Notes from the Nest Cam

4/8/17 – Finally, a glimpse of Hr 5!

4/8/17 – At long last…viewers have been anxiously awaiting to catch a glimpse of a second eaglet in the Harmar Bald Eagle’s nest, and it seems like the long wait is finally over!

Look closely inside the circle to glimpse an eaglet. 4/8/17

This screen shot captures one eaglet, but you should be able to see both Hr 4 and Hr 5 in this video of a feeding from this afternoon if you watch for movement where the circle indicates. The very end of the video shows a close-up of a brief clip of some typical sibling interaction.

My guess is Hr 5 made its way out of the shell overnight, or in the very early hours of 4/8/17, as there was no indication of an attempt to feed the second eaglet until this afternoon.

 

4/5/17 – A glimpse of Hr 4

4/5/17 – The Harmar eagles gave us a brief glimpse of the new eaglet this morning. It is hard to know what you are looking at in this screen shot, but the circle lets you know where to look for movement in the video.

First glimpse of Hr 4 on 4/5/17

Also, there was an attempt at a first feeding just a bit later in the morning. It does not appear very much food made it into the little eaglet on this attempt, but that is normal. After the remainder of the nutrition from the yolk is used the eaglet should become more successful in feeding.

4/4/17 – Hr 4 seems to have arrived on 4/4!

4/4/17 – This evening at 6:28 pm EagleStreamer saw an egg shell being removed from the nest bowl at the Harmar nest. It seems there has been a hatch! We have yet to see any feedings, however both the male and female have ‘considered’ it. There is food on the nest and they have gone to the food and looked into the nest bowl several times.

Harmar female removes what appears to be egg shell on 4/4/17

Here is a video of the event, and I will be sure to post more videos once we see a feeding and actually get a sighting of the chick.

Another peek at what appears to be egg shell from Hr 4, taken on 4/4/17.

Here is a great close-up:

Close-up of egg shell in female’s beak 4/4/17

4/3/17 – Eaglet season in Pittsburgh

4/3/17 – Eaglet season is upon us in Pittsburgh. At the Harmar nest we have seen behavior that looks like the adults ‘listening’ in the nest bowl. This may be an indication that hatching is imminent. Keep your eyes on the camera on the nest for signs of feeding to let us know that a hatch has occurred.

Also, it seems the Hays female surprised us with more eggs than we knew about. After the nest tree fell, the pair rapidly re-built a new nest. Nest building is a bonding ritual that can boost the hormonal surge, and apparently, combined with the loss of the previous eggs, was enough to keep the female ovulating. With all the great photographers in the area, I suspect there will be solid evidence of this coming soon.

 

3/17/17 – Happy St. Pip Day?

3/17/17 – Fans of the Hanover Bald Eagle‘s nest can celebrate this year’s St. Patrick’s Day with pip-watch! What is pip-watch? It is when people who watch nest cameras anxiously anticipate the coming pip, of course! What is a pip? Pip stands for ‘peep is pecking’ and it means an egg is beginning to hatch.

There are two forms of pip, the internal pip is when the chick breaks through the inner membrane, underneath the shell, and the chick can begin to breathe the air inside the shell. The external pip is when a small hole appears in the shell, and the chick can start to breathe air from outside the shell. The internal pip can occur 1-2 days before the external pip.

How do these pips occur? There are complex hormonal and chemical changes that occur that influence hatching, but simply put there are two main adaptations that assist the chick in hatching: the egg-tooth and the hatching-muscle.

The egg-tooth is a sharp projection on the top of the bird’s beak that breaks the inner membrane, and then the egg-tooth is scraped against the shell to create the hole that we can see in the shell. The egg-tooth falls off or is worn away within a few days after hatching. The hatching-muscle is a strong muscle on the back of the neck that helps the chick push its head back or up against the shell.

Image result for egg tooth raptor
Egg-tooth visible at the end of the beak. Photo credit: Raptor Resource Project.

These processes take time. Once the external pip occurs it can take up to a day or more for hatching to be complete. The chick’s body has to adjust to the physiological changes that take place when it goes from getting nutrition from the yolk to breathing air. The yolk is also resorbed in this time. The respiratory and circulatory system need to adjust to these changes. Some of this time is spent resting and recovering from the exertion of breaking out of the shell.

Vocalizations may also occur while the eaglet is still inside the shell. Eaglets can be heard 12 hours or more before the pip occurs. For some types of birds these vocalizations serve to synchronize hatching of the clutch.

Here is some more information about the anatomy inside an egg. If you would like to see a closer look at a pip, here is a video made from this season’s hatching at the Southwest Florida Eagle Cam.

There are always exceptions to the rule! Did you know that kiwi, and ‘megapodes’ like the Australian Brush-turkey and NewGuinea Scrubfowl, use their feet, instead of an egg-tooth, to break out of their shell?

3/14/17 – Hanover eagle covered in snow by nor-easter

3/14/17 – The nor-easter dumped enough snow on the Hanover nest to cover the female (again) as she incubates two eggs.

Hanover female covered in snow 3/14/17. Image courtesy of the Pennsylvania Game Commission and HD of Tap.

The female took her time coming out from under her snow blanket this morning. The eggs likely remained warm under the blanket of snow, as snow is a good insulator. Feathers are a wonderful insulator too, as evidenced by the fact that none of the snow melted off the back of the eagle. The trick over the next few days will not be keeping the eggs warm, but keeping them dry, as the snow melts. This time-lapse video shows the Hanover female uncovering her eggs briefly this morning. You can see the eggs, and the egg cup, appear to have remained dry. The female’s feathers under her body and legs appeared to be dry also. There are plenty of grasses and straw near the nest and I suspect we will be seeing new nest material brought in as the snow begins to melt.

That does not mean that there is no chance of nest failure, as the Pennsylvania Game Commission is studying the effects of severe winter storms on the nesting success of Bald Eagles. What can you do to help the eagles thrive through severe weather? Tell your politicians that you believe in science and understand the impact that high carbon emissions have on a changing climate. Support the use of ‘green-energy’ alternatives over the increased use of coal. Be aware though, no matter how much we curb greenhouse gas emissions today, it will take many years before an impact is felt, as the climate is expected to continue to warm due to emissions that have already occurred.

Hanover female buried in snow early morning 3/14/17. Image courtesy of the Pennsylvania Game Commission and HD on Tap.

2/27/17 – Harmar’s turn for an egg!

2/27/17 – Well, after dark this evening the Harmar female returned to the nest while no one was watching and she now appears to be incubating an egg! Since this happened after dark, when no one was watching, we will have to see if footage is available to be reviewed later, so it is unclear at this time exactly when this happened, but it seems to have occurred between 8pm and 8:42pm. EagleStreamer was kind enough to set up this HatchWatch Clock for us. If footage does become available I will be sure to pass it on for everyone.

Annette Devinney captured this shot of the Harmar eagles a few days ago, thanks for sharing, Annette!
Annette Devinney captured this photo of the Harmar eagles on 2/26/17, thanks for sharing, Annette!

2/19/17 – Hays eagles re-nesting after loss

2/19/17 – It was one week ago when the Hays Bald Eagles lost their nest, nest tree, and first egg of the season, when a severe storm uprooted the tree from its water-logged soil. For a storm to topple a nest is not uncommon for Bald Eagles, and I expected the pair to  get right down to re-building a nest (or to steal a nest from some local hawks) very fast. Why? Because there was every reason to believe there were more eggs to come, and very soon!

It takes about 10 days from the beginning of development until an egg is laid. An ova (an immature egg) needs a few days to ‘mature’ in the ovary, growing about 1,000 times larger. Once the ova is released it takes about three more days to travel down the oviduct to become fertilized, and then another three or four days for the membranes and shell to develop before subsequently being laid. Ova are released from the ovary about every 3-4 days, so with the first egg laid on February 10, that meant egg the second egg would have been released from the ovary on February 3rd or 4th, and the third egg would have been released from the ovary somewhere near the 6th through the 8th of February—before the loss of the nest.

Once the egg is released from the ovary there are only two (good) options: lay the egg, or resorb the egg; if one of these options does not happen a serious condition called egg-binding can occur. So, it is highly likely that the second egg was laid, and abandoned, as there was no nest to use for incubating. The reports of what appear to be incubation activity would likely represent the third egg, and be part of the first clutch. So far, the Hays female has laid three eggs in each of the years they were viewed with a nest camera, so there was reason to believe she would have three eggs again.

In the rare instances when eggs are removed, or lost, from a Bald Eagle they sometimes re-clutch. However, this involves a hormonal surge to prepare the ovary to mature an ova and release it, plus the week or so it takes for the egg to travel down the reproductive tract before being laid, so there is quite a delay in the laying of a second clutch.

I doubt there will be another egg, representing a fourth, but the disruption in the nesting season, followed by the hormone-boosting nest-rebuilding could theoretically lead to the maturation of more ova. However, this represents yet another problem. If another ova began maturing and was subsequently laid there would be a big gap in the timing of the hatching of the egg from the first clutch and that of the second clutch. This would lead to the probable demise of the second-hatched chick due to siblicide, as older, larger chick would dominate the food. There is no evolutionary advantage to this scenario, as the second clutch would be costly yet unlikely to yield a benefit, hence my doubt that it will occur.

Francis Herrick, who pioneered the use of blinds to study nesting birds, reported back in 1932 that Bald Eagles can build a nest in as little as four days, which is exactly how long it took the Hays pair to build the nest they appear to be using for incubation. I suspect this rapid nest-building is an adaptation for exactly this type of situation, and in cases where nesting season is farther in the future, they take their time building the nest.

For the remainder of this season the Hays fans will have to rely heavily on ‘trail reports’ for information, as the camera can not be moved to another location now. This would disturb the birds and is illegal. PixController is able to give you a glimpse of the nest through the trees from the current camera installation.

What a wonderful learning opportunity these nest cameras represent! If you want to learn more about what is inside an eagle’s egg, or how they develop, check out these sources:

Which came first, the chicken or the egg?

Eagle eggs, when and how they develop

2/11/17 – Bald Eagle nesting season has arrived

2/11/17 – You may already know that the Bald eagle nesting season in Pennsylvania has arrived! Both the Hays and Hanover females laid their first eggs of the season within minutes of each other on Friday evening 2/10/17. Because they are on live camera there is video of the Hays female laying her egg, with the male coming in to assist the best a male can in these situations, as well as the Hanover female laying her egg. The Hanover female has been incubating with some time off the egg, which is perfectly fine at this stage of development. The Hays female, on the other hand, has not been incubation her egg as much. She has not abandoned the egg, but it is possible she is attempting to delay incubation. This is a possible adaptive strategy aimed at assuring the first and second eggs hatch more closely together, thus reducing the size difference between the two chicks and potentially increasing the chances that both get enough food to grow rapidly. Delayed incubation was not previously thought to occur in Bald Eagles, but nest cameras have allowed scientists to witness nesting activity in ways they never could before. If you would like to contribute to a study of nesting behaviors of Bald Eagles by watching nest cameras, you can find more information about the Egalitarian Science study I am currently working on.

If you recall, the Harmar female generally lays her eggs a few weeks later than the Hays and Hanover females. Annette Devinney captured this photograph of the Harmar pair getting ready for the nesting season, thanks Annette!

Harmar Bald Eagles mating on February 8, 2017
Harmar Bald Eagles mating on February 8, 2017. Photograph by Annette Devinney

Meanwhile, the Harmar nest had a visitor again this season, a Red-tailed Hawk was seen spending several minutes in the nest. It is impossible to know if this was one of the hawks that used to claim this nest, as several are frequently seen in the area. Thank you Dollyqueen and Jerseyme for capturing and posting the video!

 

 

1/6/17 – Visit to Sea-EagleCAM

1/6/17 – I have just visited with Geoff Hutchinson, a researcher at the Sea-EagleCAM who is studying the White-bellied Sea-Eagles that are nesting at the Sydney Olympic Park. Geoff is responsible for providing the nest camera and live streaming of the video to the public. I had a wonderful visit learning about the research that they are doing and have several new ideas to incorporate into our research of the Harmar and Hays Bald Eagles for the upcoming season.

White-bellied Sea-Eagles (Haliaeetus leucogaster) are closely related to Bald Eagles (Haliaeetus leucocephalus) and share a similar lifestyle. You can learn more about White-bellied Sea-Eagles from their website, and be sure to explore the information provided about the research they are doing.

During our visit the pair was sitting side by side on their fishing tree and I snapped these pictures.

Sydney Sea Eagles in their fishing tree 1/6/17
Sydney Sea Eagles in their fishing tree 1/6/17
Sea Eagles up close 1/6/17
Sydney Sea Eagles up close 1/6/17