Long-tailed Cuckoo (Eudynamis taitensis) (Fig. 16) 



The long-tailed cuckoo breeds in New Zealand and winters 

 in the southwest Pacific. The center of its winter range lies in 

 central Polynesia, but birds have been recorded as far as Palau 

 in the northwest and Pitcaim Island in the southeast. Although 

 occurring throughout French Polynesia and the Cook Islands, 

 it had not been recorded from the Line Islands prior to our 

 expedition (Bogert, 1937: Clapp& Sibley, 1 97 1 a,b; Pratt et al. , 

 1987; Ellis etal, 1990). 



We found long-tailed cuckoos on 4 of Caroline's 39 motus 

 (Fig. 16). We heard its distinctive monosyllabic and disyllabic 

 call notes on South, Long, and Pisonia, identified one on Nake, 

 and on 28 September collected a male in a mist net on Tr. 4, 

 Long Island ( USNM 607 191). Soon after our return home we 

 sent a description and photograph of this species to the Falconers: 

 they, and AKK, have since seen them several times on Motu 

 Ana- Ana in March, April, and May 1989-90. 



All the cuckoo sightings were at canopy or subcanopy 

 level, and three of the four birds were found in Pisonia. 

 The South Island cuckoo was located in a Cocos canopy over 

 20 m high. The netted male flitted secretively within an 

 undisturbed, tangled low-canopy (4—6 m) Pisonia-Tournefortia 

 interface. We suspect that this elusive migrant occurs throughout 

 the mid-to-upper levels of Caroline's forest canopy. 



These records establish the long-tailed cuckoo as a winter 

 visitor to Caroline Atoll. Our observations on four islets, 

 including the southernmost, northernmost, windwards, and 

 leewards, suggest that many individuals were present. A 

 March 1990 first sighting on Vostok (J. Phillips, personal 

 communication) further suggests that the species disperses 

 regularly to the Southern Line Group. 



Other Vertebrates 



Lizards 



Although "small lizards" were observed on Caroline 

 in 1825 (Paulding, 1831), it wasn't until 1965 that the 

 first collections were made (Clapp & Sibley, 1971a). We 

 collected four additional lizard species, which increased the 

 known terrestrial herpetofauna from three to six (Table 8). 

 Although all are indigenous, the azure-tailed skink (Emoia 

 cyanura) is suspected of being partly dispersed by man 

 (Brown, 1956). All but two of the small lizard species known 

 from the Line Islands (Crombie, 1 990) have now been found on 

 Caroline. 



Turtles 



We found three Pacific green sea turtles ( Chelonia mydas), 

 a threatened species (McKeown, 1978), at Caroline in 1988. 

 Two were swimming over the lagoon reef flats, one west of 

 Arundel, the second east of Ana- Ana. The third was in the open 

 sea about 1 00 m west of South Island near the "boat entrance." 

 Ron Falconer has seen up to seven turtles in the lagoon in a 

 single day. In April and May 1990, AKK saw workers from 

 Tahiti capture and kill a minimum of four green turtles in the 

 lagoon; two more entered the lagoon during the following 

 4 months (R. Falconer, pesonal communication). 



In March 1990, AKK and G. Wragg found three old nests, 

 presumably of this species, on the northwest coast of Nake 

 within 100 m of the northern tip of the islet. These are the first 

 known turtle breeding records for the atoll. Young (ca. 1922) 

 notes that the copra plantation laborers ate green turtles from 

 September to December each year. The February 1990 storm 

 added large amounts of sand to Caroline's shorelines, providing 

 potential new habitat for turtle nesting. 



Terrestrial Mammals 



None of the terriers (see Subchapter 1.1) that were 

 introduced to control rats on South Island in the early part of 

 this century (Young, ca. 1922) have survived (F. Sibley, 

 personal communication; R. Falconer, personal 

 communication). In May 1990 the Falconers kept a dog and a 

 cat on Motu Ana-Ana. Despite the fact that both animals 

 generally remained close to the settlement, the dog regularly 

 visited the other Southern Leeward Islets and accompanied the 

 family on excursions in their sailing canoe throughout the atoll. 

 As a result of our recommendations, the cat was removed from 

 Caroline in October 1990. The Falconers, with their dog, 

 vacated the atoll in mid- 1991. 



Bennett ( 1 840) noted "rats of a red-brown color," the first 

 reference to rodents on Caroline. Dixon ( 1 884) found that rats 

 were "not numerous" and that they nested "just at the base of 

 the fronds" of the coconuts. Two specimens collected by the 

 POBSP proved to be Rattus exulans (Clapp & Sibley. 1 97 1 a). 

 They reported that rats were uncommon and restricted to South 

 Island. 



The 19th and 20th century settlers found rats (presumably 

 R. exulans) to be extremely abundant and very destructive to 

 the coconut plantations. Maude (ca. 1938) states that rats 

 destroyed the nuts, and that they contributed greatly to the 

 eventual abandonment of copra enterprises on Caroline and 

 Flint. They voraciously devoured both growing and fallen 

 nuts, as well as dried copra. Being arboreal, they also lapped 

 the juices of the flower stalks, preventing nut development 

 (Young, ca. 1922). In a single year ( 1920) over 4,600 were 

 trapped on South Island (Maude, ca. 1938). Thousands more 

 were killed by terriers introduced to Caroline in a vain attempt 

 to control them. 



We found rats on almost every islet; they were especially 

 abundant on South, Long, Nake, and in the vicinity of coconut 

 palms on smaller islets. We recorded rats during daylight hours 

 on most transects, especially within the Pisonia forests. At our 

 campsites on Long and South we noticed groups of 1 0-20 each 

 night, so tame as to approach within 1 m while we were eating. 

 The rats evidently undergo wide population fluctuations, as 

 they were less abundant in March and May 1990 than in 

 September 1988. 



We suspect that rats periodically reach most motus, and 

 that the islets apparently lacking rats ( such as Noddy Rock ) are 

 too small and/or depauperate to support a resident population. 

 Because/?. e.v;</fl/f5isaknown seabird predator (Kepler, 1967; 

 Fleet, 1972; Norman, 1975), the restriction of some species 

 (i.e., red-tailed tropicbird) to small islets may be due to rat 

 populations on larger islets. 



149 



