Huemul heresies: beliefs in search of supporting data. 2. Biological and ecological considerations

FLUCK, WT; SMITH FLUECK, JM

Huilo Huilo

Congreso; 7th International Deer Biology Congress; 2010

The continuing lack of well-substantiated information about huemul (Hippocamelus bisulcus) results inreliance on early sources of interpretations. The repeated citing of such hearsay is scrutinized here fortheir validity. Huemul antlers provide clues about well-being and past changes as up to 5 tines havebeen documented historically. Antlers are misinterpreted by erroneously considering >2 tines asabnormal. The question is: “What conditions in the past allowed many tines, and allowed antlerexpressions to be closer to the species norm?” Significant past changes resulted in only few earlyrecords of large groups, abundance and killing many huemul. Current orthodox descriptions of huemulare based on little data from remnant populations in marginal habitats. Relying on such biasedinformation results in circular reasoning when interpreting zooarcheology, paleodiets, prehistoricdistribution, and huemul ecology in general. Claims of inadequate antipredator response due toevolutionary absence of cursorial predators is unsupported as several Canis species arrived togetherwith cervids, overlapping with dogs having arrived with paleoindians. Huemul reactions toward dogsare similar to other Odocoilines. However, any predation event in severely reduced huemulsubpopulations may be important due to dynamics of small populations. There is no evidence thatlivestock or red deer (Cervus elaphus) have caused declines or prevented recovery of huemul. Incontrast, huemul have disappeared in numerous areas lacking livestock or red deer, but have persistedelsewhere with livestock for several hundred years. Recent sympatry with red deer affects <2% ofhuemul populations and in one case livestock outnumber red deer 2100%. Cervids including huemulexhibit great variation in feeding behavior, irrespective of dental and gastrointestinal features, due toflexibility in behavior, physiology and morphology. Although presence of other herbivores will shiftspatio-temporal habitat use and affect performance, persistence of multi-species assemblages is therule, like huemul coexisting with guanaco (Lama guanicoe), pudu (Pudu puda) and livestock.However, impacts from management of livestock, particularly the presence of people and dogs exertheavy pressure on wildlife and create incompatibilities. Concerning diseases from exotic ungulates,huemul coexisted with livestock for several centuries, but only recently in a few cases with red deer(but outnumbered 21-fold by coexisting livestock). Parasites found so far in huemul were only at verylow levels. These are mostly considered nonthreatening, are found in red deer but commonly inlivestock and therefore occur in most areas with livestock. Thus, the primary factor regardingcontagious diseases is feral and free-ranging livestock, and being regularly researched and inspected atslaughter, these provide a good proxy for diseases afflicting sympatric red deer.