Tigers in Sumatra and Indonesia are smaller and darker than northern subspecies
A point worth noting is that tigers in the south are quite different in appearance to those in the north of planet. So, I am comparing the very rare and endangered Sumatran and Indonesian tigers with the Amur tiger and even the Bengal tiger which not only lives throughout India in reserves but also on the foothills of Bhutan 4,000 meters above sea level.
The difference between the 'southern tigers' and those in the north are as follows. The differences are due to evolution.
- They are considerably smaller. For example, in tropical areas adult male tigers average about 2.2-2.5 metres in length which is about half a metre shorter than males from northern areas. They weigh only 100-140 kg. Adult females in tropical areas weigh between 75-110 kg which is about the same size as a large leopard or jaguar. The smaller size allows for better body heat loss which helps tigers to maintain a correct body temperature. A larger body mass helps to conserve body heat which is why Amur tigers are the world's biggest cats.
- The fur of southern tiger subspecies is less dense and shorter than the subspecies living in colder regions in the north. Shorter fur also allows for better body heat loss as needed to keep cooler in a generally hot climate
- The fur is also darker in tigers on Sumatra and other Indonesian islands compared to those subspecies in more northern regions. National Geographic say the darker coat better blends in with the habitat in which it lives. I would add that it also might be because darker fur protects against harmful, bright sunlight. The fur contains more melanin. Hot sun can be damaging. There won't be this need for protection in the freezing temperatures of Siberia.
|Sumatran tiger. Photo: National Geographic.|