Migratory Connectivity at High Latitudes: Sabine’s Gulls (Xema sabini) from a Colony in the Canadian High Arctic Migrate to Different Oceans

Abstract

The world's Arctic latitudes are some of the most recently colonized by birds, and an understanding of the migratory connectivity of circumpolar species offers insights into the mechanisms of range expansion and speciation. Migratory divides exist for many birds, however for many taxa it is unclear where such boundaries lie, and to what extent these affect the connectivity of species breeding across their ranges. Sabine’s gulls (Xema sabini) have a patchy, circumpolar breeding distribution and overwinter in two ecologically similar areas in different ocean basins: the Humboldt Current off the coast of Peru in the Pacific, and the Benguela Current off the coasts of South Africa and Namibia in the Atlantic. We used geolocators to track Sabine’s gulls breeding at a colony in the Canadian High Arctic to determine their migratory pathways and wintering sites. Our study provides evidence that birds from this breeding site disperse to both the Pacific and Atlantic oceans during the non-breeding season, which suggests that a migratory divide for this species exists in the Nearctic. Remarkably, members of one mated pair wintered in opposite oceans. Our results ultimately suggest that colonization of favorable breeding habitat may be one of the strongest drivers of range expansion in the High Arctic.

Abundance and species diversity hotspots of tracked marine predators across the North American Arctic

“…(, ), Ferguson, Dueck, Loseto, and Luque (), Gaston et al. (), Fisk, Lydersen, and Kovacs (), Peklova, Hussey, Hedges, Treble, and Fisk (), Spencer, Gilchrist, and Mallory (), Harwood, Smith, Auld, Melling, and Yurkowski (), Maftei, Davis, and Mallory (), Davis, Maftei, and Mallory (), Auger‐Méthé, Lewis, and Derocher (), Lunn et al. () and Bartzen, Dickson, and Bowman ().…”

“…We used existing telemetry data collected from 1989 to 2016 from 1,283 individuals across four species groups (Table 1) Table 1). These individuals were captured and instrumented as part of other studies that are described by Orr, Joe, and Evic (2001), Mallory and Gilbert (2008), Dietz et al (2008Dietz et al ( , 2014, Ferguson, Dueck, Loseto, and Luque (2010), Gaston et al (2011), Fisk, Lydersen, and, Peklova, Hussey, Hedges, Treble, and Fisk (2012), Spencer, Gilchrist, and Mallory (2014), Harwood, Smith, Auld, Melling, and Yurkowski (2015), Maftei, Davis, and Mallory (2015), Davis, Maftei, and Mallory (2016), Auger-Méthé, Lewis, and Derocher (2016), Lunn et al (2016) and Bartzen, Dickson, and Bowman (2017).…”

Migration strategy and site fidelity of the globally threatened Sociable Lapwing Vanellus gregarius

“…A very small sample of Pallid Harriers tagged in central Kazakhstan all wintered in Africa, but a single Pallid Harrier tagged in India also returned to central Kazakhstan (Terraube et al 2012), so the pattern may be common to Central Asian steppe species. Davis et al (2016) tracked Sabine's Gulls Xema sabini from one breeding colony in Arctic Canada, and indeed in one case from one breeding pair in that colony, to both the Pacific and Atlantic oceans and concluded from this that the colony lay on the migratory divide itself. We consider that this is an unlikely explanation for the patterns we observed in Sociable Lapwing, since of the two birds tagged in eastern Kazakhstan, at the eastern edge of the species' breeding range, one took the western flyway and one the eastern.…”

Diet dichotomy between two migrant seabirds breeding near a high Arctic polynya

“…The decreasing trend in the δ 13 C n values following date sampled, and the negative effect of date sampled by year on the δ 15 N values might also suggest a diet depleted in carbon and nitrogen at this high Arctic colony for Sabine's gull compared to the food consumed during recent migration, and that isotopic equilibrium was not yet attained upon the switch in diet after arrival at the breeding ground [37,38], especially in 2008 when Sabine's gull were sampled earlier. Sabine's gulls nesting at Nasaruvaalik Island spend the winter off the coast of Peru [21] and were recorded in the Beaufort Sea typically by 6 June on their spring migration north, reaching Nasaruvaalik Island by 9–25 June [39]. The isotopic values of marine invertebrates (i.e.…”