Greer Burkitt, of Palmerston North, asks :-
Why are there no mynah birds in Palmerston North?
Isabel Castro, an ecologist at Massey University's Institute of Agriculture and Environment, responded.
The common mynah (Acridotheres tristis) is native to Central Asia, from India to Afghanistan where it is typically found in open woodland, cultivation areas, and around human habitation. The IUCN declared the common mynah as one of the world's 100 worst invasive species (two other birds also figure in this list: the red-vented bulbul and the European starling. Both of these species are also present in NZ, but the bulbul is not considered as established, only a visitor). Self-sustaining populations of common mynah have been found in regions where the mean warmest month temperature is no less than 23.2 Â°C and the mean coldest month temperature no less than -0.4 Â°C.
Indian mynahs were introduced in the 1870s to both the North and South Islands. Today they only survive and thrive in the mid to northern North Island. It has been suggested that the cooler summer temperatures in the South Island (10-22 degrees) and lower North Island (13-20 degrees), both lower than the known threshold of 23 degrees known for the species to reproduce successfully, have lowered the breeding success of the southern populations, preventing the establishment and/or survival of the species.
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