ABOVE: This adult Diadem Roundleaf Bat Hipposideros diadema was hanging above a forest path on a nightwalk at Bako. The Diadem Roundleaf Bat is both one of the largest and most common insect eating bat in Borneo. Very large numbers gather to breed in limestone caves at Gomantong in Sabah and Mulu in Sarawak but they also occur alone.
This bat is “flycatching ” waiting near an open space for a large insect or small bat or bird to fly through the clearing. Movement is detected by constant frequency sonar – high pitched sounds emitted by the bat. The sound reflected by the fluttering of the prey returns to the large ears and allows the bat to triangulate the source of the sound and fly out to capture the prey.
There are 11 different species of Rhinolophus Bat and 12 different species of Hipposideros bat in Borneo each with differing nose leaves used to modulate the constant frequency sonar sounds they emit. This indicates that each bat species specialises in a different prey or capture strategy.The Diadem Horseshoe Bat can be easily recognized by the patches of different coloured fur. This individual is probably a male. A breeding female would have more obvious reddish fur.
Note the red arrow pointing to two tourists at the far end of the beach. to show the scale.
(1) Bako National Park (2) Buntal Bay (3) Santubong Peninsula
