Competition between mourning Doves and Eurasian collared doves

1. Competition between mourning Doves and Eurasian collared doves A research project conducted by Philip Earhart Undergraduate Student Tennessee Technological University Cookeville, TN 38505

2. 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.

3. 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.

4. 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

5. 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).

6. 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).

7. 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.

8. 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.

9. 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.

10. 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: ________ ______ ________ ______ ________ ______

11. 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 out-compete 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.

12. 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.

13. 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 Collared-Dove in North America and the Caribbean. North American Birds 53 (4): 348-353. • Stedman, S.J. 1998. Changing Seasons: The Nesting Season. North American Birds52 (4): 424-426.