Skull and horn features of Chamois from Bulgaria: morphometric evidence for its taxonomic detachment

Abstract

espanolLas caracteristicas craneometricas de los machos y hembras de rebeco de la poblacion de Bulgaria se determinaron sobre la base de 14 variables morfometricas. Se encontro dimorfismo sexual en cinco de las variables estudiadas. Las caracteristicas craneometricas de los machos y hembras de rebeco de Bulgaria se compararon con datos clasicos sobre distintas subespecies en el area de distribucion europea de dos especies: R. rupicapra, con las subespecies canusiana, balcanica y caucasica, y R pyrmaica, con las subespecies amata y pyrenaica. La evaluacion de las similitudes y diferencias craneometricas entre el rebeco de Bulgaria y las subespecies escudiadas se realizo para ambos sexos por separado. Esta demostro que existen diferencias c.raneometcicas entre las dos especies, y concretamente que el rebeco de Bulgaria pertenece a la subespecie R. r. balcanica Bolkay. Se determinaron las caracteristicas metricas de los cuernos y su tasa de crecimiento en machos y hembras de rebeco de Bulgaria de entre 2 y 18 anos de edad, donde se pone de manifiesto que la mayor tasa de crecimiento del cuerno se produce el primer ano de vida. Ademas, se obtuvo un modelo matematico de su crecimiento en ambos sexos del rebeco bulgaro, obteniendo una base para poder comparar el desarrollo del cuerno de R r. balcanica con otras subespecies de R. rupicapra dentro del area de distribucion europea. EnglishCraniometrical charateristics of male and female chamois of the Bulgarian population were carried out on the basis of 14 morphometric variables. Sexual dimorphisrn was found in five of the studied variables. The established craniometrical characterisrics of Bulgarian male and female chamois were compared with classical data concerning different subspecies within the European cange of rhe two species: R. rupicapra, consisting of cartusiana, balcanica, caucasica, and R. pyrenaica. consisting of ornata and pyrmaica. The assessment of craniometrical similariey and distinction between Bulgarian chamois and studied subspecies, separacely for each sex, demonstrated craniometrical separation of me two species and, in particular that Bulgarian chamois belong ro che subspecies R r. balcanica Bolkay. Metric characters of the horns in males and females Bulgarian chamois aged between 2 and 12 years were measured, their growth rate was determined and a mamematical model for their growth in both sexes was found. Both empirically established and computed hom growm dynamics of Bulgarian chamois showed that the greatest annual increment was observed during the first year after that it decreased rapidly with advancing age, until an almost constanr growth per year was reached. The drawn equations for absolute annual growth and variarion of absolute and relative annual growth of the horns in both sexes of Bulgarian chamois could become a basis for comparative studies of developrnent of the horn of subspecies R. r. balcanica with the omer subspecies of R. rupicapra within its European area.