The subspecies living in regions of sparse vegetation have shells curled up like a saddle, helping them to stretch their neck and obtain food from larger bushes and trees, while the dome shaped shells are seen on those with greener habitats.
Their shells do not have a solid form but comprise of honeycomb structures having small air chambers, helping them to bear its weight easily.
Having a slow metabolism, their food is stored in their body whereas water gets stored in the bladder and pericardium (root of the neck), enabling them to remain without food or water for upto a year.
They have low hearing capacity, mostly depending on their sense of smell and vibration to find food and avoid any danger.
The smaller subspecies often have longer legs to help them get their food from high branches.
