Peeking into the bleak midwinter: Investigating nonbreeding strategies of Gentoo Penguins using a camera network

BLACK, CAITLIN; REY, ANDREA RAYA; HART, TOM

AUK

AMER ORNITHOLOGISTS UNION

Año: 2017 vol. 134 p. 520 - 529

0004-8038

When monitoring species with extensive ranges in harsh climates, comprehensive studies across a species? range areboth logistically and technically challenging and therefore rare. Such scarcity in data collection is particularly true inthe polar regions where sea ice and weather constraints prevent widespread access to sites for much of the year,specifically during winter. Penguins (Spheniscidae) show large variations in winter strategies with many speciesmigrating long distances while others are distinctly sedentary, remaining at the colony year-round. However, in somespecies, their attendance at the breeding site during the nonbreeding winter period depends greatly on the colonylocation and environmental factors. Here we aim to examine fluctuations in winter attendance at the breeding site inGentoo Penguins (Pygoscelis papua) along a latitudinal gradient of 7 sites, ranging from Martillo Island, a colony inArgentina, to Petermann Island, a colony located toward the southern edge of the species? range on the WesternAntarctic Peninsula. We use an established network of cameras to observe winter populations of penguins across alarge latitudinal gradient. This study provides the first evidence of across-year variation in Gentoo Penguinnonbreeding attendance at the breeding site. We found that both temporal and spatial factors drive winterattendance in this species with distinct patterns between years and colony locations, particularly at the edges of itsrange. Additionally, environmental and temporal factors, including sea ice extent directly offshore and photoperiod,appear to dictate Gentoo Penguin winter attendance across their range. As Gentoo Penguins are neither sedentary normigratory during the nonbreeding period, understanding patterns in winter site occupation across time and spaceprovides insight into half of the species? annual cycle and has important implications in the face of changes in climate,direct human disturbance, and fisheries activities.