research paper Wader Study 127(1): xx-xx. doi:10.18194/ws.00172 Tracking the migration of Pacific Golden-Plovers from nonbreeding grounds at Moorea, French Polynesia, using Pinpoint GPS-Argos tags Oscar W. Johnson1, T. Lee Tibbitts2, Michael F. Weber3, David R. Bybee4, Roger H. Goodwill5, Andrea E. Bruner4, Errika J. Smith4, Emmalee L. Buss4, Trinity Q.A. Waddell4, Daxton C. Brooks4, Carolyn D. Smith6 & Jean-Yves Meyer7 1Dept. of Ecology, Montana State University, Bozeman, MT 59717, USA. [email protected] 2U.S. Geological Survey Alaska Science Center, 4210 University Drive, Anchorage, AK 99508, USA 3Dept. of Biochemistry & Physical Sciences, Brigham Young University-Hawaii, Laie, HI 96762, USA 4Dept. of Biology, Brigham Young University-Hawaii, Laie, HI 96762, USA 53459 E. Kesler Ln, Gilbert, AZ 85295, USA 6500 Mitchell Rd., Cape Elizabeth, ME 04107, USA 7Délégation à la Recherche de la Polynésie française, B.P. 20981 Papeete, Tahiti, French Polynesia Johnson, O.W., T.L. Tibbitts, M.F. Weber, D.R. Bybee, R.H. Goodwill, A.E. Bruner, E.J. Smith, E.L. Buss, T.Q.A. Waddell, D.C. Brooks, C.D. Smith & J.-Y. Meyer. 2020. Tracking the migration of Pacific Golden-Plovers from nonbreeding grounds at Moorea, French Polynesia, using Pinpoint GPS-Argos tags. Wader Study 127(1): xx–xx. We used Pinpoint GPS-Argos tags to track migration of Pacific Golden-Plovers Keywords Pluvialis fulva in 2017 and 2018 from Moorea Island, at the extreme southeastern Pluvialis fulva edge of the species’ winter range. Of 20 tagged birds, 13 uploaded locations during all or part of their northward migration. The birds departed in mid-April trans-Pacific flights traveling a long (8,250–10,200 km) northwestward track. Ten individuals signaled spring stopover from Japan, where they stopped over (or ‘staged’) for periods up to about one month. Almost all stopovers were on the island of Honshu, with coordinates migratory connectivity indicating inland habitats, most likely rice fields. In May, at least nine of the flight speed plovers left Japan on a mid-length (3,200–5,400 km) northeastward track to the Japan Bering Sea region, where one bird reported from a possible nesting site in Kam- chatka Krai and eight from traditional breeding grounds (three from Chukotka, rice fields five from Alaska). Thereafter, contact with tags was intermittent and gradually lost. We received signals from only two individuals during fall migration; one bird flew 1,600 km southeast from Alaska before its tag ceased transmitting, and the other flew >8,600 km directly southward from its post-breeding site in south- west Alaska and made landfall in Samoa where transmissions ended. Throughout the study, lengthy transoceanic flights appeared to be nonstop, and the annual migratory pathway (though defined by only a single bird in fall) was circular. As we have shown in other studies, Japan emerges as a key stopover site for Pacific Golden-Plovers during northward migration. INTRODUCTION populations, that are among the most impressive in the avian world (Conklin et al. 2017). Based on tracking with We report here the first successful GPS tracking of trans- geolocators, the migrations from Hawaii to Alaska and Pacific migration by a shorebird, the Pacific Golden- return are nonstop along a direct north-south path, Plover Pluvialis fulva (hereafter Plover). This species nests whereas more distant connections to and from wintering on tundra from western Alaska to the Yamal Peninsula in grounds beyond Hawaii in the Central and South Pacific Siberia, and winters on inland and coastal habitats of the follow a circular clockwise pathway (Johnson et al. 2011, insular Pacific, Australia, New Zealand, SE Asia, India 2012, 2015, 2017). The latter consists of three legs, each and NE Africa (Hayman et al. 1986, Byrkjedal & Thompson apparently flown nonstop: a northwestward leg in spring 1998, Lappo et al. 2012, Johnson et al. 2019). The species’ to refueling sites (particularly in Japan), then a north- annual migrations between these far-flung regions often eastward leg to breeding grounds in the Russian Far East involve extensive over-water flights, particularly for eastern and Alaska, and finally a mid-Pacific return leg in fall. 2 Wader Study 127(1) 2020 Fig. 1. Study site at Temae, Moorea Island, French Polynesia. Pacific Golden-Plovers were captured on the golf course (foreground) and on grassy areas (dashed arrows) adjacent to tidal mudflats (solid arrow). Photo courtesy of Green Pearl Golf, Moorea. Heretofore, there had been no tracking studies of Pacific of Plovers at spring departure. We used these tags because Golden-Plovers from the island of Moorea or elsewhere they collect high-quality location data (±10 m) and in French Polynesia. The island lies at the southeastern transmit these data remotely over the Argos system edge of the species’ winter range, far from all previous (Collecte Localisation Satellites; CLS America 2016). tracking studies of Plover movements, the nearest being Remote transmission is important because Plovers are a geolocator study at American Samoa (Johnson et al. often difficult to recapture on nonbreeding grounds. We 2012) some 2,300 km to the west. Thus, Moorea was an re-visited the study site for 2–3 days in both November ideal place to further document extremely long trans- 2017 and January 2019 and searched for tagged returnees. Pacific flights, to determine whether birds at a site so far The entire tagging process for each bird, including color- to the east used the same circular route described above, banding (generic in 2017, individual-specific in 2018) and to discover the breeding origin of Plovers wintering and recording standard measurements averaged approx- there. In addition, the study was an opportunity to field- imately 15 minutes. Recovery was rapid: birds walked test 4.0 g Pinpoint GPS-Argos tags (Lotek Wireless, Inc.) awkwardly at first, but gait normalized usually within 30 over extreme long-distance migrations, and to further minutes and ability to fly appeared unaffected. Each evaluate this emerging technology (see Scarpignato et al. tagged bird was closely observed after release, typically 2016). for several days, and all were walking and flying normally when last seen. Fourteen of the birds were captured on METHODS the golf course and six were netted on grassy areas bordering the mudflat. When captured, the Plovers were Much of Moorea is steep and forested, thus unsuitable in pre-alternate molt that had not progressed enough to for wintering Plovers as the birds prefer open low-growth enable identification of sex. Based on primary feather conditions (Johnson et al. 2019). Favorable habitat for wear (tips unworn in adults, frayed in first-year birds; see Plovers is mostly limited to the Temae area at the north- Johnson et al. 2019), all the tagged birds were adults. eastern end of the island (17.48°S, 149.77°W) where there is a golf course and an adjacent mudflat (Fig. 1) which We programmed the tags to obtain GPS locations more together hosted about 100 birds in both years of this frequently during presumed periods of migratory flight study. With mist nets in the predawn, we captured 20 and less frequently during presumed nesting and stopover Plovers there (10 each in the nonbreeding seasons of periods. In 2017, tags collected up to a maximum of 30 2017 and 2018) and fitted them with GPS tags. Birds GPS locations before transmitting the data over the Argos were captured and tags deployed during 27 February–10 system. In 2018, a newer version of the tags carried an March in 2017 and 18–24 March in 2018. We used Lotek added feature that enabled more locations to be collected Pinpoint GPS-Argos 4.0 g tags and attached them with a and transmitted more frequently (‘pass-prediction’; Lotek leg-loop harness (Rappole & Tipton 1991) made of 1.0 Wireless, Inc.). Theoretically, based on our programming, mm diameter stretchable polymer cord (‘Stretch Magic’, battery life in the 2018 tags was sufficient to obtain and Pepperell Braiding Co., USA). The tag plus harness broadcast locations throughout the entire migratory cycle weighed about 4.2 g, roughly 2.0% of probable body mass including return flights in fall. Johnson et al. l Tracking Pacific Golden-Plover migration 3 Fig. 2. Circular pattern of migratory movements of Pacific Golden-Plovers tagged with GPS transmitters in spring 2017 and 2018 at Moorea Island. Of the total sample (20 birds): 13 signaled departure on a northwestward heading, 10 of these were tracked to stopovers in Japan, and 9 were tracked northeastward from Japan to breeding grounds in Chukotka and Alaska. Two birds were tracked southward from Alaska in fall; one was last recorded in Samoa, and the other during flight over the Pacific. Small circles represent positions received and lines between circles are interpolated track lines. Map is a Plate Carrée projection. In 2017, tags were programmed to obtain one location reported locations) and track speed of nonstop portions per day from 10 April–1 May and one location per three of flights. days from 2–24 May. To take advantage of the pass pre- diction feature, tags in 2018 were programmed to obtain RESULTS one location per day from 5–20 April, one location per three days from 23 April–29 May, one location per 10 Variable programming together with lapses in satellite days from 8 June–27 July, and one location per two days communication made it difficult to precisely determine from 30 July to the end of battery life. Tags that stopped the timing of events for each bird. Thus, the times and transmitting prematurely were considered to indicate a durations indicated below should be regarded as approx- broken harness, a malfunctioning tag, or death of the imate.