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Sunday, April 01, 2007

The Real Sea Hawk

Dana over at Principled Discovery did such a good job connecting bird migration to homeschooling issues that I was inspired to return to my look at birds, the original reason I started this blog.

The osprey is found throughout western hemisphere. They can be seen year round in Florida and Baja California and the like, but they migrate from the northern areas of Canada and Alaska all the way to Chile and Argentina. Indeed, ospreys can be found on every continent except Antarctica.

Ospreys are one of the largest birds of prey in North America. They are perhaps 2 feet (54-58 cm) long with a wingspan of up to 6 feet (180 cm) and weighing up to 4 pounds (2000 g). (Like most birds, the females are typically larger than the males, up to 20% more in weight.) Their primary (almost exclusive) diet is fish (thus the common name, "fish hawk" or "sea hawk"). These birds were seriously impacted by pesticides in the late 20th century, but their numbers have since increased dramatically thanks to Man's intervention.

As it turns out, ospreys don't seem to mind at all being around humans. They are quite happy to build nests on top of man-made poles, platforms, or any elevated flat surface. (Take a drive across Florica sometime, and you'll likely see a whole bunch of these platforms, mostly with osprey nests on top.) So they have taken up residence wherever they can as long as there is water and fish nearby, and the climate is suitable.

Ospreys are amazing fishers. Their keen eyesight allows them to see fish from a height. Their flying skills will often put them in a hover over their intended prey. Their brains automatically calculate speed, trajectory, parallax, all that is required to figure out where they will need to be to land on this fish and how to get there. When the time is right, they fold their wings and plummet into the water, hitting feet first. They are known to sometimes completely submerge to reach their fish. Without giving it a thought, they sink their massive claws into the prey, holding it in such a way that when they fly it will be facing forward, making it aerodynamic. Ospreys rarely release the fish they grab. They have been known to latch onto fish bigger than they can fly away with and end up being drowned, but letting go is just not one of their options. Generally there is no reason to let go. They are powerful fliers. They have long, curved talons, spiny pads called "spicules", and a reversible outer toe all to assist them in gripping large, slippery, struggling fish. According to those who know, ospreys can catch fish up to 74% of their dives. I suspect that's far better than most human fishermen.

Ospreys tend to be monogamous, so to speak. They will typically mate for life. In fact, they will typically use the same nest year after year. (Typically a great deal of time is spent in repairs each year before any kids arrive.) The female will lay three or four eggs. These eggs don't hatch simultaneously. They spread out over 5 days or so, with the first one ending up dominating the rest. As long as food is abundant, this is irrelevant. If food is sparse, the younger ones are likely to starve. Then, after 8 weeks or so, these offspring begin to leave the nest. When the eggs are laid, the female will spend most of her time on the nest, while the male provides for her. Once they are hatched, both parents will switch off hunting and caring for the young.

Ospreys teach us a lot. They illustrate, obviously, design in nature. Their structures, from beaks to wings to eyes to talons are all "designed" to do what they do -- fishing. Evolutionary naturalists find it hard to avoid the word "design" in the case of the osprey because it is so evident. Their talons and spiculed feet would have little use if it weren't for their sole food source -- fish. And the fact that they can submerge in a dive and hold their large prey in an aerodynamic way in flight just screams "design" over "chance". They also illustrate tenacity. No fish too big, no task too large, no letting go. They will do what God designed them to do and they won't easily surrender, even when it gets tough. One thing that ospreys say to me, however, is in their nesting. They go to great efforts to make a "spiny" nest on a poorly accessible platform to defend their young against predators. Then ... they leave the results up to God. Sometimes we have trouble balancing the two concepts. Is it a lack of faith to take precautions? Or is it foolishness to fail to take precautions? Finding the balance between "taking precautions" in life and "trusting God" isn't always easy. Ospreys do what they can and don't sweat what they can't control. I like that approach.

Photo credit:
My father sent me the picture. It was taken in Carlsbad, California, by an avid bird photographer he knows. I had to include the picture; it is stunning.

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