HUEMUL HERESIES: BELIEFS IN SEARCH OF SUPPORTING DATA. 3. REPRODUCTION

The general absence of recovery of remnant huemul populations (Hippocamelus bisulcus) hinges on factors affecting the population dynamics. We analyze recent published findings about reproduction and behavior with regard to their possible implications. The life history of huemul is characterized by age at maturity of one year with evidence that fawns may also breed. Reports of twinning need confirmation, but it occurs in congeneric taruca (H. antisensis) and other Odocoilines. Huemul breed every year and frequently raise fawns successively. Life cycle calculations should apply these parameters because unrealistic parameters may cover up ongoing processes and lead to spurious conclusion. Sexual segregation in huemul is facultative, similar to many other cervids and reflects relationships between populations and their environment. Dominance group breeding systems were described several times without indications of territoriality, as with taruca. Recently, huemul bucks were characterized as territorial all year, life-long, defending and monopolizing female groups and two ‘territorial’ bucks sired most offspring. These two bucks though sired only 26% of fawns in their respective social groups. In their area, ‘territorial' bucks bred about as many wandering females than resident females, whereas 32-45% of fawns from resident females were sired by outside males. Furthermore, when applying one year as the age at maturity rather than three years, there were unaccounted fawns and possibly <50% of all neonates were sampled. Overall, these data do not support territoriality in huemul. Regarding movements, extant huemul occupy flat grasslands, and at times nearly exclusively so, while historically huemul occurred up to 270 km from forests and in rolling topography. The claim that 5 km of open valley inhabited with guanaco (Lama guanicoe) present a barrier to huemul causing genetic isolation is unwarranted: moreover, huemul coexist with guanaco currently and historically. Erroneously considering landscape features as barriers and underestimating reproductive capacity may distract from discovering the factors underlaying the lack of recolonizations generally observed in currently reduced huemul populations. Additional keywords: Hippocamelus bisulcus, reproduction, sexual segregation, territoriality, resource defense, genetic isolation. INTRODUCTION Securing reliable data is difficult on species highly reduced in numbers and remaining mainly in remote refuge areas. In the accompanying paper (Part I. Historical and zooarcheological considerations, this issue) we analyzed information regarding historical conditions which influence the current interpretation of the biology and ecology of huemul (Hippocamelus bisulcus). Part II addresses antlers, group size and density, predation, diet, competition, and diseases. These papers together aim to improve our understanding of huemul and its conservation. Here we analyze older and more recent sources and focus on issues related to reproduction, sexual segregation, resource defense, and genetic isolation to reveal discrepancies. We show that current beliefs do not stand up under close scrutiny. METHODS We reviewed literature via Cross-Search of ISI Web-of-Knowledge and 17 external databases, three books and three dissertations on huemul, historic and grey literature available in a collection containing 286 entries, plus publications on other related deer species to allow a comparative approach to analyze and interpret huemul literature, including questionable information, which continues to be used to describe huemul. RESULTS Reproduction