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Showing posts with label cannibalism. Show all posts
Showing posts with label cannibalism. Show all posts

Monday, February 1, 2010

More on cannibalism in bonobos


Following the publication of filial cannibalism in wild bonobos, the BBC has done the following write up:

Bonobo 'cannibalises' own infant
By Matt Walker

A wild bonobo has been seen cannibalising her own recently deceased two and a half-year-old infant.

Among apes, such behaviour is extremely rare, only being reported before among orangutans, and never by bonobos, our closest relative alongside chimps. Though uncommon, the behaviour may not be aberrant, says the scientist who witnessed it. But it does further challenge a widely perceived notion that bonobos are an especially "peaceful" ape species. The discovery is reported in the American Journal of Primatology.

Bonobos ( Pan paniscus ) were once known as pygmy chimps, due to their similarities with the common chimpanzee ( Pan troglodytes ), from which they diverged in the past one million years. Researchers have often emphasised the differences in behaviour between the two species; bonobos are reported as being less aggressive, hostile to one another, and living in societies dominated by females rather than high-ranking males that control communities of common chimps. They were also regarded as less violent, being thought not to commit infanticide or hunt and eat other primate species. Last year, however, that more peaceful image was shattered when scientists discovered that bonobos do kill and eat monkeys.

Now, primatologists Dr Andrew Fowler and Dr Gottfried Hohmann of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany have recorded an example of a bonobo ape consuming, along with other apes in her group, the body of her recently deceased infant.

Dr Fowler and colleague Ms Caroline Deimel were conducting routine observations of a group of bonobos living in the forest at Lui Kotale in the Democratic Republic of Congo. Through the trees, they saw a female called Olga carrying her dead infant, Olivia, over her shoulder. That morning Olivia had been seen alive, and her body showed no signs of injury. The next day, Olga still carried her dead infant, and spent an hour or so grooming her body.

"After an hour, Marta, a dominant female then took the body, retaining it despite initial resistance from Olga. She then began to consume it, joined by most of the community including the mother," Dr Fowler told the BBC. "Consumption took several hours, and possession of the carcass changed several times. At times Olga and Ophelia, her remaining daughter, were not involved but remained nearby throughout the period," he says. "When a single foot and hand only remained attached to a long skin fragment, Olga took the remains, placed them over her back and walked away."

Dr Fowler says that such behaviour is not usual, but it may be more widespread than this one incident. Researchers may have witnessed it, but been unwilling to report it for fear of drawing undue attention to cannibalism among our close relatives, he says. Or there may simply not have been enough long-term studies of bonobos to previously notice it.

Infanticide, the practice of killing younger members of the same species, occurs among common chimps and gorillas, as does cannibalism, where animals eat their own kind. Biologists believe that infanticide is often triggered by males who wish to eliminate infants carrying genes different to their own. By killing infants, they can also make the mothers sexually receptive again, increasing their own chances or mating with her. Filial cannibalism, where a mother eats her own offspring, is much rarer, particularly among great apes, in which it has only once been reported before.

Last year, Dr David Dellatore of Oxford Brookes University in the UK reported two incidences of female orangutans eating their recently deceased babies. He suspected the orangutans may have acted this way due to stress. But Dr Fowler believes the behaviour may occur among apes more often. Like Dr Dellatore, Dr Fowler is reluctant to make any definitive claims as to why the behaviour occurred. He suspects that Olga and the other bonobos consumed Olivia's body for nutritional gain, even though it carried a risk of contracting disease from the dead infant. However, says Dr Fowler: "I am not sure there are wider implications from a scientific point of view."

"I don't see that occasionally consuming dead infants, however distasteful it might seem to us, is a sign of pathology or aberration per se." "I don't think it necessarily says anything about 'empathy' or 'morality'," he adds. "It had been suggested in the past that bonobos might feel more sympathy for victims, which is why they didn't hunt monkeys, for example.

"But we now know they do hunt monkeys. So I think eating an already dead baby says little about bonobos in that respect. "Bonobos are often used in a symbolic way, held up as the sexy, peaceful 'Hippy Chimps'. "The fact that they eat monkeys and consume their own dead offspring may not accord with this view, but I personally don't see this as a problem." "The idea of the 'Hippy Chimp' is more a metaphor than a scientific argument," he continues.

"I think the major implication is that we don't need to see it as an aberration among other apes. "A more interesting question is why this female bonobo, Olga, allowed her infant to be eaten, because this is not always the case in chimpanzees. "The incident might tell us more about relationships between adults, and particularly adult females, in the sense that Marta was able to take and consume the body of another female."

Story from BBC NEWS:
http://news.bbc.co.uk/go/pr/fr/-/earth/hi/earth_news/newsid_8487000/8487138.stm

Saturday, January 23, 2010

Cannibalism in wild bonobos

Last year we found out bonobos eat monkeys and now a case of cannibalism in bonobos is being reported by Drs. Fowler and Hohmann from the MPI-EVA. The chimpanzee-bonobo gap gets smaller and smaller...-MA

Fowler A, Hohmann G (2010) Cannibalism in wild bonobos (Pan paniscus) at Lui Kotale. Am. J. Primatol. 71:1-6

Abstract

We describe the cannibalization of an infant bonobo (circa 2.5 years old) at Lui Kotale, in the Democratic Republic of Congo. The infant died of unknown causes and was consumed by several community members including its mother and an older sibling one day after death. Certain features concerning the pattern of consumption fit in with previously observed episodes of cannibalism in Pan, whereas others, such as the mother's participation in consuming the body, are notable. The incident suggests that filial cannibalism among apes need not be the result of nutritional or social stress and does not support the idea that filial cannibalism is a behavioral aberration.

Wednesday, December 2, 2009

Canadian polar bears turning to cannibalism in Hudson Bay


Image from Zareen's blog
From the WWF-Canada blog
by Peter J. Ewins, D.Phil.
Senior Officer, Species
Arctic Program

In the last few days the polar bears in western Hudson Bay, Canada, the best-studied subpopulation among the 19 across their Arctic range, have been giving us a dramatic and stunning new signal of population stress - at least 10 reported cases now of cannibalism.

In the last few days the polar bears in western Hudson Bay, Canada, the best-studied subpopulation among the 19 across their Arctic range, have been giving us a dramatic and stunning new signal of population stress - at least 10 reported cases now of cannibalism.

I was born in a coal-mining town in England, and was trained as a scientist, especially in marine animal ecology. The well-worn references to, and use of, the "canary in the coalmine" reflected very hard-learned lessons from past generations of miners in my birth-town. Better to read the signs in the canary in its cage 100 ft underground than to keel over yourself as carbon monoxide or other gases built up then poisoned you and your fellow miners.

In the last few days the polar bears in western Hudson Bay, Canada, the best-studied subpopulation among the 19 across their Arctic range, have been giving us a dramatic and stunning new signal of population stress - at least 10 reported cases now of cannibalism. Three decades of intensive polar bear studies here have hardly ever recorded such cannibalism. This is very new, and dramatic. The Nobel prize-winning IPCC team of 3000 world class scientists used this polar bear subpopulation and its responses to declining sea-ice coverage as an important signal in their assessments and modeling of the impacts and projections of/for rapid climate change. As an ecologist, I know that these are great studies over the past 30 years, and that the trends of key population parameters (cub survival, recruitment, adult survival, body condition, and eventually total population estimate) are familiar to any animal population experiencing major stress. It’s not specific to polar bears; most species when experiencing major habitat or population stresses respond in just these ways. That is the forces of nature at work. That's why the miners used the little canary in its cage.

It's December now, and to the amazement of local people and polar bears, and even cautious Arctic scientists, the sea ice has not yet returned to Hudson Bay! It’s late, very late, and so the polar bears who have spent the past five months or so along the coastline without significant fat-rich food , waiting for their sea-ice platform to return, are forced to wait even longer. It's likely that the hungriest, skinniest individuals are starving and desperate.... probably killing the weak and the young. That sea-ice used to be back in early November, then the bears all headed out quickly to catch ringed seals. Polar bears cannot survive on seaweed, berries or dried grass. They are top carnivores, evolved on a high fat diet. They have no option but to catch marine mammals from a stable sea-ice platform. No ice means no bears; it’s as simple as that. And our inattention to the GHG problem is thinning and shrinking the sea-ice at unprecedented rates.

The big question now is whether Canada's leaders are reading these signs, and whether these urgent alarm bells rung by the polar bear will be heeded as heads of state gather in Copenhagen to make decisions that will take care of GHG emissions, and hence the future of not only polar bears and sea-ice, but also the stability of our planet's climate patterns and economies. Perhaps the coal-miners could teach some of the world's leaders a few fundamental lessons about the need to pay serious attention to such biological signs, and then to take very quick actions in response!