Cannibalism: A Perfectly Natural History(18)

Cannibalism of adults can also take place when several mature golden hamsters are kept in the same cage, and this includes siblings, who reach sexual maturity at around four weeks of age. Under these conditions, fighting is common, and serious injuries or even fatalities can result. In the latter instances, the survivor of the battle typically consumes the carcass of the loser.

Although mice, rats, guinea pigs, and rabbits also occasionally cannibalize their young in captivity (primarily when food and water are scarce), there are several factors that appear to make golden hamsters even more prone to this type of behavior. Most significant is the fact that M. auratus has the shortest gestation period (16 days) of any placental mammal, and they can become pregnant again within a few days of giving birth. This means that females, already weakened and stressed out by the rigors of pregnancy, birth, and nursing, may be tending a new brood of eight to ten pups less than three weeks after their previous delivery.

When non-human primates (i.e., monkeys and apes) are compared to other mammal groups, cannibalism is rare, having been observed in only 11 of 418 extant species. Many examples of primate infanticide and/or cannibalism were thought to be stress-related and, generally, this turned out to be true. Overcrowding, unnatural circumstances (like the transfer of a troupe of rhesus monkeys to a new island), and deficient captive conditions play a role in most of these reports, with the latter blamed for incidents of infanticide in bush babies, lemurs, marmosets, and squirrel monkeys. In each case, the victims were invariably neonates, while the aggressors were either group members or relatives, including siblings. Responding to the problem, caretakers at facilities housing breeding primate colonies began isolating pregnant females before they gave birth, and these efforts have proven effective.

One primate group in which infanticide and cannibalism are relatively common practices is the chimpanzees (Pan troglodytes), and descriptions of the behavior among our closest relatives are both chilling and fascinating.

Initially, reports of chimpanzee cannibalism focused solely on adult males, who routinely killed and sometimes consumed infants belonging to “strangers” (i.e., adult females from outside their own groups). According to Dr. Jane Goodall, female chimpanzees sometimes transferred from one community to another. “A female who loses her infant during an encounter with neighboring males is likely to come into oestrus within a month or so and would then, theoretically, be available for recruitment into the community of the aggressors.” Similar behavior is seen in bears and large cat species, like lions.

Other attacks by male chimps on infant-bearing females took place during “inter-community aggression” as occurs, for example, when groups of male chimpanzees patrolling the outer edges of their territories encountered individuals from adjacent communities.

Then, in 1976, Goodall reported on three observations in which two female chimps were involved in within-group infanticide and cannibalism in Tanzania’s Gombe National Park. What made these attacks unique was the absence of male involvement. Stranger yet was the fact that the individuals involved were a mother (Passion) and daughter (Pom), whose seemingly premeditated tag-team approach to somewhere between five and ten infant-bearing females provided researchers with a grim explanation for previously unexplained infant disappearances. Goodall believes that the attacks on the mothers functioned solely as a means to acquire food, since “once they had established their claim over their prey they made no further aggressive attacks on the mothers.”



Thirty years later, similar attacks were carried out by female chimp coalitions against infant-bearing mothers in in Uganda’s Budongo Forest. A team led by comparative psychologist Simon Townsend believes that the lethal attacks were triggered by an influx of females, leading to increased competition for resources.

Although acts of cannibalism in chimpanzees are not everyday occurrences, some researchers have suggested that the encroachment of humans into the areas surrounding preserves inhabited by chimps will eventually lead to population density issues and more competition for dwindling resources. If this occurs, incidences of cannibalism by our closest relatives may be expected to increase.



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9 Biological nomenclature is full of misleading scientific names. Vampyressa, Vampyrodes, Vampyrops and Vampyrum are all bat genera, but none of them feed on blood. There are also bad puns, like Apopyllus now (a sac spider) and Ittibittium (a tiny mollusk), as well as rude sounding names, like Pinus rigida (the pitch pine) and Enema pan (a scarab beetle).



10 Although Anti-pix specks are now collector’s items, the idea behind them lives on in plastic clips called “Peepers,” which can be attached via a pin through the nostrils of various commercially raised game birds. For an extremely entertaining short on the original Anti-pix specks, check out the following link: http://www.nationalband.com/Chickenglasses.mov





5: Bear Down


In Panama, I found a spider that eats it own limbs during lean times. I am told they grow back. But though the distinction is razor-thin, desperation is not the same thing as determination.

— Taona Dumisani Chiveneko, The Hangman’s Replacement: Sprout of Disruption, 2013

If you believe the news reports, this is not a good time to be a polar bear. Over the past several years, there have been dozens of headlines that ran something like this: “Polar Bears Are Turning to Cannibalism as Arctic Ice Disappears,” “Is Global Warming Driving Polar Bears to Cannibalism?” “Polar Bear Cannibalism Linked to Climate Change.”