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the following modifications were implemented: (1) wrap additional "bridge trees" with metal flashing; (2) raise the metal flashing on multi- stemmed trees to the height at which the stems were separated by at least 24 inches (60 cm); (3) rotate the seam on the metal flashing to the downward side of the trunk if possible; and (4) fell "suckers ", as needed, near the main trunk of the tree (typically on basswoods, Tilia americana). Colony status With only 36 active nests in 24 trees, the 2005 season marked the lowest population of the Peltier Lake colony since 1990. In 2005 only four Great Blue Herons fledged from three nests located in two trees. However, these juveniles represented the first confirmed productivity from Peltier Lake since at least 2003 and possibly since 2000. From 2006 to 2008, ground survey data (Table 5) indicated a general increase in the size and productivity of the Peltier Lake colony. In 2008, a minimum of 29 active trees, 54 active nests, and 70 chicks were documented. This represented an increase above 2007 levels by 7.4 %, 28.6 %, and 29.6% respectively (Figure 31). As of 8 July 2008, a minimum of 58 surviving chicks (presumed to have fledged) were documented; this estimate was a 34.9% increase above that recorded for the 2007 season. Since 2005, the Peltier Lake colony experienced significant growth in the number of successful trees An examination of the metal flashing on the two successful trees in 2005 showed no sign of mesopredator climbing activity on one tree, but the second tree appeared to have been climbed successfully (i.e., „breached ") despite having a predator guard. Given that this tree produced fledglings, I assumed that the raccoon climbed past the predator guard after the chicks fledged. Scratch patterns in the painted sheet -metal suggested that raccoons attempted to climb 47% (n = 81) of all protected trees during the 2005 season, 60% (n = 49) of which appeared to be successful (Figure 32). Overall, 28% of the protected trees were successfully climbed. Thirty -nine trees showing evidence of climbing attempts contained intact nests. Of the 19 active nest trees within the colony, 79% (n = 15) showed evidence of attempted climbs and 58% (n = 11) appeared to have been successfully climbed. Trees containing active nests were scratched disproportionately more than those containing inactive nests (Chi- squared test, X2 = 11.15, df = 1, p = 0.0008). Based on nest status (active vs. inactive), no significant difference in predator guard failure rate was detected. Furbearer removal In the fall of 2005, a total of 10 raccoons (3 ?) and 7 opossum (4 y) were harvested over a total of 181 trap nights. During the fall of 2006, a total of four raccoons (4 ?) and 14 opossum (only 2 9 were recorded) were harvested over a total of 324 trap nights (Figure 34). During both seasons, trapping activity was temporarily halted when island access became impossible during the lake°`s winter "freeze -up" and as raccoon activity decreased with the temperature. An interesting example of the benefits of tree guards is illustrated by the history of a specific large basswood which was composed of three large trunks in close proximity (tag numbers #708, #709, #999). This tree complex contained five and four active heron nests in 2005 and 2006 respectively.