Project Number: WVA00090
CRIS Number: 0187202
Consequences of the no-spray alternative on bird nesting ecology in a gypsy moth impacted forest
Investigators: Whitmore, R. C.
Performing Department: Forestry -- 1240
Start Date: 10/01/2000
Termination Date: 09/30/2005
Reporting period: 01/01/2001 to 12/31/2001
Progress Report:
This project evaluates the affect of not using pesticides to control gypsy moth (Lymantria dispar) populations. Principally, we are looking at the change in vegetation structure and its relationship to bird populations. Since 1984, we have monitored vegetation structure and bird population parameters at the Sleepy Creek Public Hunting and Fishing Area in Morgan and Berekely Counties, WV. The area has periodically received heavy gypsy moth defoliation and concomittant tree mortality during outbreak years throughout the study period. In 2001, we evaluated the affect of these outbreaks on the populations of cavity nesting birds. We found that after a short time (about 2 years) after an outbreak, populations of cavity nesting birds greatly increased to levels exceeding 10 times those of pre-outbreak periods. However, 5-7 years after an outbreak, cavity nesting bird populations decreased significantly. Examination of the vegetation data showed that this decrease correlated (p < 0.01) with a decrease in snags (standing dead trees). We were able to show that, once the tree was dead, its usable life for cavity nesters is 5-7 years and then the tree usually falls down. Also, in 2001 we used GPS methodology to create accurate maps of our 42 permanent plots and this year we plan to use landscape ecology principles to investigate the site as a whole, rather than on an individual plot or species basis.
Publications:
Showalter, C R. and R. C. Whitmore. 2001. The affect of gypsy moth defoliation on cavity-nesting bird communities. Forest Science, Vol. 48(2):1-9
Impact:
A working knowledge of bird/vegetation interactions in areas not chemically treated to control gypsy moth will allow land managers to more accurately predict the affect of outbreaks on wildlife populations. It is possible that pesticide use can be greatly reduced if it can be shown that wildlife populations are not negatively impacted by insect outbreaks. It has been repeatedly shown that broadscale applications of most insecticides has long-term detrimental affects on wildlife populations.