Species Assessment for Great Basin Spadefoot Toad (Spea Intermontana) in Wyoming
Author(s):Publication Date: 2005-01
Douglas A Keinath
Tags: BLM, WLCI Agency Report, WLCI
The Great Basin spadefoot toad (Spea intermontana) is currently recognized by the Canadian
government as a threatened species. In addition, some state agencies throughout its range
recognize S. intermontana as a sensitive species, often because too little is known about it to
provide evaluations on population status and viability throughout its range.
In the last couple of decades, amphibians around the world have experienced population
decline, range reduction, and even extinction. This observed trend has been attributed to habitat
degradation and loss, chemical pollution, acid precipitation, increased ultraviolet radiation,
introduced species, and pathogens, which all combine with the natural fluctuation of amphibian
populations to compound the affects. This has resulted in 18 amphibians being listed on the
United States federal endangered and threatened species list (one of which is in Wyoming), and it
is expected that this number will continue to rise. Given the dearth of information and a suspected decline in numbers, it is possible that S. intermontana may be of concern. Primary threats to S. intermontana are habitat alteration (aquatic and terrestrial), toxic chemicals, and invasive species.
Given the scarcity of recent observations in Wyoming, it is important to determine presence
and abundance of S. intermontana within the state. Once populations have been identified, it is
important to determine habitat associations in order to apply proper conservation management for
this species. Continual and consistent monitoring of known populations is recommended to help
define local populations, establish habitat-use, and evaluate conservation measures. Management actions should insure that key life history stages (terrestrial and aquatic) are not disturbed, the habitat connectivity is preserved for persistence of these populations, and exposure to potentially detrimental chemicals is eliminated. More specific issues of conservation concern are discussed in Buseck, Keinath, and Geraud - Spea intermontana greater detail later in this assessment. Fulfilling the information needs listed at the end of this document will clarify population status and contribute to refining these conservation goals.
This assessment addresses the biology, ecology, and conservation status of the Great Basin
spadefoot toad (Spea intermontana) throughout its current range, with particular attention given to
that portion occurring within and near Wyoming. Our goal is to provide a summary of published
information and expert interpretation of this information that can be used by the Bureau of Land
Management (BLM) to develop management plans. Spea intermontana was selected for
assessment because it occurs on the Wyoming BLM sensitive species list due to the lack of
biological and ecological information known about the species as a whole.
Relatively little is known about most S. intermontana populations and very few specifics of
this species and its habitat are available for Wyoming. Therefore, this assessment attempts to
summarize information documented throughout its North American range (mostly the Great
Basin), and provide an objective and informed overview in order to relate this information to S.
intermontana in Wyoming. Primary literature was the main source used, supplemented by various agency reports. As with all pieces of literature synthesized from disparate data, this assessment has some imitations. Since most data presented comes from specific studies with restricted research areas, interpolation and extrapolation of this data must be done with caution. It seems that aspects S. intermontana biology, ecology, and conservation vary over the geographic extent of its range. Therefore, the information in this assessment should not be taken as definitive of S. intermontana in any particular area. Rather, it should be used as a guide to the range of biological parameters Buseck, Keinath, and Geraud - Spea intermontana and behaviors possible for S. intermontana, which can then help direct specific investigation to clarify the status of local populations in Wyoming as a prelude to major management action.