Habitat selection and nest success of the Upland Sandpiper (<em>Bartramia longicauda</em>) in Ivvavik National Park, Yukon, Canada

Abstract

The Upland Sandpiper (Bartramia longicauda) is a grassland shorebird species associated primarily with prairie habitats in central North America. A disjunct and poorly studied population also occurs in Yukon, Canada, and Alaska, United States. We studied habitat selection of nesting Upland Sandpipers in Ivvavik National Park, Yukon, at the scales of microhabitat (1-m radius around nest) and putative home range (11.3-m radius plots at nests and within 50 m of nest). At the microhabitat scale, the Upland Sandpiper selected nest sites with lower visibility from above than that of their home range (median 91.5%, range 70–98% versus median 99.0%, range 85–100%) and less-variable composition of vegetation than at random sites within the home range. Vegetation adjacent to the nest in the eastern quadrat was significantly shorter (mean ± standard error: 10.6 ± 1.55 cm) than that in other directions around the nest (&gt; 13 cm); nest sites and microsites within home ranges were more often hummocky than random sites in the park. At the mesohabitat scale, Upland Sandpipers selected sites within home ranges with fewer trees than random sites within the park (10.3 ± 3.0 trees per 11.3-m-radius plot around nest versus 32.9 ± 5.9 trees per 11.3-m-radius plot in the park) and greater herbaceous cover (70.7% ± 3.0% versus 56.2% ± 3.7%). Despite the disproportionate use of sites with fewer trees, more herbaceous cover, and lower vertical visibility, these factors did not relate to nest success in our sample. Of the 24 nests found in 2010 and 2011, 22 contained four eggs and 2 contained three eggs. Upland Sandpipers at this high latitude site had a nesting success rate of 0.85 ± 0.01 and 0.56 ± 0.01 in 2010 and 2011, respectively, for a 21-day incubation period. Further assessment of the selected characteristics of nesting sites will improve our ability to predict the effects of northward shrub and tree encroachment on this grassland species.

A global threats overview for Numeniini populations: synthesising expert knowledge for a group of declining migratory birds

“…For instance, Numeniini may be especially sensitive to alterations to the phenology and abundance of food resources during the breeding season (Pearce-Higgins 2010, Leito et al 2014, Senner et al 2017), although as yet, few breeding population changes having been quantitatively linked to climate change through these mechanisms (Senner 2012, Senner et al 2017). Nevertheless, changes in woody plant distribution in the Arctic may already account for some localised population displacement of Arctic-nesting Whimbrel (Ballantyne and Nol 2015) and could potentially impact the southerly limit of populations more broadly in the future (Miller et al 2014). An upwards shift in the altitudinal distribution of Eurasian Curlew breeding in the UK has also been documented (Massimino et al 2015).…”

Wildlife species benefitting from a greener Arctic are most sensitive to shrub cover at leading range edges

“…Contingency arose where species only responded to specific attributes of shrub cover, effects were landscape‐dependent, or were determined by multiscale shrub characteristics. Some species are sensitive to shrub cover over a certain height, or are affected by overhead but not lateral visibility (Miller, Nol, Nguyen, & Turner, ; Wheeler et al., ). For some species, local shrub cover may influence prey survival and foraging efficiency by providing cover from predators where vegetation structure is open and prey exposed, but once shrub cover becomes denser, benefits of local increases in shrub cover may be lost or reversed (e.g.…”

Hyperabundant herbivores limit habitat availability and influence nest site selection of Arctic‐breeding birds

“…Many shorebirds nest among grasses and sedges in graminoid-dominated habitats (Cunningham, Kesler, & Lanctot, 2016;Saalfeld et al, 2013;Smith, Gilchrist, & Smith, 2007) to conceal their nests from predators (Smith et al, 2007). By doing so, some species increase their nest survival (Bentzen et al, 2017;Walpole, Nol, & Johnston, 2008) and may receive thermoregulatory benefits (Miller, Nol, Nguyen, & Turner, 2015). If removal of vegetative cover by geese limits the availability of preferred habitats, then birds may forgo nesting or select habitat that makes them more susceptible to predation.…”