Much like the Cervidae (deer) species of today, M. giganteus was sexually dimorphic, meaning that males were significantly larger than the females (Barnosky 1985). Only males grew the species’ characteristic antlers, which required massive amounts of nutrients. This, coupled with a period of fasting during the mating season, led to high amounts of ‘winterkill’ (death during winter) among the males (Barnosky 1985). This actually kept the population as a whole healthier, because usually only the sick and weak perished during winter.
Though there is discussion surrounding the subject, experts generally believe that the species’ massive antlers were mostly used for display, rather than fighting (Barnosky 1985, Gould 1974). Females tended to mate with individuals with bigger and more impressive antlers, as they were an indicator of health and proper nutrition. A malnourished or old individuals’ antlers would be considerably smaller and more fragile than a male in his prime (Barnosky 1985).
The Irish Elk, M. giganteus, was one of the largest members of the Cervidae (deer) family in the late Quaternary. Despite the name, it was found throughout western Eurasia in the latter half of the Pleistocene (400,000-20,000 years ago). After the Last Glacial Maximum, a period of extreme cold between 26,500 and 19,000 years ago, it clung on in small parts of Southeastern Europe until climate change and possible human hunting drove it to extinction (Stuart et al. 2004). With a span of almost 4 meters, its gigantean antlers are the most notable attributes of this animal (Gould 1974).
Although often referred to as the Irish Elk, Megaloceros giganteus actually belongs to the family Cervidae (deer). Because of this it is sometimes called the ‘Giant Deer’. The species first emerged in the fossil record during the mid Pleistocene, around 400,000 years ago, and was present until the early Holocene, (11,000 years ago –present)(Stuart et al. 2004, Gould 1974, Gonzales et al. 2000). It emerged with few evolutionary precursors. Although called the Irish Elk, M. giganteus actually lived throughout Western Eurasia, and even into parts of northern Africa (Gould 1974). The misnomer is because the vast majority of M. giganteus fossils have been found in Ireland, as thepeat preserves the specimens extremely well (Gould 1974). M. giganteus had a geographic distribution that ranged from Ireland to central Russia, past Like Baikal (Stuart et al. 2004). It is believed that they were both widespread and abundant in this range. During the Last Glacial Maximum, a period of extreme cold between 26,500 and 19,000 years ago, the species receded from much of this area, as colder weather forced it into the Mediterranean areas of Southern Europe (Stuart et al. 2004). M. giganteus actually only returned to Ireland approximately 12,000 years ago, (Barnosky 1986, Stuart et al. 2004) and died off on the island around 10,600 years ago, making its tenure there relatively small in the species’ overall history. M. giganteus was extinct in Ireland before humans arrived on the island, some 9,000 years ago, but the fossil record indicates that it clung on longer, to historical times, in parts of Eurasia (Stuart et al. 2004, Gould 1974, Gonzales et al. 2000).
There is conflicting evidence in terms of why it eventually went extinct. Some authorities argue that the climate changes associated with the Younger Dryas caused the extinction, as the cooling climate reduced the open woodland that was the species’ ideal habitat (Stuart et al. 2004). In the areas where M. giganteus survived into the Holocene (11,000 years ago - present), it is certainly possible that humans contributed to the extinction, but currently there is limited data to support or discredit this theory (Stuart et al. 2004).
The most distinct characteristic of M. giganteus was its colossal antlers, which were unmatched in mammal evolution. The largest measured to date reached almost 4 meters in length (Gould 1974) and weighed more than 35kg (Barnosky 1985). As only males grew them, these were most likely used by males for display and to attract mates. Impressively, the males shed and regrew these antlers every year. The Irish Elk’s body was similarly massive; it’s shoulder regularly reached a height of 2 meters (Stuart et al. 2004) and it was estimated to weigh an average of 700 kg (Smith et al. 2003). Males probably weighed even more. To put this in perspective, this is 4 times the average weight of the red deer, C. elaphus and almost 9 times the size of the average white-tailed deer, O. virginianus (Smith et al. 2003).
It was once thought that the antlers sheer size was actually responsible for the species’ extinction; theories ranged from restricted blood flow to antlers preventing swimming. In fact, the antlers are proportionally normal for Cervidae (deer) (Gould 1974).
M. giganteus’ massive antlers most likely prevented the males from journeying into dense forest for at least a portion of the year (Gonzales et al. 2000). This, coupled with the shape of its molars, meant that M. giganteus was an herbivorous mixed feeder, staying in open woodland and feeding on both grass and shrubs (Stuart et al. 2004). It’s size meant that it had to consume huge amounts of food, both to grow enormous antlers, in the case of males, and to store fat reserves to survive the cold winters.
Because of its dietary needs, M. giganteus probably lived in woodland areas with abundant vegetation. During the Late Glacial Interstadial, an especially warm period in the late Pleistocene (13,000- 12,600 years ago), M. giganteus was restricted to Northwest Europe, most likely because of the type of vegetation. In these areas, there was dense grass and low shrub growth, with scattered birch trees, M. giganteus’ optimal habitat (Stuart et al. 2004).
