In my review of the day’s happenings, I note that each time a feeding took place or on one occasion when a parent simply moved a fish, and another when Middle did absolutely nothing, Big began physically attacking the younger sibling. Big’s crop was completely full on several of these occasions. Middle has learned to be careful and to move around watching. Middle even stood on a piece of fish and pulled off some pieces today. That was wonderful!
What is worrying is that despite food today and both with full crops, Big continues its rampage. In fact, the last attack today was the most frenzied and the longest (5 minutes) since Big killed Little Bit and turned on Middle.
Both had crops by 17:30. Big had eaten first then Middle.
WARNING: There are images showing Big beaking Middle.
At 17:56:05 Obey delivers a fish to the nest. Both chicks are so full that despite River’s calling, they don’t even think about eating.
Obey leaves the fish by Middle along the edge of the nest. It is a fair size Sucker with its head.
River goes to move the fish over for a feeding at 18:22:15. Big begins her attack on Middle. This is meant to completely intimidate the younger sibling from eating and is referred to as ‘sublethal’ fighting.
It is a good time to stop and look at the size difference between the two siblings in the image below. Big is an enormous eaglet. According to Mock, Drummond, and Stinson in their article, “Avian Siblicide” published in American Scientist, “…the size difference between siblings was important in determining the outcome of bouts of sibling aggression. When the size difference was large early in the nesting period, the first-hatched chick almost invariably pecked, bit, and thrashed the second-hatched chick into submission (189).” In the Dale Hollow nest, Big turned on both but focused her attention on killing Little Bit. She then turned on the second sibling, Middle. It is believed as the size difference decreases, so will the frequency of aggression. Big requires lots and lots of food. They are both 25 days old today and are entering a period of super growth. Will Big’s growth slow? and Middle’s increase? We can hope.
Look at the difference in size between her wing and Middle’s – even the tail and head are more than twice the size. Middle would be killed if he tried to fight her – and for what? He finished eating about half an hour before this fish lands on the nest. He had a nice crop. Best to hunker down, hide his head and hope that she gets tired of attacking him and goes to eat.
It is clear that Big actually enjoyed the frantic beaking. It lasted from 18:22:15-18:27:42. That is almost five minutes. This is an increase in not only time but the amount of beaking in the frenzy.
Big tried to reach over Middle so that he could get to his head.
Then he physically moved so he could. Big was determined to not only frighten but, it appears, to injure his sibling despite the fact that his crop was full and he had eaten in the last hour.
That is the longest attack since the ones the day Big killed Little Bit. Middle is terrified and does not hardly move during the entire time that River fed Big. Middle really needs a huge growth spurt to help it counter these attacks. It is well know that once it reaches a larger size, Big will no longer be able to fatally injure it.
Once River finishes, Middle raises its head cautiously. You can see that there is a large portion of fish remaining. Obviously enough for a calm feeding for two! So why is Big amping up the frenzied attacks on Middle today? This is the worst one yet.
Sweet little Middle looks over at its sibling. Does it wonder if it is safe to move?
River flew off and Big fell asleep. Middle is looking around from the centre of the nest by Big.
River flew in. She did not feed either chick. She is brooding them.
It has been quite an unnerving day on the Dale Hollow nest. The eaglets were not fed til late and this clearly agitated Big whose attacks on Middle during the day increased in their time and frenzy. Let us hope that tomorrow is a better day for our little Middle.
Thank you for joining me. I am sorry that this is not a joyful jumping up and down report. This nest is still very unstable and anything can happen, sadly. Take care everyone.
Thank you to the Dale Hollow Eagle Cam where I took my screen captures.