l)R.Vn KIS APPKNDIX I 



reintroduction (Smith ct al. 2000). The average annual growth rate for this population is 36%, based on minimum 

 counts on December 31 and including pups (USFWS et al. 2001 ). 



It is likely that population growth rates will slow for both the core Yellowstone and central Idaho populations 

 becau.se of declining availability of suitable, vacant habitat. However, these populations will be a source of founders 

 for new packs outside YNP, central Idaho, Wyoming, and Montana. While population growth slows or levels off in 

 core areas, wolf numbers and distribution outside core areas arc expected to increase rapidly in the next few years as 

 wolves bom in the initial pul.se sexually mature and disperse to colonize vacant habitats elsewhere. 



Pack membership typifies the predominant manner in which a wolf exists in the wild. The pack is the mechanism 

 by which wolves reproduce and populations grow. However, in most wolf populations, some lone, nomadic 

 individuals exist as dispersers — looking for vacant habitat, waiting to be found by a member of the opposite sex 

 within a new home range, or searching for an existing pack to join. Up to 10-15% of a wolf population may be 

 comprised of lone animals. 



This is a temporary transition. Wolves in northwestern Montana usually found other wolves in an average of 66 

 days (range 2-202 days) (Boyd and Plet.scher 1999). Occasionally, lone wolves get into conflict with people and/or 

 hvestock, ultimately being lost to the population through legal or illegal means. For a wolf to make a contribution to 

 the population, it must affiliate with other wolves. Until they affiliate with a pack, lone wolves are generally 

 counted separately or omitted from population counts altogether because they do not contribute to population 

 growth. 



Interactions with Other Species 



The relationships between carnivores and other species, and the ecosystems in which they live, could be the most 

 poorly understood and controversial dimension of carnivore ecology (Estes 1996). The real question is not whether 

 carnivores play important, unique roles in the natural functioning of ecosystems, but rather how they go about it, to 

 what degree, and at what scale (Mcch 1996). 



Wolves could function as a "keystone species," which exists at relatively low abundance, whose effect on its 

 community or ecosystem is relatively large and involves multiple trophic levels (Power et al. 1996, Estes 1996). 

 Despite the volumes of published literature on gray wolves, there is remarkably limited evidence of the precise 

 nature, degree, and mechanisms by which the species demonstrates ecosystem-level effects. 



Wolves kill ungulates, but the effects on ungulate populations are varied. Scavenging species, such as coyotes, 

 common ravens, and wolverines feed on wolf kills. A wide variety of scavengers and other carnivores benefit from 

 carrion being readily available year round, rather than just a pulse in the early spring because of winterkill (Stabler 

 et al. 2001 ). Wolves may directly or indirectly compete for food with other carnivores (e.g. mountain lion) by 

 selecting similar prey, or by usurping kills (Kunkel et al. 1999). Wolves have even been observed harassing grizzly 

 bears in an attempt to take over ungulate carcas.ses (D. Boyd pers. comm.). Wolves sometimes kill other carnivores, 

 such as mountain lions, coyotes, or grizzly bear cubs (White and Boyd 1989, Boyd and Nealc 1992, Arjo 1998, 

 Crabtree and Sheldon 1999). 



VALUES OF WOLVES IN MONTANA 



Biological 



Predatory mammals such as the gray wolf are probably vital to the integrity of many ecosystems (Estes 1996). 

 Interactions between top-level carnivores and prey species through evolutionary time has shaped and fine-tuned 

 each one morphologically and bchaviorally into what they are today. In the absence of those functional 

 relationships, ecological systems may not be balanced. 



Top-level carnivores may speed up nutrient cycling, provide carrion for other species, cull sick or weak animals, and 

 contribute to biological diversity. Broader habitat managcnicnl and conservation purposes arc also served by the 

 presence of large carnivores such as the gray wolf (Fritts et al. 1994). Providing and sustaining an adequate prey 



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