Blog #379 His Third Threesome

 

(L-R) Orpheus, Ophelia, and Ursula on the nest in 2021. 

Polygyny—a form of polygamy in which a male mates with more than one female—sounds like  deviant behavior, something to keep hushed and never spoken of, but not if you are a noisy Osprey advertising every fish and stick delivery to two mates in separate nests. Ospreys are famous for their  monogamy and faithfulness to the same female throughout their long lives. But peer carefully into high density colonies such as in the Connecticut River Estuary and you may see different loyalties and an  alternative mating system. 

It's a small nest for three adults.

The true target of an Osprey’s fidelity and devotion is not to its mate but to the nest they share.  Functionally, nest and mate loyalty look about the same. The pair build a nest and life together; he feeds  and defends her, and she puts forth offspring. Just like males, females feel the allure of nest ownership.  It’s been reported that in crowded populations with a deficit of males, some females chose polygynous  relationships as a way of laying claim to their nests. It is this loyalty that allows polygyny to occur and for  the nest and gene pool to be passed successfully through the generations 

Polygyny is rare in Ospreys, and almost always involves a single male attending two nests positioned  within a few hundred yards to 1–2 miles apart but within sight of each other. More rare is a nest occupied  by two females and one male as we’ve had at Salt Point. Not to be a spoiler, but polygamous relations in  Ospreys very, rarely lead to offspring. 

This is the third year polygyny has occurred at the Salt Point nest. When Ophelia arrived at Salt Point this  spring albeit a week late she found Ursula, the third wheel from last spring, in her place at the nest.  Instead of fighting and driving her from the territory, Ophelia let Ursula remain. Orpheus, mantling on the  nest edge most of the time, sat beside Ophelia and Ursula in a cold-war détente. He seemed to be  sending a signal to his two mates to coexist (or merely trying to stay out of trouble.) Still early in the  season, Orpheus has no trouble supplying ample fish to both Ophelia and Ursula. However, three-in-one nest polygamous relations rarely produce young and are a huge waste of energy and effort.  

Orpheus, left, and his backup singers. 

After a few days of sharing Salt Point with Ursula, Ophelia migrated to the Salmon Creek nest. Why did  she leave her nest of ten years without any contest? Is Ophelia unable to fight for some reason? If this  season mirrors the other polygynous ones, Orpheus will probably lose interest in the Salmon Creek nest  when the trees leaf out and block his line of sight. The Salmon Creek nest is doomed unless Ophelia is  able to incubate and somehow guard her chicks against predation while catching sufficient fish for them.  Is Ophelia up to this tremendous challenge? Raising Ospreys is a two-bird job for a reason. 

It would be easy for a male Osprey to be polygynous if the situation was right—if, for instance, he was  presented with a group of unmated females occupying undefended nests close to his primary nest.  However, such situations seldom occur in nature as Ospreys instinctively space themselves farther apart.  In this case, the Salt Point and Salmon Creek platforms were placed unnaturally close to each other, a  distance determined by NYSEG and not the Ospreys. Ideally, platforms should be at least a half-mile to a mile apart to eliminate conflicts. 

Watch some of this behavior on the Salt Point Osprey Nest Cam channel on YouTube. Nest camera  studies provide great insight into the day-to-day lives of these birds, revealing new behaviors and  uncovering other secrets—keep watching! 

Eyes to the sky! 

Candace 

Candace E. Cornell 

Friends of Salt Point, Lansing NY 

Cayuga Osprey Network 

cec222@gmail.com 

HELP PROTECT OSPREYS:  

• Keep a distance (100-300 feet) from active nests in the breeding season. If an 

animal vocalizes when you are near, you are too close! BACK OFF IMMEDIATELY. • Carry binoculars to view wildlife from a distance. 

• Help keep local waters clean and healthy. Preserve and clean shorelines. 

• Recycle or dispose of used fishing line and other materials that can entangle 

Ospreys and other aquatic animals. 

• Volunteer to monitor Osprey nests with the Cayuga Osprey Network.  

Write to: cec222@gmail.com. Thank you. 

EYES ON OSPREYS  

WATCH! 

Salt Point Osprey Nest Cam 

READ! 

OnOspreyTime: Ospreys of Salt Point 

VISIT! 

Cayuga Lake Osprey Trail

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