Browsing by Author "Johnson, Oscar W."

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Migratory linkages of Pacific Golden-Plovers Pluvialis fulva breeding in Chukotka, Russian Far East
(2017-04) Johnson, Oscar W.; Tomkovich, Pavel S.; Porter, Ronald R.; Loktionov, Egor Y.; Goodwill, Roger H. E.
For the first time, we have tracked the annual migrations of Pacific Golden-Plovers nesting in northern Russia. We used geolocators to determine the timing and migration routes of four male plovers trapped at one site in SE Chukotka. Before leaving the north in autumn, each bird moved from nesting grounds and made one or two pre-migratory stopovers of 13-22 days (presumably on coastal tundra) in either Russia (Kamchatka and Khabarovsk Krai) or the USA (St. Matthew Island and the Pribilof Islands). After departing these sites, three birds traveled southward via eastern Asia and Japan to non-breeding grounds in the Philippine Islands, and one bird followed an oceanic route to Majuro Atoll in the Marshall Islands. All of these linkages were previously unknown. Two birds made nonstop flights of 4-6 days directly to non-breeding grounds, whereas two made additional stopovers en route (16 d in Japan and 18 d in China, respectively). In spring, return migrations from the Philippines variously included stopovers in South Korea, Taiwan, and China; the bird migrating from Majuro stopped-over only in Japan. Mean minimum flight speed on all legs in both autumn (after pre-migratory stopovers) and spring was 53 kph. On average, plovers spent 24 days at stopovers during the autumn journey, and 36 days at stopovers during the spring passage. Stopover sites and also non-breeding grounds probably included agricultural lands, most likely rice fields. While the migrations of these four birds shed light on migratory connectivity of Pacific Golden-Plovers nesting in Chukotka, additional studies are needed to: (1) further explore the non-breeding range of plovers breeding there and elsewhere in northern Russia, (2) better define important stopover sites including pre-migratory sites in the north, and (3) more fully understand the relationships between plovers and trophic resources associated with agriculture.
Tracking the migration of Pacific Golden-Plovers from nonbreeding grounds at Moorea, French Polynesia, using Pinpoint GPS-Argos tags
(2020-04) Johnson, Oscar W.; Tibbitts, T. Lee; Weber, Michael F.; Bybee, David R.; Goodwill, Roger H.; Bruner, Andrea E.; Smith, Errika J.; Buss, Emmalee L.; Waddell, Trinity Q. A.; Brooks, Daxton C.; Smith, Carolyn D.; Meyer, Jean-Yves
We used Pinpoint GPS-Argos tags to track migration of Pacific Golden-Plovers Pluvialis fulva in 2017 and 2018 from Moorea Island, at the extreme southeastern 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 traveling a long (8,250–10,200 km) northwestward track. Ten individuals signaled 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 indicating inland habitats, most likely rice fields. In May, at least nine of the plovers left Japan on a mid-length (3,200–5,400 km) northeastward track to the Bering Sea region, where one bird reported from a possible nesting site in Kamchatka Krai and eight from traditional breeding grounds (three from Chukotka, 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 southwest 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.