1997 Volume 29 Issue 1 Pages 1-26_1
To develop successful restoration programs for wildlife, conservation biologists should consider features of animal behavior to help design restoration plans. This paper presents case studies of the first restored colonies of Arctic Terns (Sterna paradisaea), Common Terns (S. hirundo) and Roseate Terns (S. dougallii), Atlantic Puffins (Fratercula arctica) and Leach's Storm-Petrels (Oceanodroma leucorhoa). These restoration projects are based on the use of two fundamental and commonly occurring features of colonial waterbird behavior: social facilitation and philopatry.
Social facilitation, the influence of one animal's behavior on that of its associates, was adapted for conservation purposes by placing decoys and sound recordings at historic nesting islands to simulate established colonies. The use of decoys and audio recordings to simulate and encourage social facilitation is referred to as social attraction. Philopatry, the tendency for young birds to recruit to nesting populations at their natal home, was adapted for conservation purposes by translocating puffin chicks from a large colony at the center of the range to historic nesting islands at the southern, historic limit of the puffin's range where they were extirpated nearly a century earlier by excessive hunting for food and feathers. Young puffins, reared and released from artificial burrows at two historic sites learned the location of the release sites and eventually returned to the long-extinct colonies rather than their hatching place.
To restore colonies of terns and puffins that were displaced by Herring and Great Black-backed Gulls, nesting population of these gulls were reduced at Eastern Egg Rock and Seal Island National Wildlife Refuge (NWR) to encourage recolonization by terns and puffins. Common, Arctic and Roseate Terns were attracted to island recolonization sites off mid-coast Maine, USA using decoys and 24-hour playback recordings. By 1996, Seal Island NWR was the largest Arctic Tern colony in Maine with 956 pairs and Eastern Egg Rock was the largest Roseate Tern colony in the state with 126 nesting pairs of this endangered species. These successes using social attraction are compared to tern restoration on Petit Manan Island, Maine where gull control alone resulted in recolonization. In this example, terns were absent for only 4 years and many were still living with a memory of nesting on the island. After gull removal, these birds quickly recolonized in the same year that gull control began. In contrast, using gull control and social attraction, it took 3 and 5 years respectively for terns to re-colonize Eastern Egg Rock and Seal Island NWR (where terns had not nested for 44 and 36 years). In these cases, no living terns with a memory of nesting on these islands were available for recolonization.
Puffin colonies at Eastern Egg Rock and Seal Island NWR were restored by translocating 3-40 (average 17) day-old puffin chicks from Newfoundland, Canada (approx. 1610km distant). A total of 954 and 950 chicks were translocated to Eastern Egg Rock and Seal Island NWR respectively. These were captive-reared in individual sod burrows which were opened at their entrance after the first week. The chicks were banded and permitted to fledge into the adjacent ocean. Translocated puffins began to return when two years old; many also visited nearby puffin colonies where some eventually nested. Recolonization at the historic nesting sites occurred in 1981 and 1992 respectively at Eastern Egg Rock and Seal Island NWR-in both cases 8 years after initiation of translocations. Four pairs nested in 1981, a number that increased to 19 pairs by 1985 and has remained constant at 16-19 pairs, due to recruitment of native-hatched chicks. At Seal Island NWR, 7 pairs nested in 1992 and increased to 40 pairs by 1996.
