Reingestion in the Black-Tailed Jack Rabbit

Abstract

It has long been known that the domestic rabbit produces both hard and soft fecal pellets (Morot, 1882). The hard pellets are the normal waste product of the digestive tract and are the feces one finds in the field. The soft pellets are a special product of the caecum, and the rabbit takes them directly from its anus and swallows them whole. Morot's observations went virtually unnoticed until they were confirmed by Madsen (1939), but since that time many workers have become interested in the phenomenon and it has been variously termed “pseudo-rumination,” “refection,” “coprophagy,” and “reingestion.” The latter term is perhaps most appropriate (Watson, 1954) and is used throughout the present paper. Most of the investigations have been concerned with reingestion in domestic varieties of Oryctolagus cuniculus , but Southern (1940) showed that reingestion was a normal part of the biology of the species in the wild. Watson (1954) and Meyer (1955) confirmed and amplified the observations of Southern on wild populations of the same species in New Zealand and Australia, respectively. As early as 1895 it was suggested that the same phenomenon occurred in the European hare ( Lepus europaeus ) and Watson and Taylor (1955) verified this in the introduced hares of New Zealand. The latter authors suggest that reingestion may be a normal feature of lagomorph biology, and emphasize the scarcity of data on reingestion in the many North American species. Hamilton (1955) notes the presence of fecal pellets in the stomach of a swamp rabbit ( Sylvilagus palustris ) from Florida, and Kirkpatrick (1956) describes the act of swallowing feces by a cottontail rabbit ( Sylvilagus floridanus ). Except for these two reports, no other published information is available on reingestion in any of the American lagomorphs. During …