Lepczyk Christopher A, Mertig Angela G, Liu Jianguo
Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI 48824-1222, USA.
Environ Manage. 2004 Jan;33(1):110-25. doi: 10.1007/s00267-003-0036-z. Epub 2004 Feb 2.
Fluctuations of bird abundances in the Midwest region of the United States have been attributed to such factors as landscape change, habitat fragmentation, depredation, and supplemental feeding. However, no attempt has been made to estimate the collective role of landowner activities that may influence birds across a landscape. To investigate how landowners might influence birds when the majority (> 90%) of land is privately owned, we surveyed all 1694 private domestic landowners living on three breeding bird survey routes (approximately 120 km) that represent a continuum of rural-to-urban landscapes in Southeastern Michigan from October through December 2000. Our survey was designed to investigate (1) the proportion of landowners involved in bird feeding, providing bird houses, planting or maintaining vegetation for birds, gardening, landscaping, applying fertilizer, and applying pesticides or herbicides; (2) whether differences existed between urban, suburban, and rural landowner activities; and (3) whether landowners that carried out a given activity were sociodemographically different from those who did not. Of the 968 respondents (58.5% response rate), 912 (94%) carried out at least one of the activities on their land and the average landowner carried out 3.7 activities. A total of 65.6% fed birds, 45.7% provided bird houses, 54.6% planted or maintained vegetation for birds, 72.7% gardened, 72.3% landscaped, 49.3% applied fertilizer, and 25.2% applied pesticides or herbicides. Significant differences existed between the landscapes, with rural landowners having more bird houses and applying pesticides or herbicides in greater frequency. Similarly, urban landowners had a greater density of bird feeders and houses, but planted or maintained vegetation in the lowest frequency. Participation in activities varied by demographic factors, such as age, gender, and occupation. Scaling each activity to all landowners, including nonrespondents, across all landscapes indicates that between 14% and 82% of landowners may be engaged in a particular activity, with application of pesticides or herbicides having the least potential involvement (13.9%-55.4%) and gardening having the greatest potential involvement (40.1%-81.6%). Taken collectively, our results indicate that landowners are both intentionally and unintentionally engaged in a wide range of activities that are likely to influence bird populations.
美国中西部地区鸟类数量的波动归因于景观变化、栖息地破碎化、捕食和补充性喂食等因素。然而，尚未有人尝试估算土地所有者活动对整个景观中鸟类的综合影响。为了研究在大多数（>90%）土地为私人所有的情况下土地所有者可能如何影响鸟类，我们在2000年10月至12月期间，对居住在密歇根州东南部三条繁殖鸟类调查路线（约120公里）上的1694名私人家庭土地所有者进行了调查，这些路线代表了从乡村到城市景观的连续区域。我们的调查旨在研究：（1）参与鸟类喂食、提供鸟屋、为鸟类种植或维护植被、园艺、景观美化、施肥以及施用杀虫剂或除草剂的土地所有者比例；（2）城市、郊区和农村土地所有者活动之间是否存在差异；（3）开展特定活动的土地所有者在社会人口统计学特征上是否与未开展该活动的土地所有者不同。在968名受访者中（回复率为58.5%），912人（94%）在其土地上至少开展了一项活动，平均每位土地所有者开展3.7项活动。共有65.6%的人喂食鸟类，45.7%的人提供鸟屋，54.6%的人为鸟类种植或维护植被，72.7%的人从事园艺，72.3%的人进行景观美化，49.3%的人施肥，25.2%的人施用杀虫剂或除草剂。不同景观之间存在显著差异，农村土地所有者拥有更多鸟屋且施用杀虫剂或除草剂的频率更高。同样，城市土地所有者的鸟类喂食器和鸟屋密度更大，但种植或维护植被的频率最低。参与活动因年龄、性别和职业等人口统计学因素而异。将每项活动扩展到所有景观中的所有土地所有者（包括未回复者）表明，14%至82%的土地所有者可能参与某项特定活动，其中施用杀虫剂或除草剂的潜在参与度最低（13.9%-55.4%），园艺的潜在参与度最高（40.1%-81.6%）。总体而言，我们的结果表明，土地所有者有意或无意地参与了一系列可能影响鸟类种群的活动。
