The control of predators is an l 'i~portant priority for all zoos and parks, both for captive birds and animals and particularly for those which are allowed to roam free. At Jurong BirdPark, various methods have been applied to this problem and the number of birds now lost to predators is reduced. The most troublesome category of predators in Singapore is that of snakes and monitor lizards, which kill a large variety of birds. Rats, pigeons and mynahs are a problem as they bring disease, destroy nests and compete for feed. Another danger to birds is the bee, the sting of which is always fatal. The last category of predators is stray dogs and cats which occasionally attack and kill the birds.
Methods of Control Snakes and Monitor Lizards
• An effective means of trapping snakes and lizards is a relatively simple rectangular box. The 6' x 1.5' x 1.5' box is made of wood and wire mesh with upward sliding doors at both ends. One side of the door is held open with the support of an 8" stick. The bait is placed at the other end of the box. The bait and stick are tied at each end of a nylon string. Once the bait is taken, the stick is pulled out of place and the door slides down, trapping the predator inside.
•A snake catching rod is useful to catch poisonous snakes which are not attracted to the trap and also to remove snakes from the box.
•Rat Traps - Various types and sizes of rat traps are used. Here at the Jurong BirdPark, we find the most effective rat trap is the metal cage type, which can be bought from the local hardware stores. Although it is designed to trap one rat at a time, we
can find as many as four rats trapped inside. Banana or papaya is used as bait.
• Rodenticide - Two forms of rodenticide are used in the Jurong Bird Park. Both contain 0.05 gm of Brodifacoum per kg., an anticoagulant agent. The poison is not accessible to the birds or the public and is checked daily.
1. 20 gm wax blocks are either placed in bait stations outside the aviaries or hung in secluded places where rats have been seen.
2. Pellet form is placed in bait stations inside the aviaries. From time to time, roasted peanuts, cheese or minced meat are added to enhance the bait as a special treat to attract the rats.
• Flushing rats in burrows - All entrance/ exit points should be covered with nets and pegged to the ground before water is flushed into the burrows. This is to prevent the rats from es ca ping.
• Flushing rats in nest boxes - In order to flush rats hiding in nest
boxes, a rigid cage trap is used. Simply place the nozzle over the nest box opening and rattle the box. Frightened by the intrusion, the rats will run out of the box and into the trap. A oneway trap door is attached to the base of the nozzle to prevent the rats from
re-entering the nest box. ·
Pigeons and Mynahs
A simple wire-mesh cage with cone shaped openings has proved to be an effective means of catching pest birds. The openings can be adjusted so that different sized birds can be caught. Chicken pellets and grains are used as bait.
Bees also pose a threat to smaller birds when they colonize the nesting boxes in the display aviaries.
As a line of defense, bee traps (old bird nest boxes) splashed with honey solution are hung out on nearby trees to distract the bees from the display aviaries. This has been quite sue::essful.
A pest control company sprays the park when necessary, for example when the bee nests are unreachable.
Cats and Dogs
Simple traps are used when necessary with meat as bait. Stray dogs and cats caught are handed over to the local authorities.
The problem of predators is worldwide. Although the predators themselves may vary from country to country, these simple methods can be adapted to solve a variety of problems. It is, however, certainly true that prevention is the best form of predator control and care should always be taken to ensure that leftover food is removed and enclosures are kept as clean as possible. Daily checking of all predator control devices is, of course, crucial to success.