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VDGIF/Norfolk Botanical Garden Eagle Cam: 03/01/2010 - 04/01/2010

The Virginia Department of Game and Inland Fisheries, in partnership with the Norfolk Botanical Garden and WVEC, is providing a rare glimpse into the life of two bald eagles and their offspring!

Wednesday, March 31, 2010

“Just How Big Is That Nest?”

Tree climbers from Nuckols Tree Care accessed the bald eagle's nest at the Norfolk Botanical Garden today to help band the young eaglets. All three of the nestlings were in fine shape. You can read more about the banding by biologists from the Center for Conservation Biology here.

While up at the nest the climbers were able to collect some data about the size of this nest. The nest is approximately 64 inches across and 32 inches deep. The inner bowl of the nest (the portion the chicks occupy right now) is 36 inches wide. This is actually somewhat small compared to other nests in the region. The overall size of the nest is determined in part by what the tree will support. The adults regularly add nest material to replace pieces that may fall away. Regardless of the size of the nest - it has been more then enough to successfully raise many eaglets. This year marks the fourth time this pair has had a three egg clutch, making them one of the most productive bald eagle pairs in the region.

Photo courtesy of Joe Foreman

Tuesday, March 30, 2010

“Doing Well and Growing Quickly”

The chicks continue to become more mobile, moving around the nest and starting to explore the world around them. Last week they were strong enough to clamber out of the nest cup and get a look at the world around them over the rim of the nest (see the CCB blog).

Today the oldest of the chicks was able to briefly stand up on its feet. This is a sign of both improving balance and growing strength. Prior to this the nestlings have waddled on their tarsometatarsus (the leg bone above their foot). It will be some time yet before the eaglets will be able to balance on their feet for any length of time.

Tomorrow morning, beginning at approximately 9am EST, the Center for Conservation Biology will band these three eaglets. Banding provides important information about where these young birds will disperse to, where they might eventually breed and even how long they may live. All of this helps us make decisions regarding the management and conservation of these birds. You can follow the banding with the Eagle Cam, and more information will posted following the activities tomorrow.

Monday, March 29, 2010

“Eaglets feeding”

Here's a short video of the chicks being fed late this afternoon, you'll notice that only one of the eaglets seem very interested in the fish its mother offers. The chicks are slightly damp, but none the worse for wear from the heavy rains that fell earlier today. The adults were able to keep them brooded and warm through the worst of the rainstorm. We hope that the camera will be back on-line tomorrow morning.

video

“Camera Outage”

The camera is temporarily off-line due to technical issues at the Norfolk Botanical Garden. Staff there are aware of the issue and working to fix it. The necessary repairs have been complicated by heavy rainfall in the area today. Service will be restored as soon as possible

Friday, March 26, 2010

“A little bit of independence”

The nestlings continue to grow rapidly and have molted in a new warmer down, they are starting to spend more and more time uncovered by either parent. This is normal, the larger size of the chicks helps them retain body heat, as does an increasingly efficient circulation. Their heavier down acts as great insulation. As spring progresses the temperatures are becoming more moderate as well.

This isn't to say that the adults don't keep a close eye on the young. As you can see the female was perched quite close to the nest while her nestlings dozed.



The forecast for the next few days in Norfolks includes rain, wind and cooler temerpatures so we'll see more brooding behavior by the adults. You can see the female spreading her wings to provide cover for the chicks - as they get larger and more mobile, it is harder to keep all three tucked under.






Friday, March 19, 2010

“VDGIF and Eagle Conservation”

What Does the Department of Game and Inland Fisheries (VDGIF) do to conserve eagles in Virginia? This article from Virginia Wildlife provides a great look at some of the work VDGIF biologists do.

The Virginia Department of Game and Inland Fisheries is the state agency responsible for the conservation and management of the Commonwealth of Virginia’s wildlife and fisheries resources as well as recreational boating.

Nongame species (those that are not hunted or otherwise harvested) are monitored and managed by the Nongame and Endangered Species program of VDGIF. Biologists with this program work to increase our knowledge regarding these species and provide guidance regarding the conservation practices necessary to maintain the rich diversity of Virginia’s wildlife. More information about Virginia’s wildlife and VDGIF’s conservation efforts can be found here http://www.dgif.virginia.gov/wildlife/.

VDGIF and Eagles
Here’s some of the of the ways VDGIF works to conserve bald eagles and golden eagles:
• Funding for Virginia Coastal Plain bald eagle nest monitoring 1977-2008
• Boat and Aerial Surveys of bald eagle Concentration Areas
• Twice monthly monitoring of Cats Point Creek Bald Eagle distribution and abundance
• 2010 – 1st ever survey of Piedmont and Mountain area bald eagle nests
• Capture and banding of bald eagles
• GPS telemetry of bald eagles
• GPS telemetry study of golden eagles in Virginia

You can support these efforts through a contribution to the VDGIF Nongame Wildlife Fund

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Sunday, March 14, 2010

“All Three have Hatched”

As of Sunday March 14th, all three of the bald eagle eggs at the Norfolk Botanical Garden have hatched. The second chick was seen in the early morning hours on March 13th, having hatched at some point during the night. At approximately 12:30 pm a pip was noted in the third egg. Early this morning pieces of the third eggshell were seen and shortly after 9:00am the third chick was seen being fed.


It wasn't until shortly after 2:00pm that all three chicks were seen at the same time. The third chick wasn't fed in this video, but still has the absorbed yolk to hold it over until its ready to join in regular feedings.
video
These three young eaglets will grow rapidly over the coming weeks. Apart from increasing in size one of the first notable changes will be the replacing of their fluffy down with a heavier, gray woolly second down. This second down is typically grown in at about two weeks, by which time the young birds will be able to thermoregulate (control their own body temperature) and won't need to be brooded as much by the adults.

Friday, March 12, 2010

“Signs of Hatching for Second Egg”

We have seen a clear pip (initial hole at the end of the egg) in the second egg. This is an outward sign that the hatching process is moving along. This hole will be enlarged as the chick works to hatch out of the egg. The chick will continue rasping at the egg with its egg tooth until the two halves of the egg fall apart. This process may happen relatively quickly but can take days.

An eagle cam viewer managed to capture a video that shows the pip.
video
Also note in this video that the 1st chick is being fed and has been quite frequently today. The female delicately tears tiny chunks of fish to feed the tiny eaglet, which probably weighs somewhere in the neighborhood of 3 ounces. the male has been bringing in plenty of fish and they are stocked in the nest for easy access. the fish are gizzard shad, a common fish in nearby Lake Whitehurst, and a frequent prey item for this pair.

“Rainy Day”

The eaglet at the Norfolk Botanical garden has started to gain strength, and is now able to raise its head. despite the rain in Norfolk today the adults are keeping the chick warm and dry.

The chick hasn't had its first meal yet. This isn't unusual, the chick is still using the yolk it absorbed before hatching. The female has shared a few drops of water from her bill with the eaglet and we'll watch to see if the male returns with food.

Thursday, March 11, 2010

“First Egg has Hatched”

After watching and waiting for a couple of days we can confirm that one of the bald eagle eggs at the Norfolk Botanical Garden has hatched. Almost 39 days since the first egg was laid biologists (and camera viewers) were able to see an empty eggshell at 1:10pm on March 11. Both adults had been quite restless while incubating throughout the day - often peering down at the eggs, letting us know that something was happening there.

It took a while for us to get a clear look at the young chick, but you can see it in the video below. The chick would have been wet when it hatched but has now dried out and is covered in fluffy white feathers called natal down. The young eaglet will need to rest for a bit before it is able to raise its head and move around. It doesn't need to eat right away, as it absorbed the yolk from the egg prior to hatching. When it does eat its first meal the adults will tear the food into pieces small enough for it to eat. The adults will continue to keep the hatchling warm by brooding it (keeping it tucked under their breast) because the young eagle can't yet control its own body temperature. Keep watching over the next several days while we wait to see the other eggs hatch.

Many thanks to Mrs Westlund's 1st Grade class at Yorktown Elementary School for letting me watch the hatching with them

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video


Wednesday, March 10, 2010

“Still waiting”

Throughout the day we watched the nest closely hoping to catch sight of a pip (the first hole a hatchling makes in the egg). The female was quite attentive to the eggs, often raising up to peer down intently at them, perhaps indicating that she can feel or hear the chicks efforts to break through the egg. There were some intriguing views of the eggs which suggested that here might be small pips started...but nothing definitive was noted. We'll simply have to wait and see what tomorrow brings.

Given the 1st egg's delivery into a snowy nest there has been speculation that this "late" hatch indicates a problem. Keep in mind that this pair has incubated longer in the past. In fact, the first egg from last year was incubated for almost 39 days (38 days 20 hours).

Tuesday, March 02, 2010

“Inside The Eggs”

The embryos inside the eggs continue the final stages of development. At this point many recognizable structures are in place and the major organ systems are largely formed. There are no highly detailed studies of the embryology of bald eagle eggs - but we can use studies from other raptors, namely American kestrels (Falco sparverius) as a rough guide to what might be happening inside the egg.

By now the feathers of the natal down are in place. The bill has started to harden and scales are covering most of the legs and toes. The eyes are closed and the complexus muscle (hatching muscle) has begun to swell. Much of the remaining amniotic fluid inside the chorioallantois membrane (see archive for egg diagram) has been absorbed. We’ll post again in the coming days with more of what’s happening inside the eggs as they get closer to hatching.

This information is based on:
Pisenti JM, Santolo GM, Yamamoto JT, Morzenti AA. 2001. Embryonic Development of the American Kestrel (Falco sparverius) External Criteria for Staging. J Raptor Res. 35(3):194-206

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