You are not currently logged in.
Access JSTOR through your library or other institution:
If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Synchronous Eruptions of Boreal Seed-Eating Birds
Carl E. Bock and Larry W. Lepthien
The American Naturalist
Vol. 110, No. 974 (Jul. - Aug., 1976), pp. 559-571
Stable URL: http://www.jstor.org/stable/2459578
Page Count: 13
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
Analysis of Audubon Society Christmas-count data (1962-1971) revealed a generally synchronous pattern of winter eruptions between eight species of seed-eating birds whose winter ranges normally include boreal forests. Species and populations occupying montane conifer forests in the West did not fit this pattern as well. Literature analysis revealed a circumboreally synchronized pattern of seed crop fluctuations in certain high-latitude tree species and an apparently resulting pattern of southward eruptions of birds dependent upon these foods. Between 1948 and 1971 eruptions were relatively large in 1949, 1955, 1957, 1959, 1961, 1963, 1965, 1968, 1969, and 1971.
The American Naturalist © 1976 The University of Chicago Press