OSPREY, the Migratory Piscivore

Dr. James J. S. Johnson

While the earth remaineth, seedtime and harvest, and cold and heat, and summer and winter, and day and night shall not cease.

Genesis 8:22

Migrating birds remind me of what God said in Genesis 8:22, about the predictability of annual seasons. It’s really amazing if you think much about it: God selected Moses to report a conversation that God once had with Noah, at the conclusion of the worldwide Flood. In that conversation God promised Noah (and Noah’s family and descendants, which include all of us) that God would not send another global deluge.

Rather, day-night periods would continue with constant periodicity, plus weather patterns would be stabilized with predictable patterns, such as the cyclical seasons we know as summer, autumn, winter, and springtime. God’s creatures depend on day-night cycles, as well as on annual cycles–such as the 4 seasons which provide predictability to growing and harvesting food crops (Genesis 8:22, quoted above).

But not only do humans depend upon such phenology patterns, so do animals–especially migratory animals, such as many insects and birds. One such migratory bird is the OSPREY (Pandion haliaetus), also known as the Fish Hawk.

Although not all ospreys migrate, most do, according to Donald & Lillian Stokes, A GUIDE TO BIRD BEHAVIOR, volume III (Boston: Little Brown & Company,1989 ), pages 169-170. In fact, most ospreys of North America–such as those of the Chesapeake Bay region–are known for over-wintering in or near South America, regularly returning to North American ranges during spring:

The warmer temperatures have brought with them a familiar Chesapeake icon. Ospreys (Pandion haliaetus) occur in nearly every corner of the globe, but nowhere as abundantly as on the Chesapeake Bay.

Ospreys return to the Chesapeake every spring from southern wintering grounds. Their abundance in the Bay region is due to the availability of food: They feed exclusively on live fish.

Their curved, sharp talons and rough-soled feet are designed to hold on to slippery fish.

Large brown and white birds of prey, they’re about 2 feet long with wing spans of 4-5 feet. When in flight, their long, narrow wings take on the shape of an outstretched M.

Ospreys hunt by soaring over water, periodically hovering on beating wings to scan the surface for schooling or spawning fish. Upon sight of its prey, the osprey makes a spectacular dive. Folding its wings tightly, it descends swiftly and plunges feet first into the water, often submerging itself completely. Another technique is a shallow scoop for fish at the water’s surface.

In addition to food, the Chesapeake provides many favorable nesting areas over the water such as duck blinds, navigation markers or man-made nesting platforms. Offshore structures offer protection from predators like raccoons, and rapid detection and escape from danger. On land, ospreys may nest on high trees and utility poles.

Ospreys 3 years or older usually mate for life, and will use the same nest site year after year A recently reunited pair will begin the task of nest building or repair.

Kathy Reshetiloff, “Chesapeake’s Ospreys Mark Return of Spring”, CHESAPEAKE BAY JOURNAL (June 19th, A.D.2020).

Thanks for that report, Kathy Reshetiloff–that report that repeatedly fits the return of spring. This year (A.D.2022) is no exception, according to a short report in the CHESAPEAKE BAY JOURNAL:

Standing watch over a channel marker, soaring above the water, effortlessly snatching a fish — ospreys are among the most recognizable bird species in the Chesapeake Bay region. And they have begun their annual springtime return from South America.

Staff writer, “A Sign of Spring: The Return of the Chesapeake’s Ospreys”, CHESAPEAKE BAY JOURNAL, 32(2):3 (April 2022).

The Osprey is a daytime-hunting raptor, like others hawks and eagles, seizing its prey after a successful chase. And for the Osprey, that hapless prey is most likely fish of some kind–more than 99% of the Osprey’s diet is some kind of fish!

However, according to the University of Michigan’s Museum of Zoology website “Animal Diversity Web” [ AnimalDiversity.org entry for Pandion haliaetus ], an extra-hungry Osprey might catch and consume rodents (mice, rats, voles, squirrels), lagomorphs (rabbits, hares, pikas), small birds, salamanders, snakes, juvenile alligator, or even carrion (e.g., dead opossum, deer carcass). But those are rare dietary choices for an Osprey, because they have earned their common nickname, “Fish Hawk”.

Ospreys are not bashful about seizing fish prey, whether those prey are near the water’s surface or whether such prey is well below the water’s surface.

[The Osprey] is the only raptor that plunges into water feet first to catch fish. Can hover for a few seconds before diving. Carries fish in a head-first position for better aerodynamics [for post-catch flying]. Often harassed by Bald Eagles for its catch.

Stan Tekiela, BIRDS OF TEXAS FIELD GUIDE (Adventures Publications, 2004), page 79.

Hmm. that last “kleptoparasitism” fact–about eagles robbing ospreys of caught fish–where did I read about that recently? Oh yeah, I saw something about that on the best birdwatching blog in the world, LEESBIRD.COM — https://leesbird.com/2022/05/17/a-fisherman-robbed-chapter-20/ .

It pays to be a regular reader of LEESBIRD.COM ! — thanks, Mrs. Lee Dusing, for the ongoing blessing your birding blog has been, for years, is now, and continues (God willing) to be. (And thanks also for your sterling service as an Adjunct Professor to ICR’s School of Biblical Apologetics, over the past few years.) But mostly, thanks for honoring the Lord Jesus Christ, (our Creator-Redeemer) and for continually blessing birdwatchers, like me, with the wonderful service that LEESBIRD.COM provides. : )