I guess they don't care about freshness

Spotted hyena (Crocuta crocuta) have a bad reputation; they look strange, they have an unnerving repertoire of yips and yowls, the females have a pseudo-penis, and they are often portrayed as ruthless scavengers. I actually like hyenas quite a bit, and although not much can be done about their looks, they are not simply mangy scavengers that steal kills from the more "noble" lions (Panthera leo). Alone or in groups, hyenas are effective hunters, and lions try to steal hyena kills just as hyenas will compete for lion kills (the relationship between the two carnivores varies from place to place, but it almost always a tense one). Hunting behaviors and competition with other species are interesting enough alone, but the habits of hyenas are also important to understanding paleontology & human evolution. As agents of bone transport and destruction, spotted hyena have contributed to the creation of fossil assemblages, and the rarely-mentioned behavior of water-caching is one way in which they unintentionally might have created fossil assemblages.



The African carnivore most commonly associated with caching kills is the leopard (Panthera pardus, see video above), although cougars (Puma concolor) in North America have been known to stash deer carcasses in trees, as well. In these cases the cats often return to their kills and aren't very far away, but what spotted hyena do with water-cached carcasses is a bit different. According to Selvaggio (1998), hyenas deposited five carcasses (four adult wildebeest [Connochaetes sp.] and one adult Grant's gazelle [Gazella granti]) over a three week period in 1990 in Lake Macat with Ngorongoro Crater in Tanzania, the flesh from the limbs of the animals largely being consumed before the carcasses were stashed. The carcasses persisted for a number of days, failing to attract groups of vultures as well as being ignored by felids that came to drink at the lake, and the hyenas often were far away from the carcasses during the hottest parts of the day when they had to seek shade.

If crocodiles lived in Lake Macat the hyenas probably would have experience come competition for their stored meat, but no crocodiles were seen in the lake or in nearby water holes. In areas where there are no crocodiles (or at least no large ones), hyenas seem to take advantage of the water to store prey as other predators do not seem to be interested. If the prey was left out in the open it would probably be quickly consumed or transported elsewhere by a competing carnivore, but water-caching by hyenas appears to be a unique way to store excess food while not having to spend a lot of energy defending it. The carcasses may eventually be abandoned or forgotten, though, and in this case the hyenas will have moved a carcass from an area where it was more likely to have been destroyed (the forest or plains) to a place where it is more likely to be preserved.

This type of behavior is of primary interest to Selvaggio and others because it plays into the active vs. passive scavenging debate that revolves around Plio/Pleistocene hominids. Some say that hominids took advantage of carcasses when predators were not around, making the most of catastrophes like floods or leopard-cached carcasses in trees. Perhaps they did, but passive scenarios present problems involving the amount of meat available (the meatiest parts of the carcass, the limbs, are often consumed first or ripped off to be carried away) and disease, a passively scavenged carcass being subjected to bacteria from carnivore saliva, the gut contents of the prey, and insects. On the other hand, active scavenging would allow hominids access to fresher, more intact carcasses, but obtaining the carcasses would require direct confrontation with predators. Solitary predators like cheetahs and leopards would put the hominids in the least amount of risk, but studies of people who steal carcasses from carnivores today (i.e. the Hadza of Tanzania) reveal that cats don't always give up their food so easily resulting in a fair number of maulings. Both scavenging techniques present advantages and disadvantages, but the question of which was the preferred method of hominids remains a hotly-debated issue.

References;

Selvaggio, M.M. (1998) "The Archaeological Implications of Water-Cached Hyena Kills." Current Anthropology, Vol. 39 (3), pp. 380-383.

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