USGS Science⌕ Search

Geology topics

Oscar W. Johnson

Publications and source records attributed to Oscar W. Johnson.

6 recordsLinked to original sources
USGS2025

Power source, data retrieval method, and attachment type affect success of dorsally mounted tracking tag deployments in 37 species of shorebirds

Animal-borne trackers are commonly used to study bird movements, including in long-distance migrants such as shorebirds. Selecting a tracker and attachment method can be daunting, and methodological advancements often have been made by trial and error and conveyed by word of mouth. We synthesized tracking outcomes across 2745 dorsally mounted trackers on 37 shorebird species around the world. We evaluated how attachment method, power source, data retrieval method, relative tracker mass, and biological traits affected success, where success was defined as whether or not each tag deployment reached its expected tracking duration (i.e. all aspects succeeded for the intended duration of the study: attachment, tracking, data acquisition, and bird survival). We conducted separate analyses for tag deployments with remote data retrieval (‘remote-upload tag deployments') and those that archived data and had to be recovered (‘archival tag deployments'). Among remote-upload tag deployments, those that were a lighter mass relative to the bird, were beyond their first year of production, transmitted data via satellite, or were attached with a leg-loop harness were most often successful at reaching their expected tracking duration. Archival tag deployments were most successful when applied at breeding areas, or when applied to males in any season. Remote-upload tag deployments with solar power, satellite data retrieval, or leg-loop harnesses continued tracking for longer than those with battery power, other types of data retrieval, or glue attachments. However, the majority of tag deployments failed to reach their expected tracking duration (71% of remote-upload, 83% of archival), which could have been due to tracker failure, attachment failure, or bird mortality. Our findings highlight that many tag deployments may fail to meet the goals of a study if tracking duration is crucial. Using our results, we provide guidelines for selecting a tracker and attachment to improve success at meeting study goals.

Journal of Avian Biology↗
USGS2024

Return rates of GPS-tagged Pacific Golden-Plovers: A controlled study in Hawaii

In a study of GPS-tagged Pacific Golden-Plovers wintering at Moorea, French Polynesia, Johnson et al. (2020) raised questions about possible tag-induced mortality. Similar concerns in other species have generated considerable attention in recent years. Of 19 tagged plovers that departed Moorea on northward migration, only one bird (5 %) uploaded a complete migratory cycle to Argos. Furthermore, contact was lost with 12 birds (63 %) variously during overwater flight, at stopover sites, or on nesting grounds; and no signals at all were received from 6 individuals (32%). Such observations suggest that carrying a tag might be a life-threatening burden. We cannot exclude the possibility that tag weight caused difficulties for the Moorea birds. However, this seems an unlikely factor in that the device (tag plus harness) being carried weighed less than 3 % of body mass (see beyond). Such a load is in accord with generally accepted albeit arbitrary limits. Other tag-associated concerns such as altered aerodynamics, increased vulnerability to predation, and (given the complex nature of geomagnetic navigation, the possibility that tag electronics might interfere with sense of direction, are more difficult to evaluate. Alternatively, loss of contact with tagged birds may be simply a matter of tag malfunction, battery failure, or a broken harness. To shed light on these uncertainties, and to explore the survival of GPS-tagged plovers on a nonbreeding ground in Hawaii, we conducted a controlled study using birds that winter in the National Memorial Cemetery of the Pacific (known locally as the Punchbowl).

Hawaii↗
USGS2024

Sixty-fifth supplement to the American Ornithological Society’s check-list of North American birds

This is the 24th supplement since publication of the 7th edition of the Check-list of North American Birds ( American Ornithologists’ Union [AOU] 1998 ). It summarizes decisions made between April 25, 2023 and April 30, 2024 by the American Ornithological Society’s (formerly American Ornithologists’ Union) Committee on Classification and Nomenclature—North and Middle America. The Committee has continued to operate in the manner outlined in the 42nd Supplement ( Banks et al. 2000 ). During the past year Oscar Johnson joined the committee, and J. V. Remsen, Jr. and Kevin Winker left the committee.

Ornithology↗
USGS2024

Comments on the species limits of certain North American birds, part 1

Although species limits of North American birds are relatively well-delineated, discrepancies among global lists identify species complexes that are subject to differences of opinion. As part of our work with the North American Classification Committee (NACC) of the American Ornithological Society, we here assess species limits in 11 such species complexes of North American birds: Spruce Grouse (Canachites canadensis), Band-tailed Pigeon (Patagioenas fasciata), Antillean Mango (Anthracothorax dominicus), Greenish Puffleg (Haplophaedia aureliae), Black Oystercatcher (Haematopus bachmani), Hook-billed Kite (Chondrohierax uncinatus), Sharp-shinned Hawk (Accipiter striatus), Elegant Trogon (Trogon elegans), American Three-toed Woodpecker (Picoides dorsalis), Golden-olive Woodpecker (Colaptes rubiginosus), and Olive-throated Parakeet (Eupsittula nana). We provide updated information on the taxonomic history of these species, and recommend updated taxonomic treatments by using published works, analysis of museum specimens, and citizen/community science databases. We hope this work will provide a foundation for future taxonomic research in these species complexes.

Bulletin of the British Ornithologists' Club↗
USGS2020

Tracking the migration of Pacific Golden-Plovers from nonbreeding grounds at Moorea, French Polynesia, using Pinpoint GPS-Argos tags

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.

Wader Study↗