Saturday, February 8, 2014

Pride and Joy in an eagles' nest

The first hatched of the two eaglets in the nearby Pembroke Pines nest is four weeks old this weekend (February 8). I try to get out to the nest as often as possible to monitor their progress. We do not have the luxury of a nest camera, so we must do our watching the old-fashioned way.  See a "Family Album" of all the known eaglets over seven breeding seasons.

This morning (February 7) it was cool (68 F), very foggy and drizzling. The eaglets were hunkered down and I never caught sight of them. Only the female parent was present, drying her wings on a Melaleuca snag near the nest tree.

Bald Eagle female 2-20140207

She then flew to a dead tree along the road where the light was better and also the fog was lifting, so she looked more presentable.

Bald Eagle female 3-20140207

Bald Eagle female 5-20140207

Two days earlier, arriving at the nest a little before 9:00 AM I was joined by several others including local nest watchers Millie, Phil and Mary, as well as Deborah, a newcomer visiting from Illinois who hosts the Evanston Peregrine Falcon Watch, a Yahoo group that she started in 2009.  

At first no adults were present and  the older eaglet, the twelfth we have observed since 2008 (whom we designate as P Piney 12), was sitting high up in the nest and her little sibling was hunkered down on the other side. 

The eggs hatch sequentially in the order they were deposited, about 2-3 days apart. We really do not know the sex of the first hatchling, but Bald Eagles selectively produce a female chick first in up to 2 out of 3 successful nestings. Female Bald Eagles are larger than males at all ages and also "resource intensive,"needing more food to survive.

The ordinary gender sequence in good years is equally FM, FF or MM, which results in a 50-50 sex ratio.  If a male hatches out before a female this produces conflict, especially if prey is scarce. The female grows more rapidly and struggles to dominate her older sibling. 

Over a 17 year period on two lakes in Saskatchewan, females were the first or only hatchling in 97 instances versus 67 males. The tendency towards producing females from the first egg was more pronounced during years when food was abundant: 68 females to 32 males. (Reference).

Bald Eaglets P Piney 13 and 12 20140205

At about 9:03 AM the female parent (the eagle watchers know her as Joy) flew in from the east carrying a large long-legged bird. Bald Eagles have adaptations for catching fish, including bare lower legs, very sharp claws and rough scales on their feet. They are generally grouped with sea eagles or fish eagles, but are very adept at capturing other prey and also eat carrion. This pair seems to catch as many Cattle Egrets and White Ibises as it does fish. 

Bald Eagle female brings bird 20140205

Within seconds, the male (Pride) flew in from the west. The second eaglet, P Piney 13, now on the right, is noticeably smaller and has more natal down than his older sibling. 

Bald Eagle male joins female and eaglets 20140205

Pride appeared to want to either share in the meal or to feed the eaglets. I think the latter as he has been an excellent provider. However, Joy spread her wings over the prey and rebuffed him.

Bald Eagle female defends her catch 20140205

Pride retreated to a perch just above the nest, but continued to protest loudly. Joy screamed back in a wailing call that I had not heard before.

Bald Eagle screaming match 20140205

The eaglets kept low during their parents' confrontation, and Joy turned to resume feeding.

Bald Eagle female turns to feed the eaglets 20140205

Joy tore at the prey as the eaglets waited.

Bald Eagle female tears at prey 20140205

She continued feeding the eaglets.

Bald Eagle female continues feeding 20140205

P Piney 12 appeared to be trying to grasp the prey with her huge yellow foot! Like little puppies, they grow into their feet.

Bald Eaglet with big yellow foot 20140205

The eaglets suddenly seemed to be begging to be fed by Pride!

Bald Eaglets beg from male parent 20140205

Pride returned to the nest but Joy again protected the prey. Note the smaller size of the male, and also his very low forehead, helping us distinguish him from his mate.  

Bald Eagle male returns to nest 20140205

They all posed for a family portrait but the eaglets seemed distracted.

Bald Eagle family 20140205

As Pride prepared to fly off, Joy continued to feed her brood, making sure that both got attention.

 Bald Eagle female feeds as male preapare to fly 2-20140205

Mother and daughter provided me with a tender photo op.

Bald Eagle mother-daughter portrait 20140205

Only 20 minutes later, Pride returned with a fish.

Bald Eagle male returns with fish 20140205

The eaglets engaged in a brief confrontation that appeared rather hostile. The older chick suddenly moved towards her sibling, who retreated as the older one seemed to peck at him.

Bald Eaglets hostile confrontation1 20140205

Bald Eaglets hostile confrontation 2 20140205

Joy belatedly became aware of their conflict.

Bald Eaglets hostile confrontation 3 20140205

Identifying the eagles by name probably helps watchers and the many others who visit our FORUM take a greater interest in them as individuals. Over the years we have noted some distinguishing traits and idiosyncrasies such as dominance, favoring certain perches and Pride's avid care and feeding of the eaglets. There is a danger of romanticizing and anthropomorphizing, as it is often difficult or impossible to know the meaning of certain behaviors. The larger eaglet is not a bully or mean-- she is doing what gives her and the species the best chance of survival.

17 comments:

  1. The eaglets are cool, great collection of photos.

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  2. HI Kenneth These shots are priceless and well done that you got them so well. it is wonderful to see the adults and how they behave in the nest. Mum seems to keep order around there!

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  3. Wow, a marvellous series. I really enjoy looking at these magnificent birds. I like that the birds are named!

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  4. family dynamics at work. amazing raptors.

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  5. They are good parents it seems. Wonderful pictures. Sending best wishes to your nest!

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  6. Wow... I didn't know this, thank,you.... Michelle

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  7. Awesome shots! The eaglets are growing so fast.

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  8. Wonderful post! I enjoyed reading it very much and the photos are excellent.

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  9. Amazing family shots! That's a great nest.

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  10. Very nice series, Ken! Good to see a healthy Eagle family.

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  11. Wonderful series. A great angle in to the nest. Fine job.

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  12. Wonderful series. A great angle in to the nest. Fine job.

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  13. I had to come back and look again! Fabulous!

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  14. The good news keeps comming Ken, as regards the Eaglets, I hope they are both of a size now, that no harm will come to either of them.
    All the best Gordon.

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  15. Wow!! They're such an awesome bird. The young look in good shape.

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  16. These are the best pictures I've ever senn around a family of birds! You should be very proud!

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