05/01/2006 Council Packet - Laserfiche WebLink

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Further Action Protecting important trees on Peltier Island with metal flashing likely contributed to the small amount of recruitment during the 2005 season. Given the lessons learned, adjustments and modifications to improve the performance of the flashing can be done relatively easily. These modifications include: raising the flashing in areas where tree trunks are within 12" of each other; raising flashing above the level of the understory; adding more flashing to angled trunks; and selective thinning of suckers and other understory plants that may compromise the integrity of the flashing. Also, addition of flashing to selected trees which were not previously flashed will decrease available routes into the forest canopy. As such, a crew is continuing to make these adjustments to the flashing in anticipation of the herons' return. Raccoons have been shown to be remarkably adaptive and motivated when foraging. Historically, raccoon removal campaigns have been largely ineffective. In order to make a small dent in a population, numbers in excess of the maximum sustainable yield must be removed; a number amounting to roughly 50% of the local population. And, given their broadly overlapping territories (Zeveloff 2002), removal would by necessity have to be an ongoing effort. Exacerbating this is the urbanization of the local landscape. Raccoons typically thrive in human dominated landscapes where they can achieve substantially higher population densities than in rural landscapes. As such, trapping and removal with the goal of decreasing the local raccoon population is not recommended. However, nest raiding behavior does not appear to be limiting to other metro area heronries, which may suggest that at Peltier Island this behavior is culturally transmitted from generation to generation. With this in mind, a small scale focused campaign of trapping is currently being conducted. If, over a period of a few seasons, this cultural behavior is trapped out or at least minimized, the Peltier Island colony may have time to recover. Finally, ongoing local and regional monitoring of waterbird colonies is important. Tracking the ebb and flow of local waterbird colonies will help develop an understanding for how wildlife reacts to such events as large scale alteration of the landscape, loss of nesting and foraging habitat, and shifts in water quality. Monitoring can also help to identify environmental problems as they arise. This knowledge is directly applicable to large scale environmental management and planning that can help ensure healthy ecosystems for all. 16 • •