Woodpecker abundance and nest-habitat in a managed balsam fir ecosystem

• Main Author: Setterington, Michael A.
• Format: Thesis
• Language: English
• Published: Memorial University of Newfoundland 1997
• Subjects: Newfoundland
• Online Access: https://research.library.mun.ca/11400/; https://research.library.mun.ca/11400/1/Setterington_MichaelA.pdf

Much of the balsam fir forest of western Newfoundland is limited to a 60-year timber harvest rotation, resulting in limitations on the amount of potential woodpecker habitat available in the later successional stages of these forests. The abundance of and nest-habitats of black-backed, downy, and hairy woodpeckers were quantified in 40-, 60-, and 80+ -year-old balsam fir forests in western Newfoundland. -- There were no significant differences in abundance among forest age-classes, but there has been a consistent trend for black-backed woodpeckers to be found in the oldest age class forests available throughout their range, and almost exclusively in the 80+ year-old balsam fir forests in western Newfoundland. Downy woodpeckers were more abundant and were equally distributed among the three age classes. Hairy woodpeckers were scarce and only found in the 40- and 60-year-old age classes. An extensive 60-year harvest rotation balsam fir timber management regime is reducing the habitat available for black-backed woodpeckers. Downy and hairy woodpeckers are associated more with the hardwood components of mixed stands, so they will most likely be unaffected by the loss of later successional stages of balsam fir stands. -- Woodpeckers have historically shown greater use of older forests because there was a greater density of cavity-trees in 80+ -year-old forests than in 40-, and 60-year-old forests. The mean diameter of cavity-trees was within the upper 25% of the diameter classes of trees found among the three age classes. The diameter of cavity-trees in the older forests was two diameter classes larger than in the younger forests. The diameter of active nest-trees were within the upper 5% of the diameter classes of trees found among the three age classes. -- All woodpeckers were found at nest-sites surrounded by a mean density of trees approximately 50% less than found in 40-year-old forests, and 25% less than found in 60- and 80+ -year-old balsam fir forests. Canopy cover was equally sparse~ and tree height ...