Animals with high-risk strategies to find food 'more likely to face extinction'
Animal populations are shrinking due to their high-risk strategies in finding food, according to researchers.
Those using such strategies are particularly susceptible to extinction, as they fail to gather to gather food for their young before they starve.
In the first study of its kind, thumbnail-sized electronic tags were fitted to condors, cheetahs, penguins and sheep in Argentina, South Africa and Northern Ireland over a six-year period.
The tags recorded a large amount of data, including each animal’s minute movements, the temperature of their environment and light levels.
Data was used to measure the probability that each animal finds food items, the size of the food items, the effort used to find the food and the effort used for all other activities such as rest and play.
Professor Rory Wilson of Swansea University, which led the research, said the study provided an explanation as to why some animal populations were shrinking.
“We know that animal populations across the world are taking a hit, with the most charismatic animals like lions and cheetahs being among the worst affected, but up until now it hasn’t been clear why,” Prof Wilson said.
“Our study has revealed that animals that use a high-risk gambling strategy to find food, like lions and tigers, which have to search for long periods before they get lucky and find prey, are more likely to fail to accrue the energy they need to breed, compared to animals that adopt a low-risk gambling strategy, like herbivores such as zebras.”
The average time the young of each species can survive without food depends on their size – with larger animals surviving for longer.
However, none of the newly hatched or newly born animals studied in the research could live without food for more than a few days.
Prof Wilson said the result of these animals using a high-risk food strategy was highlighted in the study by comparing two penguin species.
Magellanic penguins, living in Argentina, can find fish easily but African penguins have poor odds at finding food.
“It appears that commercial fishing has changed the game rules for the worse for the African penguins,” Prof Wilson said.
“When animals are taking rare prey anyway, even small changes in the ecosystem stemming from human activities can be the straw that breaks the camel’s back in terms of breeding success, and this seems to be the case for the African penguin, whose population is now just 1% of what it was 100 years ago.”
The researchers hope their model can be used to predict the fortunes of species across the world and help to forumlate conservation plans.
The research is published in the journal Current Biology.