Naturespeak A naturalist's view of the world

May 5, 2011

Fish Eagles on a Sparrow Nest

Filed under: Uncategorized — wykes @ 9:29 pm

There is life on the rugged looking Osprey nest at Estral Beach once again. Although this pair actually built the nest last year, they were unable to complete their breeding cycle. A monster late spring windstorm might have had something to do with it – disturbing the nest and eggs and forcing the pair to write the 2010 breeding season off. Fortunately, they are back this season and now appear to be making another go of it.

Arriving the week before Easter, or thereabouts, the pair wasted no time in starting new construction on the old homestead. I tried to check in with them as much as possible throughout the process, but my visits were brief. Weeks of rainy weather, steel gray skies, and high winds made osprey watching difficult to say the least. Each and every time, however, I was able to witness one of the birds either in the act of delivering or positioning a new nest stick.

On Easter morning, during one of the few recent rainless periods, my son and I watched as the birds “hunted” for nest material. There is a woodlot about a half mile away, and they would fly straight to this location to seek their wooden prey.  Once on site, they would dive down on a selected branch and grasp it with their talons. By the force of momentum and sheer body weight (the birds weight about 4 pounds soaking wet), the dead wood would snap off under pressure and the liberated stick would be carried back to the nest. Each was then carefully placed into proper position. Much of this work appeared to be done by the female, but it was difficult to tell them apart.

Female ospreys tend to be larger (15%-20%) and slightly darker than the males, but this is a relative statement. The gals tend to have a bib of dark speckling across the upper breast as well, but, then again this is not an absolute thing. Both birds in this pair have neck bibs, but one has a distinctly darker band. It is reasonable to peg this darker bird as the female. I am too much the gentleman to tell her that she looks fatter than the male, so this will have to do for the present.

In between nest construction, the birds paused to feast on freshly caught fish. This is their forte after all – they are superbly adapted to the task with extremely long talons, rough foot pads, and wickedly long bill hooks. It takes but a short time for them to render a whole fish into a memory as they rip off bite sized chunks (see here). In the manner of parrot, ospreys hold and deftly manipulate their food using one foot at a time. In the shot below, you can see that the bird just plucked the last chunk out of his raised left foot .

Probably no other bird of prey, save for owls, have such large forward facing eyes (see here). These big bright beautiful orbs are yet another key to their fishing prowess. They are able to pin point their targets with the aide of precise binocular vision. It might not be too forward to suggest that they could be better called Opt-preys in honor of their optical abilities (the “Os” in Osprey, by the way, refers to “bone” – they are bone crushers). Yes, I know that is a stupid suggestion but I thought I’d just throw that one out there.

The piscatorial delights of Sandy Creek and Lake Erie are only a short distance away from this couple’s nest location which is why they built the thing where they did. Just like human real estate, nesting is all about location, location, location. When those kids and their hungry mouths arrive, the super market needs to be close by.

The female (the “bigger” one) started incubating late last week. The pair has settled down to a regular routine as they now wait out the 32-40 day process. On one of the recent warm days (the only warm day last week) I even caught a bird napping (see below) in the late afternoon sunlight. I would not call this cat-napping because, well, it is a bird and that particular word might offend feathered types. Let’s just call it a Sushi sleep.

I will keep you updated on the future events as they unfold but there is one more thing worth mentioning in this case. Because the nest structure is so large, there are actually several bird pairs producing young in that tangle of sticks. A set of House Sparrows have taken up residence in the lower apartment space and a Starling couple were seriously looking into the east room. The tenants will not need to fear their fish-eating landlords. At any rate, there are going to be a lot of hungry little mouths chirping in that pile of sticks within a few weeks.

1 Comment »

  1. I hit the light switch a nanosecond before the door opened a crack. Then stopped.

    Comment by casquette supreme — May 20, 2014 @ 8:55 am

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