The Identity of the Dingo II.* Hybridization with Domestic Dogs in Captivity and in the Wild

Abstract

The possibility that wild canids in south-eastern Australia were hybrids of Canis familiaris dingo and C.f. familiaris was examined by breeding known hybrids in captivity and comparing eight skull measurements in canonical analyses. The resulting distribution of the known hybrids was mainly intermediate to but overlapping those of the calibrating samples of dingoes and dogs whose distributions were separate. The distribution of the unknown wild canids closely resemblzd that of the known hybrids. An extra sample of wild dingoes resembled the calibrating dingoes. Comparisons with 95% population confidence limits of calibrating samples classified 12% of unknowns as dogs. 52% as hybrids and 36% as dingoes. The similarities of known hybrids and wild unknowns resulted from different assemblages of skull characters, but the two prime characters in the discrimination, bulla volume and alveolar distance of PI to P,, were commonly reduced in size in both groups. Maxillary width was dog-like in the unknowns but dingo-like in known hybrids. In the latter. increase in domestic dog ancestry caused an increase in the rate of change of skull morphology; but even so small an ancestry as 0.125-0.25 domestic dog caused marked changes compared with the eight parental dingoes. There was also evidence of skull changes due to the domestication process. The most indicative was foreshortening of the alveolar distance from P*1 to P*4 found in 34 of the 41 known hybrids and in four of the eight parental dingoes. There was no evidence for inheritance of the trait.