conservation.arizona.edu - fire

Response to fire by a forest specialist in isolated montane forest

mmerrick — Thu, 16 Apr 2020 21:10:54 +0000

Authors

Mazzella, Maxwell N.

Koprowski, John L.

Fire events have increased in scale and severity due to hotter, drier conditions brought on by climate change and fire suppression. Extreme fire events can be detrimental to forest specialists, especially populations at the edge of the species range, where conditions can vary from those within the core of the range. The San Bernardino flying squirrel (Glaucomys oregonensis californicus) is the southernmost subspecies of Humboldt’s flying squirrel and occurs only in the San Bernardino Mountains of southern California after apparent extirpation from the nearby San Jacinto Mountains. We used non-invasive methods to assess how fire affects flying squirrel occupancy. We surveyed for flying squirrels in burned and unburned areas of the San Bernardino Mountains, and measured habitat features to construct occupancy models. Our top models indicated that flying squirrels occupy lower burn severities but could still occur at higher burn severities if canopy cover remained intact, forest duff remained deep, and tree mortality remained low, especially on steeper slopes. Our study illustrates the ability of San Bernardino flying squirrels, and the potential for other flying squirrels, to survive major fire events and maintain their role in the forest ecosystem. Such results are especially important for species management and understanding how parts of an ecosystem can react as fire frequency and severity increases.

Additional Information

Forest Ecology and Management

Date of publication:

2020

Topics

fire

San Bernardino flying squirrel

occupancy modeling

hair tube

non-invasive sampling

Research Categories

Disturbance Ecology Sky Islands Spatial Ecology Threatened and Endangered Species

Merrick, M.J. R.N.Gwinn, R.L. Minor, R.R. Jessen, T.G. Jessen, V.L. Greer, J. L. Koprowski. 2010. Endangered Mount Graham Red Squirrel (Tamiasciurus hudsonicus grahamensis) uses nest following lightning strike. Southwestern Naturalist. 55: 123-124.

thackerk1 — Tue, 23 Jul 2019 23:36:28 +0000

Authors

Melissa J. Merrick

R. Nathan Gwinn

Rebecca L. Minor

Rosa R. Jessen

Timothy G. Jessen

Vicki L. Greer

John L. Koprowski

Few studies have documented behavioral response of small mammals to fire. Here we report use of a nest by an adult Mount Graham red squirrel (Tamiasciurus hudsonicus grahamensis), an endangered subspecies endemic to the Pinaleńo Mountains of southeastern Arizona, following a direct lightning strike to a tree. After 2 days, the squirrel nested in this tree and remained in the area for another 136 days. This is evidence that red squirrels may tolerate some degree of fire on the landscape.

Additional Information

ENDANGERED MOUNT GRAHAM RED SQUIRREL (TAMIASCIURUS HUDSONICUS GRAHAMENSIS) USES NEST FOLLOWING LIGHTNING STRIKE

Date of publication:

2010

Topics

Mount Graham Red Squirrel

fire

behavioral response

Pinaleño Mountains

Leonard, K. M. and J. L. Koprowski. 2009. Effects of fire on endangered Mt. Graham red squirrels (Tamiasciurus hudsonicus grahamensis): responses of individuals with known fates. Southwestern Naturalist 55:217-224.

thackerk1 — Tue, 23 Jul 2019 22:33:20 +0000

Authors

Katherine M. Leonard

John L. Koprowski

We studied demography and behavior of endangered Mount Graham red squirrels (Tamiasciurus hudsonicus grahamensis) inhabiting areas within and outside low-intensity burns following the Nuttall Fire in the Pinaleńo Mountains, Arizona. Body mass, proportion of individuals in reproductive condition, and distance squirrels traveled to nest did not differ between squirrels within and outside the perimeter of the fire. Within the perimeter, red squirrels had smaller home ranges and shifted territories less frequently and had shorter distances from their previously held territories than squirrels outside the perimeter. Mount Graham red squirrels evolved with patchy, low-intensity fires like those that burned in mixed-conifer forests in the Pinaleńo Mountains and may be able to persist in areas affected by this level of disturbance.

Additional Information

EFFECTS OF FIRE ON ENDANGERED MOUNT GRAHAM RED SQUIRRELS (TAMIASCIURUS HUDSONICUS GRAHAMENSIS): RESPONSES OF INDIVIDUALS WITH KN

Date of publication:

2009

Topics

Mount Graham Red Squirrel

Pinaleño Mountains

body mass

fire

level of disturbance

Differential response to fire by an introduced and an endemic species complicates endangered species conservation

thackerk1 — Thu, 27 Jun 2019 22:58:10 +0000

Authors

R. Nathan Gwinn

John L. Koprowski

Fire is a natural component of, and serves as a tool for, the restoration of forested ecosystems worldwide; however, disturbance due to fire also has been implicated in the proliferation of invasive species. How these fires affect occupancy and use of the forest by wildlife is of great concern, in particular, the differential response of non-native and native species. In the North American Southwest, prior to European settlement, frequent wildfires helped to maintain forest structure. We examined the effect of a large wildfire on an introduced population of the Abert’s squirrel (Sciurus aberti) that has invaded the high elevation forests inhabited by the critically endangered Mt. Graham red squirrel (Tamiasciurus fremonti grahamensis). We found that introduced Abert’s squirrels were more common than native red squirrels in burned areas. Abert’s squirrels did not abandon burned areas but nested, foraged, and did not adjust their home range size in burned areas. This suggests that invasive Abert’s squirrels are better able to exploit burned areas than native red squirrels and that fire can favor non-native species. This interaction between non-native species, native species, and fire adds new insight into the complexities of conservation and restoration of ecosystems and helps to inform conservation activities worldwide.

Additional Information

Hystrix

Date of publication:

2016

Topics

Mount Graham Red Squirrel

Abert’s squirrels

non-native species

invasive species

fire

Research Categories

Disturbance Ecology Sky Islands Spatial Ecology Threatened and Endangered Species