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New distribution records of Cetaceans from the Federated States of Micronesia

By Donald W. Buden* and Allain Bourgoin

Abstract Photographs of a initially found alive in mangroves in Pohnpei, Federated States of Micronesia (FSM) in July 2016 document the first record of the in the Caroline Islands. In its small size and what can be seen of its dentition, it most closely resembles a dwarf , Kogia sima, but the possibility of it being an immature , K. breviceps, cannot be excluded. Additionally, we report the first documented record of a short- finned , Globicephala macrorhynchus for Pohnpei State, and the first confirmed records of killer , orca, and false killer whales, crassidens for the FSM and the Caroline Islands, respectively.

*Corresponding Author E-mail: [email protected]

Pacific Science, vol. 72, no. 4 May 4,, 2018 (Early view) Introduction

Relatively few documented records of cetaceans exist for the Federated States of Micronesia

(FSM). Miller (2009:31) remarked that surveys dedicated to the study of marine diversity within the FSM are lacking and “it is primarily anecdotal reports that have been used to identify within these waters.” Wiles (2005), after reviewing previously published records for accuracy, and applying a 320-km (200-mile) offshore geographic distribution limit, recorded

21 species of cetaceans in Micronesia, but only eight of them in the FSM—Bryde’s whale

( edeni), sperm whale ( macrocephalus), Cuvier’s (Ziphius cavirostris), pantropical spotted ( attenuata), (S. longirostris), (S. coeruleoalba), (Orcinus orca), and short-finned pilot whale

(Globicephala macrorhynchus). Miller’s (2009) list of cetaceans recorded in the FSM included ginkgo-toothed beaked whale (Mesoplodon ginkgodens) based on a carcass found aboard a

Chinese fishing vessel in 2003 and said to have been caught near the island of Pohnpei (Dalebout et al. 2008). Miller (2009) also included records of Fraser’s dolphin (Lagenodelphis hosei) and melon-headed whale (Peponocephalus electra) recorded outside the 320-km limit applied by

Wiles (2005) but treated FSM records of killer whale, pantropical spotted dolphin, and Cuvier’s beaked whale as unconfirmed. In the present paper, we report the first record of the genus Kogia for the FSM and the Caroline Islands, the first documented record of short-finned pilot whale in

Pohnpei State, and the first photographically confirmed records of killer whale in the FSM and (Pseudorca crassidens) in the Caroline Islands.

Study Area

The Pacific island nation of the Federated States of Micronesia (FSM) includes hundreds of small islands distributed among four states across approximately 2,750 km of the west-central

Pacific Ocean, from Yap in the west to Chuuk, Pohnpei, and Kosrae States in the east (Figure 1).

2 The FSM, together with the islands of Palau immediately to the west, make up the Caroline

Islands Archipelago. The Carolines, along with the Mariana Islands and Wake Island to the north, the Marshall Islands to the east, and the republics of Kiribati and Nauru to the southeast, make up the region known as Micronesia, or greater Micronesia to distinguish it from the FSM. Wake

Island, Kiribati, and Nauru have been variously included or excluded in biological surveys and faunal checklists of the region—Wiles’s (2005) checklist of birds and of Micronesia includes Wake Island, but not Kiribati and Nauru.

MATERIALS AND METHODS

We identified a small whale killed by a fisherman after it was first found swimming in mangroves in western Pohnpei in July 2016 as Kogia sp. based on photographs provided by the

Conservation Society of Pohnpei (CSP). We did not have the opportunity to examine the specimen firsthand and the geographic coordinates of the precise location were undetermined.

Tissue samples obtained by CSP were given to us for possible DNA analysis. However, unresolved issues regarding application for a permit to send the tissue overseas precluded analysis at this time and the samples were returned to CSP. On 12 May 2017, after being notified by a visiting anthropologist of a whale found dead in southern Pohnpei, we visited the site and examined the carcass of a short-finned pilot whale. Geographic coordinates were accessed online after locating the stranding site on a Google Earth map of Pohnpei. The head was removed from the body and transported to the national campus of the College of Micronesia where it was buried to be exhumed later and the skull prepared as a voucher. The identification of killer whales observed off the coast of Pohnpei was confirmed by Ingrid Visser (Orca Research Trust) based on photographs taken by Selino Maxin (CSP), and identification of false killer whales, off the coast Pohnpei was confirmed by Robin Baird (Cascadia Research Collective) and I. Visser based on screenshots from a video taken by Allois Malfitani (Pohnpei Surf Club).

3 RESULTS AND DISCUSSION

Family

Kogia sp.

A small whale was killed by a local fisherman after it was first observed swimming in mangroves near the village of Pehleng, Kitti Municipality, Pohnpei, sometime between 7 and 9 July 2016.

Photographs dated 10 July and others undated show it to be an example of the genus Kogia. It was brought to a market in Kolonia where it was kept in a freezer for a time before being returned to the fisherman who kept it frozen until it was cut into pieces, cooked, and fed to pigs

(J. Anson, pers. comm.). None of the images provides enough detail to distinguish unequivocally between the two currently recognized congeners in the Kogiidae —the , Kogia sima (Owen), and the pygmy sperm whale, K. breviceps (de Blainville). Useful field characters such as the position of the dorsal fin relative to the head and tail and species- specific differences in “false gill slit” pigmentation pattern (see Keenan-Bateman et al. 2016) were not visible. However, the extremely small size of the Pohnpei specimen (estimated total length 2.0 m) as seen in one photograph (Figure 2A) and the few widely spaced teeth that are visible in another (Figure 2B) appear to match more closely the characteristics of K. sima as reported by Nagorsen (1985) and Bloodworth and Odell (2008)—total length 2.0-2.6 m in K. sima vs up to 4.5 m in K. breviceps; mandibular toothrow 7-12 (rarely 13) in K. sima vs 12-16

(rarely 10 or 11) in K. breviceps. But the possibility of it being a juvenile K. breviceps cannot be excluded.

Kogiids are one of the least known groups of cetaceans in the global ocean (Moura et al.

2016). Both species occur in temperate and tropical waters worldwide (Nagorsen 1985, Reeves et al. 1999, Bloodworth and Odell 2008), with K. breviceps appearing to prefer more temperate waters (Taylor et al. 2012b). However, both species are elusive and difficult to identify at sea

4 (Bonato et al. 2016) and details of their distribution are poorly known and derived largely from records of stranded specimens (Baird 2016, Bonato et al. 2016). Records of kogiids from

Micronesia are especially scanty. The Pohnpei specimen is the first documented record of the genus for the FSM and the Caroline Islands. Elsewhere in Micronesia, both species have been recorded in the Mariana Islands in Guam (Eldredge 1991, 2003; Hill et al. 2014) and Saipan

(Trianni and Tenorio 2012), and K. breviceps is known also from the Gilbert Islands, Republic of

Kiribati, based on DNA analysis of a partial lower jaw collected on Butaritari Island in 2009

(Baker et al. 2013). Taylor et al. (2012a,b) included the FSM among countries of occurrence for both K. sima and K. breviceps, respectively, but they apparently listed all of the countries within the hypothetical ranges of the two species, with or without confirmed records.

Family Delphinidae

Globicephala macrorhynchus Gray

On 12 May 2017, DWB received an email from Takuya Nagaoka, a visiting anthropologist affiliated with NGO Pasifika Renaissance, regarding a whale found dead by a local resident several days earlier on the eastern shore of Temwen Island, Madolenihmw Municipality, in

Pohnpei lagoon at 6° 51ʹ 06ʺ N, 158° 19ʹ 58ʺ E. Later in the day, we (DWB and AB) visited the site and examined the carcass of a presumed adult (based on size: total length 4 m) short-finned pilot whale (Figure 2C,D) and salvaged the head to prepare the skull as a voucher. Short-finned pilot whales range widely in tropical and warm temperate ocean waters throughout the world

(Reeves et al. 1999). There are numerous records of G. macrorhynchus from throughout

Micronesia, but it has been previously recorded within the FSM only from Chuuk (Wiles 2005).

The Temwen specimen was in an advanced state of decay with numerous fly larvae feeding on the decomposing flesh, and it had many shallow, concentric wounds visible on the exposed left side of the body consistent in appearance with bites of cookie cutter sharks (Isistius

5 sp.). At least 49 species of cetaceans, including G. macrorhynchus, have been recorded in the literature as bearing bites from cookie cutter sharks (Dwyer and Visser 2011). The one exposed fin was badly damaged, being reduced to a stub, and its length could not be accurately measured to compare with that of the similar-appearing long-finned pilot whale, G. melas. However, G. melas inhabits subpolar and cold temperate zone waters and is unlikely to occur in Micronesia.

The southern hemisphere population of G. melas is found generally between 27° S and 62° S

(Department of the Environment 2017), whereas the northern Pacific population apparently is no longer extant (Taylor et al. 2008a). The species is not known to occur in the Pacific islands region north of New Zealand and southern Australia (Miller 2009, Department of the

Environment 2017).

Orcinus orca (Linnaeus)

Killer Whales are distributed worldwide but are more numerous in colder waters at higher latitudes than in the tropics (Reeves et al. 2017). Wiles (2005), citing Iwashita et al. (1963), recorded killer whales in the FSM in Yap, Chuuk, Pohnpei, and Kosrae. However, Reeves et al.

(1999) regarded the Iwashita et al. report as not sufficiently well-documented, as did Miller

(2009) who considered O. orca unconfirmed in the FSM. Reeves et al. (1999) also remarked on a

Guam newspaper article in which Rock (1993) referred to unconfirmed reports of killer whales near Yap (as well as Guam and Palau). Accounts of killer whale sightings in Pohnpei not previously mentioned in the scientific literature appeared in a now defunct Pohnpei Island newspaper. Dixon’s (1999) article in The Island Tribune describes three independent sightings on

21 February and another on 1 March 1999. In one incident, two fishermen (Mike Collins and

Kembo Nakasone) observed an unstated number of killer whales (the largest estimated 12-14 feet

[~ 3-4 m] in length) that swam under and circled their boat three times while they were anchored in about 250 feet (76 m) of water off Old Harbor Passage on 21 February 1999. Collins identified

6 the as killer whales by their white markings and long dorsal fin. On the same day, and fishing in the same general area, Alex Tretnoff, pilot for Carolines Islands Air, observed four killer whales that approached a neighboring boat, with at least one of them brushing up against the boat, biting the anchor line, and tugging the boat a short distance. He estimated the largest to be about 15 feet (4.6 m) in length, with a three-foot (0.9 m)-long dorsal fin. In another incident that occurred on the same day, according to Simon Mix, a local resident, about six whales circled the boat of some Kapingamarangi fisherman while they were fishing for tuna. The locality was unspecified but presumably outside the Pohnpei reef and off the northern end of

Pohnpei where the Kapingamarangi village is located. According to Tretnoff (in Dixon 1999) another encounter occurred on 1 March when a local fisherman reacted to the presence of killer whales circling his boat outside Pohnpei reef by tossing his catch overboard and retreating to the shallow waters of the lagoon. The animals followed the boat into the shallows but eventually lost interest and left.

A more recent encounter with killer whales off the coast of Pohnpei, and not previously reported in the literature, was related to DWB by Selino Maxin and Kirino Olpet of the

Conservation Society of Pohnpei. On 23 July 2013, they observed three O. orca about 200-400 m outside the reef off the northern end of Pohnpei. Two of the animals were presumed adults based on size and one was a young about 2.0 m in length. One of the adults swam away from the boat accompanied by the young. The other followed the boat a short distance. Identification was recently confirmed by Ingrid Visser (pers. comm.) based on the overall size of the dorsal fin relative to the body, the grey saddle patch behind the dorsal fin, and the white postocular patch seen in the photographs (Figure 3) taken by Maxin. This is the first photographically confirmed record of O. orca in the FSM.

Pseudorca crassidens (Owen)

7 False killer whales are widely distributed in tropical and temperate zones worldwide (Taylor et al. 2008b), but the only hitherto confirmed records for Micronesia are from Guam (U.S. Navy

2007 [cited as Thorson et al. 2007 in Miller 2009], Hill et al. 2014) and the Commonwealth of the Northern Mariana Islands (Masaki 1972 in Wiles 2005, Norris et al. 2007 in Miller 2009, Hill et al. 2014). Wiles (2005) remarked on a record beyond the 320-km geographic distribution limit south of Yap that was erroneously reported by Eldredge (1991) as west of Palau, and Miller

(2009) alluded to unconfirmed records of P. crassidens from Kiribati and Palau.

In September 2015, Allois Malfitani, Director, Pohnpei Surf Club, videographed a pod of at least six whales he tentatively identified as false killer whales. The animals (estimated to be about 3-4 m in total length) briefly followed alongside the boat, which was about five miles (8 km) off the eastern shore of Pohnpei (Malfitani pers. comm.). Species identification was recently confirmed by Robin Baird and Ingrid Visser from screenshots extracted from the video. This is the first confirmed record of false killer whale in the Caroline Islands.

CONCLUSIONS

The paucity of well documented records of cetaceans in the FSM is likely due more to an absence of trained and knowledgeable observers than to an absence of animals. We have heard of many incidental encounters of unidentified species of cetaceans by visiting tourists, local fishermen and recreational boaters, but most of these sightings at sea are unconfirmed and unreported in the scientific literature. Furthermore, stranded specimens are likely to go undetected (except by local islanders) and unreported from many of these far-flung, remote, and either sparsely populated or uninhabited islands. The photographically documented records for

Kogia sp. and false killer whales reported here are the first records for these species in the

Caroline Islands, and the photographs of killer whales and short-finned pilot whale are the first definitive records for the FSM and Pohnpei State, respectively.

8 ACKNOWLEDGMENTS

We thank Glenn McKinlay (a regularly visiting naturalist), and Takuya Nagaoka (NGO Pasifika

Renaissance) for calling our attention to the strandings of the Kogia and Globicephala specimens, respectively. We also thank Eugene Joseph and Douglas Kusto (Conservation Society of Pohnpei) for furnishing photographs of the Kogia specimen,and Jorg Anson (Environmental

Protection Agency, Pohnpei) for additional information on its history and ultimate disposition of its remains. Robert Gallen (Madolenihmw Police Department) provided directions to the location of the G. macrorhynchus stranding, and, along with several bystanders, assisted in the onerous task of carrying the salvaged head from the stranding site to the transport vehicle. We thank

Selino Maxin and Kirino Olpet (Conservation Society of Pohnpei) for sharing their observations and photographs of killer whales off the coast of Pohnpei, Allois Malfitani (Pohnpei Surf Club) for information and photographs of false killer whales off Pohnpei, and Robin Baird (Cascadia

Research Collective), and Ingrid Visser (Orca Research Trust) for confirming identifications.

For responding to our queries and sharing their knowledge of cetaceans we thank Olive

Andrews, R. Baird, Scott Baker, Susan Chivers, Sarah Dwyer, Kris Helgen, Brian Lynch,

William McLellan, Mark Omura, I. Visser, and Gary Wiles. We also thank B. Lynch for contributing Figure 2C, Shaun Suliol for preparing photo composites, and G. Wiles and anonymous journal reviewers for their constructive comments on the manuscript.

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13 Figure 1. Location of Pohnpei and the Federated States of Micronesia in the west-central Pacific

Ocean,

14 Figure 2. Cetaceans recorded on Pohnpei for the first time. Kogia sp.: A, whole body, ventral view; B, undersurface of head showing teeth and jaws. Globicephala macrorhynchus: C, whole body; D, oblique view of head showing teeth and jaws.

15 Figure 3. Killer whales photographed off the coast of Pohnpei in July 2013.

16 Figure 4. False killer whales photographed off the coast of Pohnpei in September 2015.

17