Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-04T19:06:29.239Z Has data issue: false hasContentIssue false

WOODPECKER PREDATION ON BARK BEETLES IN ENGELMANN SPRUCE LOGS AS RELATED TO STAND DENSITY

Published online by Cambridge University Press:  31 May 2012

Roland S. Shook
Affiliation:
Department of Zoology, Colorado State University, Fort Collins, Colorado
Paul H. Baldwin
Affiliation:
Department of Zoology, Colorado State University, Fort Collins, Colorado

Abstract

Eighty Engelmann spruce logs (Picea engelmannii Parry), which were distributed in open (bulldozed to clearcut), semi-open (selectively cut), and dense (uncut) spruce forest, were infested with Dendroctonus obesus (Mann.) and Ips pilifrons Sw. and fed upon by northern three-toed and hairy woodpeckers. Sections of the infested boles were covered with screen to prevent woodpecker feeding and all logs were left in the field over one winter and through the following summer. By spring, the spruce beetle brood was reduced approximately 50% in all three forest areas. By fall, the spruce beetle brood suffered a 71, 83 and 52% reduction in the open, semi-open and dense forest, respectively. Spruce beetles appeared to be in greatest numbers in the semi-open forest, resulting in the greatest woodpecker predation there. Woodpeckers did not feed in the open meadows. Estimates in the spring, before the Ips emerged from the logs, showed that woodpeckers reduced the Ips brood by 76 and 11% in the open and semi-open forest, respectively. Ips were not found in dense forest or in meadows.

Type
Research Article
Copyright
Copyright © Entomological Society of Canada 1970

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Footnotes

1

Research was conducted while Mr. Shook was employed by the Rocky Mountain Forest and Range Experiment Station, U.S. Dept. Agric., Forest Serv., Fort Collins, Colo.

References

Baldwin, P. H. 1960. Overwintering of woodpeckers in bark beetle-infested spruce-fir forests of Colorado. Proc. XIIth int. Ornith. Congr. (Helsinki, 1958), pp. 7184.Google Scholar
Baldwin, P. H. 1968 a. Woodpecker feeding on Engelmann spruce beetle in windthrown trees. U.S. Forest Serv. Res. Note RM-105. Rocky Mountain Forest and Range Exp. Stn, Fort Collins, Colo.Google Scholar
Baldwin, P. H. 1968 b. Predator-prey relationships of birds and spruce beetles. Proc. North Central Branch — Ent. Soc. Am. 23: 9099.Google Scholar
Cottam, G., and Curtis, J. T.. 1956. The use of distance measures in phytosociological sampling. Ecology 37: 451460.CrossRefGoogle Scholar
Holling, C. S. 1961. Principles of insect predation. A. Rev. Ent. 6: 163182.CrossRefGoogle Scholar
Hutchison, F. I. 1951. The effects of woodpeckers on the Engelmann spruce beetle, Dendroctonus engelmanni Hopk. M.S. Thesis, Colo. State Univ., Fort Collins.Google Scholar
Knight, F. B. 1958. The effects of woodpeckers on populations of the Engelmann spruce beetle. J. econ. Ent. 51: 603607.10.1093/jee/51.5.603CrossRefGoogle Scholar
Koplin, J. R. 1967. Predatory and energetic relations of woodpeckers to the Engelmann spruce beetle. Ph.D. Thesis, Colo. State Univ., Fort Collins.Google Scholar
Koplin, J. R. 1969. The numerical response of woodpeckers to insect prey in a subalpine forest in Colorado. Condor 71: 436438.CrossRefGoogle Scholar
Massey, C. L., and Wygant, N. D.. 1954. Biology and control of the Engelmann spruce beetle in Colorado. U.S. Dep. Agric. Cir. 944.Google Scholar
Nagel, R. H., McComb, David, and Knight, F. B.. 1957. Trap tree method for controlling the Engelmann spruce beetle in Colorado. J. For. 55: 894898.Google Scholar
Yeager, L. E. 1955. Two Woodpecker populations in relation to environmental change. Condor 57: 148153.10.2307/1364863CrossRefGoogle Scholar