Koprowski, J. L. 2005. Management and conservation of tree squirrels: The importance of endemism, species richness, and forest condition. USDA Forest Service Proceedings RMRS-P-36: 245-250.

thackerk1 — Mon, 22 Jul 2019 23:19:59 +0000

Authors

John L. Koprowski

Tree squirrels are excellent indicators of forest health yet the taxon is understudied. Most tree squirrels in the Holarctic Region are imperiled with some level of legal protection. The Madrean Archipelago is the epicenter for tree squirrel diversity in North America with 5 endemic species and 2 introduced species. Most species of the region are poorly studied in keeping with an international dearth of data on this taxon; 3 of the 5 native species are the subject of <3 publications. Herein, I review literature on the response of squirrels to forest management from clearcutting to less comprehensive operations. Major threats to squirrel diversity in the Madrean Archipelago’s Sky Islands are the introduction of species, altered fire regimes, and inappropriate application of forestry practices.

Additional Information

Management and Conservation of Tree Squirrels: The Importance of Endemism, Species Richness, and Forest Condition

Date of publication:

2005

Topics

forest health

tree squirrels

endemic species

introduced species

Madrean Archipelago’s Sky Islands

Koprowski, J. L., M. I. Alanen, and A. M. Lynch. 2005. Nowhere to run and nowhere to hide: Response of endemic Mt. Graham red squirels to catastrophic forest damage. Biological Conservation 126: 491-498.

thackerk1 — Mon, 22 Jul 2019 23:16:00 +0000

Authors

John L. Koprowski

Marit I. Alanen

Ann M. Lynch

A consequence of isolation is increased susceptibility to catastrophe. Insect damage to fragmented and isolated forests has the potential to serve as a catastrophic force; such damage has increased worldwide due to climate change and fire suppression policies. We examined the response of endangered endemic Mt. Graham red squirrels to catastrophic insect damage due to moths, beetles, and introduced aphids. Insects changed the forest environment significantly for the endemic squirrel by reducing basal area and stem densities of live stems, while increasing number and basal area of standing dead stems. Availability of two major foods, fungi and tree seeds, declined in insect-damaged forests relative to trends in undamaged forests. Numbers of Mt. Graham red squirrels declined precipitously in insect-damaged forests suggesting a catastrophe. Conservation options are limited in such situations. Forest-insect induced catastrophes are likely to become more common in the near future as forest health declines due to past management tactics and climate change. Prudent conservation measures include the anticipation of insect outbreaks and effective forest treatments to decrease likelihood of such catastrophes to species of precarious conservation status, while avoiding abrupt changes to critical habitat.