Date: May 12, 2016
Source: University of Washington
Over their 52-million-year history, a few bats have evolved a
taste for their fellow vertebrates. Now biologists are shedding light on how
these so-called 'carnivorous bats' adapted to the daunting task of chowing down
their backboned prey.
Vampire mania aside, bats don't go for a diet that would make
for an exciting Hollywood blockbuster. Most are insectivores, chomping on
insects. Some large species prefer fruit. And yes, a few like blood.
But over the 52-million-year history of these flying mammals,
a few have evolved a taste for their fellow vertebrates. Now biologists at the
University of Washington and the Burke Museum of History and Culture are
shedding light on how these so-called "carnivorous bats" adapted to
the daunting task of chowing down their backboned prey.
"Vertebrate prey are a unique challenge for carnivorous
bats," said lead author Sharlene Santana, a UW assistant professor of
biology and curator of mammals at the Burke Museum. "They eat flesh, bones
and everything else within their prey, and we wanted to understand the
evolutionary changes that help them accomplish this."
Santana and co-author Elena Cheung, a UW undergraduate, wanted
to understand how these adaptations influenced changes in skull shape and size.
When talking about diet, this is no small question.
"The skull and mandible provide attachment points for the
jaw muscles, and variation in these attachment sites results in differences in
bite force, and how wide of a gape the jaws are capable of," said Santana.
Their findings, published May 11 in the Proceedings of
the Royal Society B, reveal surprising patterns of change that helped
carnivorous bats catch and eat vertebrates. Though there are currently more
than 1,300 species of bats, only a few dozen eat vertebrates, from fish to land
animals -- including a few species that eat other bats. This evolutionary
transition -- from insects to vertebrates -- has occurred at least six times
over bat history.
Santana and Cheung took high-resolution images of skulls from
140 bats across 35 species, representing all six lineages of carnivorous bats
as well as bats that eat insects, or a combination of vertebrates and insects.
The skulls were from the Burke Museum and the Los Angeles County Museum.
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