The myna man

Forest and Bird, Issue 281, 1 August 1996, Page 34

The myna man

AVID TINDALL spent much of D 1995 painstakingly trapping 457 common mynas on Moturoa Island in the Bay of Islands. His research showed that when mynas were removed from an area, numbers of other birds quickly increased within the space of only a single breeding season. And the birds that bounced back the most were native birds, particularly tui. Tindall, an Auckland University masters student, has suggested that for native birds, mynas may be the most threatening of the 36 introduced birds that have established in New Zealand since 1840. They are capable of colonising relatively unmodified habitats and have been reported in recent years in significantly increased numbers in a number of

northern native forests. The main impact of mynas on native birds appears to be through "interference competition" — physical attack, egg and chick destruction or other territorial behaviour — whereby mynas inhibit native birds from nesting in myna territories. Tindall developed a trap for his research — a kind of cylindrical version of the magpie letterbox trap, but with ground-based funnels leading into it, and baited inside with copious amounts of bread and a call bird in a separate small cage. He reported that it worked well but is labour intensive. Avoiding all contact with the trap during daylight hours is essential. With the enormous size of myna flocks — 1,000 in a single roost have been

documented — it seems that baits using the avian narcotic, alphachloralose, are the control method of choice. A former Noxious Animal Board officer reports destroying some 3,000 mynas in a single operation. Alphachloralose is legal for use by the general public at concentrations below 2.5 percent, and stupefies the birds painlessly for a short while, during which they must be dispatched, using the same methods as with magpies. Any uneaten bait must be gathered up. Any non-target birds affected can be put in a warm dark place such as a cardboard box with ventilation holes placed in a hot cupboard, to sleep it off. Alphachloralose is also useful for catching your first magpie call bird.