Location: Pest Management ResearchTitle: Urban and natural components of Korean magpie (Pica pica sericea) territories and their effects on prey density Author
Submitted to: Polish Journal of Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/24/2011
Publication Date: 9/11/2012
Publication URL: http://handle.nal.usda.gov/10113/57719
Citation: Kim, S., Srygley, R.B., Lee, J.Y., Lee, S.I., Choe, J.C. 2012. Urban and natural components of Korean magpie (Pica pica sericea) territories and their effects on prey density. Polish Journal of Ecology. 60: 407-417. Interpretive Summary: Magpies and other corvids do well in urban communities. We wondered whether magpies adjusted territory size when building occupied space on territories. We also wondered whether they used vegetation and human-constructed features on their territory as indicators of prey density. Territory size increased and the density of potential prey decreased with the square-root of building area. So buildings had a negative impact on prey density and the birds adjusted territory size accordingly. Magpies did not appear to use vegetation or artificial structures as cues to adjust territory size. Instead they appeared to use prey density directly. The magpies’ success at rearing young also decreased with the square-root of building area. With declining prey density, magpies utilized more paved areas and incorporated trash bins in their search for prey.
Technical Abstract: Urban landscapes have a negative impact on bird species diversity, yet particular species thrive in urban communities. Like many other corvids, the Korean black-billed magpie is a successful colonizer of urban environments. On the semi-urban campus of Seoul National University in Korea, we investigated whether magpies adjust territory size with building area and secondarily whether they use vegetation and artificial components of their territory as indicators of prey density. We measured territorial areas and divided these into vegetation and artificial areas, distinguishing building area as a separate feature. We sampled prey density on each territory during the nestling stage. Territory size increased with the square root of building area (SRBA). As the length of building perimeter also increases with SRBA, we conclude that territory size was proportional to building perimeter. Prey density decreased with SRBA indicating that buildings had a negative impact on prey. Breeding success was also negatively related to SRBA. We suggest that magpies adjusted territory size according to the length of building perimeter due to a decline in prey density. As prey density declined, artificial area was added to include open trash bins, which increase the availability of anthropogenic refuse. Vegetation area declined as prey density increased, but changes in vegetation area were minor and had little impact on prey availability measured at ground level. Structural cues were not used to adjust vegetation area, and artificial structural cues were not used to adjust territorial size over direct monitoring of prey density.