27 Mar
2020

Posted in: 41 North Magazine, ASRI, Audubon Society of Rhode Island, Kettle Pond, National Audubon Society, Natural Science, Ningret Wildlife Refuge, Ninigret, Ocean State Bird Club, Outdoor writing, Rhode Island DEM, RINHS, The Sibley Field Guide to Birds of Eastern North America, Trustom Pond National Wildlife Refuge, Uncategorized, US Fish and Wildlife, USFW
By Hugh    2 Comments

Ospreys Return

Photo: Gary Carlson ifishri@aol.com

Note: This story appeared in the Providence Journal 3/27/20, and in hard copy 3/29/20.

All photos by Gary Carlson: ifishinri@aol.com. Used with permission.

The human world is in turmoil, but spring is arriving unconcerned. Skunk cabbage is popping its pungent leaves through the marsh. Forsythia is only days away from its sunlight yellow show of flowers. And in the skies, the Ospreys are returning.

The males come first, making a 1600-mile journey from South America all the way to our shores. These are large birds, and their brilliant black and white coloration make them easy to identify. Most return to their old nests, often perched on tall platforms, in trees, and even on cell phone towers. They can be seen in flight trailing sticks and reeds bigger than their own 22-inch bodies. In another week or two, their mates will arrive and will aid in building and repairing the nests, which can be ten feet across and three feet deep. Eventually the nest may hold the two adults and up to four chicks, so they build with an eye toward a large family.

Jon Scoones, Audubon Society of Rhode Island’s (ASRI) manager of Caratunk Wildlife Refuge and of the state’s Osprey monitoring program, says the birds are doing well.  “Generally speaking, the population is on the rise. On a

Photo: Gary Carlson ifishri@aol.com

given year, we might have between 150 and 250 nests monitored for breeding behavior which includes nest building, copulation, and incubation.” In the 1960’s and 1970’s, the population was decimated by the use of the deadly pesticide DDT, and nests plummeted to a low of eight to ten. Years of careful monitoring and conserving has led to a steady increase in the population since then.

Scoones says 98% of an Osprey’s diet is fish, whether fresh or salt water. In salt, they often stay near the shore or in salt ponds, as their average dive takes them about three feet deep.  They’re the only raptors that survive almost exclusively on fish, and can sometimes be seen hovering over the water, tucking their wings, and diving with a spectacular crash. They grab a two to four-pound fish in their talons, which can be turned backwards so that two are in front and two in the back, the better to hold the fish in place. Their feet are scaly, which allows them to better grip their squirmy prey. They will even turn the fish to face forward while in flight, which is thought to be more aerodynamic.

Photo: Gary Carlson ifishri@aol.com

Once a pair has mated, it’s up to the female to incubate the eggs, which will take a month or more to hatch. During that time, the male will be responsible for feeding her. “Males will eat four fish a day, but they will have to catch eight a day to feed themselves and the females,” Scoones says. “By July or August, males may have to find 16 fish a day to feed the female and chicks.” It makes for exhausting work, not to mention the time both may spending defending the nest from predators like crows, who will often gang up on the pair in an attempt to either get to the chicks or to drive the raptors off.

Photo: Gary Carlson ifishri@aol.com

By the end of summer, the new family will begin their flight south. “The reason we know the birds overwinter in South America is because of the wonderful work of Rob Bierregaard,” Scoones says. Bierregaard has spent most of his life studying New England Ospreys, and since 2000 has been placing tiny, lightweight transmitters on the birds to monitor the migration.  His research confirmed that those we watch in spring and summer will move south. Think of it as a Rhody road trip.

“Adults will follow the shoreline, then stop at Cuba, Jamaica, and the islands before making it to South America,” Scoones says. Juvenile Ospreys will spend a full year in the warm climate, which is more conducive to the learning curve involved in hunting for a meal. The adults will return the next spring, beginning the routine again.

So right now, the Ospreys will continue to arrive. They know nothing of viruses, politics, or social distancing. For the human seeking a bit of solace, now is a good time to stroll along the shore, watching the cycle of life continue as it has for centuries.

Note: Jon Scoones says that while most of the training is over for his cadre of citizen scientists, there may be a few nest watch opportunities for those interested. His contact information is below.

Learn more about Ospreys:

Rob Bierregaard’s web site: www.ospreytrax.com

ASRI’s Osprey monitoring site: www.riosprey.info

Photo: Gary Carlson ifishri@aol.com