Blog #378 Don’t Bother Nesting Ospreys
Skunk cabbage in the Fuertes Sanctuary, Stewart Park, Ithaca.
Spring brings nesting and rebirth in the natural world with the promise of new generations. It’s an exciting time to roam the woods, fields, and wetland watching nature reawaken, but with that privilege comes the responsibility to do no harm. As you slosh around the spring-wet world, remember you are not alone, and keep care not to disturb any breeding animals.
Early birds, especially long-lived predatory species with extended breeding periods such as the Osprey, return to the Finger Lakes beginning in late March to start their breeding season immediately. After a brief three-week courtship to unite or reunite the pair and bring their gonads into breeding condition, Ospreys lay small clutches of 1–4 eggs. Like most breeding animals, Ospreys become ultra-sensitive to stress and outside annoyances. Leaving the nest to drive away intruders is risky as it leaves eggs vulnerable to drying-out or predation.
Ospreys abandon their nests if perturbed by people and dogs getting too close or if repeatedly attacked by intruding Ospreys vying for ownership of the nest. Disturbance of Ospreys is prohibited under the Federal Migratory Bird Treaty Act of 1918. Reproductive suppression may occur in pairs that are naïve to
Orpheus approaches Ursula to mate, courtesy of Karel and Cindy Sedlacek.
commotion and disruptions and in remote localities when subjected to sudden intrusions, but many nests across the eastern US are successful despite high levels of proximate human activity.
Orpheus and Ophelia abandoned their nest at Salt Point in 2019 after weeks of relentless disturbances. Several pairs of Osprey intruders vying for the Salt Point nest attacked the pair more than a dozen times a day for over a week until Orpheus and Ophelia relocated to the nearby and empty Salmon Creek nest. Unfortunately, the platform had no predator guard and the eggs were lost to some sort of predator.
When young fill the nests in May and June, the adults are their most protective and are continually on high alert to defend the nest. Disruptions during this critical period can cause the adults to frequently leave the nest and for extended periods, jeopardizing embryos and small nestlings. Time spent on protecting the nest translates into less time spent fishing and feeding the family. If the disturbances are sufficient to warrant the female leaving the nest as well, the parents risk losing the young to predators.
What stresses an Osprey? These remarkably tolerant birds don’t flinch at the constant droning of our society—the background noises of our daily lives—be it from automobiles, boat engines, trains, air traffic, lawnmowers, or off-road vehicles, as long as such traffic ignores them. Stress levels increase as people confront the birds at close range. A safe distance from which to observe Ospreys varies with the
Female defending her nest from another female intruder, courtesy of Karel and Cindy Sedlacek.
individual bird, the breeding season, and the layout of the area. Observers of wildlife, especially birds, should always use binoculars or a scope and stay at least 300–500 feet away from the nest. Using your car for a “blind” can be quite helpful when viewing local Osprey nests. If the adults react with a cry or lift off the nest in defense you are, by definition disturbing the Osprey. Leave quietly and immediately!
(L) Competitive birders stress their subjects if they do not respect necessary boundaries and birding ethics, courtesy of Newscientist, and (R) Owen Wilson, Steve Martin, and Jack Black playing aggressive birders in the “Big Year,” courtesy of the New Yorker.
It is important to note, however, that different pairs of Ospreys, as in most birds, have different sensitivities to disturbances, especially if they have been exposed to and prepared to cope with them. Pairs nesting along walking trails, such as those in Stewart Park, Ithaca, are much more tolerant of people and dogs than those located in fields away from humans. The Salt Point nest in Lansing is about 50 feet from a walking trail, which does not disturb the breeding pair.
Technology has introduced another hazard that has killed and maimed Ospreys and other hawks— unmanned aerial vehicles (UAV) or drones. As technology and access to drones expand, more people will be flying these aerial vehicles in areas where Ospreys nest. Even if all the FAA guidelines are followed, including staying 1,000 feet away from any active nest, Ospreys and other hawks are still harmed. To a drone operator, seeing adult Ospreys on their nests may be a thrill, but to the bird, a flying drone is a lethal threat to its family that must be attacked. While drones can get remarkable wide angle photos, it is the wrong tool for wildlife photography. Sadly, many people learn to avoid this activity only after putting an animal at risk.
Eyes to the sky!
Candace
Candace E. Cornell
Friends of SaltPoint, Lansing, NY
Cayuga Lake Osprey Network
cec222@gmail.com
EYESTOTHESKY!
WATCH!
Salt Point Osprey Nest Cam
READ!
OnOspreyTime: Ospreys of Salt Point
VISIT!
Cayuga Lake Osprey Trail
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