Rhys Harrison 90694287 02/22/2011
The effect of habitat on the range expansion of a native and
an introduced bird species in North America.
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Joseph A. Veech, Michael F. Small, John T. Baccus. Article first published online: 22 SEP 2010.
DOI: 10.1111/j.1365-2699.2010.02397.x. Journal of Biogeography, Volume 38, Issue 1, pages 69–77,
January 2011. © 2010 Blackwell Publishing Ltd
Joseph A. Veech is with the Department of Biology, Wildlife Ecology Program, Texas State University,
San Marcos, TX 78666, USA. Michael F. Small is with the Department of Biology, Wildlife Ecology
Program, Texas State University, San Marcos, TX 78666, USA. John T. Baccus is with the Department
of Biology, Wildlife Ecology Program, Texas State University, San Marcos, TX 78666, USA.
What is the effect of habitat on the range expansion of the White-winged dove and the Eurasian
collared dove across Continental North America?
Currently range expansion and spatial spread of invasive species has been predicted through
models, theory and mathematical calculation. Recently researchers have recognized that range
expansion has many more complexities than earlier predicted and may have intricate ties with the
invaded landscape and environment.
The species of birds chosen prefer woodland, shrub land and areas without complete canopy
cover. Data on the occurrence of both species is used. Routes used are gathered by well trained
observers which follow a surveyed route once a year. This process is conducted by the North American
Breeding Bird Survey. The routes that were selected had both species recorded in the last year and the
route had been monitored for the past five years or more. The data were then used to calculate the
expansion pattern of the species. Areas without the doves within 60 km of any dove route were used to
provide adequate sample sizes to statistically compare the dove and non-dove routes. The three main
areas data was obtained and used were South Florida, South Texas and the arid South-west of the USA;
See Fig1 below. Include the caption for the figure. I’m not sure what it is saying. -2
Rhys Harrison 90694287 02/22/2011
It is indeed true that the pattern of which species of native and invasive birds saturate their
range of expansion and spatial spread is affected directly by the habitat ecology of the species. It is also
seen that the role of a habitat in a species movement and range is dependent on the geographical
setting. Range expansion is therefore seen as very dynamic and greatly dependent on surrounding
physical and biological settings; See Fig2/Table2 below. Good. Captions are included.
This particular study was very well conducted and extensively planned. Unfortunately the vast
data of this project was accumulated visually by humans spotting species along certain marked routes
annually. This could be a major flaw due to a high error risk. It is easy for an individual to miss count, be
distracted or simply not see a bird. The fact that the historical data that were obtained from the North
American Breeding Bird Survey was collected only once annually could also be an area for
misrepresentation of species. The experiment could therefore be improved greatly. The project could
also be implicated {??} by the local immediate climate and data should be collected more continuously
throughout a larger time scale than seen during the project and historically. The findings depicted are
valid but more could be done to improve the project. Predation in the areas may also be on the rise with
the increasing Hawk and Eagle populations but this is not addressed and could provide some interesting
information.
Invasive and native species range expansion is affected by habitat, geological setting and the
overall environment. It is a lot more complicated than previously thought and quite hard to
predict/compute. The more time, resources and monetary funds devoted to such projects will help with
the understanding of various migration and expansion patterns, including that of invasive species. This
may help us protect our environment, expand/restore our wildlife and better understand nature as a
whole.
Rhys Harrison 90694287 02/22/2011