thank those teachers for their emails, and we also want to thank each and every student who tunes in to watch our fascinating raptors. We feel privileged to know that young people are interested in our birds and want to learn more about them. In fact, we often brag here at the refuge that we have students watching our website. :-)

In honor of the young people in attendance, I want to offer some fun web links for you to visit. First, be sure to check out our picture quizzes here on the Friends of Blackwater website. We have interesting quizzes about eagles, ospreys, and the refuge itself. And for the younger crowd, be sure to also check out the Albert the Squirrel section on the US Fish and Wildlife Service Blackwater Refuge website, which has coloring pages and also information about our Junior Refuge Manager program.

If you've never seen a bald eagle up-close or never seen a bald eagle fishing, then we want to offer two video clips that are neat to watch. The first one shows a bald eagle softly calling while looking straight into the camera, and the second one shows a bald eagle gently floating down over a river to pluck out a fish for dinner. Right-click on the images below and choose "Save Target As" or "Save Link As" to download the video clips (courtesy of the USFWS).

eaglevoice.jpg fishingeagle.jpg

Speaking of video clips, there is a European website called ARKive that is a lot of fun to visit if you like wildlife. The ARKive website calls itself a Noah's Ark for the digital age, and the people who run it collect images, video clips, and audio recordings of endangered and threatened species.

On their website they have a large collection of fantastic video clips showing European white-tailed eagles, which are the closest relative to our American bald eagle. Be sure to take a look at the video clip that shows the adult eagle fishing and also the clip that shows the eaglets getting fed by their parents. The European chicks look a lot like our cam eaglets.

At the ARKive website you can view the streaming video clips or you can download the QuickTime movies to your school computer. I've found that the video clips play better if you download them. Just click on the "Download QuickTime" button on each video page.

Also, if you have questions about bald eagles that I haven't answered yet in the Web Log, be sure to check out the Journey North eagle website, where they have a collection of questions sent in by students who are interested in bald eagles. The students' questions were answered by bald eagle expert Peter Nye, who works for the New York Department of Environmental Conservation.

And finally, if you're interested in one day working with raptors as a career, be sure to read the story of Jim Watson, a raptor biologist who works for the Washington Fish and Wildlife Department. Maybe one day in the future you can spend your time like Jim does -- climbing trees, tracking raptors, and helping to make the world safe for eagles and ospreys.

We once again thank all the students for joining us on our exciting raptor adventure. And we hope we can provide you with more interesting moments as our eaglets turn into mighty birds of prey.

Until next time,
Lisa - webmaster
(contact)

Posted by Webmaster at 08:24 PM

March 18, 2006

Eaglet Gender

familyNest Update: First, we want to remind our cam watchers about the website maintenance that will occur on early Monday morning. Moving our website from one server to another will help our web host more than it will our website, in that cam watchers will probably not notice any faster service on the cams. But since our site is drawing a large amount of traffic, our web host asked if they could move us to a more powerful web server.

Also, some excellent news on the cam front: We have been told that, weather permitting, Craig Koppie -- the US Fish and Wildlife Service endangered species specialist -- will likely climb the cam tree between March 22-24, but most likely on March 23. He will check the family and the nest structure, and while he's there, recenter our camera. So keep your fingers crossed that he's able to make the climb.

As for the eaglets, they will be one month old next week, and our latest gallery update has photos that indicate our chicks are beginning to discover their wings. This is an exciting event, as it starts their transformation into mighty birds of prey. As the eaglets grow bigger, we'll see more of this flapping behavior, and once they have their feathers, we'll see them take short hop flights around the nest. Then they'll begin branching -- or sitting in the branches of their nest tree -- and not long after that they'll have their first flight.

And speaking of the eaglets, a cam watcher recently asked about the eaglets' weight. I would guess that they're between 3.5 lbs to 5.5 lbs at this point. The oldest is certainly heavier than the youngest since it is fed more and since it was born two days earlier.

On a final nest topic, one of our cam watchers pointed out a good photo from the Llano, Texas eagle website showing how the parent sits above the nest to watch the chicks. You can see the photo here; this is a good example of what our eagle parents do when we can't see them in the cam image. Also notice that the eaglet in the shot is making a hop flight in the nest.

You can see all the photos of the Llano, Texas eagle nest by visiting their home page. They have a remarkable collection of images that chart the eaglet's growth from chick to fledgling.


Eaglet Gender

At this point we naturally wonder about the sex of the cam eaglets. Determining sex is hard when chicks are young because the order of their birth can determine how big they look in the first month or so of their lives. As they get closer to full size, it might be easier to tell.

But is there a sex bias in newborn eaglets? Does one gender dominate at birth? In the book The Bald Eagle: Haunts and Habits of a Wilderness Monarch , Canadian eagle biologist Dr. Gary Bortolotti offers evidence of a sex bias based on observations that he collected while studying 37 eaglet broods around Besnard Lake in Saskatchewan, Canada. He reports, "Even though there was an overall nestling sex ratio of one to one, the order in which the sexes hatched was not random; 63% of first-hatched eggs were females, and 68% of second-hatched eggs were males. A sex bias in hatching sequence has only recently been discovered in birds."

Bortolotti speculates that this arrangement might benefit the family because a male eaglet develops faster than a female eaglet, and females being born first would help even out competition in the nest.

Last year we had three eaglets at the Eagle Cam nest. As those who followed last year's cam know, Craig Koppie climbed the cam tree to remove the middle eaglet so it could be taken to Vermont, where they are attempting to reestablish a breeding population of bald eagles. After Craig left the nest, he reported that the oldest and youngest eaglets appeared to be males. We now know that the middle eaglet (the one that went to Vermont) was in fact a female, as she was measured and tested after she was removed from the nest.

If Craig's observation was accurate, then according to Dr. Bortolotti, that means last year's Eagle Cam nest was unusual in that a male was born first and a female second. We'll never know for sure because our males were never tested, but it's still interesting to think about.

This also brings up the question of how to tell the difference between an adult male and female bald eagle. First, it's important to note that bald eagles in different parts of North America are different in size. Eagles that live in Alaska are larger than their fellow eagles in southern areas such as Florida.

call eagleBut for eagles that live in the same range, females are about 1/3 larger than the males in body size. Also, biologist Dr. Mark Stalmaster discovered that two size measurements -- beak depth and hallux (toe claw) length -- can be used to differentiate between the sexes because the female's beak and claws are bigger.

Biologists who have actually handled bald eagles also report that they have their own way of judging gender. Jim Watson, who is an eagle expert for the Washington Department of Fish and Wildlife, has said that he can tell gender by the eagle's temperament: females are docile, while males are very aggressive in hand. He also reports that he can tell the sex of an eagle by its call: the female has a lower pitched call, while the male's fluting call is more like a scream. You can hear an eagle call here (143KB MP3 file).


Until next time,
Lisa - webmaster
(contact)


Posted by Webmaster at 11:30 AM

March 14, 2006

Eaglets Up Close

explore.jpgNest Update: Our explorer chicks continue to enjoy lying near the edge of the nest and looking down. I wonder if they make mom as nervous as they make some of our cam watchers. :-D

Both chicks will be three weeks old this week, so each is regulating its own body temperature now. Some cam watchers have commented on the fact that it looks like the eaglets are sometimes left alone. Keep in mind that we cannot see the front of the nest and we cannot see the surrounding branches, and many times the parent is in one of those areas but isn't visible.

Also, one of our viewers sent in a question that I thought I'd answer here: They asked, "How do the chicks relieve themselves?" The parents likely relieve themselves away from the nest, but raptor chicks that are nest-bound learn early on to eject their feces over the edge. Falconers call this "slicing."

If you're watching the live video when one of the chicks slices, it looks like the chick has quickly shot out white liquid from a squirt gun. And since hawks and eagles have very strong anal muscles, the chick can shoot it really far. In this photo you can see one of our osprey chicks from last year slicing to keep its nest tidy.


Eaglets Up Close

A helpful cam watcher recently sent me a link to a wonderful photo of two eaglets from the Montezuma Wetlands Complex in Seneca Falls, New York. I wanted to share the link because the photo gives you a very detailed look at two developing bald eaglets. Note that these chicks are a little older than ours.

In the photo you can see that the chicks have their second coat of down, and it is much woollier than the white fluffy coat they had when they were first born. Also on top of their heads is the last bit of softer fluff (see my version of the photo with text).

As for their feet, it's hard to miss the big yellow talons. Also notice that the chick in front has a numbered and colored band on its foot. The band will be used to identify the chick after it's fledged.

As for the feathers, notice that on the front chick's right wing you can see its blood feathers -- or new feather shafts.

flap.jpgFeathers come from follicles (tiny bumps) that grow in rows or tracts on the bird's skin. When the feather first comes out, it is rolled and protected inside a tube-like sheath that contains blood vessels, which nourish the feather's growth. The bluish-coloring in the sheaths is blood; this is why they're called blood feathers.

Once the feather has developed and burst through the sheath, the protective tube will fall away or possibly the bird will pull it off while preening. The blood vessels will have withered and the quill will be the white color we are familiar with seeing.

Blood feathers are also called "pin feathers," because the smaller ones look like pins. Blood feathers are sensitive and if broken could cause severe bleeding.

Here is a photo of a Maryland osprey chick that is just beginning to get its feathers, and you can see the large blood feathers as well as some smaller pin feathers.

As for our bald eaglets, here is a photo from last year's Eagle Cam showing the outstretched wing of one of our chicks. You can see the small pin feathers on the end of his wing.

If you'd like to learn more about the different types of bird feathers, here is a good article that discusses the topic in more detail. They also have a photo of an eaglet with his newborn down.

Thanks to everyone for their Gallery submissions. We'll update the Gallery in a couple days.

Until next time
Lisa - webmaster
(contact)


Posted by Webmaster at 07:28 PM

March 12, 2006

Cam Business

treeclimber.jpgCam Update: First we want to apologize for our downtime. We believe we have located the problem, and it is with our Linux computer. We plan to have our Linux person check it tomorrow to see if the issue is a software or hardware problem. Then we will know more about what we need to fix.

The good news is that the problem is not the camera itself. We're fortunate that the issue is with the computer and is something we can troubleshoot from the ground. We appreciate your patience as we work through this problem.

While we're talking about the cam, I want to bring up another topic. As our cam watchers probably noticed, our cam slipped out of position a little more last week. At the beginning of the year, we had a huge wind storm that pushed the camera down, and we're actually lucky that we still have sight of the nest. Since then it's been shifting a little more each month. There is no chance the cam mount will fall, as it's attached to the tree, but the cam itself is slipping closer to the trunk.

We have heard that Craig Koppie, our USFWS eagle specialist from last year, might make a trip up to the nest to check on the family and the nest structure. If he does that, we'll have him recenter the cam. This won't happen until the chicks are a few weeks older and more self-reliant, but we just wanted to mention it in case the cam moves further out of position. Also, if Craig goes, we're not sure yet if he will band the chicks like he did with last year's brood.

One other bit of cam business: Since ospreys are now migrating back up the coast from South America, we plan to bring the Osprey Cam back online sometime this week after we get the computer problem solved. When that happens, we will keep the Osprey Cam on a 3-minute refresh until the osprey action picks up. Once the ospreys start building their nest, we will go to our usual 1-minute refresh on both cams.

We understand that many folks will not want to leave the 30-second refresh on the eagle nest, but the reality of the situation is that we are limited by our satellite dish company in how much traffic we can send out from our refuge PC to the Internet. So the best way to work within those limits is to have both cams at a 1-minute refresh for the majority of the nesting seasons.

At this moment, we are trying to get our satellite dish provider to allow us to send more traffic and thus keep a 30-second refresh on both cams, but we haven't heard yet if they're willing to let us do that.


Daredevil Chick

As for the nest action, on Wednesday we had an interesting moment when the chicks decided to accommodate us and move closer to our part of the screen. However, one chick worked its way so close to the edge of the nest, that it was making some of us a little nervous. Fortunately mom was right there standing over the eaglet.

Last year we had a similar incident when one of the chicks decided he wanted to see what was over the edge at night. Keep in mind that the cam nest is about 80 feet off the ground, so for a flightless chick, it's a one-way ticket down. The parent eagle watched the chick closely, and when the chick seemed reluctant to pull back, the parent went over and herded him back to the center of the nest.

Cam watchers have asked if the chicks can tell how high they are. We can't say for sure, but we've never seen one just shuffle over the edge, so the eaglets must have some sense of the danger involved if they try to leave before they can fly. Parents keep a close eye on the chicks, and we can also see that they've added sticks to the edges of the nest. Our osprey parents often added sticks to the perimeter of their nest as the chicks became more mobile. So maybe the eagle parents did it as well in order to provide a little corral to keep the chicks from exploring too far.

shade.jpgAnd one other nest topic: We noticed last week that as it got warmer, the parent spent more time off the chicks. With the sun beating down and temperatures in the low 70s, the chicks got a little warm in the afternoon on Friday. When this happened, they sometimes sought out shade provided by the eagle parent. This is a behavior that we often saw with our osprey family in the dead of summer when it was very hot. Raptor parents will provide shade, with their bodies and their wings, if the sun gets too intense for the chicks.

Blackwater Photos:

Finally, we want to offer links to some excellent Blackwater Refuge photos. Bob Quinn -- who is a wonderful refuge photographer and a frequent contributor to our website -- just sent me a new eagle photo that I wanted to share. This photo was taken not far from the Eagle Cam nest, so it might be one of our adults.

Also here are the woods where the adult was perching.

You can visit Bob's online galleries and see his other Blackwater photos as well. He has some wonderful shots of nesting ospreys, and also some beautiful photos of bald eagles looking out over the Blackwater River and its marshlands. These are the same areas where the eagles and ospreys fish for food.

Finally, one of Bob's newest creations is a fun animated GIF showing one of our Great blue herons trying to catch a fish. Check it out.

Small Version

Large Version

And much thanks to Bob for sharing his talents with us.

Until next time,
Lisa - webmaster
(contact)


Posted by Webmaster at 08:11 AM

March 07, 2006

Chick Competition

Nest Update: The chicks are developing quickly, like little eaglets do. Soon they'll start regulating their own temperature, and they will also develop a second coat of down (woollier and darker), which feathers will eventually replace. Also their large, awkward yellow talons will become more noticeable.

feedingIn this photo comparison of the 2006 and 2005 chicks, you can see what is in store for us. Notice that in the 2005 photo, each of the eaglets was in a different stage of development at the time. The woollier down is being replaced with dark feathers on the two oldest chicks, while the youngest still has most of his second coat of down.

Chick Competition

I was at the Visitor Center this weekend and spent some time watching the chicks interact on the live monitor. Our staff and volunteers at the Refuge can watch the monitor throughout the day, and after talking with them and watching some of the video myself, we can say one thing about the oldest -- the chick is a typical firstborn bully.

When watching the two chicks together, you sometimes see the oldest push and peck at the youngest, until the second chick takes a submissive position -- usually lying with its face down in the nest. This isn't a surprising development -- firstborn raptor chicks are known to be bullies, and are driven by instinct to establish themselves as king of the nest. The younger chick learns to act submissively, which earns the youngest a reprieve from harassment, at least for a little while.

Eagle biologists report that sometimes when food is not abundant in a crowded nest (like a three-chick brood), the youngest eaglet could succumb to starvation because the oldest eaglets will make feeding too difficult.

In the Eagle Cam nest, this is not a problem with the two chicks. We have a father eagle that is providing plenty of food, and a mother eagle that does her best to make sure that both chicks get fed at meal time -- whether the oldest chick is happy about it or not.

While watching the mother, it is remarkable to see her efforts to feed the youngest. The youngest knows that it will always eat second, so sometimes its head will be turned away from the mother while the oldest is eating. The mother eagle will tear off a piece of fish and hold it out to the youngest until it turns its head and sees what she is offering. She also holds out food to the youngest even while it's laid out in a submissive posture on the nest. Regardless of the youngest's position, she finds ways to feed it.

Folks at the Refuge did say that the bullying seems to be lessening, and this is common too. As the youngest chick gets bigger, the pecking and pushing will diminish. The chicks might still act aggressive at times, but soon the youngest chick won't be as easy to push around.

feeding2.jpgSeveral cam watchers have asked if a parent will ever intervene when chicks are fighting. Most eagle biologists say that it is not common for the parents to intervene. They explain this by saying that either the attacks are so quick that there is nothing the parent can do or that maybe this is the parent's way of making sure the strongest chick survives to carry on the species. Approximately 50% of fledgling eaglets will not survive to breeding age, so it's imperative that the strongest chick is well fed and healthy if it's going to have a solid chance of surviving. It's also possible that chick death is a natural correction in an area where the food supply is just not large enough to support big raptor families.

But does this mean the parent never intervenes? No -- as is usually the case with animals, even when we think we know them, they will often surprise us. In the book The Bald Eagle: Haunts and Habits of a Wilderness Monarch, the Canadian author describes several incidents he witnessed of eagle parents attempting to stop chick violence. He reports that in some nests he saw parents toss grass on feuding chicks, or immediately begin feeding the eaglets to break up the tussle. One parent even pecked a chick on the head when the oldest chick pecked its younger sibling.

But the most interesting story the author mentions is about a younger chick, called C2, that decided he had been harassed enough by his older sister, C1.

  "In a flash, little C2 lunged forward and bit C1 on the side of the head. The force of the attack knocked C1 backward into the nest. C2 held on. I could not believe my eyes; C2 was twisting and shaking C1 from side to side. This was no ordinary fight...It wasn't long before C1 began to call out with a high-pitched chittering sound. I had only rarely heard this distress call before. Peck, bite, shake; C2 showed no sign of diminishing his assault."

The author goes on to say that the mother eagle finally bent down and took the littlest chick's beak in hers. By gently rocking back and forth, the mother tried to get the youngest to let go, but it didn't work. Finally the mother sat down on both eaglets and started rocking back and forth to separate them with her body.

A little less than twenty seconds later, C2 was seen peering out from under his mother's breast. But it wasn't until over an hour later, when the male landed on the nest and the female stood, that C1 was seen squatting in the nest, apparently with no permanent damage from her attack.

The author stated that the younger male never tried attacking his big sister again and remained subordinate to her for the remainder of their nest life. But who knows how the attack would have ended if the mother had not intervened.

Gallery

As a reminder -- we updated the Gallery today with many amazing photos, so be sure to check it out. And thanks to everyone who sent in their shots. Even though we don't have room to display them all, we greatly appreciate receiving them as they are a valuable record of the chicks' development.

And for those who missed it, this week we posted a special Bald Eagle Wallpaper for our cam watchers.

Until next time,
Lisa - webmaster
(contact)

Posted by Webmaster at 06:54 PM

March 04, 2006

Feeding and Crops

pairNest Update: Based on the scenes we've seen over the last few days, it appears that the father eagle enjoys hunting for food early in the day. This morning we saw two fish and part of a bird in the nest waiting for the chicks. It was interesting that when given the choice, the mother fed the chicks part of the bird first.

Also on the nest we've been seeing some interesting behaviors regarding temperature regulation. In the wonderful book, The Bald Eagle: Haunts and Habits of a Wilderness Monarch, the two authors share the knowledge they gained from observing eagle nests in Saskatchewan, Canada, and they mention how an eagle parent regulates a chick's temperature: "Quite commonly, a chick will rest at its parent's breast, and in the first ten days at least, the adult may pull dried grass on top of the little bird." Thursday we saw the parents put so much grass on the chicks that at one point they briefly disappeared. And then later we saw the eaglets peeking out from under mom's warm breast. The chicks are about eight and ten days old today, so the timing for these behaviors is right on target.

Several cam watchers have asked about the feeding habits of the eagle family. Eagle biologists report that in nests that they've observed, the chicks are fed every 2-3 hours. On our nest we've seen that to be true, but we've also occasionally seen the feedings done in shorter periods as well as over longer periods. There has been plenty of fish in the nest, so the mealtime variances may be affected by how much the chicks are expressing their hunger.

At this stage the chicks are small, so they fill-up faster. Also the chicks have their crops to aid them. A crop is an organ located near the base of the bird's neck, and it stores food for later consumption. Our chicks are still small, so it's hard to see their crops right now, but we have a pair of photos from last year where you can see our youngest eaglet's crop growing in size as he gets fed.

night feedingFor the parents, the advantage of a crop is that it means the chicks don't have to be fed as often, since the young have food stored in their pouches. Adult eagles and most other birds have crops too, but they're often harder to see under all the feathers. It's been reported that an eagle with a full crop can usually survive at least five to seven days without eating.

An interesting raptor note: Owls do not have crops. They swallow their prey whole and it immediately goes into their gizzard -- fur, bones, beaks and all. Both owls and eagles regurgitate pellets (small projectiles of indigestible food). The eagle does not eat its prey whole and does not eat as many mammals and birds as the owl, but the eagle's crop collects fur and bones it can't digest. Also the eagle's strong stomach acids dissolve most smaller fish bones, so the eagle's pellets do not have as many bones. But the owl's pellets often contain much of the skeletons of the animals it ate.

This Owl Pages website gallery has an interesting photo of a barn owl's pellet showing not only skeletal remains but also pieces of eggshell.

If you'd like to see how an owl expels a pellet, the Owl Pages website has a short video of an immature great horned owl discharging his pellet.

Until next time,
Lisa - webmaster
(contact)

Posted by Webmaster at 09:02 AM

March 01, 2006

Eagle Festival

Nest Update: The father eagle has brought in a bounty of fish lately, and this is good to see because abundant food will reduce the competition between the chicks.

One of our cam watchers asked what the father does with his time and where he sleeps. The father roosts (or sleeps) in a nearby tree. He might even have a favorite roosting spot. The father eagle can sleep standing up because when he begins to fall asleep, his leg muscles contract and tendons in his feet automatically close his toes around the branch, locking him to the limb so he doesn't fall.

During the day, the father fills his time with fishing, perching, and looking out for unwanted visitors near the nest. If he sees another bird flying into the region around the nest tree, he'll chase it away.

pair.jpgAs for the chicks, they're looking healthy, and each day they get a little bigger and a little stronger. Speaking of the siblings, something we can't really appreciate on the Eagle Cam's static images is the interaction between the chicks. The eaglets look rather passive on the cam, but they're moving and vocalizing even if we can't see or hear it.

If you'd like to see young eaglets in action, there is an amusing video posted on the Santa Catalina Island Eagle Cam website. Go to their Photos and Video page, and look for the video titled, "Chicks fighting in brooder at about 3 days of age." It's a WMV file (527KB), and it shows the eaglets wrestling with each other and with a towel. You can hear their high-pitched squeaks and see how they use the one tool they have -- their little beaks. Even though they're only three days old, you can already see them working the muscles that they'll one day use to tear apart a meal. I would certainly think twice about putting my hand in there with them. :-)


Eagle Festival

In this log post I also wanted to mention an important event that's coming up at Blackwater Refuge. Each year, around the middle of March, we celebrate the anniversary of the National Wildlife Refuge System by holding our annual Eagle Festival. This year is our 6th Eagle Festival, and it will be held on March 11 from 8am - 4pm. If you're within driving distance of the Refuge, we encourage you to come because it's our most popular event of the year.

On our website we have a schedule of events for the Festival, which includes activities for both adults and children. One of our most popular activities is the Eagle Prowl, where you can get expert help in spotting eagle nests and eagles around the refuge. We'll also have educational programs, live birds of prey, music, food, nature crafts, and an endangered species puppet show. Also we'll have a sale in our newly expanded Eagle's Nest Gift Shop where we have many wonderful nature items that are unique to Blackwater Refuge.

And while you're visiting the gift shop in our newly renovated Visitor Center, you can also see our Eagle Cam monitor, which features live video from the cam nest. Be sure to also look at the authentic eagle nest that we have on display near the store.

Several local nature centers will bring in live raptors for visitors to see up-close. The birds on display have been injured and can no longer live in the wild, but they are now ambassadors educating children and adults about raptors and what they need to prosper. Below are several photos taken at a previous Eagle Festival:



So be sure to join us if you can. The festival is free and is a lot of fun for anyone who enjoys nature. It's also a great event for parents who want to teach their children to enjoy and respect nature as well.

A final note: March 14, 2006 marks the 103rd anniversary of the founding of the National Wildlife Refuge System, which Teddy Roosevelt started in 1903. The Refuge System is special because it's the only set of public lands in America where wildlife is supposed to come first. If you'd like to learn more about the National Wildlife Refuge System, take a moment to view the slide show we put together for the Centennial Anniversary, which occurred in 2003.

Until next time,
Lisa - webmaster
(contact)

Posted by Webmaster at 07:54 AM