Methods for Determining Strategy Species

The U.S. Fish and Wildlife Service (USFWS) requires all State Wildlife Action Plans to designate “Species of Greatest Conservation Need” as well as to provide specific information about problems that may affect those species, information needed to improve conservation, and recommended conservation actions.

The Oregon Conservation Strategy uses the term “Strategy Species” to represent “Species of Greatest Conservation Need”, with the Strategy Species list developed to meet these requirements for Oregon. The Strategy identifies wildlife (amphibians, birds, mammals, and reptiles), fish, invertebrates, and plants and algae as Strategy Species, including species occurring within the nearshore.

Background

The original list of Strategy Species was developed by regional biologists and species experts in 2006. This was done by first creating a list of all declining species in Oregon, and then using spatial models of Oregon’s vegetation types to produce species-habitat associations that estimated the extent of habitat loss experienced by each species. The 2006 Strategy also identified “Data Gap Species”, defined as species that may be of conservation concern, but insufficient information was available to fully assess whether they met the Strategy Species criteria.

For the 2016 revision, all 2006 Strategy Species and Data Gap Species were reviewed and updated. The Oregon Department of Fish and Wildlife (ODFW) divisions and partner organizations took the lead on reviewing and updating the various taxonomic groups. The ODFW Wildlife Division updated the Wildlife (amphibians, birds, mammals, and reptiles) Strategy Species. The ODFW Fish Division updated the Fish Strategy Species. Experts from the Oregon Department of Agriculture (ODA), Oregon Biodiversity Information Center (ORBIC), the Xerces Society for Invertebrate Conservation, and independent species experts were consulted to update the Invertebrate Strategy Species. The ODA reviewed the Plant and Algae Strategy Species, with additional information provided by the Institute for Applied Ecology. Nearshore Strategy Species were updated by the ODFW Marine Program.

Although efforts were made to standardize criteria, available information and the conservation criteria for Strategy Species do vary between taxa.

Wildlife Strategy Species List

The ODFW’s Wildlife Conservation Program staff led a comprehensive review process for the Wildlife Strategy Species list, including amphibians, birds, mammals, and reptiles. The conservation criteria used were based on the original 2006 criteria. New scientific literature and available data were reviewed to determine whether to keep, remove, or add species to the Strategy Species list dependent on whether they met the conservation criteria. All 2006 Strategy Species were reviewed. The list of 2006 Data Gap Species, and species that experienced elevated conservation status (e.g., federal Endangered Species Act status, NatureServe Global or State Rank) during the 10 years were reviewed to determine whether they met the conservation criteria to be added as a 2016 Strategy Species or Data Gap Species.

Information from literature searches, agency and partner databases, and expert review was used to update the content associated with each Strategy Species, including: special needs, limiting factors, data gaps, recommended conservation actions, and key references. The ODFW consulted with species experts throughout Oregon to review and update the Wildlife Strategy Species list and information associated with each species.

Wildlife Strategy Species Conservation Criteria:

If three or more of the criteria below apply to a species within an ecoregion, the species may be considered a Wildlife Strategy Species:

1. Life history traits render the species vulnerable to potential threats, such as: low reproductive rates, low dispersal ability, dependence on uncommon or at-risk habitats and/or structures, or the species gathers in concentrations for some part of its life cycle, including nesting, roosting, or feeding sites.
2. Population size is small or greatly reduced from its historical population size, suggesting the species could become extirpated in much or all of the ecoregion.
3. The population is at-risk because it is: (a) declining in the ecoregion, and the ecoregion is especially important for conservation, or (b) declining statewide.
4. The species is at-risk because it has a restricted distribution. This includes species that:
   • are considered an ecoregion endemic or near-endemic (e.g., a notable proportion of the species’ range occurs in this ecoregion), or
   • have had a significant retraction from historical geographic range, or
   • represent a disjunct (isolated) population that is important to conservation of the species throughout its range.
5. Populations of this species are known (or strongly suspected) to be impacted by a Key Conservation Issue or major threat, including:
   • Climate Change (University of Washington Climate Change Vulnerability Assessment)
   • Land Use Changes (including renewable energy)
   • Water Quality and Quantity
   • Barriers to Animal Movement
   • Disruption of Disturbance Regimes (i.e., fire, flooding) or ecological processes (stream hydrology or nutrient flows)
   • Invasive Species
   • Other known threats to populations including: disease, predation, pollutants, hybridization, or parasitism

Fish Strategy Species List

The ODFW Fish Conservation and Recovery Program staff led the review for the Fish Strategy Species list. The comprehensive review was based on a number of criteria, which closely match the Wildlife Strategy Species Conservation Criteria. If a fish species or Species Management Unit (SMU) is listed under the Endangered Species Act as threatened or endangered, either at the state or federal level, it was automatically designated as a Strategy Species. Additionally, the ODFW updated the ODFW Sensitive Species List to inform the Conservation Strategy Species update, and any fish species that was designated as an ODFW Sensitive Species was also designated as a Strategy Species.

A variety of resources were used to update the Sensitive Species List. Status assessments in recently approved conservation and recovery plans were used. For species and SMUs with no recent written assessment or plan, ODFW staff used information from recent research or monitoring efforts (e.g., fish distribution and abundance surveys), prior listing on the Sensitive Species List, the 2005 Oregon Native Fish Status Report, or professional knowledge and judgment to determine the status. When applicable, ODFW staff consulted with partner scientists and agencies to help inform decisions.

To account for the lack of data and multiple sources of uncertainty (e.g., taxonomic, range, abundance) surrounding many of the non-game species, the conservation risk was assessed based on a rarity model that assesses species vulnerability to drought, wildfire, climate change, or nonnative fishes. The model data were sourced from the Oregon State University Fish Collection and expert opinion, including ODFW District Fish Biologists and researchers. Two metrics were developed to assess distribution or range. For the first metric, fish distribution was defined as narrow (limited) when a species was found in four or fewer districts and broad (widespread) when a species was found in 5-16 districts. For the second metric, fish distribution was defined as narrow if only “limited distribution” or “rare” status responses were received for a species and broad if a species was “widespread” or “common” in any district. An abundance metric was developed, where a “low” abundance score was assigned if the minimum district score for a species was 4-6 (limited, not locally abundant; rare; or unknown) and a “high” abundance score was assigned if the minimum district score for a species was 1-3 (widespread; common; or limited, but locally abundant).

A metric for habitat specificity was also developed, where fish were assigned to the “narrow” category if a species inhabited fewer than three of the five habitat types (i.e., large river, small river, creek, spring, lacustrine) and did not occupy both lowland and upland habitats, and to the “broad” category if the species inhabited three or more habitat types or occupied both lowland and upland habitats. The data for habitat types and elevation (upland, lowland, or both) were obtained from the online FishTraits.

The range/distribution, abundance, habitat specificity, and endemism (y/n) data for each species were then compiled and each fish was assigned to one of eight rarity categories (see figure below), according to Yu and Dobson (2000), based on distribution/range (high or low, assigned once for each of the two metrics), population abundance (high or low), and habitat specificity (broad or narrow).

 

Invertebrate Strategy Species List

The ODFW consulted with experts from the ODA, ORBIC, the Xerces Society for Invertebrate Conservation, and independent species experts to update the Invertebrate Strategy Species list and the information associated with each species. To the extent possible, the Wildlife Strategy Species Conservation Criteria were used to review invertebrate species. Over the past 10 years, more information has been gathered to indicate a lack of knowledge for many species, resulting in several species moved to Data Gap Species status.

Plant Strategy Species List

The ODFW consulted with the ODA’s Plant Conservation Program and with the Institute for Applied Ecology to consider new information and references for plant species. Numerous data gaps exist for plant species of conservation concern, and few surveys are conducted regularly. The list of Strategy Plants remains the same as the 2006 list; however, new information was incorporated regarding taxonomy, special needs, limiting factors, data gaps, recommended conservation actions, and key references.

Nearshore Strategy Species List

The ODFW Marine Program led the update process for Nearshore Strategy Species. Nearshore Strategy Species are species occurring within the Nearshore that were determined to be in greatest need of management attention. Identification as a Nearshore Strategy Species does not necessarily mean the species is in trouble. Rather, those identified as Nearshore Strategy Species have some significant nearshore management and/or conservation issue connected to that species that is of interest to resource managers.

Development of the 2016 Nearshore Strategy Species list began with a review of the original list of Nearshore Strategy Species developed a decade ago, including species that utilize the nearshore but that had only been included in the Oregon Conservation Strategy. The species that were still recognized as species of concern, at-risk, important, or a priority by federal or state agencies, stakeholders, experts, non-government organizations, scientific researchers, tribes, or other conservation processes were included on the revised list. In addition, a comprehensive list of species that occur in the nearshore was evaluated for potential new additions to the Nearshore Strategy Species list. To maintain a nearshore ecosystem focus, attention was focused on both harvested and non-harvested species that predominantly occur, or are common, within Oregon’s nearshore environment.

To assist with the identification of Nearshore Strategy Species, the following information was compiled from published literature, available online data, scientific databases, and personal communication from experts for each species on the list:

• taxonomic information
• distribution, including species geographic range and depth
• harvest/collection information, including sector(s) (commercial, sport, aquarium trade, and/or scientific/medical research) and whether targeted or incidental catch
• life history information, including mode of reproduction, fecundity, timing of reproduction, timing of egg/larval/juvenile stages, longevity, age at maturity, and migratory behavior or seasonal distribution
• habitat use for each life history stage
• trophic interactions, including prey, predators, and competition
• population status information, including whether a population assessment has been conducted and if the species is listed as overharvested, listed as threatened or endangered, has experienced a population decline, is rare, has small range, or is endemic, has specialized habitat requirements, or has low productivity

This information was used to help examine the conservation needs of each species with regards to four separate criteria, each weighted equally. Each species was evaluated for each of these four criteria to identify those species in greatest need of management attention:

1. Species status – examples of species status include overharvested, rare, declining population throughout its range or in Oregon.
2. Ecological importance – examples of ecological importance include habitat forming, habitat engineer, keystone species, or prey species.
3. Vulnerability to human or natural factors – examples of vulnerability include susceptible to oil spills or water pollution, life history traits render it particularly vulnerable (low productivity, specialized habitat requirements, climate change or ocean acidification effects, etc.), or there are significant data gaps or research needs on vulnerability for that species.
4. Economic/social/cultural importance – examples of importance to humans include commercially important, recreationally important, culturally important to Oregon tribes, and flagship or sentinel species.

Those species whose conservation needs were determined to best be met through existing management affecting habitats or communities of organisms were separated from the list. Through extensive examination, deliberation, and consultation with subject matter experts, 73 species were identified as Nearshore Strategy Species. These species, or distinct populations, were determined to have conservation needs in greatest need of management attention and to have the greatest potential for benefit from management actions.

The supplemental information on the special needs, limiting factors, data gaps, and conservation actions for each Nearshore Strategy Species is provided for use by managers, research and monitoring projects or programs, those producing education and outreach materials, planners, and the general public. Readers should note that management jurisdiction varies for each species. For instance, some Nearshore Strategy Species are managed by the ODFW, National Oceanic and Atmospheric Administration, and USFWS, and many species are under shared management authority by multiple resource agencies and institutions.