Flexible reproductive timing can buffer reproductive success of Pygoscelis spp. penguins in the Antarctic Peninsula region

Abstract

Varying the timing of reproduction in response to local environmental conditions is a key factor influencing reproductive success. We used 19 yr (1991 to 2009) of data on breeding chronology and reproductive success of Adélie penguins Pygoscelis adeliae and gentoo penguins P. papua at King George Island, Antarctica to compare clutch initiation dates (CIDs), hatch rates, and crèche rates at population and individual levels. The CIDs of both species occurred earlier with warmer October temperatures, but gentoo penguins adjusted CIDs twice as much per °C of temperature as Adélie penguins. Gentoo penguins also exhibited lower variances in hatch and crèche rates than Adélie penguins, suggesting that greater ability to respond to ambient conditions can buffer reproductive success. Mixed-effects models revealed that individual-and yearspecific random effects on the overall population mean best accounted for observed variation in CIDs, with some individuals routinely breeding earlier than others. However, individual differences in the relative timing of breeding provided no advantage for long-term reproductive success. The results suggest that, among gentoo and Adélie penguins, plasticity in CIDs with respect to environmental conditions is primarily a population-level rather than an individual-level response. Energetic constraints of contrasting migratory and fasting behaviors likely contribute to the different abilities to respond to warming spring temperatures. Overall, larger responses of gentoo penguin CIDs to October temperature and lower variability in reproductive success, despite reduced reproductive success with delayed breeding, suggests that gentoo penguins are better equipped than Adélie penguins to adjust to rapid warming in the Antarctic Peninsula ecosystem.KEY WORDS: Phenology · Adélie · Gentoo · Climate change · Migrant Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 454: 91-104, 2012 92 should exhibit higher and/or less variable reproductive success relative to those less able to respond to ambient conditions. In the present study, we compared the response in breeding chronology to changing environmental conditions in the Antarctic Peninsula region of 2 species of Pygoscelis penguins that have exhibited long-term divergent trends in abundance. We specifically investigated the relative importance of population-versus individual-level plasticity on reproductive success among Adélie penguins P. adeliae and gentoo penguins P. papua.The Antarctic Peninsula region is currently undergoing rapid environmental changes, including increased air and sea temperatures (Meredith & King 2005, Turner et al. 2005a, declines in the duration of winter sea ice (Stammerjohn et al. 2008), and increases in frequency and amount of precipitation (Turner et al. 2005b, Thomas et al. 2008. These environmental factors are important for penguins, as they can influence marine primary production (Schofield et al. 2010), food distribution (Loeb et al. 1997), and physical cond...

Adélie penguin (Pygoscelis adeliae) survival rates and their relationship to environmental indices in the South Shetland Islands, Antarctica

“…Complex environmental effects on Adélie penguin survival Large-scale atmospheric indices and associated regional changes in marine conditions have been implicated in trends in numerous seabird populations around the world (Veit et al 1996;Croxall et al 2002;Sandvik et al 2005;Devney et al 2009). In Antarctica, the responses of penguin populations to environmental variability have included changes in abundance (e.g., Trathan et al 1996;Wilson et al 2001), but also included shifts in range (Emslie et al 1998), changes in breeding phenology Hinke et al 2012), and changes in foraging behavior (Fraser and Hofmann 2003). Despite major changes in environmental conditions in the Antarctic Peninsula region (Turner et al 2005a;Stammerjohn et al 2008a;Meredith and King 2005), the majority of interannual variation in survival rates of Adélie penguins was not well explained by the selected indices of environmental conditions.…”

“…Local weather conditions, such as air temperature and precipitation, affect breeding chronologies and breeding success of Adélie penguins (Boersma 2008;Hinke et al 2012). Here, we include such local weather conditions to ask whether annual survival and recapture rates are also affected by local weather conditions.…”

“…Here, we include such local weather conditions to ask whether annual survival and recapture rates are also affected by local weather conditions. Following Hinke et al (2012), we used mean spring (September-November) temperatures and total spring precipitation amounts observed at Bellingshausen Station, a Russian research station located approximately 22 km southwest of the study colony. Data were acquired online at http://www.…”

Contrasting specialist and generalist patterns facilitate foraging niche partitioning in sympatric populations of Pygoscelis penguins

“…Gentoo penguins may also benefit from competitive release as other Pygoscelis species decline (Miller et al 2010, Trivelpiece et al 2011) and as reductions in spring sea ice allows greater accessibility to ice-free coastlines for colony establishment near their southern range limit (Lynch et al 2012). Other factors, such as a greater flexibility in the timing of breeding and longer parental investment during chick rearing, likely benefit gentoo penguins relative to other Pygoscelis species (Polito & Trivelpiece 2008, Hinke et al 2012.…”

Adélie penguins coping with environmental change: results from a natural experiment at the edge of their breeding range

“…Adélie penguin natural history has been well-studied Antarctic-wide (Ainley, 2002) with recent research focused on long-term temporal and spatial patterns in abundance and demographics (Jenouvrier et al, 2005;Dugger et al, 2006Dugger et al, , 2010Lynch et al, 2012a;Lyver et al, 2014), foraging ecology (e.g., Watanuki et al, 2002;Ainley et al, 2003Ainley et al, , 2004Ballard et al, 2010a;Lescroël et al, 2010Lescroël et al, , 2014, and breeding biology (Ainley et al, 1983;Emmerson and Southwell, 2008;Hinke et al, 2012). In summary, it appears that population responses of Adélie penguins to environmental drivers can vary temporally and spatially, with contrasting responses of vital rates to patterns of sea ice extent and/or concentration (Croxall et al, 2002;Forcada and Trathan, 2009;Ainley et al, 2010;Lynch et al, 2012a;Hinke et al, 2014).…”