SYDNEY: Peering inside the brain of an endangered bird has offered insights into the animal’s behaviour that will aid in efforts to protect the species, according to New Zealand scientists.
A team from the University of Auckland used Magnetic Resonance Imaging (MRI) to compare the brains of the flightless nocturnal kiwi to those of bird species whose behaviour and its relation to brain structure is better known. The results gave new insight into how the kiwi uses its senses of vision, smell and touch.
The frozen brains used in the study were donated by the Northland Office of New Zealand’s Department of Conservation (DOC) and came from birds that died of natural causes. New Zealand’s indigenous people, the Maori, for whom the endemic kiwi is sacred, were also consulted and gave permission for the study.
Jeremy Corfield, a PhD student at The University of Auckland, conducted the research through the University’s Centre for Advanced MRI, the Department of Anatomy and the Biomedical Imaging Research Unit. His findings were published in the U.S. journal Brain, Behaviour and Evolution, and his methods were published online in Nature Protocols, a resource provided by the British journal Nature.
“There are over five thousand endangered species worldwide and thus far it has been close to impossible to study their anatomy due to the rarity of specimens and the considerations of dissecting the few existing preserved specimens,” said Corfield.
“However, this research demonstrates the feasibility of using modern imaging techniques to study the brains of extinct or endangered species to get a better understanding of how they behave,” he said.
Georg Striedter, Associate Professor in Neurobiology and Behaviour at the University of California Irvine, said that the study “definitely deserves highlighting” and that “the use of MRI to look into the skulls of rare, endangered birds also seems very clever and useful”. Striedter was not part of the research team.
Clues to behaviour
According to Corfield, examining brain structure and comparing the size of specialisation areas gives detailed information about how the kiwi uses its senses. His work shows that kiwis have an enlarged olfactory cortex and forebrain, and a reduced visual cortex.
This suggests that the bird relies more on smell than on sight. According to Corfield, this is significant because most nocturnal birds have enlarged visual cortices, and rely mainly on excellent vision to navigate at night. The enlarged forebrain may indicate a higher than average intelligence, he said.
Prior to Corfield’s findings, no one knew how the kiwi found food or interacted with its environment. The information from this work “fills in the gaps” regarding kiwi behaviour, he said, and will be instrumental in designing future kiwi conservation strategies.
In their current program, the DOC takes kiwis from the wild and relocates them to an artificial habitat that offers protection from predators. According to Corfield, the behavioural information provided by his study will help them better tailor that habitat.
Corfield also said that his methods can be applied to any species and can even work for specimens that are not well preserved. The brains used in his study were from animals that had died more than a week previously and were not perfectly preserved; yet the team was still able to gather useful information about behaviour.