Unravelling the mystery of seabirds 



To most people rarity is a function of how often 

 something is seen. If you don't see it, then its rare or 

 endangered. Simple, right? 



Well, for some species like the loggerhead turtle 

 that may be true. But Sea Grant researcher David 

 Lee is finding out that for offshore or pelagic birds, it 

 could well depend on how hard you look. 



If you're an avid birdwatcher, you probably know 

 that the sooty tern is usually seen only after a 

 hurricane or violent storm and that the bridled tern 

 is a casual visitor to Atlantic waters. At least that's 

 what it says on page eight of the birder's Bible, Birds 

 of North America. 



Yet in five months Lee has already seen record 

 numbers of both. 



With the funds of a UNC Sea Grant mini-grant and 

 the aid of several North Carolina State University 

 zoology graduate students, Lee and his skillful 

 navigator John Booth, Jr. of Manteo, were able to 

 survey waters off Oregon Inlet this summer for 

 offshore birds. 



Weather permitting, Lee, Captain Booth, and a 

 crew of three or four "mates" traveled across the inlet 

 out into the Gulf Stream and the edge of the con- 

 tinental shelf. During each trip, birds were identified, 

 counted and collected for further study in the 

 laboratory. Mammal sightings were also recorded. 

 And by the end of the summer, a 50-mile area had 

 been surveyed in a huge gridiron pattern, following 

 the oscillations of the Gulf Stream. 



Studying offshore birds and mammals is not a 

 typical afternoon sight-seeing trip. It's a pre-dawn to 

 dusk day of hard work. It means peering through 

 binoculars across endless miles of ocean for even the 

 slightest sign of life flitting across the horizon or ris- 

 ing out of the water. It means standing upright to 

 count a group of birds while your boat is bounced 

 back and forth by rough, choppy seas. And it means 

 ignoring that wave of seasickness as you run along 

 the side of the boat to retrieve a bird. 



So why bother? 



Lee finds offshore birds and marine mammals 

 fascinating. As curator of birds and mammals at the 

 North Carolina Natural History Museum in Raleigh, 

 he has been studying these species for several years. 

 But it was not until he received additional mini-grant 

 support that he was able to pursue such studies with 

 any degree of regularity. 



"Seabirds in general represent our weakest area in 

 knowledge of North American birds," Lee remarks. 

 "Previously, our knowledge of pelagic birds in North 

 Carolina has been limited to dead birds that had 

 washed up on the beach and reports from bird 

 watchers." Because of this informational void, Lee 

 sees the offshore system as "virgin territory— you're 

 starting from ground zero so almost anything you 

 find is new." 



Of course there are some legitimate reasons why 

 offshore birds have been neglected in the past. For 

 one thing they aren't very accessible. Most seabirds 

 migrate along the continental shelf where upwellings 

 bring nutrient-laden waters to the surface. As a 

 result, surveying can be an expensive proposition. 

 Lee paid an average of $240 per trip to charter a boat. 

 Multiply that cost by several trips and it adds up to a 

 lot in a hurry. 



Equally important, surveying is time consuming. 

 Most of the pelagic birds seen near North Carolina 

 breed in either the tropics or on the arctic tundra. To 

 complicate things, migration periods vary from 

 species to species. Thus Lee believes year-round cen- 

 susing is necessary to fully understand the birds' 

 migration patterns, feeding habits and other life 

 history characteristics. 



One more hurdle 



And there is still yet another hurdle that Lee has 

 run into— getting well-seasoned birdwatchers to go 

 out on more than one trip. "Eighty per cent of the 

 birdwatchers that I go out with get violently 

 seasick," muses Lee. "And once they get sick, well, 

 they don't want any part of it." 



Despite the adverse conditions, Lee's perseverance 

 has paid off. From black-capped petrels, to Cory's 

 shearwaters, bridled terns, sandwich terns, and 

 albatrosses, he's seen them all. And he is discovering 

 that for pelagic birds, North Carolina waters are 

 among the most productive in the Atlantic. "On a 

 typical trip you would see five to ten species that you 

 wouldn't see from the beach . . . We are seeing more 

 tropical stuff up here than they are off of Florida." 

 According to Lee, the meeting of the Labrador 

 Currents and Gulf Stream off the Outer Banks 

 creates ideal conditions for a diverse mix of both 

 northern and southern species of birds and mam- 

 mals. 



For Lee each trip has been a unique experience. 

 "Each trip I go on I get more and more excited." 

 Probably the most significant finding was made late 

 in September when Booth spotted and collected a 

 white-faced storm petrel about 40 miles off the coast. 

 Though there have been scattered reports of similar 

 sightings in earlier years, Lee notes that this par- 

 ticular species is not officially known in North 

 America. This is the first confirmed observation. He 

 theorizes that the bird may have become lost during a 

 storm and wandered into coastal waters. 



Although colder weather has arrived and most of 

 the birds are well on their way to wintering grounds 

 thousands of miles away, Lee is continuing his sur- 

 vey. Little information has been collected on North 

 Carolina's offshore bird fauna in late fall and winter. 

 Lee hopes that the data gathered during these 

 seasons will fill some of the many gaps in our un- 

 derstanding of pelagic birds. 



