The Indian Myna Bird (blog #3 for 24.03.14)

Source: Andrew Tatnell. viewed 21.03.2014

The  Common Indian Myna bird (Acridotheres tristis) has been declared by the Worlds Conservation Union as only one of three birds among the 'Worlds 100 worst  invasive species' (Peacock et al 2007).  They are becoming an increasing environmental nuisance for more than one reason. They rob endemic and native birds and possums of their nests by aggressively chasing them out of their natural habitat and eating their eggs, as well as compete with other omnivores for food resources (Canning 2011). They  also eat native fruits and insects that are important for pollination.  It has also been suggested that they pose a threat to human well-being through the spread of parasites and diseases and agricultural crop damages.

The Indian myna bird is native to southeast Asia occurring from Afghanistan through the Indian subcontinent and Burma to Indochina. They have been deliberately introduced to many parts of the world and now occur on all continents except South America and Antarctica. They were originally introduced into many areas as a potential biological control agent of insects, in particular grasshoppers and locusts.  The generic name Acridotheres means 'grasshopper-hunter'! However as they spread rapidly they are increasingly causing more negative impacts on biodiversity 
(Baker et al. 1987).

 In addition to deliberate introductions by humans, the Indian mynah has been undergoing a natural range expansion . This is thought to be a result of extensive clearing of natural vegetation for agriculture and increasing population densities. A study was done to establishish if there was a relationship between the human population size, land-transformation and mynah bird distribution. The results showed a strong possitive correlation. It showed that most highly successful allien bird species are closely accociated with human habitation and modified habitats, one of which being the Indian Myna bird. The study was conducted over the highly transformed parts of South Africa which represent urban areas and perminent cultivated lands which are both suitable habitats. 

The eradication program to reduce the damage caused by these pests is ongoing through  live trapping devises followed by the birds being humanely enuthanized.


References:
 Baker, A.j 1987, 'Rapid Genetic Differentiation and Founder effect in Colonizing Populations of Common Mynas (Acridotheres tristis) Society for the study of Evolution, Vol.41, no.3 p.526
viewd 21 March 2014 
URL <http://www.jstor.org/stable/2409254?seq=2>

Canning, G 2011, 'Eradication of the Invasive Common Myna, (Acridotheres tristis) from Fregate Island, Seychelles'  Phelsuma p.43 Viewd 21 March 2014
URL <http://islandbiodiversity.com/Phelsuma%2019d.pdf>

Peacock, D.S, Van Rensburg, J.B, Robertson M.P 2007, 'The distribution and spread of the Invasive alien common myna, Acridotheres tristis L. (Aves: Sturnidae), In Southern Africa', South African Journal of Science, vol.103 no. 11-12
view on 21 March 2014
URL <http://www.scielo.org.za/scielo.php?pid=S0038-23532007000600008&script=sci_arttext&tlng=es>