Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.
Location
Saratoga Springs, NY
Start Date
4-5-2009 12:00 AM
Description
Previous research has suggested that high deer densities negatively impact bird communities. Most of this research was conducted using a very high deer density compared to no deer. Our research investigated deer impacts across a density gradient to determine an appropriate density for deer management efforts. Using Breeding Bird Survey (BBS) data from 2005- 2006 and Delaware Department of Natural Resources and Environmental Control (DNREC) deer density data for the same time period, we compared avian richness and relative abundance for BBS points to deer density in Delaware. We divided deer densities into 3 categories: low (<12 deer/km2), medium (12-23 deer/km2) and high (>23 deer/km2). We placed birds into the following deer-sensitive guilds: interior obligates, forest ground nesters, shrub nesters, ground gleaners, low canopy foragers, and tropical migrants. The species richness of ground gleaners was higher in high deer densities (F1.36 = 17.05, P = 0.0002). No other guilds' species richness was affected. The relative abundances of ground gleaners (F1.36 = 25.60, P = <0.0001) and tropical migrants (F1.36 = 4.11, P = 0.0501) were lowest in low deer densities. Relative abundance of wood thrush (Hylocichla mustelina) was also lowest in low deer densities (F1.36 = 21.60, P = <0.0001). Richness and abundance of all guilds were positively influenced by the percent forest cover within a 50 m buffer. The effects of deer density on these bird communities were generally opposite of what past literature has suggested. In order to better understand this trend I have also conducted 618 of my own point counts and corresponding vegetation surveys throughout Delaware. This data was collected from May- August 2008 and will be repeated in the summer of 2009.
Recommended Citation
Tymkiw, L., Bowman, J. L., & Shriver, W. G. (2009) Effect of deer density on breeding birds in Delaware. In Boulanger, J. (Ed.), The Thirteenth Wildlife Damage Management Conference (71-73). Saratoga Springs, NY: Thirteenth WDM Conference.
Included in
Effect of Deer Density on Breeding Birds in Delaware
Saratoga Springs, NY
Previous research has suggested that high deer densities negatively impact bird communities. Most of this research was conducted using a very high deer density compared to no deer. Our research investigated deer impacts across a density gradient to determine an appropriate density for deer management efforts. Using Breeding Bird Survey (BBS) data from 2005- 2006 and Delaware Department of Natural Resources and Environmental Control (DNREC) deer density data for the same time period, we compared avian richness and relative abundance for BBS points to deer density in Delaware. We divided deer densities into 3 categories: low (<12 deer>/km2), medium (12-23 deer/km2) and high (>23 deer/km2). We placed birds into the following deer-sensitive guilds: interior obligates, forest ground nesters, shrub nesters, ground gleaners, low canopy foragers, and tropical migrants. The species richness of ground gleaners was higher in high deer densities (F1.36 = 17.05, P = 0.0002). No other guilds' species richness was affected. The relative abundances of ground gleaners (F1.36 = 25.60, P = <0.0001) and tropical migrants (F1.36 = 4.11, P = 0.0501) were lowest in low deer densities. Relative abundance of wood thrush (Hylocichla mustelina) was also lowest in low deer densities (F1.36 = 21.60, P = <0.0001). Richness and abundance of all guilds were positively influenced by the percent forest cover within a 50 m buffer. The effects of deer density on these bird communities were generally opposite of what past literature has suggested. In order to better understand this trend I have also conducted 618 of my own point counts and corresponding vegetation surveys throughout Delaware. This data was collected from May- August 2008 and will be repeated in the summer of 2009.