NATURALIST'S 



NOTEBOOK 



Ospreys have keen eyes for fishing and well-designed talons for 

 holding on to their slippery catch. 



the other hand, wander significantly to mate. 

 "This keeps the gene pool mixed up, some- 

 thing species 'know* to do in an evolutionary 

 sense," Bierregaard explains. 



Ospreys are highly specialized for fish 

 eating. Their remarkable eyesight accom- 

 modates water refraction, enabling them 

 to accurately target fish. When an osprey 

 emerges with its catch, seemingly schooled in 

 the laws of aerodynamics, it positions the fish 

 headfirst in its talons for the flight to its nest. 

 Its flexible outertoe and spiny bottom scales 

 are designed to hold slippery fish. 



While Bierregaard lauds the parenting 

 skills of ospreys, he is quick to lay aside the 

 notion that parent osprey "teach" the young 

 to fish or fly. 



"It's more like the parents are less inter- 

 ested in bringing food to nest," he observes. 

 'Youngsters are on an allowance until they 

 polish their skills. Besides, the parents don't 

 have to teach the young to fish. Birds are 

 wired to catch fish." 



Shorter fall days probably trigger migra- 

 tion south. 



"While they are inseparable during nest- 

 ing, the family takes separate vacations. First 

 momma, then dad, then baby. It's not clear 

 why they don't travel together," he says. 



The birds leap frog south along the 

 migration path that brings them to a range 

 from Florida to South America. For reasons 



unknown, ospreys don't build nests or breed 

 in the tropics. And, young birds instinctively 

 know they are not going to breed for two years, 

 and so remain in the tropics until their second 

 birthday. 



Ospreys are believed to live to the ripe old 

 age of about 20, Bierregaard explains. 



HOMEWARD BOUND 



In the spring, the male osprey returns to 

 the nesting ground ahead of his mate. A delay 

 could result in an unexpected guest in the home 

 nest. That was the case two seasons ago at 

 Jim Teache/s Intracoastal Waterway lot near 

 Wlmington. 



A great homed owl had commandeered 

 the osprey nest thatTeachey — and the world 

 — had been watching for two previous seasons 

 thanks to a well-placed Web camera. Teache/s 

 first reaction was to ask U.S. Fish and Wildlife 

 Service officials how to get rid of the owl. "You 

 don't," they warned. It's a federal offense to 

 disturb an endangered bird. Besides it's a rarity 

 to document the nesting and rearing habits of a 

 great homed owl, they told Teachey. 



And so, the Web camera enabled global 

 visitors into the great homed owls' nest to 

 watch the pair raise two chicks. Only one 

 made it to fledge, Teachey reports. 



The resident osprey — no match for the 

 fiercest bird of prey — wisely did not contest 

 the 2002 takeover. In 2003, though, the 

 original osprey couple reclaimed their home 

 nest Of the three chicks that hatched, only 

 one made it through to fledge. 



Typically, Teache/s Web site gets about 

 40,000 hits each nesting season. He receives 

 e-mails from people from Japan to the United 

 Kingdom. "One touching message was from 

 a bedridden woman in England. She thanked 

 me for helping her 'go outdoors' to enjoy 

 nature that she loves so much. She said it 

 freed her. What can you say? That makes it all 

 worthwhile," he recalls. 



"It's a privilege to have this treasure in 

 my own backyard, and to share what I enjoy 

 so much with the people in my community 

 and the world." 



As of press time, no osprey has claimed 

 the Teachey nest for the 2004 season. E 



OSPREY ODDITIES 



LATIN NAME: Pandion haliaetus, from Greek, literally sea eagle 



AKA: fish hawk or sea hawk LENGTH: 21 -26 inches 



WEIGHT: 2.2-4 pounds WINGSPAN: 59-67 inches 



DESCRIPTION: Dark back and wing with white on the top of head and extending 

 from under the chin down the belly. Females have a dark "necklace." In flight, they are 

 distinguished from the bald eagle by the white belly and the crooked wings with dark 

 "wrist" patches. 



NESTING: Ospreys usually are territorial. In most places, their nests are scattered 

 atop tall trees, power poles or channel markers. Where there are abundant fish 

 and no predators, they can become colonial. Osprey lay an average of three eggs at 

 intervals of one to three days. Incubation lasts 34-40 days, and is done by both sexes. 

 Success rate varies from one to two chicks per clutch. Average fledgling at 48-59 days. 

 Young remain dependent on the parents for another four to eight weeks, ending in fall 

 migration, that is triggered by shortened days. 



SOURCE: Rob Bierregaard and Carolina Raptor Center: www.carolinaraptorcenter.org 



WEB SITES OF INTEREST: 



Rob Bierregaard's home page: www.biowebMncc.edu/bierregactrd/ 

 North Carolina Aquarium: www.ncaquariums.com 



View nest at Jim Teache/s lot: http://home.ec.rr.com/ospreynest/autoupdate.htm 

 Blackwater National Wildlife Refuge, Md.: www.friendsofblackwater.org/osprey.html 



COASTWATCH 29 



