Biology

Birds in the Hawaiian ecosystem are facing extinction due to degradation and loss of their habitat from effects of animals such as the feral ungulates. These animals eat native plants and destroy ground cover through their hooves and grazing activities. According to the bird channel website, there has been a 64 reduction in the birds population during the period 1973-2000. It is estimated that nearly two thirds of birds extinctions in the United States have happened in Hawaiis habitats. These birds are also killed by avian malaria transmitted by mosquitoes. In order to restore the Hawaiian ecosystem, the population of ungulate animals needs to be regulated. Birds such as the Akikiki and Akekee have already been classified among the birds facing extinction through the Endangered Species Act, (ESA).

Animals such as feral pigs are usually omnivorous and chew tree trunks leaving holes. They also eat immature trees and young seedlings. Rain water collects in these hollows creating breeding places for mosquitoes. This facilitates the spread of malaria. Their hooves also leave behind pits which may form shallow ponds on the ground that acts as breeding places. The Axis deer and feral sheep feed on native trees and seedlings that birds depend upon as sources of their food. This has led to devastating effects on the survival of birds such as the honey creeper. Destruction of seeds and seedlings result to food shortages as a result of the disruption of the food chain. Goats and feral cattle are able to graze over large areas of land in search of pasture. They act as agents of deforestation leading to reduced numbers of bird population that live in forests. This is due a reduction in the level of vegetation cover since cattle are heavy feeders and graze in large numbers. They dont allow space for regeneration of new vegetation growth (Drost and Fellers). Their breeding rates are also very high and if left uncontrolled will lead to total removal of vegetation cover. Initially most of the vegetation cover consisted of lowland ecosystems that can not adapt easily to ungulate activities and therefore urgent measures needs to be taken to conserve the ecosystems.

Ungulates are also known agents of seed dispersal through their hooves and also through their feeding habits, they are able to spread seeds of invasive weeds such as the naturalized vascular alien plants which are aggressive in terms of out competing the survival of native plant species which are depended upon by birds as food (Jenkins and Maguire).

Soil erosion caused by hooves of ungulates has facilitated the growth of invasive plants. Ungulates destruction of vegetative cover has made it possible for rodents like rats to survive in the destroyed vegetation. These rats prey directly on the birds and also eat eggs laid by birds. This makes it difficult for the population of birds to grow.

It can clearly be seen that measures taken to conserve the Hawaiian ecosystem will be very difficult without the elimination of ungulates. The most important measure towards successful restoration efforts of birds survival will be to eliminate control the ungulate population. Measures such as monitoring the population of ungulates by creating separate areas for these animals can be achieved through fencing. Spread of ungulates should controlled by preventing further migration of these animals to new areas within the ecosystem. The government should also fund conservation efforts towards restoring the ecosystems of birds. This can help in preventing birds from facing possible extinctions (Stone and Loope).