Pattern of nipple use by puppies: A comparison of the dingo (Canis dingo) and the domestic dog (Canis familiaris)

Surprisingly little information is available about the behavior of newborn mammals in the functionally vital context of suckling. We have previously reported notable differences in the pattern of nipple use by kittens of the domestic cat and puppies of the domestic dog. Whereas kittens rapidly develop a "teat order," with each individual using principally 1 or 2 particular nipples, puppies show no such pattern. We asked whether the more "chaotic" behavior seen in puppies of the domestic dog (Canis familiaris) could be the result of relaxed selection due to domestication. In a first test of this hypothesis, we studied suckling behavior in 4 litters of wild-type captive dingoes (Canis dingo), a canid species that has inhabited the Australian mainland in substantial numbers for at least 5,000 years with minimal human influence. On all measures of individual puppies' behavior-time spent attached to nipples, lack of individual use of particular nipples and consequent absence of a teat order, lack of synchronized suckling with other littermates, lack of agonistic behavior-we found no differences between the 2 species. In conclusion, we suggest that the difference between the pattern of suckling behavior of kittens of the domestic cat (and other felids) and the domestic dog is not an artifact of domestication, but rather reflects phylogenetic differences between felids and canids as a consequence of their different lifestyles and associated patterns of parental care. These findings emphasize the need for comparative studies to avoid simplistic generalizations from 1 or 2 species across broad taxonomic groups.