Biometrics, Testosterone, Cortisol and Antler Growth Cycle in Iberian Red Deer Stags (Cervus elaphus hispanicus)

Abstract

Contents In this article, we aimed to describe the changes related to mating season in red deer, especially those related to antler growth, body condition score, testosterone and cortisol. Antler growth was studied in 17 Iberian red deer males, including body weight, antler length, biometric measures and testosterone and cortisol determination during 15 months. Body weight, body condition score, thoracic perimeter (TP), neck perimeter (NL) and testicular diameter (TD) showed the highest values immediately before mating season (autumn), decreased during it and remained constant at winter. Antler growth lasted 158 days and produced antlers with a final length of 80.8 ± 2.0 cm. Testosterone and cortisol showed seasonal changes with maximum values at September and May, respectively. Final antler size was related positively to cranial longitude, TP, NL, TD and body weight at casting time. No relationship between weight loss during precedent mating season and current antler size was found, but spring recovery weight was positively related to final antler size. Final length was related to the descent in testosterone values during previous mating season and to body weight before it. Spring recovery weight was related to relative weight loss during previous mating season. These results suggest that there is no relationship between the reproductive effort performed during one season and the next year size of the antler. In contrast, antler size was positively related to spring recovery weight, in the sense that those deer that recover a higher percentage of body weight at the early stages of antler growth develop higher antlers.

The mechanical properties of red deer antler bone when used in fighting

“…Antlers start to grow from bony pedicles, permanently present on the head of the males, in late winter or early spring (Goss, 1983;GasparLópez et al, 2008). They grow at the fastest rate known for bone and, in southern Spain (the location for our studies), this can be 1.2cm per day during the 70days of fastest growth (Gaspar-López et al, 2008). Growing antlers are covered by a thick 'velvet', the periosteum, with many associated blood vessels.…”

“…Growing antlers are covered by a thick 'velvet', the periosteum, with many associated blood vessels. By the middle of summer growth ceases, the antlers mineralise fully, and the velvet dies (Gomez et al, 2006;Gaspar-López et al, 2008). After this, in late July and (mainly) in August, the deer rub their antlers against vegetation in such a way as to remove the dead velvet skin, and the naked antlers appear, ready for fighting.…”

“…Fighting occurs during the rutting season, lasting in southern Spain from mid-late August until late December (our own observations and those of nearby game managers). In late winter the males grow an abscission layer across the base of the antlers, which are then cast in the last 2weeks of March (Goss, 1983;Li et al, 2005;Gaspar-López et al, 2008). Shortly thereafter the growth of the next season's antlers starts.…”

Morphometric characterization of Mesola red deerCervus elaphus italicus(Mammalia: Cervidae)

“…When reared with a high-quality diet, Iberian red deer attain the body weights of central European populations. Iberian stags, which normally weigh about 125 kg (Martıńez et al 2005), in farm can reach an average body mass of 150-200 kg (Gaspar-López et al 2010).…”

La composición y propiedades mecánicas de cuernas y huesos de ciervo como fuente de información para gestionar ecosistemas

“…La velocidad de crecimiento del tejido precursor de la cuerna es la mayor de cualquier tejido animal (salvo el cáncer), variando de 0.5 a 4 cm/d (ver Goss 1983); así, en ciervos ibéricos adultos, el promedio es de 0.51 cm/d a partir de los datos en Gaspar-Lopez et al (2010), y 0.68 cm/d según Gómez et al (2013). Esta velocidad es tan rápida que la alimentación no logra aportar la cantidad de minerales necesarios para la formación de la cuerna, de modo que un ciervo tiene que transferir un 28 % de su esqueleto óseo hacia las cuernas (ver Muir et al 1987).…”