Biologists and ocean scientists can't say precisely what has prompted species more common to warmer climes to extend their ranges, but this summer has been a treat for birders, fishermen, and naturalists.
Mother Nature choreographs the rituals of migration and mating each spring and summer. Fish, such as menhaden and herring, that serve as food for larger species travel north, drawing game species like tuna and grouper behind them.
Shore birds including egrets, ibis, and herons also come from southern waters, pulling crayfish, minnows, and other nutrition from the ocean and marshlands. Some mate or lay eggs; others seek only the bounty they find on the way.
But sometimes species that don't normally migrate meander into the region, perhaps to expand their range after familiar habitats shrink, biologists say.
"Nature does sometimes provide a wonderful opportunity for people to be able to see things in an area where they normally wouldn't," said Bob Schoelkopf, founder of the Marine Mammal Stranding Center in Brigantine, N.J. "Each summer is a different array."
Take the manatee that has hung around the Raritan River and Raritan Bay north of Sandy Hook all summer. Schoelkopf has been keeping an eye on the tropical mammal, and the U.S. Fish and Wildlife Service is tracking it to see whether it's the one that has been spotted as far north as Cape Cod in recent years.
Pelicans, a rare sight in New Jersey two decades ago, now are regulars in these parts. Biologists theorize that the large, stocky birds - whose range had been south of North Carolina, in South America, and on the Pacific Coast - may soon nest here, Schoelkopf said.
