The Use of Avian Focal Species for Conservation Planning in California1
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The Use of Avian Focal Species for Conservation Planning in California1 Mary K. Chase2 and Geoffrey R. Geupel2, 3 ________________________________________ Abstract Introduction Conservationists often try to facilitate the complex task of Protecting biological diversity is an extremely complex protecting biological diversity by choosing a subset of process, and conservationists often lack even the most species from a larger community to help them plan their basic data on which to base management and planning conservation objectives. Biological knowledge about decisions. Conservation planners often try to facilitate this these species then is used to plan reserve systems or to process by choosing a subset of species from a larger guide habitat restoration and management efforts, with the community to help them formulate their conservation assumption that the implementation of these recommen- objectives. Biological knowledge about these species then dations will maintain overall biodiversity. Partners in is used to plan reserve systems or to guide habitat Flight (PIF) is developing Bird Conservation Plans to set restoration and management efforts, with the assumption conservation priorities and specific objectives for bird that the implementation of these recommendations will populations and habitats throughout the United States. maintain overall biodiversity. Here, we use the general Many of these plans use focal species in some way. Here term “focal species” to describe any species chosen for we briefly review the issues surrounding the use of focal special attention in a multi-species planning effort. species in conservation planning, and present the focal Although the use of focal species has been criticized on species strategies being developed and implemented by both theoretical and empirical grounds, many conserva- Partners in Flight in California. California PIF created tion biologists believe that their use can be valuable if the focal species lists by identifying focal habitats, and then assumptions underlying their choice are stated explicitly selecting those species associated with important habitat and subjected to scientific testing (Caro and O’Doherty elements or ecosystem attributes, as well as those species 1999, Lindenmayer et al. 2002, Poiani et al. 2001, Soulé with special conservation needs. Thus, a suite of species 1995). was chosen whose requirements define different spatial at- tributes, habitat characteristics, and management regimes In the past, focal species often have been selected on the representative of a healthy system. This process resulted basis of their threatened or endangered status, largely in a diverse list of focal species for each habitat that because these species are given the strongest legal protec- includes both common and uncommon or rare species. tion. However, the species that are at the greatest risk are Because focal species lists are based on numerous not necessarily the most effective focal species (Franklin hypotheses and assumptions, these should be made as 1994). Partners in Flight (PIF) is developing Bird Conser- explicitly as possible and tested in ongoing monitoring vation Plans (BCPs) to set conservation priorities and studies as part of an adaptive management program. specific objectives for bird populations and habitats throughout the United States. Many of these plans use focal species in some way. Here we briefly review the issues surrounding the use of focal species in conservation Key words: adaptive management, bird conservation planning, and present the focal species strategies being plans, monitoring, surrogate species, umbrella species. developed and implemented by Partners in Flight in California, as well as in Oregon and Washington. The Uses of Focal Species in __________ Conservation Planning Focal species may be used to guide several components of 1 A version of this paper was presented at the Third Interna- conservation planning: (1) the selection and design of tional Partners in Flight Conference, March 20-24, 2002, habitat reserves, (2) habitat restoration and management, Asilomar Conference Grounds, California. 2 Point Reyes Bird Observatory Conservation Science, 4990 and (3) population monitoring, both of population trends Shoreline Highway, Stinson Beach, CA 94970-9701. over time and effects of management actions. Planning a 3 Corresponding author, e-mail: [email protected]. reserve system involves selecting which sites should be preserved and determining what their configuration USDA Forest Service Gen. Tech. Rep. PSW-GTR-191. 2005 130 Focal Species in Conservation – Chase and Geupel should be, for example, for size, shape, and connectivity. management involves treating management as a continual Thus, the distribution and ecological needs of one or more experiment in which the results of previous actions are focal species may be useful in site selection and reserve monitored and used to modify future management configuration, both of which are major foci of conserva- (Holling 1978, Ringold et al. 1996). Thus, focal species tion planning (Margules and Pressey 2000). However, to also can be monitored to test the effectiveness of ensure the persistence of biodiversity, conservation plan- management activities (Gibbs et al. 1999). ners must also identify effective forms of habitat restora- tion and active habitat management to maintain desired Clearly, a number of different classes of focal species conditions, both in habitat reserves and in working are needed to address such a variety of conservation landscapes. One way to accomplish this is to design goals. In table 1 we define several classes of focal restoration and management to benefit one or more focal species that are used or have been proposed for use in species. Monitoring is an essential companion to the other conservation planning. Caro and O’Doherty (1999) components of conservation planning, especially when provide a more in-depth review of focal species types management takes place in an adaptive manner. Adaptive and their characteristics. Table 1— Classes of focal species1 that are used or have been proposed for use in conservation planning. Focal species class Definition Flagship Species that attract the attention of the public and generate popular support for the conservation of their ecosystems (Caro and O’Doherty 1999). Keystone Species whose presence is especially crucial in maintaining the organization and diversity of their ecological communities (Mills et al. 1993). Special status Species that have been given special status as endangered, threatened, or “of special concern” by local or national governments. Indicator Organisms whose characteristics are used as an index of attributes too difficult, inconvenient, or expensive to measure for other species or environmental conditions of interest (Landres et al. 1988)2. Umbrella Species requiring large areas of habitat, which if given sufficient protection, will provide for the needs of a larger suite of species occupying the same habitat (Noss 1990)3. 1Here we use focal species as a general term to describe individual species chosen for special attention in a multi-species conservation effort. The term surrogate species also has been used for this purpose (but see Armstrong 2002). 2Indicator species can be further divided into health indicators, population indicators, and biodiversity indicators (Caro and O’Doherty 1999). 3Some authors use umbrella species in a more general manner to include any species whose protection provides for the needs of a larger suite of co-occurring species (e.g., Launer and Murphy 1994). The Pros and Cons of Focal Species consideration that is crucial given real-life time, log- istical, and funding constraints. The use of focal species has a number of advantages. First, planning and managing for the habitat require- However, there are a number of problems associated ments of every species present in a planning unit is with some uses of focal species (Landres et al. 1988, often impractical, if not impossible. Second, know- Lindenmayer et al. 2002). Here we discuss three ledge of the needs of individual species can help problematic uses of focal species. First, the use of direct ecosystem or landscape level planning indicator species (as defined in table 1) to assess (Simberloff 1998, Wilcove 1994). Third, the legal population trends of other species has been criticized protection assigned to species in the United States on the grounds that individual species have unique (rather than to higher levels of biodiversity, such as ecological requirements (Taper et al. 1995). Indeed, habitats, ecosystems, or landscapes) sets up a funding empirical studies have shown that population res- and incentive structure that is species-specific (Noss ponses to habitat change often cannot be extrapolated 1990). Fourth, some species are simply much more from one species to another, even within the same amenable to monitoring and research than others, a guild (Landres et al. 1988), or from one population to another of the same species (O’Conner 1991). USDA Forest Service Gen. Tech. Rep. PSW-GTR-191. 2005 131 Focal Species in Conservation – Chase and Geupel Second, the use of focal species to delineate habitat less reliable and more expensive (Landres et al. 1988, reserves also may be questionable if focal species do O’Conner 1992, Strong 1990). Even when an not reliably co-occur with a large proportion of other endangered species appears to be a good umbrella for species in the area of interest (Andelman and Fagan co-occurring