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Lifting Capacity of Eagles

Bald Eagle Biology

Eagles are predators but they have a very small lifting capacity.  Many times I have described our experiments and field observations on what eagles can lift. 

Generally a male can lift about 1.5 pounds and a female up to 2.5 to 3 pounds -- the latter if there is a good headwind.  However, this is not even lifting this weight for more than a few 100 yards and not necessarily up to a nest.

On the other hand, many a small cat, or parts of a road killed cat, can be lifted.  Eagles have great difficulty handling mink or cats because of 'fighting back' with sharp claws.  So a big 8 -10 pound cat is certainly beyond a bald eagle's capacity but parts of one, particularly cut by vehicle traffic, can and are lifted. 

We have the same frequent problem here but the predator is the coyote -- some live almost exclusively on cats. Raccoons take cats but a big cat can out-climb and out-fight or out-run most coons.

As you probably know cars take most cats.  I and a few close neighbors lose one or two of our barn cats each year. We see them dead on the road or their blood smear left when the coyotes got to them before I could even throw them off the road or bury them.  I recently wrote an item about road kills -- and the good source of food they are for eagles.  However, the other side is that eagles are often killed eating road kills and I spend a lot of time throwing kills off the road for this purpose.

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Bald Eagle US Legal Status Update

Bald Eagle Biology

Bald Eagle US Status Update -- from the Center for Biological Diversity.   (DH wrote this June 24, 2007  7:54pm)
((June 22, 2007))

It is always good to see something positive in the conservation field. Generally we humans continue on our destructive path: overusing and overpopulating the world -- our ecological footprint ever destroying the worlds natural resources that we depend upon. The Center of Biological Diversity has just correlated the latest estimates of breeding pairs of bald eagles for every southern state in the US. . 11,040 pairs for 2007. WOW!

In their Washington State data,
up from 100 pairs in the 1970's to over 835 pairs for 2007, I feel the British Columbia's population has done wonders in repopulation our southern neighbors territory. Lets hear a round of thanks!

When I started eagle surveys in the early to mid 1950's as I was logging time for first my private pilots license and then my commercial license, I could not find a single nesting pair of bald eagles down the entire coastline and adjacent San Juan Island between BC and southern Puget Sound around Seattle. I had over 100 nests in the adjacent BC southern Gulf Islands. And another 1000+ nests around Vancouver Island.

The Alaska bounty,
just ending in 1953, had had its incredible impact. As I have reported elsewhere many of the Alaskan commercial fisherman lived and wintered in the Washington State ports just south of Vancouver BC. For years, all winter long the fisherman had shot the "vermin" eagles, cut off their feet and legs, thrown them in the plastic pails on their boats, ready for turning in for $2.00 when they returned to Alaska in the summer fishing season. The bald eagle had been shot out of coastal Washington by the mid 1950's and had almost disappeared from the Lower Mainland / Fraser Valley region of Great Vancouver. In 1963-65 I could only find 3 pairs of nesting bald eagles in the Greater Vancouver area. Today, another sign of how they have come back so successfully, I have over 200 pairs in the same area -- and they produce almost twice as many young per nest as wilderness eagles.

Fortunately British Columbia did not offer the bounty. Unfortunately the "vermin" attitude -- the position that all predators or creatures not overtly useful, were therefore definitely negative, was continent-wide. All hawks, falcon, eagles, coyotes, wolves etc were the 'target focus" of all the rifle, ammunition and scope ads in every hunting magazine -- in the US and Canada. Now the gun and ammunition sellers have promote "fear of fellow humans" to continue gun sales. If you can't shoot eagles, shoot a religious extremist!

Eagles, the biggest and most vulnerable target suffered immensely. But every seal, sealion and orca was also pasted with bullets -- by sportsman and government fisheries officials as well. Persecution of predators was a national pastime and disgrace. Thank goodness for the attitudinal shift on the late 1960's -- the result of Rachael Carson's pesticide alert. Predators, who had suffered the most from loss of habitat, shooting persecution and then pesticide poisons working up through the food chain, began to be appreciated for their necessary role in the ecosystem. Most have responded very favorably. The bald eagle is a spectacular recovery story.

I have posted the Center of Biological Diversity summary map showing the southern states updated figures and the details for Washington State -- they give them for every state Check it out -- you all have lots to be proud of.

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Just think, what if we gave them back their trees along the shoreline (or artificial ones in the meantime!) and their waterways unpolluted -- no that's too much to expect so lets just be thankful for what the eagles have done with just by not being bountied --- and with a few souls truly loving and appreciating them.

Sure some of you are worried that without this extra protection, particularly to nest trees and habitat, some habitat will be lost. And this is true. But we should be protecting the habitat not just for eagles but to protect the entire ecosystem. Conservation is about preserving biological diversity -- the interrelationships that keep all living systems going. It is habitats that sustain ecosystems: not individual trees. Get out and protect the woodlots, the ponds, the forests , the beach and intertidal zones. That will protect the eagles and their food supply and nesting trees. It is totally counter productive to be thinking about one species. We are dependent upon communities of life. Get involved with you local governments and protect what little is left. Enough is enough.

Thanks to the Center for Biological Diversity for a great deal of effort to correlate the data pointing out a small step in the right direction,

david hancock

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Thoughts on Nesting Problems

Bald Eagle Biology

 

Thoughts on Nestling Problems:    Written:  Sat May 23, 2009 6:02 am

Nature does not always progress on a parallel course to our thoughts of kindness. The lessons are often rough and seemingly not compassionate. And the lessons are many.

Each year we have been through sibling rivalry that nearly resulted in death -- but never has in any of our nests. This in fact is a constant threat for the younger or smaller chick in every nest. Then there are totally unexpected or even previously unknown causes of death like we all suffered through with the loss of Echo.

Concerns on Rescue or Not to Rescue a Chick!

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Bald Eagle Nesting Season -- a Review of Dates and Events

Bald Eagle Biology


Recap of Bald Eagle Nest Sequence:  territory defence, egg laying, hatching & fledging.


Bald eagles occupy almost the entire calendar year with their breeding cycle.  This cycle covers 10 to 11 months from territory occupancy or re-occupancy, territory defense, nest repair and building, egg laying, incubation and feeding of young through fledging, to also include a short   ... for more ....

 

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To Lay or Not to Lay -- is that an Imperative?

Bald Eagle Biology

 


What can Stop an Eagle Laying?.



Interesting question.  The process of laying an egg is not without some considerable preparation on the part of the female.  Probably some months -- maybe a few weeks in eagles -- the body begins to prepare for the egg.  The pair bonding, the hollering, the courtship flights, the intimate moments including frequent mating,  has already stimulated the flow of hormones and started the process by which the ovary starts to develop minute eggs into full sized yolks that will erupt the body.

So for a few months the development is within the ovary but there are simultaneous changes taking place in the oviduct. It is growing the different areas where the protein and.....

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