October 8, 2012

Looking over the shoulder of a migrating osprey

By Iain MacLeod

Our Osprey Tracking project is proving to be enthralling, fascinating, and occasionally anxiety-producing. For background information about the project and to continue to follow the fortunes of our Ospreys, go to http://www.nhnature.org/osprey_project/overview.html.

The project, in a nutshell, is that we are using state of the art satellite transmitters to track the migrations of three Ospreys from their nests in New Hampshire to their wintering sites in South America. This is part of a multi-year project partially funded by Public Service of New Hampshire (PSNH) that also includes a new school program that allows students and teachers to learn about migration and follow the Ospreys using interactive Google Earth software. Another component which I hope to launch this winter is connecting school children here in NH with students in schools in South America where the Ospreys winter.

The lightweight (30g) transmitters are worn by the Ospreys like a backpack. Every three days, the transmitter uploads data to a satellite. Each upload includes an exact GPS location, altitude, direction, and speed of flight each hour during daylight hours. I can access that raw data, then plot the data in Google Earth, providing an incredibly detailed “over the shoulder” look at the movements of these birds that allows us to understand so much about migration that was previously unknown and learn about the threats they face.

We tagged three Ospreys in 2012 – Art, Jill and Chip. Here are their stories so far:
Art is an adult male Osprey. He was caught and tagged at his nest in Bridgewater on May 29. In addition to learning about his migration, we were able to follow his foraging behaviors throughout the summer as he hunted (Ospreys eat exclusively fish) around the Lakes Region. The data showed that he generally stayed close to his nest and hunted along the Pemigewasset River, the Baker River and various lakes and ponds within 8 miles of his nest. The furthest trip he took was 11 miles away up to Thornton. Art has nested in Bridgewater since 2007, so is at least seven years old (Ospreys don’t breed until they are at least two years old). He and his mate reared one chick this year. Art stuck close to his nest feeding his daughter until she left on her migration around August 31. For the next three weeks Art fattened up on trout at Sky Pond in New Hampton and began his migration on September 11 (after one more trout). Over the next several days, Art made a steady inland flight south through northern Pennsylvania and then down through Virginia, North and South Carolina, and Georgia, reaching Florida on September 21. By the 24th he was in Cuba. He took his time traveling through Cuba and then crossed to Haiti on October 1. By 9am on October 4 he had left the southern coast of the Dominican Republic and by 10 pm reached the northern coast of Venezuela. Where will he go now? Ospreys are very faithful not only to their nests in summer but to their wintering areas too, so Art has a particular place in mind; perhaps in Venezuela, perhaps in Brazil. Soon we will know. We will be able to keep tabs on him all winter and then watch his migration back to Bridgewater next spring.
Track Art here.

Chip and Jill are siblings from a nest in Tilton. They were tagged on August 2 two weeks after they took their first flights. Their migration strategies so far could not be more different. Chip was eager to head out on his own – likely motivated by having to compete for food with Jill and their sister (female Ospreys are bigger than males). Chip left the nest for the last time on August 21 and after stopping off for a night on one of the Boston Harbor Islands, he headed down to the Pettaquamscutt River near Narragansett Bay in Rhode Island. He has been there ever since (as of October 5)!!
Track Chip here.

Jill hung around the nest for several weeks after Chip left. She barely seemed to leave the area immediately adjacent to the nest until September 10, when she started heading south. Unlike Chip, when she decided to head south, she never stopped. Young Ospreys have no idea where they are going. They are making this incredible journey on their own; relying on instinct and luck. Jill made a picture perfect migration along the eastern seaboard, averaging about 160 miles per day. She crossed over to Cuba on September 19, then across to Haiti on the 23rd, then left the Dominican Republic on the 25th, arriving in Colombia on September 26. She kept on going south without hesitation ending October 4 in the Amazonian rainforests of southern Venezuela, just 30 miles from Brazil. She will continue to explore for the next couple weeks until she settles down in an area that she can call home for the next 18 months. The she (and Chip) will head north in spring 2014 towards New England and hopefully back to New Hampshire to try and find a place to nest. It will be fascinating to follow their fortunes and hopefully – with a little luck – see them establish themselves as part of the New Hampshire Osprey breeding population.
Track Jill here.

You can follow along to, either by checking my regular Osprey blog or with your own version of Google Earth. Check our website for details.

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