Blog #456 It’s Zugunruhe Time

 

Migrating Osprey courtesy of Michael Coiello.

The 2023 exodus of our migrating Ospreys in the Northeast began in August—nearly a month early—as the birds began their epic journeys, dodging deadly hurricanes and tropical storms spawning in the Caribbean and other unforeseen perils. Migration is the most dangerous time in an Osprey’s life, with a barrage of unforeseen dangers waiting to happen.

The 2016 map (below) shows a fall migration route of an adult Osprey. In this case, the male Osprey named Wausau (route is in aqua) flew from NH to Colombia in 31 days. The other colors represent radio signals from other Ospreys tracked by Dr. Rob Bierregaard.


Route of Osprey on fall migration in 2016.

Each year, an incredible winged migration takes Ospreys nesting in the northeastern two to four weeks to travel 3,500-4,000 miles one-way as they leave their temperate breeding grounds for the tropical wintering zones along the coastlines and riversides of Central and South America with some females tracked as far south as Argentina. Their first autumnal migration is an especially treacherous venture for the young of the year. These inexperienced progenies travel alone to places unknown, charting their own courses southward using a host of navigational tools to cross hemispheres to a place guided only by instinct. Those juveniles lucky enough to find food, evade being shot, or killed by motor vehicles, collisions with buildings, and deadly storms, make it south to spend their first year and a half maturing in lush tropical wintering grounds. This time is spent fishing before returning north to look for nest sites to breed.

Autumn is a restless time in nature as organisms prepare for the coming winter. In September juvenile Ospreys explore their natal areas, imprinting on the topography, and eating as much fish as they can catch in preparation for their first migrations. Once a brood

fledges, the adult female leaves the nest to condition her body depleted from tending to her offspring all season. Once her hormones are plentiful, the female experiences Zugunruhe, a German word describing this intense “migratory restlessness period”—the poorly understood but irrisistable urge to migrate—at which point she begins arduous journey.


Lily, now a juvenile, is ready to migrate, courtesy of Cindy Sedlacek.

What tells the birds to begin their journeys? One minute a bird can be perched contently, and in the next it succumbs to Zugunruhe hormones, powerful internal cues that prompt the uncontrollable urge to travel thousands of miles despite past hungry predators, strong winds, food shortages, and stormy weather to get to the safety of their winter home in the tropics.

Ospreys, the pack-rats of the hawk world, fill their nests with objects that sometimes endanger the resident birds and their offspring. A common cause of Osprey mortality is strangulation as mobile chicks become entangled in the strings, ropes, fishing gear, ribbons, and netting that the parents bring to the nest. In western states, bailing twine from ranches commonly makes its way into Osprey nests, strangling chicks. In the east, the young often become entangled in monofilament fishing line left behind by careless fishermen, endangering wildlife.

Dangerous tangled fishing line and tackle  on wires, courtesy of Cindy Sedlacek.

In the photo below, a migrating juvenile Osprey near Stewart Park struggled to free his leg from a tangle of fishing line. After pulling and tugging at its bound foot for hours the juvenile freed itself and was able to continue its travels.


Osprey has its foot caught in a tangle of fishing line and tackle, courtesy of Cindy Sedlacek.


Eyes to the sky!

Candace

Candace E. Cornell

Friends of Salt Point, Lansing, NY

Cayuga Lake Osprey Network

cec222@gmail.com

 

EYES ON OSPREYS

WATCH!

Salt Point Osprey Nest Cam 2022-23

READ!

 On Osprey Time: Ospreys of the Finger Lakes 

VISIT!

Cayuga Lake Osprey Trail Nests Driving Tour

Complete Cayuga Lake Osprey Trail

HELP PROTECT OSPREYS:

•Stay 300 feet away from nests during the breeding season.

If the Osprey vocalizes, you are too close! BACK OFF IMMEDIATELY.

•Carry binoculars to view wildlife from afar.

•Join the Cayuga Osprey Network: cec222@gmail.com.

•Recycle used fishing lines, twine, and nets, which can kill Osprey.

•Help keep local waters clean, healthy, and safe. Pick up trash and do not litter.

Trash stays in the ecosystem a long time before it disintegrates.

Plastic breaks down into smaller and smaller pieces.

Disintegration Times

Orange or Banana Peel-------Up to 2 years

Leather----------------------------1 to 5 years

Wool Socks----------------------1 to 5 years

Plastic Coated Paper----------5 years

Plastic Bags----------------------10 to 20 years

Plastic Film Container---------20 to 30 years

Nylon Fabric---------------------30 to 40 years

Tin Cans--------------------------50 years

Aluminum Can-------------------80 to 100 years

Plastic 6-pack Holder----------100 years

Glass Bottles---------------------1,000,000        

Source: NYSDEC

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