DMWR surveying population of Common Myna
The Department of Marine and Wildlife Resources (DMWR) is spearheading a project that focuses on surveying the invasive Myna population. The Common Myna is a bird that is readily identified by its brown body, black hooded head, and the yellow patch behind the eye, while the bill and legs are bright yellow. The sexes are similar and they are usually seen in pairs.
The range of the Common Myna is increasing at such a rapid rate that in 2000, according to Wikipedia.com, the International Union for Conservation of Nature (IUCN) Species Survival Commission declared it one of the world's most invasive species and one of only three birds in the top 100 species that poses an impact to biodiversity, agriculture, and human interests.
According to a statement from DMWR, the Common Myna has been introduced with human help to many parts of the world to which it is not native, including the Samoa archipelago. In American Samoa, Mynas are now a common sight on the islands of Tutuila and Aunu'u.
First recorded in Tutuila in the early 1980s, the Myna population has grown and expanded throughout the developed areas of the island. “These birds may wake you up in the morning, or you may have seen them digging through the garbage,” wrote DMWR’s Chief Wildlife Biologist Dr. Nicole Dauphine in an email correspondence to Samoa News yesterday morning.
She added, “Neighboring islands have seen similar invasions by this bird. As an invasive species, the Myna may pose a threat to native wildlife, which is why the Department of Marine and Wildlife Resources has turned a focus towards it.”
Dr. Dauphine explained that the purpose of DMWR’s project is to assess the extent of the Myna invasion here on Tutuila by estimating the current population size, identifying potential environmental predictors of Myna abundance, and determining areas where Mynas are having negative effects on the native bird populations. She said information and data collected from the project will be used to make recommendations for future management of the Myna population here in American Samoa.
Several researchers from the DMWR's Wildlife Division are involved in carrying out different components of the project. They can be seen walking transects to count Mynas, assessing habitats along the road, or counting birds in their roost trees.
Currently, the focus of the project is to monitor and count all of the birds and assess how they are permeating into the natural environment. “We are also working with Leone High School student Leuatea Faiai to evaluate how Myna aggressions towards native species and flock size vary with the environment,” Dr. Dauphine said.
Leuatea Faiai’s participation in the project is made possible through the Short-Term Education Program for Underrepresented Persons (STEP-UP), which is coordinated locally by Netini Sene and Mark Schmaedick through the University of Hawaii.
“For greater success of this project, we kindly ask the public for their help,” said Dr. Dauphine. “All the information we can collect and gather from the people around the island will help us progress towards more effective management for the future of our native wildlife.” Anyone who is aware of any Myna roost trees are encouraged to either contact Dr. Nicole Dauphine directly at 633-4456 or project leaders Iofi Ace" Mauga at 731-8076 and Colleen Nell at 252-4646.
THE COMMOM MYNA
The Common Myna or Indian Myna (Acridotheres tristis) is a species of bird native to Asia but has been introduced in many other parts of the world such as Canada, Australia, Israel, New Zealand, New Caledonia, Hawaii, South Africa, and islands in the Indian, Atlantic, and Pacific Oceans.
Common Mynas are popular as cage birds for their singing and “speaking” abilities. These birds are believed to pair for life. They breed through much of the year depending on the location.
“The Common Myna is a hollow-nesting species; that is, it nests and breeds in protected hollows found either naturally in trees or artificially on buildings (for example, recessed windowsills or low eaves).”
Wikipedia.com says the Common Myna uses the nests of woodpeckers, parakeets, etc. and easily takes to nest boxes; it has been recorded evicting the chicks of previously nesting pairs by holding them in the beak and later sometimes not even using the emptied nest boxes. This aggressive behavior is considered to contribute to its success as an invasive species.
It feeds on insects, arachnids, crustaceans, reptiles, small mammals, seeds, grain and fruits and discarded waste from human habitation. “It forages on the ground among grass for insects, and especially for grasshoppers, from which it gets the generic name Acridotheres, (grasshopper hunter).”
“Common Mynas roost communally throughout the year, either in pure or mixed flocks with Jungle Mynas, Rosy Starlings, House Crows, Jungle Crows, Cattle Egrets and Rose-ringed Parakeets. The roost population can range from less than one hundred to thousands. The function of communal roosting is to synchronize various social activities, avoid predators, and exchange information about food sources.”
“Both male and female Common Mynas will fiercely protect roosts at all times, leading to further exclusion of native birds.”
“Compared to native hollow-nesting species, the Common Myna is extremely aggressive, and breeding males will actively defend areas ranging up to 0.83 hectares in size (though males in densely populated urban settings tend to only defend the area immediately surrounding their nests). This aggressiveness has enabled the Common Myna to displace many breeding pairs of native hollow-nesters, thereby reducing their reproductive success.
“In Hawai’i, where the Common Myna was introduced to control pest army-worms and cut-worms in sugarcane crops, the bird has helped to spread the robust Lantana camara weed across the islands’ open grasslands. It also has been recorded as the fourth-ranking avian pest in the fruit industry by a 2004 survey of the Hawaiian Farm Bureau and the sixth in number of complaints of avian pests overall.