It’s rutting season again! The stags are full of testosterone, chasing the ladies, and calling to warn other males of the unwelcome greeting they will receive if important antics are interfered with. Last week I had a fantastic afternoon watching the males, albeit from a very safe distance, with fascination over the tireless determination used to maintain their territories. Although not all males will successfully mate with a female this year, I am sure the herd will have no trouble this autumn and winter in surviving to produce young in the spring. Whilst the Red Deer are doing very well in Wollaton however, a little reading up on this species made it all too clear that the thriving and fruitful resilience of the our population is not uniform across the continent.
Red Deer are the most widespread large mammal across Europe, however recent genetic studies suggest a number lineages dating back to the last ice age that are both distinct from the Red Deer in other regions, and endangered. During the peak of the last ice age, Red Deer populations became isolated whilst finding refuge from the cold and harsh conditions. Later, with the warming of the earth’s climate these isolated herds moved to different corners of the continent, creating the isolated lineages across Europe today. The Red Deer that seem so widespread across our continent are probably a number of separately divergent and evolved herds or even subspecies, unique to certain areas of Europe. It is really important to understand the extent of separate evolution between herds like these, as although the distinction between groups may seem trivial, it could have important consequences for conservation of the European Red Deer.
When two populations become isolated for a long enough time from a phenomena such as an ice age, they can evolve unique adaptations to their individual habitats. As two isolated populations may evolve separate adaptive traits through time, it could mean a hybrid between these two distinct and locally adapted populations would not be adapted to either habitat, but be a mish-mash of adaptations suited to the two different areas. When individuals move between populations, problems often arise that mean individuals such as the deer may suffer in the long run if hybrids become a frequent occurrence.
One isolated Red Deer lineage that is both endangered, and unique from any other populations across Europe is the Mesola Red Deer population from Italy. The Mesola population is not only small and suffering from a huge decline in genetic diversity, but is also the last Italian Red Deer population remaining since the retreat of the last ice age. Since monitoring of this population began, catastrophes and inbreeding through a lack of genetic diversity have been identified as important threats to the population’s survival. An option to reduce the risk of inbreeding is to introduce Red Deer from other populations into the Mesola population, to increase genetic diversity within the herd. As discussed before however, we need to be careful to try and maintain the locally adapted traits that make this population unique to any other Red Deer herd across the globe.
Whilst it seems I am approaching the thought of moving Red Deer between populations with some red hot and smoking barge pole, it has to be said that in European Red Deer conservation, translocations to date have been quite successful. In Croatia, two distinct populations have still been maintained with the help of translocations between populations to try and boost the genetic diversity within each herd. Without careful movement of the deer, the Croatian populations may have suffered from inbreeding and so an increase in susceptibility to disease through a lack of genetic diversity. It is still to be ironed out for sure if there will be any long term ecological consequences as a result of translocations, but at the moment things seem to be improved after these conservation efforts.
At the moment, new research is being undertaken to get a better understanding of the Red Deer species, and hopefully as a result we can continue to protect the distinct populations that remain across Europe. Whilst this exciting research is being undertaken on the continent however, we can still go out and enjoy trying to understand our native population thriving here. Whilst this is on a slightly different level to the population geneticists guiding conservation action in Italy, Croatia and Iberia, we can still enjoy investigating our own Red Deer all the same. If anything, I think knowing about the rich and interesting history of this species makes me appreciate the local animals’ company a little more than before.