The most drastic influences of human modifications result from urbanisation, a progression characterised by human disturbance, buildings and other artificial infrastructure (Hahs and McDonnell 2006). Such modifications have significant effects on biodiversity, often with little thought being given to the long term effects and ways of mitigating them.
In most cases, human alteration of the environment has reduced biological diversity by replacing the native flora with new ecological spaces. However, urbanization, especially in suburbia, can introduce many new resources (McDonnell and Pickett 1990; Pickett et al. 2001) which coexist with the natural biota and increases diversity of avifauna in semi-urban environments. It is hypothesised that “intermediate areas should have greater spatial heterogeneity of environments than other urban areas” (Marzluff 2005) which have the capacity to provide resources to a greater diversity of bird life.
A concern under much observation in the ecological community is the impacts of urbanisation on native birds. It is known that native species are declining in cities which are dominated by those that possess the specific traits to adjust with its intensely modified landscape (McKinney 2006) – predominantly the exotic species. This poses the need for conservation plans to be enforced in order to maintain native bird species within the urban environment.
This report characterises and evaluates the structural elements of specific locations around the city of Melbourne in order to observe the impacts of urbanisation on avifaunal communities. Specifically, how these influences impact native and non-native birds in urban areas and how we must stress the need for mitigation against the effects of urbanisation.
To conduct a bird survey and describe the characteristic structure in varying urban environments in order to discuss its influence on bird diversity and abundance, specifically, for the native and non-native species - Trichoglossus haematodus (Rainbow Lorikeet) and Passer domesticus (Common Sparrow).
Multiple groups visited one of seven sites allocated across the city of Melbourne. These sites varied from industrial/urban areas to native vegetation hotspots, parklands and residential areas. At each site the “standardised search” bird survey method was used (Watson 2003) – with the boundaries of the designated patch provided, the area was searched for any birds present (on ground, in trees or in flight). Each detection was recorded according to their species, number observed and the time observed. This process continued until no new species was sighted for 20 minutes. Any observations about the site’s vegetation, man-made infrastructure and number of large native trees (over 50 cm wide) were noted.
Then, a polygon was created for the shape of each site using Daft Logic (http://www.daftlogic.com/projects-google-maps-area-calculator-tool.htm) and converted into a KML file (using...