The occurrence of owls in the Marshall Islands
by Dirk HR Spennemann
Island biogeography and the assessment of the dispersal of avian species (cf. Diamond 1974) relies on reports of both sucessful and unsuccessful dispersal events. The latter are not easy to ascertain unless a bird has been observed or caught. Archival documents and older narratives often contain previously unrecognised observations of the presence of bird species (cf. Spennemann in press). Unfortunately such sources often suffer from a lack of detail thus not allowing to pin down the sighting to species level. On occasion, however, the data are detailed enough.

There are very few avian raptors in the Pacific Islands, and of these owls are the most common. The aim of this note is to present the evidence for the occurrence of owls on the Marshall Islands drawing both on observations and linguistic data.

Owls in Micronesia

There are only three owl species in the Central Pacific: the Palau Owl Pyrrhoglaux podargina, the Short-eared Owl Asio flammeus and the Common Barn Owl Tyto alba. While the first is endemic to Palau (Baker 1951: 215; Pratt et al. 1987: 215), the other two species have dispersed more widely.

Short-eared Owls, wide-spread in the northern hemisphere (Mikkola 1992), is a vagrant to the the more tropical climates of South East asia (MacKinnon & Phillipps 1993: 196). They are present with a subspecies on Pohnpei A.f. ponapensis (6deg. 50'N 158deg. 15'E) (Baker 1951: 218) and the southern Marianas of Saipan (A.f. ponapensis or A.f. flammeus ; 15deg. 15'N 145deg. 44'E); Guam (13deg. 30'N 144deg. 50'E); Tinian (14deg. 59'N 145deg. 33'E); and Pagan (18deg. 04'N 145deg. 41'E) (Prowazek 1913: 80; Baker 1951: 217). As vagrant or migrants they have been recorded on Yap (9deg. 37'N 138deg. 08'E) (Pratt et al. 1987: 216); Kosrae (5deg. 19'N 163deg. 06'E) (Baker 1951: 219; Pratt et al. 1987: 216); and on the isolated northwestern Hawaiian atolls of Kure (28deg. 25'N, 178deg. 28W) and Midway (28deg. 12'N, 177deg. 22'W) (Pratt et al. 1987: 216). Further east they are established on various islands of Hawaii (see fig. 1, Pratt et al. 1987: 216). The subspecies of Short-eared Owls on Pohnpei is regarded as endangered by the US Fish and Wildlife Service (Pratt et al. 1987: 38) and as rare by the ICBP (Pratt et al. 1987: 38).

Common Barn Owls are widespread in Australia (Simpson et al. 1996: 152; Shields 1994; Olson 1994), and occur in eastern Papua New Guinea (Behler et al. 1986:130), Melanesia (Pratt et al. 1987: 214; Eakle 1997), and Western Polynesia (Samoa, Tonga, Fiji, Niue, `Uvea and Futuna) (Pratt et al. 1987: 214), but are not on record for any of the atoll groups north of Fiji (eg Tuvalu, Kiribati and Tokelau) or indeed further east (see fig. 1). In 1958 they were introduced to Hawai'i (Pratt et a. 1987: 215).

The dispersal of owls has to be seen in the light that Common Barn Owls only rarely cross larger bodies of water and, at least in Australia, tend to be infrequent in the coastal areas (Blakers et al. 1984: 309). They can colonise across water, however: since their release in Hawai'i in 1958, for example, they have colonised all major Hawai'ian Islands, but not the more distant smaller ones to the north (Pratt et al. 1987: 215). Long-range dispersal can occur as vagrant Barn Owls from Australia have repeatedly reached New Zealand (Heather & Robertson 1997: 367). Short-eared Owls, on the other hand, are well known for their ability to cross large stretches of open water and to colonise new areas (Fuentes et al. 1994; Nilsen 1998). The distribution map (fig. 1) shows two clusters of Short-eared owls, one centred on Pohnpei and one emanating from Hawai'i.


Figure 1. Distribution of Short-eared Owls (Asio flammeus) (dots) and Common Barn Owls (Tyto alba) (diamonds)in the Pacific.

The Marshall Islands

The Marshall Islands are a group of 29 atolls and 5 islands located in the northern Central Pacific Ocean. Aligned in two chains (fig. 2) each atoll is comprised a number of small low-lying sand islets on the reef platform. The size of these atolls and islands ranges from Kwajalein, with 2174km2 enclosed lagoon area (but only 16.4 km2 combined land mass on 93 islets) the world's largest atoll, to Jemo Island with only 0.16km2 landmass. The average size of these islets is less than two hectares. The largest islands of an atoll can reach up to 2.5km in length and 1.5km in width. By way of comparison, Pohnpei Island has a land mass of 456km2 and Oahu, Hawaii, a landmass of 1573km2.

Traditionally the larger islets were the foci for human settlement and were heavily cultivated except for the ocean shore areas. Breadfruit Artocarpus altilis forests would have predominated, with a number of taro pits in the centre of the islets. The smaller islets, too small to support a groundwater lens, were not comonly permanently inhabited. Their interior would have comprised of a littoral forest of Pisonia grandis, Hernandia sonora, Barringtonia and other tree species (Fosberg 1990; Hathaway 1953; Spennemann 1992). Since the German colonial period (1886-1914) increasing areas of breadfruit and other forests were removed to make way for the more open coconut plantation, which tend to have a grassy or low shrub understory (Spennemann 1992).

On Hawaii, Pohnpei and the Marianas Short-eared Owls inhabit open grasslands, as do the Common Barn Owls in Fiji and Melanesia. This habitat, however, is essentially non-existent in the Marshalls. The main diet of the Short-eared Owl, rodents, occur throughout the Marshalls, mainly in form of the Polynesian rat Rattus exulans (Spennemann 1997); further, data from the USA and northern Europe have shown that in the absence or shortage of rodents Short-eared Owls may also feed on chicks and small species of shorebirds (Holt 1994; Sudmann et al. 1994; Nielsen 1997; Stienen & Brenninkmeijer 1997).

Observations

The presence of owls in the Marshalls is not listed in Baker's (1951) treatise on the avifauna of Micronesia nor in Amerson's (1969) seminal work on the birds of the Marshall Islands and Kiribati. Other bird surveys also failed to report them: Enewetak (Pearson & Knudsen 1967; Carpenter et al. 1968; Hailman 1979); Ujelang (Anderson 1981); Ebon (Spennemann and Benjamin 1992); Jaluit (Finsch 1880a-b; Schnee 1904); Kwajalein (Schipper 1985; Clapp 1988); the northern Marshalls (Fosberg 1966; Thomas 1989); and Wake Atoll (Porter 1953; Bryan 1959; Casey 1966; Fosberg 1966). This indicates the overall rarity of these birds in the Marshall Islands.

There are three isolated records related to the occurrence of owls in the Marshalls which can be drawn on:

Enewetak Atoll (11deg. 30' N 162deg. 20'E, 40 islets, combined landmass 5.85km2),

In July 1973 Johnson & Kienholz (1975) collected a single female Short-eared Owl as a vagrant Enewetak Atoll (fig. 2). As Berger (1987) points out, the ultimate origin (asia, Pohnpei, Hawai'i) of that specimen is unclear.

Arno Atoll (7deg. 10'N 171deg. 40' E, 83 islets, combined landmass 13km2),

The German Catholic Priest Albert Neumann, resident on Ine, Arno Atoll (fig. 2), and fond of hunting, was called in mid-1908 to investigate a bird unknown to the Marshallese which was reputedly becoming continuously bigger and was feared to eventually attack and eat people. Upon investigation the bird turned out to be a `true, German forest owl' (`echte deutsche Waldeule'; Neumann 1908). To rid the Marshallese of their fear Neumann shot the bird. The specimen was apparently not collected. It is extremely unlikely that the German priest would have been mistaken in his identification of the bird as an owl. Furthermoreis description of the bird as a `Waldeule' (wood owl) indicates an owl with ears, suggesting that it was a Short-eared Owl and not a Common Barn Owl.

Jemo Island (10deg. 07'N 169deg. 33'E, 1 island, landmass 0.2km2)

F. Raymond Fosberg (1966) reported the find of what he regarded to be an owl pellet on Jemo Island (fig. 2) in December 1951. Amerson (1969: 333) mentioned this report but could not give it too much credence in the absence of confirmed sightings. In view of the owl sigthings on Enewetak and Arno, however, the identification appears solid, especially in view of the absence of other avian raptors and other wild animals known to regurgitate pellets (such as foxes).

Figure 2. Map of the Marshall Islands with the locations mentioned in the text shown in bold.

Linguistic Data

A brief analysis of linguistic data shows just how rare owls are as vagrants in the Marshalls. While the modern Marshallese language reputedly has a term for male (mao) and female (lijemao) owls (Abo et al. 1976: 178; 213), the bird is not contained in the early word lists (Hernsheim 1880; Senfft 1900; Grösser 1902), not even in the otherwise very comprehensive and authoritative dictionary compiled by Pater Augustin Erdland (1906). It is also worth noting that Erdland (1906: 147) lists lijemao as a petrel. The modern nomenclatory identification appears rather doubtful as male and female Short-eared Owls are not readily distinguishable from their plumage and gender differentiation in Marshallese nomenclature only occurred for birds deemed significant for dietary or other cultural reasons.

Krämer & Nevermann (1938: 295), compiling the known bird species and their names, mention that owls are very rare and give the Marshallese terms djedjak and drak for the birds. However, this is most probably a compilation or typesetting error (`Eule' [owl] instead of `Ente' [duck]), drawing on Erdland's (1906: 18) generic terms for ducks (djedjak and drak).

Anderson (1981), working on Ujelang Atoll, obtained the term bao-in-mankolo from the Marshallese community, a generic construct similar to bao in ene (land bird) and bao-in-eon na (shore bird). This he assumed to be a term for owl.

On Kosrae owls are known by the English loan word ohwel (Lee 1976: 90), again suggesting rarity. Local names, however, exist for Pohnpei, where the Short-eared Owl is established (likoht, tehap; Rehg & Sohl 1979: 50; 113) and for nearby Mokil Atoll (6deg. 39'N 159deg. 53'E) (seaip; Harrison & Albert 1977: 81).

Conclusions

Short-eared owls have been noted as migrants and vagrants from Asia on various isolated islands and atolls in the northern Central Pacific Ocean, and have established themselves on Pohnpei and the Hawaiian Islands. The distribution map of sightings and other evidence suggests that Pohnpei is a dispersal centre from which various colonisation attempts moved eastwards. The record of a probable Asio flammeus for Arno Atoll is the most southeasterly record in the Pacific Ocean area. The two records of owls in hand for the Marshalls (Enewetok Atoll and Arno Atoll) coupled with Fosberg's observation of a possible owl pellet on Jemo Island demonstrate the migration capabilities of that species. The ability to find very small specks of land is suggestive of their colonising potential. It is worth noting that this colonisation must have occurred against the prevailing winds.

Acknowledgements

I am indebted to Dr. Iain Taylor (Johnstone Centre, CSU) for comments on an earlier draft of the paper. Any sins of ommission are, of course, mine.

Bibliography

Abo, T., Bender, B.W., Capelle, A. and DeBrum, T. 1976. Marshallese-English Dictionary. PALI language Texts: Micronesia. Honolulu: University of Hawaii Press.

Amerson, A.B. 1969. Ornithology of the Marshall and Gilbert Islands. Atoll Research Bulletin 127. Washington: Smithsonian Institution.

Anderson, D.A. 1981. Observations of birds at Ujelang and other northern Marshall Islands atolls. Micronesica 17: 198-212.

Baker, R.H. 1951. The avifauna of Micronesia. Its origin, evolution, and distribution. University of Kansas Publications Museum of Natural History 3(1), 1-359.

Beehler, Bruce M., Pratt, Thane K. & Zimmermann, Dale A. 1986. Birds of New Guinea.Princeton: Princeton University Press.

Berger, A.J. 1987. Avifauna of Enewetak Atoll. In: Devaney, D.N., E.S.Reese, B.L.Burch & P.Helfrich, The Natural History of Enewetak Atoll. Volume I. The Ecosystem: Environments, Biotas, and Processes. Oak Ridge, Ten.: U.S.Department of Energy, Office of Scientific and Technical Information. Pp. 215-220.

Blakers, M., Davies, S.J.J.F. & Reilly, P.N. (1984) The Atlas of Australian Birds Melbourne: Melbourne University Press.

Bryan, E.H. jr. 1959. Notes on the geography and natural history of Wake Island. Atoll Research Bulletin 66. Washington: Pacific Science Board.

Carpenter, M.L., Jackson, W.B. and Fall, M.W. 1968. Bird populations at Enewetak Atoll Micronesica 4(2): 294-307.

Casey, E. 1966. The birds of Wake Island `Elepaio 43:69-70.

Clapp, R.B. 1988. Notes on the birds of Kwajalein Atoll, Marshall Islands. Washington: National Ecology Research Center, U.S.Fish and Wildlife Service, National Museum of Natural History.

Diamond, J. 1974. Colonisation of exploded volcanic islands by birds: the supertarmp strategy.Science 184: 803-806.

Eakle W.L. 1997. Observations of raptors in the Republic of Vanuatu. Journal of Raptor Research. 31(4): 303-307.

Erdland, A. 1906. Wörterbuch und Grammatik der Marshallsprache nebst ethnographischen Erläuterungen und kurzen Sprachübungen. Archiv Deutscher Kolonialsprachen. Vol.IV. Berlin: Georg Reimer.

Everett, Michael, Prestt, Ian & Wgagestaffe, Reginald (1992) Barn and Bay Owls. in: John A. Burton (ed.), Owls of the world their evolution, structure and ecology. [London]: Peter Lowe. Pp. 36-50.

Finsch, O. 1880a. Ornithological letters from the Pacific II. The Ibis 4(14): 218-220.

Finsch, O. 1880b. Ornithological letters from the Pacific II. The Ibis 4(15): 329-333.

Fosberg, F.R. 1966. Northern Marshall Islands Land Biota: birds. Atoll Research Bulletin 114. Washington: Smithsonian Institution.

Fosberg, F.R. 1990. A review of the Natural History of the Marshall Islands. Atoll Research Bulletin. 330. Washington: Smithonian Institution.

Fuentes M A., Simonetti J A., Soledad Sepulveda M. & Acevedo P A. 1993. Diet of the red-backed buzzard (Buteo polyosoma exsul) and the short-eared owl (Asio flammeus suinda) in the Juan Fernandez Archipelago off Chile. Journal of Raptor Research 27 (3): 167-169.

Grösser, Hermann. 1902. Wörterbuch der Marschall-Sprache nach hinterlassenen Papieren des verstorbenen Stabsarztes Dr. Erwin Steinbach (von 1891 bis 1894 Regierungsarzt in Jaluit, Marshall-Inseln). Hamburg: L. Friedrichsen

Hailman, J. 1979. Notes on the birds of Eniwetok Atoll, Marshall Islands `Elepaio 40(6): 87-90.

Harrison, Sheldon, P. & Albert, Salich 1977. Mokilese-English Dictionary. PALI language Texts: Micronesia. Honolulu: University of Hawaii Press

Hatheway, W.H. 1953. The Land Vegetation of Arno Atoll, Marshall Islands. Atoll Research Bulletin 16. Washington: Pacific Science Board, National Research Council.

Heather, Barrie D. & Robertson, Hugh A. 1997.The field guide to the birds of New Zealand. Oxford: Oxford University Press.

Hernsheim, Franz. 1880. Beitrag zur Sprache der Marshall-Inseln. Leipzig: Fr. Thiel.

Holt D W. 1994. Effects of short-eared owls on common tern colony desertion, reproduction, and mortality. Colonial Waterbirds 17 (1): 1-6.

Johnson, O.W. and Kienholz, R.J. 1975. New avifaunal records for Enewetok. Auk 92, 592-594.

Krämer, Augustin & Nevermann, Hans 1938. Ralik-Ratak (Marschall Inseln). In: G.Thilenius (ed.), Ergebnisse der Südsee-Expedition 1908-1910. II. Ethnographie, B: Mikronesien. Vol. 11: Hamburg: Friedrichsen & de Gruyter.

Lee, Kee-Dong. 1976. Kusaiean-English Dictionary. PALI language Texts: Micronesia. Honolulu: University of Hawaii Press

MacKinnon, John & Phillipps, Karen 1993. A filedguide to the birds of Borneo, Sumatra, Java and Bali. Oxford: Oxford University Press.

Mikkola, Heino 1992. Wood Owls. in: John A. Burton (ed.), Owls of the world their evolution, structure and ecology. [London]: Peter Lowe. Pp. 108-140.

Neumann, Albert. 1908. "Brief des Ehrw. Br. Albert Neumann an die Laienbrüder in Hiltrup." Hiltruper Monatshefte 25: 539-542.

Nielsen O K. 1997. Observations on winter food habits of Short-eared Owl Asio flammeus in Iceland. Natturufraedingurinn 67(2): 85-88 [not seen]

Olson, P.D. 1994. Barn Owl Tyto alba. in: Ronald Strahan (ed.), Cuckoos, Nightbirds and Kingfishers of Australia. Sydney: Angus & Robertson. p. 53.

Pearson, D.L. and Knudsen, J.W. 1967. Avifaunal records from Enewetok Atoll, Marshall Islands. Condor 69(2): 201-203.

Porter, H.P. 1953. The brave young birds of Wake Island. Elepaio 13:47-48.

Pratt, H.D., Bruner, P.L. and Berrett, D.G. 1987. The Birds of Hawaii and the Tropical Pacific. Princeton, N.J.: Princeton University Press

Prowazek, S. von. 1913. Die deutschen Marianen. Ihre Natur und Geschichte. Leipzig: Johann Ambrosus Barth.

Rehg, Kennth L. & Sohl, Damian G. 1979. Ponapean-English Dictionary. PALI language Texts: Micronesia. Honolulu: University of Hawaii Press

Schipper, W.L. 1985. Observations of birds in Kwajalein Atoll, 1978-1983. Elepaio 46(4): 27-32.

Schnee, P. 1904. Die Landfauna der Marshall-Inseln. Zoologische Jahrbücher 20, 387-412..

Senfft, Arno. 1900. "Wörterverzeichnis der Sprache der Marschall-Insulaner." Zeitschrift für afrikanische und oceanische Sprachen 5:79-157.

Shield, J. 1994. Barn Owl Tyto alba. in: Ronald Strahan (ed.), Cuckoos, Nightbirds and Kingfishers of Australia. Sydney: Angus & Robertson. pp. 50-52.

Simpson, K, Day, N & Trusler, P. 1996. Field Guide to the birds of Australia. Ringwood: Viking.

Spennemann, D.H.R. 1992. Cultural Resource Managment Plan for Majuro Atoll, Republic of the Marshall Islands. 2 Vols. Washington: U.S.Department of Interior, Office of Territorial and International Affairs.

Spennemann, D.H.R. 1997. Distribution of rat species on the atolls of the Marshall Islands: Past and present dispersal. Atoll Research Bulletin 445, 1-8.

Spennemann, D.H.R. in press a. A note on a 19th century sighting of a species of ground-dwelling bird on Bokak, a northern atoll of the Marshall Islands. Corella (accpeted).

Spennemann, D.H.R., and Benjamin, H. 1992. A survey of the proposed airport location, Ebon Atoll, Republic of the Marshall Islands. Report trepared for the Ministry of Public Works. HPO-Report 1992/9. Majuro Atoll, Republic of the Marshall Islands: Historic Preservation Office.

Steadman D.W. & Freifeld H.B. 1998. Distribution, relative abundance, and habitat Relationships of landbirds in the Vavau Group, Kingdom of Tonga. Condor. 100(4): 609-628.

Stienen E W M. & Brenninkmeijer A. 1997. Food and growth of short-eared owl Asio flammeus chicks. Limosa 70(1): 5-10. [not seen]

Sudmann S., Becker P H. & Wendeln H. 1994. Short-eared Owl Asio flammeus and Long-eared Owl A. otus as predators in Common Tern Sterna hirundo colonies. Vogelwelt 115 (3). 1994. 121-126. [not seen]

Thomas, P.E. 1989. Report of the Northern Marshall Islands Natural Diversity and Protected Areas Survey, 7-24 September 1988. Noumea: South Pacific Regional Environmental Programme.

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Bibliographic citation for this document

Spennemann, Dirk HR. (2000) The occurrence of owls in the Marshall Islands.
URL: http:/marshall.csu.edu.au/Marshalls/html/birds/owls.html

CONTACT:
Dirk H.R. Spennemann, Institute of Land, Water and Society, Charles Sturt University, P.O.Box 789, Albury NSW 2640, Australia.
e-mail: dspennemann@csu.edu.au

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