Vertebrates

	A glance at the marine aquarium fish trade in Hong Kong
	Restocking - an effective measures to restore the depleted fishery stocks in Hong Kong?
	The case of the disappearing croaker, the Chinese bahaba, Bahaba taipingensis
	Modification of local wire cage traps to reduce injuries to small mammals
	Feral dogs and civet mortality on Kau sai Chau, Sai Kung
	The changing bird community of Tai Po Kau
	Is the Javan Mongoose native and does it matter?

Modification of local wire cage traps to reduce injuries to small mammals

by Kylie Chung

The local wire mesh cage traps have been used in Hong Kong for a long time to catch pest rats. These traps are very efficient and the trapping success rate can be higher than 50%. However, they can cause awful damage to the animals that are caught. Trapped rats cut their noses as they try very hard to get out of the trap by squeezing through the small mesh, and some of the rats’ tails are chopped off by the quick and powerful spring door. There is an easy way to avoid these unnecessary disasters. It just takes you 10 minutes of preparation and the traps work as efficiently as before.

A typical cage trap is 12.5 cm high, 15 cm wide and 29 cm long. Plates of 2 mm thick clear plastic are prepared to insert inside the trap, except for the door, which has to be on the outside to avoid interfering with the spring mechanism. All plastic plates should be cut into sizes at least 2.5 cm smaller than the trap measurement. The plate for the roof must be divided into two pieces, about 7 x 12.5 and 18 x 12.5 cm, because of the bait hook. Two holes are drilled in each of the four corners of each plastic plate for attachment by thin wire. The plastic plates stop the rats trying to squeeze through the mesh and also provide some protection from wind and rain. Damage to tails can be prevented by inserting a suitable stick – such as a chopstick – into the entrance when setting the trap, so the door does not close completely.

Fig.1 A modified trap.

P.15-16