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.