JUNE 23, 2020
Long-tailed tits actively
avoid harmful inbreeding by discriminating between the calls of close family
members and non-family members, according to new research from the University
of Sheffield.
Inbred animals typically
suffer from reduced survival and reproductive success, so incest is usually
avoided. But, in species where young stay close to where they were born,
relatives are often encountered as potential mates, increasing the risk of
harmful inbreeding.
Long-tailed tits often
breed close to home, allowing kin to help raise each other's chicks, but also
incurring a risk of incest that reduces the reproductive success of offspring.
The research, led by Dr. Amy Leedale from the University of Sheffield's
Department of Animal and Plant Science, found that despite this risk, close
relatives are actively avoided when pairs form each spring.
Long-tailed tits use
distinctive calls to recognize close relatives so that they can help raise
their offspring. The authors suggest that these calls also explain how the
birds avoid inbreeding.
Dr. Amy Leedale, who led
the research as a Ph.D. student at the University of Sheffield, said: "We
recorded the calls of males and females in many pairs of long-tailed tits and
found that the calls of breeding pairs were less similar than the calls of
close relatives that they could have bred with. Call similarity within breeding
pairs was, instead, similar to that observed among distant relatives or
unrelated birds."
Long-tailed tit calls are
learned in the nest, when parents, offspring and siblings are closely
associated. Call similarity can therefore act as a reliable indicator of close
relatedness in adulthood. This study reveals a potential mechanism by which
long-tailed tits can avoid harmful inbreeding as well as gaining benefits from
cooperating with kin.
