Research reveals human-driven changes to distinctive foraging patterns
in North Pacific Ocean

Date:
April 14, 2022
Source:
University of Leicester
Summary:
The first large-scale study of its kind has uncovered more than
4,000 years' worth of distinctive foraging behavior in a species
once driven to the brink of extinction.



FULL STORY ==========================================================================
The first large-scale study of its kind has uncovered more than 4,000
years' worth of distinctive foraging behaviour in a species once driven
to the brink of extinction.


==========================================================================
An international team of researchers, led by the University of Leicester, identified long-term patterns in the behaviour of the short-tailed
albatross (Phoebastria albatrus) in the North Pacific Ocean by studying isotopes found in archaeological and museum-archived samples of the bird, dating as far back as 2300 BCE.

Their findings, published today (Thursday) in Communications Biology,
show long-term patterns in foraging behaviour for the short-tailed
albatross for the first time -- and demonstrate how individual birds
foraged the same hyper- localised sites for thousands of years in spite
of the species' huge potential foraging range across thousands of miles
of Pacific coastline and open ocean.

But this behaviour, a demonstration of long-term individual foraging
site fidelity (LT-IFSF), can pose significant risks for animals who
specialise in areas which may be impacted by human activity.

The short-tailed albatross was brought to the brink of extinction
by feather hunters between the 1880s and 1930s and though careful
conservation has resulted in exponential population growth in recent
decades, this trend of LT- IFSF has not been observed in the last century.

Dr Eric Guiry is Lecturer in Biomolecular Archaeology at the University
of Leicester and corresponding author for the study, which focused on two locations close to Yuquot, Canada, and compared findings to sites in the
USA, Russia and Japan. He said: "Understanding migratory behaviour is
critical for global biodiversity restoration because it helps identify vulnerable regions for environmental protection.



========================================================================== "Although evidence for the extent and depth of LT-IFSF across other
species is still emerging, the extreme distances and time scale of
the behaviour seen here indicates that this foraging strategy may be
a fundamental, density-driven adaptation that could become widespread
again as recovering animal populations reach pre-industrial levels."
The research team from Leicester, the Land of Maquinna Cultural Society (Canada), Vrije Universiteit Brussel (Belgium) and Simon Fraser University (Canada) were able to track this foraging behaviour by examining stable
carbon and nitrogen isotope compositions in samples of bone collagen.

In contrast to most other tissues such as muscle or feather, which turn
over on a scale of days, weeks, or months), isotopic compositions from
bone collagen, which remodels slowly over the entire lifespan on an
individual, reflect an average of foods consumed over the last several
years of an individual's life.

This provides a unique perspective for exploring lifetime trends in
animal diet and migration behaviour.

By mapping these biological markers against known isotopic baselines
across the species' foraging range, linked to factors such as sea surface temperature and CO2 concentrations, the researchers were able to build up
a picture of the short-tailed albatross' migratory and foraging behaviour
over hundreds of generations.



==========================================================================
But, crucially, as this behaviour is no longer observed among these
birds, their findings show this hyper-specialised foraging in specific locations disappeared after the birds were hunted to near extinction in
the 1880s, when only a handful of birds remained. Dr Guiry continued:
"We think this behaviour could be driven by competition among birds,
meaning that, as the population recovers, we could see it re-emerge. This
kind information is important because it provides advanced warning that monitoring for this remarkable behaviour, which can make the birds more vulnerable to human impacts, may need close attention.

"One of the most exciting findings, however, is actually quite a
positive note.

Our data also indicate that Indigenous communities at Yuquot were
harvesting these birds with little impact on their population for
thousands of years.

"Not only does this tell us something about the long-term sustainability
of Indigenous marine resource use at Yuquot, it provides a clear example
of how people and the short-tailed albatross can co-exist."

========================================================================== Story Source: Materials provided by University_of_Leicester. Note:
Content may be edited for style and length.


========================================================================== Related Multimedia:
* Map_of_known_albatross_breeding_islands ========================================================================== Journal Reference:
1. Eric. J. Guiry, Margaretta James, Christina Cheung, Thomas
C. A. Royle.

Four millennia of long-term individual foraging site fidelity in
a highly migratory marine predator. Communications Biology, 2022;
5 (1) DOI: 10.1038/s42003-022-03310-2 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/04/220414110831.htm

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