Seasonal and yearly changes in consumption of hypogeous fungi by northern flying squirrels and red squirrels in old-growth forest, New Brunswick

2004 ◽  
Vol 82 (1) ◽  
pp. 110-117 ◽  
Author(s):  
Karl Vernes ◽  
Shauna Blois ◽  
Felix Bärlocher
Keyword(s):  
New Brunswick ◽  
Mycorrhizal Fungus ◽  
Food Resource ◽  
Faecal Pellet ◽  
Old Growth ◽  
Red Squirrels ◽  
Hypogeous Fungi ◽  
Flying Squirrels ◽  
Old Growth Forest ◽  
Northern Flying Squirrels

Seasonal consumption of mycorrhizal fungus by northern flying squirrels (Glaucomys sabrinus) and red squirrels (Tamiasciurus hudsonicus) was examined in old-growth mixedwood forest at Fundy National Park in southern New Brunswick between May 1999 and March 2001. Using faecal pellet analysis, we found that the amount of fungus in the diet of both species was dependent on season and year of study and ranged from 35% to 95%. Twenty fungal taxa, most of them hypogeous Ascomycetes and Basidiomycetes, were detected in diets. More taxa were detected in summer diets compared with all other seasons, but all seasonal samples contained several hypogeous taxa. Up to six taxa were identified in any one sample. Both squirrel species occurred at high densities throughout the study, and dietary overlap between them was great throughout this time in terms of both the amount of fungus and the proportions of different taxa that were consumed. Overall, our data suggest that both G. sabrinus and T. hudsonicus are abundant and important consumers of fungus in the region and that fungus may represent a key food resource, particularly during times when other foods are limited.

Interrelationships among northern flying squirrels, truffles, and microhabitat structure in Sierra Nevada old-growth habitat

2002 ◽  
Vol 32 (6) ◽  
pp. 1016-1024 ◽  
Author(s):  
Sanjay Pyare ◽  
William S Longland
Keyword(s):  
Sierra Nevada ◽  
Forest Floor ◽  
Woody Debris ◽  
Fungal Growth ◽  
Old Growth ◽  
Flying Squirrels ◽  
Old Growth Forest ◽  
Northern Flying Squirrels ◽  
Nesting Sites ◽  
Microhabitat Structure

During 1997-1998, we investigated the influence of both the relative abundance of truffles, preferred food items, and microhabitat structure on the occurrence of northern flying squirrels (Glaucomys sabrinus Shaw) in old-growth forest habitat of the Sierra Nevada Range, U.S.A. Following live-trapping sessions, we searched the forest floor for truffle diggings and sampled the soil for truffles. Diggings were more abundant where flying squirrels were captured, suggesting squirrels were active near areas of the forest floor where truffles had recently been excavated. The frequency of sampling plots with truffles was higher where squirrels were captured, further suggesting preferences for microhabitats where truffles were more abundant. We also measured 15 microhabitat variables at trap stations to evaluate the influence of aboveground microhabitat characteristics on squirrel occurrence. Results indicated that flying squirrels preferred microhabitats with understory cover, which may minimize predation from aerial predators like spotted owls (Strix occidentalis Merriam). Neither abundance of coarse woody debris, a feature conducive to fungal growth, nor the abundance of potential nesting sites (i.e., snags) measurably influenced squirrel occurrence. While various aboveground forest-microhabitat characteristics affect the use of old-growth forests by flying squirrels, these animals refine their use of these forests based on fine-scale changes in the availability of a highly preferred and ephemeral food item.

scholarly journals Cavity Nest Materials of Northern Flying Squirrels, Glaucomys sabrinus, and North American Red Squirrels, Tamiasciurus hudsonicus, in a Secondary Hardwood Forest of Southern Ontario

2007 ◽  
Vol 121 (3) ◽  
pp. 303 ◽  
Author(s):  
Jesse E. H. Patterson ◽  
Stephen J. Patterson ◽  
Ray J. Malcolm
Keyword(s):  
Hardwood Forest ◽  
Tamiasciurus Hudsonicus ◽  
Glaucomys Sabrinus ◽  
Red Squirrels ◽  
Southern Ontario ◽  
Flying Squirrels ◽  
Northern Flying Squirrels ◽  
Cavity Nest ◽  
North American Red Squirrels ◽  
Nest Materials

Through deployment of artificial nest boxes, we examined the composition of cavity nest materials used by Northern Flying Squirrels (Glaucomys sabrinus) and North American Red Squirrels (Tamiasciurus hudsonicus) in a secondary hardwood forest of southern Ontario, Canada. We collected 32 nests of known species association and found that 85.7% of G. sabrinus nests and 77.8% of T. hudsonicus nests were constructed almost entirely of shredded bark from Eastern White Cedar (Thuja occidentalis). Mean nest depth across all samples was 12.2 cm and showed no significant difference between species or between spring and summer nests. We review the antiparasitic properties of T. occidentalis and suggest that the use of shredded cedar bark by G. sabrinus and T. hudsonicus to line nest cavities may be a behavioural adaptation, which reduces ectoparasite loads in the nest environment.

Population dynamics of Glaucomys sabrinus and Tamiasciurus douglasii in old-growth and second-growth stands of coastal coniferous forest

2003 ◽  
Vol 33 (4) ◽  
pp. 587-596 ◽  
Author(s):  
Douglas B Ransome ◽  
Thomas P Sullivan
Keyword(s):  
Population Dynamics ◽  
Habitat Preferences ◽  
Coniferous Forest ◽  
Glaucomys Sabrinus ◽  
Old Growth ◽  
Flying Squirrels ◽  
Survival Percentage ◽  
Second Growth ◽  
Northern Flying Squirrels ◽  
Population Breeding

Habitat preferences and population dynamics of northern flying squirrels (Glaucomys sabrinus Shaw) and Douglas squirrels (Tamiasciurus douglasii Audubon and Bachman) were examined in old-growth and mature second-growth stands in British Columbia, Canada. Using mark–recapture techniques to estimate population dynamics, we tested the hypothesis that old-growth stands provided higher-quality habitat than second-growth stands for these species. Populations were monitored in two old-growth and two mature second-growth stands from August 1995 to May 1999. We were unable to detect major differences in movement, density, recruitment, mass of males, survival, percentage of the population breeding, and the duration that individuals remained on the study plots between stand types for G. sabrinus. Similarly, with the exception of recruitment, we were unable to detect major differences in these parameters between stand types for T. douglasii. Recruitment of T. douglasii was higher in second-growth than in old-growth stands. Old-growth stands were not higher-quality habitat than second-growth stands for either species for the period of enquiry and the parameters we measured. We also presented evidence of late fall – early winter breeding for G. sabrinus, as well as seasonal fluctuations in mass and trappability, larger movement by males than females, and the age of some squirrels exceeding 3.5 years.

Nutritional value and diet preference of arboreal lichens and hypogeous fungi for small mammals in the Rocky Mountains

2008 ◽  
Vol 86 (8) ◽  
pp. 851-862 ◽  
Author(s):  
S. A. Dubay ◽  
G. D. Hayward ◽  
C. Martínez del Rio
Keyword(s):  
Small Mammals ◽  
Nitrogen Balance ◽  
Rocky Mountains ◽  
Dry Matter ◽  
Nutrient Content ◽  
Neutral Detergent Fiber ◽  
Hypogeous Fungi ◽  
Flying Squirrels ◽  
Positive Nitrogen Balance ◽  
Northern Flying Squirrels

Many small mammals consume lichen and fungi, but southern red-backed voles ( Clethrionomys gapperi (Vigors, 1830)) and northern flying squirrels ( Glaucomys sabrinus (Shaw, 1801)) exhibit strong mycophagy compared with other North American taxa. We analyzed nutrient content of lichen and fungi and observed feeding preferences of voles and flying squirrels to understand the foraging behavior of these mammals and their strategy for surviving on relatively low-quality diets dominated by lichen and fungi. We analyzed nutrient characteristics of 10 hypogeous (fruiting belowground) fungi and four arboreal lichens eaten by red-backed voles and northern flying squirrels in the Rocky Mountains. Hypogeous fungi contained higher nitrogen, lipid, neutral detergent fiber, acid detergent fiber, ash, potassium, and phosphorous concentrations than arboreal lichens, but lichens were higher in calcium. To assess diet preferences, 10 pairwise feeding trials using four hypogeous fungi and two arboreal lichens were conducted with voles and seven trials using three hypogeous fungi and two lichens were conducted with squirrels. In general, squirrels and voles preferred hypogeous fungi over arboreal lichens. We then calculated dry matter and nitrogen digestibilities for flying squirrels and red-backed voles fed diets of arboreal lichen and hypogeous fungi. Overall mean dry matter digestibilities were ≥70% for all diets. For hypogeous fungi, nitrogen digestibility was 12.3% and 24.9% for squirrels and voles, respectively, suggesting that most nitrogen was indigestible. Animals maintained positive nitrogen balance when fed fungi but were unable to maintain positive nitrogen balance when fed lichens. Maintenance nitrogen requirements for flying squirrels were lower than predicted. Low requirements may allow for increased consumption of lichen in winter, but lichen diets must be supplemented with a source of nitrogen because animals were unable to maintain nitrogen balance when fed lichen alone. Consumption of numerous fungi and lichen taxa is necessary to sustain these animals year-round.

scholarly journals Arboreal Squirrel Response to Silvicultural Treatments for Dwarf Mistletoe Control in Northeastern Oregon

2004 ◽  
Vol 19 (2) ◽  
pp. 133-141 ◽  
Author(s):  
Evelyn L. Bull ◽  
Thad W. Heater ◽  
Andrew Youngblood
Keyword(s):  
Red Squirrel ◽  
Total Removal ◽  
Dwarf Mistletoe ◽  
Treatment Area ◽  
Red Squirrels ◽  
Flying Squirrels ◽  
Silvicultural Treatments ◽  
Treatment Type ◽  
Northern Flying Squirrels ◽  
Rest Sites

Abstract Various silvicultural treatments are commonly used to sanitize stands by removing trees infected with dwarf mistletoe (Arceuthobium spp.), yet witches' brooms in trees infected with dwarf mistletoe often provide structures used by many wildlife species. We compared relative abundance, habitat use, and area of use of red squirrels (Tamiasciurus hudsonicus) and northern flying squirrels (Glaucomys sabrinus) before and after two different treatments designed to remove a range of dwarf mistletoe-caused witches' brooms in northeastern Oregon in 1998–2002. Dwarf mistletoe sanitation treatments included: (1) an island treatment, with retention of up to 0.5 ha groups of trees containing witches' brooms in evenly distributed uncut islands, and all harvest activity confined to thinning from below outside these islands to eliminate trees containing witches' brooms; and (2) a total removal treatment, which consisted of removing all trees that contained a witches' broom estimated to be >25 cm in diameter. Before treatment, over half of the red squirrels and northern flying squirrels in the treatment area occupied summer rest sites in witches' brooms on large Douglas-fir (Pseudotsuga menziesii). Live trapping indicated a pretreatment abundance of 1.0 per 100 trap/nights for red squirrels and 0.4 per 100 trap/nights for northern flying squirrels, and a posttreatment abundance of 2.1 per 100 trap/nights for red squirrels and 0.2 per 100 trap/nights for northern flying squirrels. Type of rest site and amount of red squirrel reuse did not change after the island treatment, although the number of red squirrels located in rest sites increased with the island treatment. Most of the red squirrel locations occurred within the islands. Area of use by red squirrels did not change with island treatment. Type of rest site used by red squirrels and northern flying squirrels shifted after the total removal treatment from mostly witches' brooms to predominantly tree cavities. Area of use by red squirrels increased from 1.8 to 7.6 ha after the total removal treatment. Results suggest that retention of trees containing witches' brooms in small groups or islands offers an opportunity to retain rest site habitat, although northern flying abundance declined with both treatments. West. J. Appl. For. 19(2): 133–141.

Food habits of the northern flying squirrel (Glaucomys sabrinus) in Oregon

1985 ◽  
Vol 63 (5) ◽  
pp. 1084-1088 ◽  
Author(s):  
Zane Maser ◽  
Chris Maser ◽  
James M. Trappe
Keyword(s):  
Food Habits ◽  
Food Source ◽  
Coniferous Forests ◽  
Glaucomys Sabrinus ◽  
Hypogeous Fungi ◽  
Flying Squirrel ◽  
Flying Squirrels ◽  
Food Items ◽  
Northern Flying Squirrel ◽  
Northern Flying Squirrels

Digestive tracts of 91 northern flying squirrels (Glaucomys sabrinus) were analyzed for food items; 28 were from northwestern Oregon and 63 from northeastern Oregon. Ninety percent or more of the ingested materials were fungi and lichens, including 20 genera of hypogeous fungi. The northern flying squirrel, in using hypogeous fungi as a major food source, is an important nocturnal disperser of the spores. In Oregon coniferous forests, these fungi are obligatory ectomycorrhizal symbionts with the trees in which the squirrels live.

Fungi in the winter diets of northern flying squirrels and red squirrels in the boreal mixedwood forest of northeastern Alberta

2000 ◽  
Vol 78 (12) ◽  
pp. 1514-1520 ◽  
Author(s):  
R S Currah ◽  
E A Smreciu ◽  
T Lehesvirta ◽  
M Niemi ◽  
K W Larsen
Keyword(s):  
Tamiasciurus Hudsonicus ◽  
Gut Contents ◽  
Glaucomys Sabrinus ◽  
Red Squirrels ◽  
Faecal Pellets ◽  
Flying Squirrels ◽  
Northern Flying Squirrels ◽  
Unidentified Species ◽  
Winter Diets ◽  
Northeastern Alberta

Gut contents of 138 northern flying squirrels (Glaucomys sabrinus) and 75 red squirrels (Tamiasciurus hudsonicus), which had been trapped from November to February in the boreal forest of northeastern Alberta, were examined to determine which fungi were consumed as food during the winter months in this habitat. Spores of epigeous Boletales, Russulaceae, and Cortinariaceae were most frequent and numerous. Hypogeous ascomycetes (unidentified species of Elaphomyces and Tuber) and basidiomycetes (unidentified species of Gautieria, Hymenogaster, Hysterangium, and Rhizopogon) were sometimes present in substantial amounts but were not as frequent as the remains of epigeous fungi. Guts sometimes contained remains of the tough or carbonaceous sporocarps of unidentified species of the Hymenochaetales, Diatrypaceae, Xylariaceae, and Bankeraceae. The spores of some rust fungi (e.g., Phragmidium fusiforme) along with the conidia (e.g., Helicoma sp.) and ascospores of microfungi (e.g., Sordariaceae) were also detected. Lichen tissues were absent, and this contrasts with previous suggestions that lichens are a winter food of sciurids in regions with substantial snowfall. A parallel analysis of 110 faecal pellets from northern flying squirrels collected in the same area from June to August confirms that fungi are important in its summer diet.Key words: Glaucomys sabrinus, Tamiasciurus hudsonicus, fungi, mycophagy, Sciuridae.

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