Recent studies have emphasized that to evaluate the potential importance of any predators in prey regulation it is necessary to consider their functional (feeding) and numerical responses to variations in prey abundance (Holling 1959, Buckner 1966, 1967). For example, preliminary data from a study of bird predation on the jack pine budworm (Choristoneura pinus Freeman) in Michigan indicated that budworm consumption by the common resident birds in jack pine (Pinus banksiana Lambert) forests was only weakly related to observed budworm abundance (Mattson et al. 1968). This note reports further evidence to substantiate the preliminary data.
Mattson, William J.
"Negligible Feeding Responses by Birds to Variations in Abundance of the Budworm, Choristoneura Pinus (Lepidoptera: Tortricidae),"
The Great Lakes Entomologist, vol 7
Available at: https://scholar.valpo.edu/tgle/vol7/iss4/3