Wildlife Studies - 1994 Thunder Fire

Lynx tracking.

Final Reports (PDF) Thunder Fire Report, by G. Wooten, M. Poss, and M. Larsen (3 MB PDF file). Thunder Fire Project Appendices Links: Introduction Background and Highlights Ecology Wildlife Birds Amphibians Vegetation Threats Related pages: Boreal research Boreal Okanogan

The Meadows is home to one of the largest, viable populations of lynx (Felis lynx canadensis) in the lower 48 states. With numbers of less than 30, these animals are unquestionably endangered yet efforts to get this population listed under the Endangered Species Act have been denied.Lynx habitat, according to studies done in the late 1980's, should be composed of at least 30% young stands of lodgepole pine to allow for optimal snowshoe hare forage. Hare are the primary food source of lynx. The Forest Service recently concluded that the limiting factor for lynx survival in the Meadows is a lack of hare habitat because to much of the area is in mature stand conditions. Under this premise, logging would be essential to improve lynx habitat.

As far as lynx habitat goes, we now have small patches of young forest, deeply imbedded in more mature stands, that can provide forage habitat for snowshoe hare. This point deserves an editorial comment. A number of people, including myself, have been studying snowshoe hare forage behavior in the winter. Based on observations of tracks, feeding activity and actual animals, we find that hare prefer mature, mixed conifer stands in the cold winter months. Although the biologists are undoubtedly correct in reporting that hare prefer young lodgepole for foraging if averaged over the year, they may have overlooked the benefit of thermal and hiding cover offered by these older stands in the cold winter months. With increased amount of down wood, snags and a mosaic of new growth adjacent to mature forest, the fire has provided a good mix of habitats which should benefit all resident species on a year-round basis.

Resident species have increased and diversified since the fire burned. The most immediate response was in bird populations, but clearly that was due to both insect and small mammal influx. Lynx tracks were commonly encountered in 1995 surveys in multiple sections of the burn and travel and hunting corridors were identified. Many of the frequented areas were in high intensity burns. In 1996, lynx tracks were found in only one of the identified high use areas. This may reflect a decrease in hare numbers, and although we can not objectively quantitate this, it was not apparent from frequency of encountering hare or tracks. Equally plausible is that the increased human presence in the area from activities associated with the sale and from illegal snowmobile use in the winter have effected the behavior of these shy felids.

Pine marten tracks were undoubtedly the most common track encountered in both 1995 and 1996 and the numbers and distribution increased in 1996. They frequently were found both hunting and traveling in high intensity burns and several kills of both hare and grouse were found in these areas. Squirrel and small rodent tracks were most frequent in low or medium intensity burns adjacent to high intensity burns where there was a substantial down wood component.

The 1997 tracking season was very interesting. Some of our observations are listed here:

Mustelids
Marten activity was more variable in 1997 than in 1996, with no tracks found on several days. Activity appeared to be more concentrated, particularly along meadow edges and junctions of high to low-medium intensity burns. Most draws, and areas with mature forest characteristics, had a "resident" marten.

Small mustelid (weasel) tracks were more numerous in 1997 than in 1996, none were noted in 1995. These animals were hunting the numerous small rodents that appeared in fire areas (several examples of chases seen). There did not seem to be a habitat preference for the weasel. They were found in high intensity upslope areas, wet meadows and riparian area. Territories overlapped with marten.

No fischer or wolverine tracks were seen in 1997.

Hare
There was no subjective change in the density of hare tracks seen in 1997 relative to other years. Hare continued to forage on heat-killed fir needles (multiple runways to these areas, lots of pellets) and were in the highest density in spruce/fir forests at the edges of wet meadows and drainages. There was a notable concentration of hare in those areas that had a mature spruce/fir component adjacent to a medium/high intensity burn area. Hare continued to traverse high intensity burn areas and were using blow down holes and down wood in these areas for burrows.

Coyotes
Coyote tracks were not numerous away from roads or snow mobile tracks, but were consistently found each year. There was a travel corridor along the Dog Cr riparian area on the north side, with travel generally in a E->W direction. No coyote tracks were found in the 30 mile drainage in 1995, but were present in 1997, coming in along the new logging roads north of 30 mile meadows. Coyotes followed snowmobile tracks into Dill Cr area and continued up the west ridge in both 1995 and 1996. In the southern portion of the burn (Sheep Cr area) coyote tracks were found in 1996 crossing Sheep Cr meadows. Tracks were abundant in proximity to 20 mile meadows and coyotes were the most numerous carnivore in the Smarty Cr portion of the fire.

Snowmobiles
It's apropriate to include snowmobiles in the wildlife section for obvious reasons. From the above section on coyotes, it is clear that the presence of these machines does influence wildlife in this area. In 1997 surveys, snowmobiles were found throughout the Sheep Pk, Sheep Cr drainage for the 1st time. There was multiple use of the west fire perimeter road that transected the Sheep Cr meadows. The northern perimeter road (south of Queer Cr) was not monitored in 1997-activity was recorded there in 1995. No snowmobile use was found in unit 6 of the Thunder Salvage Sale, but snowmobiles continued to use the Dill Cr riparian area to within 1/8 mile of this unit (1995, 1996 and 1997 observations.)

Lynx
Lynx tracks were found each of the 3 years. They were most abundant during the 1995 tracking season, when 2 sets of cat/kitten tracks, and at least one single, mature animal were found. Only 1 set of tracks was found within the fire perimeter in 1996, and 1 set in 1997. (Note that tracks were found outside the fire perimeter in all 3 years.) All tracks were followed for variable distances, the most extensive being the tracks encountered in the 1997 survey. The following are general observations from approximately 10-15 miles of lynx tracking in this area. Traveling behavior is defined as straight line traversing through an area, with little deviation or investigation. Hunting is defined as a meandering, investigation of the area. A chase indicates a gait change (walk to gallop) in association with prey (snowshoe hare) tracks. Some details of the lynx observations are as follows:
(1) Lynx travel through high intensity burn area. There was no attempt to avoid these areas.
(2) Lynx travel corridors were never on ridge tops. They usually followed riparian areas, staying about 100-300 feet upslope of the drainage.
(3) Lynx travel through dense stands of lodgepole/mixed conifer. No hunting or chases were ever observed in these stands although hare tracks were encountered.
(4) All hunting activity observed was in mature spruce/fir forest, generally at the edge of a natural opening. This behavior is characterized by circumscribing each tree well throughout an area. Occasional chases were seen into a tree well. (Comment- most of the hare activity we observed was also in these stands)
(5) One kill and 4 chases were noted over the 3 years. Most of the activity was travel.
(6) Lynx were observed to use snowmobile tracks for travel on 1 of 5 occasions (lynx tracks stayed in snowmobile tracks for more than 200 yards. On all other occassions there was avoidance of these tracks. Similarly, lynx tracks crossed the fire perimeter road on 1 of 4 occassions. Avoidance was recorded when lynx tracks were following a general bearing, came within 20 feet of a fire road and implemented more than 90 degrees of a direction change.