Transcript Competition between mourning Doves and Eurasian

Competition between mourning
Doves and Eurasian collared
doves
A research project conducted by Philip Earhart
Undergraduate Student
Tennessee Technological University
Cookeville, TN 38505
Project summary
During this project I will be attempting to determine
whether or not exotic Eurasian Collared doves are
capable of out-competing native Mourning doves for food
resources.
Collared doves are a non-native species that could
potentially displace the native Mourning doves.
The collared doves are much larger than the Mourning
doves which would seem to offer them a distinct
advantage when forced to compete for food resources.
Project summary
I will try to determine if competition between these two
species exists, and if so, to what degree it occurs.
I plan to conduct this study by allowing these two
species to interact in a controlled setting and recording
the results of the study.
I expect that there will be a certain level of competition
between the two species of birds.
Introduction / background
Pair of native Mourning
doves shown Fig. 1 left
Fig. 1
Pair of exotic Eurasian Collared
doves shown Fig. 2 right
Fig. 2
Introduction / background
Mourning doves are one of the most important game
birds in the U.S. today (Hayslette 2001).
2.4 million Mourning dove hunters harvested 46 million
birds each year during the 1980’s (Romagosa 2000).
Eurasian Collared doves are becoming increasingly
more prevalent in the U.S. and causing a significant
impact on the natural ecosystems (Stedman 1998).
Mourning dove populations declined drastically around
Cedar Key, Florida after the arrival of Collared doves
(Stedman 1998).
Introduction / background
Collared doves are native to India and Sri Lanka
(Romagosa 1999).
Collared doves seem to be more aggressive than
Mourning doves and have also been seen chasing other
species of native song birds away from feeder stations
(Romagosa 2000).
The introduction of Collared doves has the potential to
displace native doves as well as the potential of disease
introduction (Romagosa 2000).
hypothesis
My hypothesis for the project is that the Eurasian Collared
Doves will out compete the Mourning Doves because of the
size advantage they possess.
Collared Doves are physically larger and therefore will be
able to force Mourning Doves away from food sources and
keep them away.
My objective is to determine whether or not the exotic
species is placing pressure on the native species and
estimate the effects may have on the natural ecosystem.
Materials and methods
Both Mourning doves and Collared doves were trapped
from areas where they existed together.
The birds were then transferred to a holding facility on the
TN Tech campus for observations.
Birds were fed and watered ad libitum prior to competition
studies.
Prior to competition studies birds were fasted for 12 hours,
but were allowed access to fresh water at all times.
Materials and methods
A feeding tray with 6 different types of seeds and grains
was then placed in the pen containing both a Mourning
dove and a Collared dove.
Observations were taken for the next 30 minutes from a
location hidden from the birds.
Interactions between the birds were tabulated from the
viewing point and classified as direct, physical contact
between the birds, and indirect, looking and chasing.
Materials and methods
Competition
Paired Bird # __________
Eurasian Collared-Dove
Mourning Dove
Band Number ____________
Band Number ____________
Mass __________________
Mass ___________________
Mass Difference_________________
Single Patch Trial
Date ________ Time Start ________ Temp Start _____ _ Weather Start _________
Time End _________ Temp End ______ Weather End __________
Interactions Between Species
Number of Interactions
ECD directly displaces MD (touch)ECD indirectly displaces MD (chase)ECD indirectly displaces MD (look)MD directly displaces ECD
(touch)MD indirectly displaces ECD (chase)MD indirectly displaces ECD (look)Total Interactions
Multi-Patch Trial
Date ________ Time Start ________ Temp Start _____ _ Weather Start _________
Time End _________ Temp End ______ Weather End __________
Interactions Between Species
Number of Interactions
ECD directly displaces MD (touch)ECD indirectly displaces MD (chase)ECD indirectly displaces MD (look)MD directly displaces ECD
(touch)MD indirectly displaces ECD (chase)MD indirectly displaces ECD (look)Total Interactions
Time in Seed TraysCorn Sun-flowerMiloWheat Browntop MilletWhite Proso MilletTotal Feeding TimeMDECDTotal time in each tray
Comments:
________
________
________
______
______
______
Expected results and benefits
I expect to find that there is a significant amount of
competition between the two species of birds.
I expect that the larger Collared doves will be able to outcompete the smaller Mourning doves by physically forcing
them away from the food tray.
If competition is found, then benefits will include the
assessment of the problem, thus paving the way for
procedures to solve the problem.
Project timelines
We began working on building the pens where the
birds will be housed as well as trapping the birds for the
study at the beginning of the summer.
The first competition study I am conducting will be
completed by the end of the Fall semester 2003.
More in depth studies will follow by other students.
Literature cited
Hayslette, S.E. and R.E. Mirarchi. 2001. Patterns of Food
Preferences in Mourning Doves. Journal of Wildlife Management
65: 816-827.
Romagosa, C.M. and Labisky, R.F. 2000. Establishment and
Dispersal of the Eurasian Collared-Dove in Florida. Journal of Field
Ornithology 71 (1): 159-166.
Romagosa, C.M. and McEneaney, T. 1999. Eurasian CollaredDove in North America and the Caribbean. North American Birds
53 (4): 348-353.
Stedman, S.J. 1998. Changing Seasons: The Nesting Season.
North American Birds 52 (4): 424-426.