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| Hungerford’s crawling water beetle (Brychius hungerfordi)5-Year Review: Summary and EvaluationBelow are the General Information, Synthesis, and Results portions of the Five-Year Review. Go here for the complete 17-page Review (PDF).
1.0 GENERAL INFORMATION
1.1 Reviewers
1.2 Methodology used to complete the review: In coordination with the Midwest Region – Ecological Services staff, the East Lansing Field Office solicited information from the public through a Federal Register notice (70 FR 41424). To complete the Review, we relied on the recovery plan because it is the most recent collection of information on the species and has undergone prior peer review, and evaluated all information and data that has become available on the species since its listing in 1994.
1.3 Background
2.0 REVIEW ANALYSIS2.4 Synthesis Presence has been documented in a few additional locations within the previously known range since listing. Numbers of beetles at these sites, however, are typically very small (only one or a few beetles found periodically). Of the six occupied streams, only one has consistently had large numbers.
Although there are only a few known occurrences, additional survey efforts would likely result in new occurrences. In general, species of Brychius are typically localized and difficult to collect (Mousseau 2004). The adults are very small and inconspicuous, and tend to hide under cobbles and in vegetation along the bottom. As a result, some surveys may not have detected the species when it is, in fact, present. In any case, survey work since listing has not been extensive, but the beetle has been discovered in three additional streams and in a greater extent of known streams. Although there are a number of similarities among the occupied sites, many have unique habitat characteristics. In fact, it is uncertain what characteristics are important to determine suitable habitat for this species, as some sites are markedly different (see USFWS 2006a for more information). The variations described for occupied sites hint that the species may not be restricted to a narrow range of habitat characteristics.
Threats to this species include stream modification, logging in riparian areas, and certain types of fish management activities. In spite of a considerable list of potential threats, very few documented adverse events are known to have occurred to this species since its discovery (1952) or since listing (1994). Nevertheless, the existence of only six small, geographically isolated occurrences seems to be a major threat to this species by increasing the risk of extinction due to stochastic events. Additional information about this species is needed to better understand threats and factors limiting this species.
At this time, the greatest threat to recovery of this species remains the lack of information on ecology and natural history. Additional information is needed on resource requirements and microhabitat preferences, life history (e.g., diet, demographics, and location, timing and duration of larval, pupal, and adult stages, oviposition location and timing), and population dynamics. This information will allow us to better assess threats, identify additional recovery actions, and develop measurable recovery criteria.
No new information is available to suggest this species’ status has changed since listing, and its long-term status appears to be stable. There is little information on this species, including information on life history, ecology, population biology, and habitat requirements; but, it appears that this species has not declined since discovery and listing. The small numbers of this species, its limited distribution, and continuing threats indicate that Hungerford’s crawling water beetle warrants endangered status.
3.0 RESULTS 3.1 Recommended Classification:
3.2 New Recovery Priority Number: no change
3.3 Listing and Reclassification Priority Number: Not Applicable
4.0 RECOMMENDATIONS FOR FUTURE ACTIONS
Above are the General Information, Synthesis, and Results portions of the Five-Year Review. Go here for the complete 17-page Review (PDF).
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Last updated:
January 3, 2013
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