Damaging effect of inbreeding in birds vastly underestimated

Destruction of bird habitats in the wild is forcing ever shrinking populations to inbreed putting the futures of whole species at risk, University of Sheffield scientists have warned.

Zebra finches were studied in the investigationNew research carried out by academics in the University’s Department of Animal and Plant Sciences suggests scientists across the world have grossly underestimated the damaging impact inbreeding is having on birds.

The scientists, the first to analyse the effects of inbreeding on the early stages of development, discovered that inbreeding – when closely related individuals mate – led to up to 75 per cent of embryos dying; much more than previously thought.

Dr Nicola Hemmings of the University’s Department of Animal and Plant Sciences said: “Inbreeding is a huge problem for many bird species around the world, particularly critically endangered species with small population sizes. Our research shows inbreeding may have even worse consequences for species survival than previously thought.

“Birds in the wild aren't choosing to mate with their relatives, but factors such as habitat loss can reduce the population size, which in turn can reduce the genetic variation in the population.

“Over generations the population may become more and more inbred. This is bad because with less genetic variation, there's more chance of problems such as health defects.”

Captive breeding programs and conservation hold the key to the survival of species and reduce inbreeding by avoiding pairing related individuals though introducing more genetic variation into populations; for example moving individuals from other populations.

Dr Hemmings added: “Our study shows that the negative effect of inbreeding on survival is strongest during embryo development. In other words, death caused by inbreeding is at its highest during the embryonic stage.”

The paper has been published in the journal Nature Communications.

Additional information

The University of Sheffield's Department of Animal and Plant Sciences
Department of Animal and Plant Sciences

The University of Sheffield
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