Tag Archives: siblicide in eagles

Thursday in Bird World

16 June 2022

Wednesday came with some surprises – each of them involving a Bald Eagle. A Bald Eagle visited the Cape Henlopen State Park Osprey Nest for starters.

The way the eagle looked over and down at the nest it appeared that it understood ‘something’ had happened. The eagle did not stay long but it was a surprise to many seeing it on the Osprey nest.

Of course, the second incident with a Bald Eagle was the predation of one of the three osplets at the Cowlitz PUD nest by an eagle. Compared to former years this nest was doing really, really well this year. I believed that the youngest was to the right of Mum when she was feeding with the Middle to the left and Big behind. I have seen mention that it was the youngest taken elsewhere so it is unclear if it was Little or Middle Bob. Regardless this is very sad, indeed.

One reader ‘L’ wondered if the Bald Eagle might have been after the fish that Mum brought to the nest and was feeding the chicks.

The third is the ongoing raising of the hawklet by the Eagle family on Gabriola Island just off the coast of Vancouver Island in British Columbia, Canada. That is one very lucky little hawklet. It arrived on the nest on 4 June as a prey item and by that evening was being cared for and brooded by the female eagle. It looks like it is going to be a good outcome just like the Sydney nest in 2017!

GROWLS just got the funds for the streaming cam last year – and what an interesting first year it has turned out to be.

The hawklet is flapping its wings – the eaglet has also fed the hawklet so it has been fully adopted into the family. In an online discussion yesterday, Christian Sasse does not believe that the hawklet’s life is in any danger because there is plenty of food for the eagles in the area.

@GROWLS

Ferris Akel had a wonderful tour of the Cornell campus last night. It was purposefully to see Big Red, Arthur and the four hawks. He found every one of them! It is nice to be able to share some images with you.

I believe this to be L1. She was the only fledgling not on the nest but was out hunting – or sitting and watching from a lovely pine. Isn’t she gorgeous? A mini-Big Red with that amazing necklace.

Arthur was moving about. He had been with Big Red on the Bradfield Building (where they sleep on the ledge) and then moved to one of the light stands. Both parents were actively watching the Ls from a distance.

Of course, not all of the family cooperated with the lighting situation for the camera!

L4 was a sleepy baby. He kept nodding off. What a little cutie. I will never ever forget this wee babe clamouring over its big siblings to get right up front to eat. L4 was fearless!

L4 has not fledged. L2 just flew onto the nest joining L4. It seems that everyone is encouraging L4 to fledge today! We will see. It has been rainy and mention of a storm system moving in makes me want L4 to stay put. 🙂

What is with the Ls loving to run up and down the rails? This is L4 last evening around 19:30.

Like L4 at Cornell, Sky is the only eaglet not to have fledged at the West End nest of Thunder and Akecheta. Here he is doing a great job of hovering. Will they both fledge today?

Harriet (E1) at the MN-DNR nest of Nancy (and Harry) is now branching.

It is hard to see little Love and Peace in the Glacier Gardens nest of Liberty and Freedom. They are both still there and they are both fuzzy – sweet. Mum has a dirty beak from aerating that nest!

Osplets watching Idris as he takes off after delivering a fish to Telyn for their lunch.

Have you noticed that some of the Ospreys are leaving the greenery growing in the nests this year? It is thought to help against predation (supposedly). The lovely Mrs G and her three osplets at the Glaslyn nest – they have quite a bit of grass growing around the sides of the nest cup.

Dylan loves Brown Trout. Today at 12:12 he delivered a whole on to Seren and the three Bobs at the Llyn Clywedog nest. He didn’t even take a single bite! Oh, the family is going to love that fish.

Poor Dorcha. The wind and rain only let up for awhile it seens at the Loch Arkaig nest in Scotland. Thankfully Louis is a good fisher. The surviving two Bobs are doing well it would appear despite the cold and wet.

There has been continuing concern over the Loch of the Lowes Osprey nest of Laddie LM12 and Blue NC0. Laddie has only been bringing in twiddlers – tiny snack fish. The question was – what is going on? Some felt that Laddie had another eye injury. At any rate, we can take a breath for the moment. He brought in a substantial fish and the chicks and Mum got to eat. Well done Laddie.

Three gorgeous osplets at the Foulshaw Moss nest of White YW and Blue 35 are growing and getting those beautiful juvenile feathers. All three are almost identical in size, too!

Blue 33 is a great provider. He arrived at the nest and there was already a fish there that Maya was feeding the trio – so he had a nice lunch himself. Well deserved for sure! I have never gone to sleep at night worrying about this nest.

It looks like the two wee surviving Bobs at the Llyn Brenig nest are doing alright. Positive energy for continuing growth and success for Mr and Mrs AX6 and family.

Both up at the front of the nest looking off to the world beyond.

Wow! One of the Bobs at the Poole Harbour nest of CJ7 and Blue 22 has grown enough for us to see it!!!!!!!!! Yes.

So far, the food deliveries at the ND-LEEF Bald Eagle nest have alluded Little Bit 17. I am hoping – beyond hope – that prey arrives at the nest and our third hatch gets some food. Send positive wishes please.

The three storklets in the care of Dr Madis Leivits in Estonia are doing great. While everyone would prefer that they could have been raised successfully in the wild by a single parent, it was not possible. The three surviving storklets continue to thrive at the Vet College. Mum has been put back in place and the wee ones can sense when fish are coming! Have a look.

And here is their lunch today!

Here is their latest feeding – a few hours after lunch.

The two Eastern Imperial Eaglets ate side by side – . Fantastic. I always worry about the Golden Eagles and the Imperial ones because of siblicide. Both of these chicks look good. The feeding is quite pleasant.

Bernd-Ulrich Meyburg wrote a paper titled, “Sibling aggression and mortality amongst nesting eagles” in 2008. In that paper he states, “In certain eagle species it is not the availability of food that effects the chances of survival but the interval between hatching. If the interval between hatching is short, the second chick can develop normally and fledge.” The two below are closer in size and it is hoped that they will both thrive and fledge.

We are two days into fledge watch at the scrape of Annie and Alden in The Campanile on the campus of UCalifornia-Berkeley. Cal Falcons have provided another great growth chart on their FB page.

We continue to have some fledge watches at various nests and lots of wishes for prey items to land on the ND-LEEF nest.

Take care everyone. Thank you so much for joining me today. See you tomorrow.

Thank you to the following for their streaming cams, videos, and/or FB pages where I took my screen captures: Liz M, Cape Henlopen State Park Ospreys, GROWLS, Ferris Akel Tours, Cornell Bird Lab RTH, Explore.org and the Institute for Wildlife Studies, MN-DNR, Glacier Gardens, Dyfi Osprey Project, Bywyd Gwyllt Glaslyn, CarnyXWild, Friends of Loch Arkaig, People’s Post Code Lotttery, and the Scottish Wildlife Trust, Friends of Loch of the Lowes and the Woodland Trust, Cumbrian Wildlife Trust, LRWT, Llyn Brenig, Edith P, Eagle Club of Estonia, and Cal Falcons.

Siblicide at Dale Hollow Eagle Nest

17 March 2022

UPDATE: Little Bit played possum. It raised its head at 17:54 and was again attacked by Big. It is unclear as to the status of Little Bit currently. Sadly, it will not – without a miracle – survive the night.

WARNING: I believe it is important to recognize that nature is very cruel and to understand what is happening when you are witnessing siblings kill one another. This blog is about the siblicide that is now happening at Dale Hollow Nest.

River brought a small fish onto the nest around 14:30. The only chick that went up to the table to eat was Big. I initially thought that Big had eaten the entire fish and so, was surprised when River flew off after alerting for some minutes to see a piece left.

The chicks moved from their positions when River flew off the nest. Little Bit moved to the left rim and Middle saw the piece of fish and went over. Middle is too weak and too young to eat it. It was so sad seeming it so hungry and that fish laying there on the nest.

I have actually been watching Little bit to see if it was breathing. Parents come in different sizes with different capabilities. Often young Bald Eagle mothers take some time to figure out how to feed their little ones especially the first chick ever. River is 23 years old. She is an experienced mother.

I continue to ask what is happening on this nest. From what I know, the eagles work to protect their territory above all else. Then they take care of themselves, and then the chicks on the nest.

Middle has moved to the piece of fish and is calling its Mum to please come and feed it.

Middle made a move to lay on the fish and this alerted Big. Big immediately went over to Middle and began beaking it.

When he finished with Middle he went over to Little Bit and began tossing its neck around.

Big stopped. Little Bit was doing some quiet crying. Big went over to the rim and then it turned on Middle again. What you are witnessing is a classic case of siblicide. The older sibling has prevented the two younger from eating through intimidation and physical beaking and neck twisting. It is killing its siblings. In this case these actions appear to be a direct result of lack of enough food for all three on the nest. Indeed, there is barely enough food for one.

Middle moved to the left rim of the nest and has now walked by the fish again and is looking over the nest. Middle seems to be in much better shape than Little Bit.

In the image below Middle has gotten into the shade next to Big. Little Bit is in the heat of the sun. Very shallow breathing.

At 15:47, Little Bit raises its head and cries for food.

Big noticed Little Bit and went over to beak it.

As far as I can tell, Big stopped because it realized that the smallest sibling on the Dale Hollow Lake nest was dying slowly, calling out to a Mum who will not hear it, for food.

Big sibling is hot and bothered today. As you know, at least one parent will be there to shade them especially when they are not able to regulate the temperature themselves.

Did Little Bit ever have a chance? On a different nest, perhaps.

Big Bob went over to Little Bit and then turned again on Middle Bob.

Then he turned on Little Bit.

It appears that Little Bit is barely breathing at 14:27. Big is there, hot and panting hard, to make sure that it doesn’t get up to eat again.

Little Bit had some mini-convulsions at 16:29 and 16:32.

It is 16:44. An adult has returned to the nest and Big has gone over to be fed the rest of the fish. Middle did not bother to go up. Little Bit is barely breathing.

At 16:45, Little Bit actually found the energy to flip a bit – or it was another convulsion. Big immediately went over to make sure that the wee babe did not get to the food.

Big grabbed Little by the neck and tossed it about many times.

Big left Little Bit in the middle of the nest barely breathing. Indeed, I am shocked that Little Bit is still alive. Meanwhile, Middle is at the rim of the nest in the shade terrified.

It is incredible what this wee little one endured over the past hour and a half and is still breathing every so shallow. Big is determined to be the only chick on the nest because the food that is being brought in is barely enough to keep it alive.

It is hard to believe but Little Bit is just hanging on barely breathing.

Big sitting triumphantly over Little Bit. It is 17:10. I do not think Little Bit is with us any longer. Its suffering has surely ended.

We expect all bird parents to be the same and clearly, they are not. I have come to understand that what we have seen on this nest at Dale Hollow is pretty typical for River and Obey. Siblicide has occurred here in previous years. There are gold star eagle families and there are others where circumstances are neglectful. It is likely we will never know what happened in its entirety at this nest to set Big off to try to kill its siblings. We might never know the combined circumstances for the lack of prey delivery or the lack of attention by the mother, River. All I know is that it is terribly sad to see a lovely little chick crying for food while it is dying. At the same time, it is important to call it for what it is – siblicide. This is directly related to the need to survive. Big is the dominant bird on the Dale Hollow nest. With little food arriving, its instincts went into survival gear.

I am attaching a bit of information on a study done on siblicide. I want you to also notice that the individual includes instances of parental neglect. I found this helpful in understanding just how rare or not siblicide is.

https://www.ournaturezone.com/index.php?topic=1495.0

If you have made it this far, thank you for hanging in with me today. This is a difficult topic and it is even more difficult to watch live on a screen. I hope that you learned something and I also hope that none of us see the instance of siblicide again this year. Please take care. It has been a rough couple of days at this nest. I am glad that Little Bit is no longer suffering. I hope that food comes on the nest and Middle is not the next victim.

Thank you to the Dale Hollow Lake Eagles for their streaming cam where I took my screen captures.