As the poultry and egg industries became established, feather pecking and cannibalism (known in the trade as “pick out”) became two of the most serious threats faced by poultry farmers. To stop cannibalism and prevent the loss of their valuable egg-laying hens, farmers routinely clipped off the tip of the bird’s beak, a reportedly painful process. In the 1940s, however, the National Band and Tag Company came up with a far more painless and fashion conscious method to deal with the problem of cannibalistic chickens. Their design team reasoned that if the birds couldn’t see “raw flesh or blood” then they wouldn’t cannibalize each other and so they came up with “Anti-pix”—mini sunglasses equipped with red celluloid lenses and aluminum frames. Purchased in bulk ($27 for 1,000) and attached to the upper portion of the bird’s beak near the base, poultry farmers were informed that having their chickens see the world through rose-tinted glasses would “make a sissy of your toughest birds,” and apparently they worked.10
Currently, only 75 species of mammals (out of roughly 5,700) are reported to regularly practice some form of cannibalism. Although this number will likely increase as more researchers become interested in the topic, the overall low occurrence of cannibalism in mammals is likely related to relatively low numbers of offspring coupled with a high degree of parental care (compared to non-mammals).
The golden hamster (Mesocricetus auratus), also known as the Syrian hamster, is a popular pet for children, but these cuddly fuzz balls are also known to display some nightmare-inducing behavior in captivity. The problems stem from major differences between their natural habitats and the captive conditions under which they are typically held. Native to northern Syria and Southern Turkey, M. auratus lives in dry desert environments. Adults are solitary, highly territorial, and widely dispersed. Individuals inhabit their own burrows and emerge for short periods at dawn and dusk to feed and mate. This crepuscular lifestyle is thought to help them avoid nocturnal predators like owls, foxes, and feral dogs. The results of a study on golden hamsters in the wild emphasized the major differences between natural conditions and those imposed on pet hamsters. For example, the researchers determined that in the wild, the average time hamsters spent on the surface during a 24-hour period was 87 minutes.
The problems between natural and captive conditions often begin in pet shops, where male and female golden hamsters are often kept in unnaturally large groups and displayed in well-lit aquaria. They are purchased singly (preferable) or in pairs (males and females if the store personnel know how to differentiate sexes). As pets, these desert-dwellers are housed in cages or trendy modular contraptions where translucent plastic tubes link “rooms” to each other. Unfortunately, the cages are often too small and golden hamsters have a hard time fitting through the plastic tubes, especially when pregnant or obese from overfeeding. Cage floors are usually covered in cedar shavings, which are pleasant enough to the human nose but hardly reminiscent of a desert environment. Regularly handled by children and often subjected to excessive noise and damp conditions (resulting from soiled cage bedding or leaky water bottles), many pet hamsters spend their existence under the watchful gaze of dogs and cats, their owners blissfully unaware that these are the hamster’s natural enemies.
As a result of this laundry list of captivity-related stresses, female golden hamsters, especially younger ones, frequently cannibalize their own pups. Beyond diet (too much or too little food) and housing conditions, cannibalism can be triggered if hamsters are handled late in their pregnancy or if the babies are handled within ten days of their birth. The presence of additional individuals (even fathers) can also lead females to consume their own pups and heterocannibalism can occur if adult females encounter unrelated young. Pet experts suggest that filial cannibalism can be prevented by isolating pregnant individuals, making sure that water and nutritional requirements are met, and refraining from handling female hamsters before and after they give birth. Finally, pet owners should not handle newborns of any species unless they are prepared to nurse the animals themselves.
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.