A dynamic model to predict and ensure the presence of avian control agents for a forest pest

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A major threat to Canada's forestry sector is reduction of wood supply due to outbreaks of spruce budworm (hereafter “SBW”). SBW outbreak cycles are not fully understood, in particular, there has been little examination of how managing for SBW predators can reduce damage from outbreaks. Several species are significant predators of SBW larvae, especially the bay-breasted warbler, Cape May warbler, and Tennessee warbler; (hereafter “SBW-linked warblers”). An untested management approach is to ensure SBW-linked warblers occupy landscapes at risk of SBW outbreaks. This is challenging because the three SBW-linked warblers have different habitat requirements, and ecological variation at multiple spatial scales can mediate whether they will inhabit an area. I propose to use surveys, experimentation, and validation to examine the factors guiding habitat selection in SBW-linked warblers that result in their co-existence within a landscape.******I will use forest inventory models to identify breeding habitat for SBW-linked warblers. SBW survey data will identify areas at risk of an SBW outbreak but are still at low SBW abundance. Combining these data sources will identify areas with the requisite habitat and current low SBW levels, but which are at risk of SBW outbreak. These areas will then be surveyed over multiple breeding seasons to map the distribution of SBW-linked warblers. Naturally, some seemingly good habitat will not be occupied by the target species. I will determine if this is due to biotic or behavioral constraints by performing attraction experiments to determine if the target species can be encouraged to settle. ******The results will yield a model to: a) identify areas the species will occupy, and b) guide forest planning to configure patches that boost a predator reservoir (SBW-linked warblers) that can dampen the extent of SBW outbreaks. This model will require validation, especially how the species use habitat and whether they are eating SBW larvae when they are at low abundance, therefore, I will examine their movement patterns and diet. A subsample of birds will be outfitted with radio-transmitters and followed constantly with automated radio-telemetry stations. Thus, I will determine how individuals of each species are foraging in areas where low-density SBW larvae are available. I will also determine if SBW-linked warblers occupying study areas are eating SBW larvae by chemically marking the larvae and assaying for the markers in birds.******This research will help us understand how birds keep SBW at non-outbreak levels, and will be a silvicultural tool for forest managers to reduce losses from SBW outbreaks. The results will be a free product for forest managers as a statistical model and a component layer for GIS-models. This study provides a monetary benefit for Canadians, a practical benefit for forest managers, numerous opportunities for collaboration, and a conservation benefit for wildlife.