Hoarding (animal Behavior) - Behaviors Related To Hoarding

Behaviors Related To Hoarding

Guarding

Most species are particularly wary of onlooking individuals during caching and ensure that the cache locations are secret. Not all caches are concealed however, for example shrikes store prey items on thorns on branches in the open.

Shared or individual hoarding

Although a small handful of species share food stores, food hoarding is a solo endeavor for most species, including almost all rodents and birds. For example, a number of jays live in large family groups, but they don't demonstrate sharing of cached food. Rather, they hoard their food supply selfishly, caching and retrieving the supply in secret. (Waite, 1992) There are only two species in which kin selection has resulted in a shared food store: Beavers (Castor canadensis) and Acorn Woodpeckers (Melanerpes formicivorous); the former live in family groups and construct winter larders of submerged branches, while the latter are unusual in that they construct a conspicuous communal larder (Koenig and Mumme, 1987).

Pilferage occurs when one animal takes food from another animal's larder. Some species experience high levels of cache pilferage, up to 30% of the supply per day. Previous models of scatter hoarding developed by Stapanian and Smith (1978, 1984), Clarkson et al. (1986), and others, suggested the value of cached food is equal to the hoarders ability to retrieve it. (cited from Vander Wall, 2003)

Reciprocal Pilferage

It has been observed that members of certain species, such as rodents and chickadees, act as both hoarder and pilferer. In other words, pilfering can be reciprocal and, thus, tolerable. Although this kind of food caching system seems cooperative, it has been suggested that it is actually driven by the selfish interests of the individual. (Vander Wall and Jenkins, 2003)

Recaching

Animals recache the food that they've pilfered from other animal's caches. For example, Vander Wall and Joyner (1998) found that 75% percent of radioactive Jeffery pine seeds cached by yellow pine chipmunks were found in two cache sites, 29% of the seeds were found in three sites, 9.4% were found in four sites and 1.3% were found in five sites over a 3-month period. These results, and those from other studies, demonstrate the dynamic nature of the food supplies of scatter hoarding animals.