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Breeding short-tailed shearwaters buffer local environmental variability in south-eastern Australia by foraging in Antarctic waters.

Berlincourt M, Arnould JP - Mov Ecol (2015)

Bottom Line: The results of this study suggest that individuals could increase their foraging range while exploiting distant feeding zones, which could indicate that short-tailed shearwaters forage in Antarctic waters not only to maintain their body condition but may also do so to buffer against local environmental stochasticity.Lower breeding performances were associated with longer foraging trips to distant oceanic waters in 2013 and 2014 indicating they could mediate reductions in food availability around the breeding colonies by extending their foraging range in the Southern Ocean.This study highlights the importance of foraging flexibility as a fundamental aspect of life history in coastal/pelagic marine central place foragers living in highly variable environments and how these foraging strategies are use to buffer this variability.

View Article: PubMed Central - PubMed

Affiliation: School of Life and Environmental Sciences, Deakin University, Burwood, VIC 3125 Australia.

ABSTRACT

Background: Establishing patterns of movements of free-ranging animals in marine ecosystems is crucial for a better understanding of their feeding ecology, life history traits and conservation. As central place foragers, the habitat use of nesting seabirds is heavily influenced by the resources available within their foraging range. We tested the prediction that during years with lower resource availability, short-tailed shearwaters (Puffinus tenuirostris) provisioning chicks should increase their foraging effort, by extending their foraging range and/or duration, both when foraging in neritic (short trips) and distant oceanic waters (long trips). Using both GPS and geolocation data-loggers, at-sea movements and habitat use were investigated over three breeding seasons (2012-14) at two colonies in southeastern Australia.

Results: Most individuals performed daily short foraging trips over the study period and inter-annual variations observed in foraging parameters where mainly due to few individuals from Griffith Island, performing 2-day trips in 2014. When performing long foraging trips, this study showed that individuals from both colonies exploited similar zones in the Southern Ocean. The results of this study suggest that individuals could increase their foraging range while exploiting distant feeding zones, which could indicate that short-tailed shearwaters forage in Antarctic waters not only to maintain their body condition but may also do so to buffer against local environmental stochasticity. Lower breeding performances were associated with longer foraging trips to distant oceanic waters in 2013 and 2014 indicating they could mediate reductions in food availability around the breeding colonies by extending their foraging range in the Southern Ocean.

Conclusions: This study highlights the importance of foraging flexibility as a fundamental aspect of life history in coastal/pelagic marine central place foragers living in highly variable environments and how these foraging strategies are use to buffer this variability.

No MeSH data available.


Simplified representation of water masses in south-eastern Australia (Bass Strait region) and location of breeding colonies. EAC: East Australian Current; SASW: Sub-Antarctic Surface Water; SAC: South Australian Current (From [36]) and Bonney Upwelling. Gabo Island (GI) and Griffith Island (GR) breeding colonies are located on the map (closed circles). Inset map shows the area’s position in relation to Australia
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Fig1: Simplified representation of water masses in south-eastern Australia (Bass Strait region) and location of breeding colonies. EAC: East Australian Current; SASW: Sub-Antarctic Surface Water; SAC: South Australian Current (From [36]) and Bonney Upwelling. Gabo Island (GI) and Griffith Island (GR) breeding colonies are located on the map (closed circles). Inset map shows the area’s position in relation to Australia

Mentions: The region of Bass Strait is mainly influenced by the South Australian Current (SAC), the East Australian Current (EAC) and the sub-Antarctic Surface Water (SASW) [36] (Fig. 1). The warm SAC and EAC have low nutrient levels while the cold nutrient-rich SASW supports high biological productivity [37]. In addition, the Bonney Upwelling, the largest and most predictable upwelling in south-eastern Australia, provides a highly productive feeding ground for a variety of species (e.g. seabirds, fishes, whales and fur seals) [38–40]. Therefore, south-eastern Australia is marked by contrasting oceanic conditions that might influence the foraging decisions of breeding short-tailed shearwaters in response to environmental variability.Fig. 1


Breeding short-tailed shearwaters buffer local environmental variability in south-eastern Australia by foraging in Antarctic waters.

Berlincourt M, Arnould JP - Mov Ecol (2015)

Simplified representation of water masses in south-eastern Australia (Bass Strait region) and location of breeding colonies. EAC: East Australian Current; SASW: Sub-Antarctic Surface Water; SAC: South Australian Current (From [36]) and Bonney Upwelling. Gabo Island (GI) and Griffith Island (GR) breeding colonies are located on the map (closed circles). Inset map shows the area’s position in relation to Australia
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4522076&req=5

Fig1: Simplified representation of water masses in south-eastern Australia (Bass Strait region) and location of breeding colonies. EAC: East Australian Current; SASW: Sub-Antarctic Surface Water; SAC: South Australian Current (From [36]) and Bonney Upwelling. Gabo Island (GI) and Griffith Island (GR) breeding colonies are located on the map (closed circles). Inset map shows the area’s position in relation to Australia
Mentions: The region of Bass Strait is mainly influenced by the South Australian Current (SAC), the East Australian Current (EAC) and the sub-Antarctic Surface Water (SASW) [36] (Fig. 1). The warm SAC and EAC have low nutrient levels while the cold nutrient-rich SASW supports high biological productivity [37]. In addition, the Bonney Upwelling, the largest and most predictable upwelling in south-eastern Australia, provides a highly productive feeding ground for a variety of species (e.g. seabirds, fishes, whales and fur seals) [38–40]. Therefore, south-eastern Australia is marked by contrasting oceanic conditions that might influence the foraging decisions of breeding short-tailed shearwaters in response to environmental variability.Fig. 1

Bottom Line: The results of this study suggest that individuals could increase their foraging range while exploiting distant feeding zones, which could indicate that short-tailed shearwaters forage in Antarctic waters not only to maintain their body condition but may also do so to buffer against local environmental stochasticity.Lower breeding performances were associated with longer foraging trips to distant oceanic waters in 2013 and 2014 indicating they could mediate reductions in food availability around the breeding colonies by extending their foraging range in the Southern Ocean.This study highlights the importance of foraging flexibility as a fundamental aspect of life history in coastal/pelagic marine central place foragers living in highly variable environments and how these foraging strategies are use to buffer this variability.

View Article: PubMed Central - PubMed

Affiliation: School of Life and Environmental Sciences, Deakin University, Burwood, VIC 3125 Australia.

ABSTRACT

Background: Establishing patterns of movements of free-ranging animals in marine ecosystems is crucial for a better understanding of their feeding ecology, life history traits and conservation. As central place foragers, the habitat use of nesting seabirds is heavily influenced by the resources available within their foraging range. We tested the prediction that during years with lower resource availability, short-tailed shearwaters (Puffinus tenuirostris) provisioning chicks should increase their foraging effort, by extending their foraging range and/or duration, both when foraging in neritic (short trips) and distant oceanic waters (long trips). Using both GPS and geolocation data-loggers, at-sea movements and habitat use were investigated over three breeding seasons (2012-14) at two colonies in southeastern Australia.

Results: Most individuals performed daily short foraging trips over the study period and inter-annual variations observed in foraging parameters where mainly due to few individuals from Griffith Island, performing 2-day trips in 2014. When performing long foraging trips, this study showed that individuals from both colonies exploited similar zones in the Southern Ocean. The results of this study suggest that individuals could increase their foraging range while exploiting distant feeding zones, which could indicate that short-tailed shearwaters forage in Antarctic waters not only to maintain their body condition but may also do so to buffer against local environmental stochasticity. Lower breeding performances were associated with longer foraging trips to distant oceanic waters in 2013 and 2014 indicating they could mediate reductions in food availability around the breeding colonies by extending their foraging range in the Southern Ocean.

Conclusions: This study highlights the importance of foraging flexibility as a fundamental aspect of life history in coastal/pelagic marine central place foragers living in highly variable environments and how these foraging strategies are use to buffer this variability.

No MeSH data available.