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.
The Japanese Marsh Warbler (Megalurus pryeri) is endemic to the Far East, and is listed as an endangered species in the Japanese Red Data List. The taxonomic position of this species is still unknown. Here, I review and compile most previously published information. Scant ecological information was known, as this warbler is cryptic and inhabits inaccesible marsh. The first breeding population was discovered 52 years after the species was described in 1884, but this population disappeared only 3 years later. Three populations were successively discovered in northern Japan in 1970s. The present population of M. p. pryeri is estimated at about 1000 birds and is restricted to only seven breeding sites. Of seven populations, two are shrinking, one is nearly extinct, three are stable and one is threatened by a development plan. The warbler selects a narrow spectrum of vegetation comprising of reed and sedge beds. Once vegetation become unsuitable, the population shrinks and has disappeared in several sites. This species might be r-strategist adapted to naturally disturbed habitat like flood plain. The warbler is a summer visitor to breeding sites and winters in small reed beds along the Pacific sea side. As the mating system is polygynous and the population is highly fluctuating, the present population might be not enough to maintain a population with an effective size of 500, which is the minimum size to maintain genetic diversity. The overwintering and migrating behaviour of this species is poorly known. To conserve the warbler population change should be monitored, and habitat should be managed if it begins to decrease. It is also important to preserve the wintering and transit habitat for this species.
The Japanese Marsh Warbler Megalurus pryeri is an endangered grassland passerine species and their distribution is restricted to a few marsh lands in Japan. To collect information important to conservation of the species, habitat characteristics of male warblers in the breeding season was studied at Hotoke-numa reclaimed area, northern Honshu, Japan, in the summer of 1993. Vegetation structure was significantly different between areas available and unavailable for male warblers. Specifically, the density of sedges (Carex spp.) was higher, and the density of reeds (Phragmites communis) was lower, in available area. These results suggested that sedges may play an important role in breeding activities of Japanese Marsh Warblers and maintenance of such vegetation can be important for conservation of the species.
The relationship between the parents and offspring of Carrion Crows Corvus corone was studied in a rural area in Takatsuki-City, Osaka, between 1990 and 1992. Four separate stages were descriminated in the development of offspring independence. In the first stage, from fledging to independent feeding, the offspring were allowed to approach their parents freely and were fed on demand. In the second stage, the male parent began to refuse their approach. The distance between the parents and their offspring increased. The female parent accepted her offspring at the beginning of this stage, but later refused them. In the third stage, the parents suddenly became more aggressive toward their offspring than in the previous stage. Thereafter, the offspring gradually increased the time spending outside of the family range and territory more often. In the fourth stage, whenever the offspring approached their parents they were turned away by their parents at a short distance. By the start of the following breeding season, the offspring no longer reappeared in the territory. The male parent was more aggressive toward the offspring in the second and third stages than the female. Their aggressive attitudes, starting in the third stage, caused the final independence of their offspring.
The distribution and morphological characters of Eagle Owls Bubo bubo were investigated using specimens from museums. Eight of thirty-six specimens found in Japan were collected in Hokkaido. Of all the characteristics examined, wing length was the only one that varied between locations. However, morphological measurements overlapped in all investigated areas. Also, with plumage, individual variations were remarkably similar to geographical ones. Consequently it seems difficult to distinguish between Bubo bubo subspecies from morphological characters alone. Considering the numbers of Bubo bubo specimens were much fewer than those of Blakiston's Fish Owls Ketupa blakistoni, it can be suggested that Bubo bubo populations in Hokkaido have been unstable throughout this century.