Cycle of violence: Chicks abused by older birds are more likely to grow up to become bullies

By Martin Robinson


Chicks bullied and abused by older birds are more likely to do the same when they become adults, scientists have claimed.

A study of a colony of Nazca Boobies, a seabird from the Galapogas Islands, discovered they follow a 'cycle of violence' similar to that sometimes found in humans.

Older birds in this species often mistreat younger ones, behaviour scientists found was generally repeated through the generations.

Violent: A Nazca Booby chick (pictured) will often become abusive themselves later in life if they are treated badly by parents or other adult birds


They claim it is the first evidence from the wild showing that, as with humans, child abuse is socially transmitted rather than genetic.

The study has been published in the journal The Auk, by Martina Müller, Dr David Anderson and other academics from Wake Forest University, in North Carolina.

'The maltreatment of nestlings by adults is really obvious,' Dr Anderson told BBC Nature. 'Essentially all nestlings experience some maltreatment.'

'The cycle of violence effect may be a widespread cause of variation in the social behaviour of vertebrates, having been identified in humans in semi-natural conditions, Nazca Boobies in natural conditions, and several mammals in artificial captive conditions.

Parent: The adult Nazca Booby regurgitates food for the young chick on the Galapagos but it does not always show the same care


'The Nazca booby model may be very useful for studies of the phenomenon, especially manipulative studies, that cannot be done with humans.'

Just like humans, Nazca parents will generally raise one child at a time and some have an abusive relationship.

Also as these birds tend to nest very close together, violence will break out between families.

Home: The birds studied by scientists live on the beautiful Galapagos Islands (pictured)


Often, when parent birds are away from the nest gathering food, non-related adults will start to interact with the babies.

This can take the form of care and feeding or in some cases sexual and physical abuse.

Scientists watched the birds, ringing them for identification purposes, for three consecutive breeding cycles.

As a result the scientists say they have proved their behaviour is not genetic but instead influenced by the birds' own society.


source:dailymail