Common myna
South Africa

In South Africa where it escaped into the wild in 1902, it has become very common and its distribution is greater where human populations are greater or where there is more human disturbance. The bird is also notorious for being a pest, kicking other birds out of their nests and killing their young due to the myna's strong territorial instinct. In South Africa it is considered somewhat of a major pest and disturbance of the natural habitat; as a result, it has been declared an invasive species, requiring it to be controlled.

Morphological studies show that the process of spatial sorting is at work on the range expansion of A. tristis in South Africa. Dispersal-relevant traits are significantly correlated with distance from the range core, with strong sexual dimorphism, indicative of sex-biased dispersal. Morphological variations are significant in wing and head traits of females, suggesting females as the primary dispersing sex. In contrast, traits not related to dispersal such as those associated with foraging show no signs of spatial sorting but are significantly affected by environmental variables such as vegetation and intensity of urbanisation.
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