Dynamics of Fire Succession on Mesocarnivore distributions in the Greater Yellowstone Ecosystem.

Authors(s): M. Shaughnessy

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Publication Date: 0000-00-00

Type: annual report

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Abstract: Objectives Fires are a naturally occurring, landscape level disturbance in northern boreal forests. Periodic fires are also important successional features of boreal forests. Fires reset successional cycles and maintain vegetative structural and taxonomic diversity within woodlands. Fires have been particularly important in driving succession and maintaining diversity in the Greater Yellowstone Ecosystem. Portions of the Greater Yellowstone Ecosystem are periodically and regularly impacted by wildfires of both natural and anthropogenic origins. These fires have the potential to significantly impact distributions and assemblages of both small mammals and mesocarnivores of the Greater Yellowstone Ecosystem. Crabtree et al. (1997) reported elevated numbers of some species of small mammals in burned areas (Deer mice, pocket gophers, water voles, Uinta ground squirrels). Fires (and the resultant burned areas) are dynamic in space and time. Fires remove canopy trees and underbrush and, depending upon their intensity, can completely denude areas of vegetation for a time. Because burns vary in time, space and intensity, the subsequent succession that occurs after a burn results in successional 'islands' of habitat that vary significantly in terms of vegetative composition and size. This situation is analogous to the scenario postulated by the equilibrium theory of island biogeography. The burn intensity, burn size and rate of vegetational succession can have profound impacts on the mammal communities that re-colonize the burned area. The objective of this study was to generate preliminary data in order to attempt to better define the role of fire in boreal ecosystems for mesocarnivores. By treating recent burns as habitat islands in a coniferous 'sea', we are examining how fire affects habitat use and community structure of mesocarnivores in the Greater Yellowstone Ecosystem. We also hope to be able to generate sufficient data to model mesocarnivore habitat use with vegetation, with the ultimate goal of producing models which predict individual mesocarnivore species and mesocarnivore assemblages for burned areas of specific recovery ages. These models would represent important management tools for managers of National Parks that are affected by periodic wildfires. Findings and Status Carn.det. Night of: Quad UTM coordinates G. gulo 6/27 Jenny Lake 525545/4852244 (Burned Area) P. lotor* 6/27 Jenny Lake 524499/4852506 (Burned Area)*possibly E. dorsatum; tracks were very smudged M. frenata** 6/26 Jenny Lake 525550/4851330 6/28 (Forested Area)6/29 **possibly M. erminae M. americana 6/30 Moose 521518/4839815 (Forested Area) M. americana 6/30 Moose 521149/4839474 (Burned Area) M. frenata 7/5 Shadow Mt. 533349/4840105(Forested Area) M. americana 7/6 2 Ocean Lake 536804/4860280(Burned Area) M. americana 7/3 2 Ocean Lake 536595/48602257/4 (Forested Area)7/6 P. lotor 7/6 Huck Fire 525302/4876928 Additionally, I have found wolf evidence (scat) at the following approximate UTM coordinates:525550/4851330 The results above account for the data collected during this project. Four carnivore species were positively identified through the tracking methods (3 mustelids and 1 procyonid) while a fifth species was documented through observation of natural tracks. Mesocarnivores were tracked reliably in burned and forested areas. Two patterns emerged from these data that indicate possible productive areas for future research. The first pattern relates to size of mesocarnivores. Larger mesocarnivores were detected exclusively in fire disturbed areas while smaller mesocarnivores were detected most often in forested areas. The size cutoff for this pattern seems to be the American marten (Martes americana) which achieves an average length of 48-66 cm and average weight of 0.6 - 1.2 kg. Martens were detected in both burned and forested areas, however, more marten detections occurred in the forested areas. The second pattern to emerge related to repetition of detections. Occasionally, the same carnivore species is detected several times at the same tracking plate over a short period of time. This pattern can be interpreted as a measure of a habitats ability to retain a carnivore (support a home range). Of the carnivores detected during this study, only smaller mesocarnivores were detected multiple times at the same plate and only at plates in forested areas. Larger mesocarnivore detections occurred only once at plates and in the burned areas. This may indicate that mesocarnivores view burn areas as sub-optimal or opportunistic habitats and use them primarily for dispersal. Forested areas may be better suited for maintaining long term, viable mesocarnivore populations. Naturally, these two observations are based on a bare minimum of data and require significantly more research in order to substantiate and validate. They do, however, point out at least two areas where meaningful questions can be asked about the role of fire disturbance in structuring mesocarnivore communities.

Keywords: fire, Greater Yellowstone Ecosystem, Grand Teton National Park, habitat, management, animal, mammal, rodent, mouse, deer mouse, Peromyscus maniculatus, gopher, pocket gopher, Thomomys talpoides, vole, water vole, Arvicola terrestris, squirrel, ground squirrel, Uinta ground squirrel, Spermophilus armatus, population, food, forage, breeding, Mustelidae, Muridae, Cricetidae, canine, Canidae, wolf, Canis lupus, wolverine, Gulo gulo, raccoon, Procyon lotor, ermine, Mustela erminae, American marten , Martes americana, weasel, long-tailed weasel, Mustela frenata, porcupine, Erethzon dorsatum