Hungerford’s Crawling Water Beetle Evaluation

COSSARO Candidate Species at Risk Evaluation for Hungerford’s Crawling Water Beetle (Brychius hungerfordi)

Committee on the Status of Species at Risk in Ontario (COSSARO) Assessed by COSSARO as Endangered

May 2011
Final

Part 1 - Current status and distribution

Current designations:

GRANK – G1 (Assessed 14/04/2009) (NatureServe, accessed 27/05/2011)
NRANK Canada – N1 (NatureServe, accessed 27/05/2011)
COSEWIC – Endangered (May 2011)
SARA – NA (Environment Canada 2011)
ESA 2007 – NA (Ministry of Natural Resources 2011)
SRANK – S1 (NatureServe, accessed 27/05/2011)

Distribution in Ontario:

Ontario has all known Canadian populations of Hungerford’s Crawling Beetle. The known distribution is limited to 3 known sites in Bruce County where the species has been collected: the Rankin, North Saugeen and Saugeen rivers. Only 2 may be extant (COSEWIC 2011a). Both general and directed field surveys in Bruce and adjacent counties over a 3 decade period support the conclusion that the species is very rare and that few if any other populations exist (COSEWIC 2011a).

Distribution and status outside Ontario:

Hungerford’s Crawling Water Beetle is endemic to the Great Lakes region and is found only in Ontario and in five streams in the northern Lower Peninsula of Michigan (COSEWIC 2011a).

Part 2 - Eligibility for Ontario status assessment

2.1 Application of eligibility criteria

Taxonomic distinctness

Yes. This is a distinct species with no subspecies or species forms (COSEWIC 2011a).

Designatable Units

There is a single DU. All Canadian populations are within the Great Lakes Upper St. Lawrence National Freshwater Biogeographic Zone and there are no known distinctions between populations.

Native status

Yes. The species is native and endemic to the Great Lakes basin. It was first documented in 1986 but is not considered a recent arrival – a glacial relict (COSEWIC 2011a).

Presence/absence

Present.

2.2 Eligibility results

1. The putative taxon or DU is valid. Yes.
2. The taxon or DU is native to Ontario. Yes.
3. The taxon or DU is present in Ontario, extirpated from Ontario or extinct? Present.

Part 3 - Ontario status based on COSSARO evaluation criteria

3.1 Application of primary criteria (rarity and declines)

1. Global rank

Endangered.

2. Global decline

Not in any category. Short-term global decline of 10-30%, long-term global trend unknown (NatureServe 2011). While clearly a rare species of limited distribution, long- term trends are unknown. One Ontario population out of a known global population of 8 streams may have disappeared in recent years (12.5%). As a glacial relict, it appears that it became increasingly rare and isolated, and nearly extirpated in post-glacial times as a result of natural forces (COSEWIC 2011a). It is listed as endangered in both the United States and Michigan.

3. Northeastern North America ranks

Endangered. Ranked as S1 in the 2 North American jurisdictions where it occurs (Ontario, Michigan).

4. Northeastern North America decline

Not in any category. As for global decline (above), there has been a short-term decline of 10-30%, but the long-term trend is unknown (NatureServe 2011). One population out of 8 known northeastern North American populations may have disappeared (12.5%).

5. Ontario occurrences

Endangered. Element Occurrences have not yet been documented for Hungerford’s Crawling Water Beetle in the NHIC's data base. There are 3 known sites in Ontario where the species has occurred - Rankin, North Saugeen and Saugeen rivers – although only 2 may be extant.

6. Ontario decline

Special concern. One of the 3 known Ontario sites appears to have been lost since 1986 despite repeated sampling efforts (COSEWIC 2011a), an inferred decline of 33%.

7. Ontario’s conservation responsibility

Endangered. Ontario makes up an estimated 40% of the global distribution (COSEWIC 2011a). Ontario contains 37.5 % of the rivers containing Hungerford’s Crawling Water Beetle populations (3 of 8) (COSEWIC 2011a).

3.2 Application of secondary criteria (threats and vulnerability)

8. Population sustainability

Insufficient information. No population viability analysis has been conducted. There is limited information on population trends or fluctuations, as well as on population and reproductive biology.

9. Lack of regulatory protection for exploited wild populations

Not in any category. Not currently protected under any provincial legislation, however there is no indication that there is any exploitation that could lead to a risk of serious decline or extirpation from overuse. Collection threat is believed to be minimal (COSEWIC 2011a).

10. Direct threats

Special concern. Habitat requirements are not well understood and thus habitat- related threats are somewhat uncertain. Threats are believed to include activities that cause the degradation of water quality, disruption of required pool and riffle habitat, alterations to stream flow, Beaver (Castor canadensis) control and dam removal (COSEWIC 2011a), and potentially predation by introduced fish such as Brown Trout (Salmo trutta) (NatureServe 2011). Geographically-specific threats that have been identified include "further planned developments at the North Saugeen and Saugeen River locations", "hydrological alterations at the Rankin River location", and "continuing declines in water quality due to events associated with increasing human populations at all locations" (COSEWIC 2011b). This species can be considered at a high risk from environmental change or disturbance given its restricted occurrence and recognition that "until more is known about the biology of this species, wise management will simply be the protection of both the physical and chemical components of its habitat and protection against unnatural levels of predation" (Wilsmann and Strand 1990, from Hyde and Smar 2000).

11. Specialized life history or habitat-use characteristics

Special concern. As an "early postglacial relict" restricted to "cool rivers in the upper Great Lakes in the Michigan region of occurrence", this species is not expected to be found outside of the watersheds within which it is known to occur (COSEWIC 2011a). The larvae appear to be reliant upon the presence of the algae Dichotomosiphon for food (COSEWIC 2011a).

3.3 COSSARO evaluation results

1. Criteria satisfied in each status category

Number of primary and secondary criteria met in each status category:

Endangered – [4/0]
Threatened – [0/2]
Special concern – [1/0]

Number of Ontario-specific criteria met in each status category:

Endangered – [2]
Threatened – [0]
Special concern – [1]

2. Data deficiency

No. There is sufficient information on which to base an evaluation, however there is limited information on population trends, biology, habitat requirements and threats.

3. Status based on COSSARO evaluation criteria

The application of COSSARO evaluation criteria suggests that Hungerford’s Crawling Water Beetle is Endangered in Ontario.

Part 4 - Ontario status based on COSEWIC evaluation criteria

4.1 Application of COSEWIC criteria

Regional (Ontario) COSEWIC criteria assessment

Criterion A – decline in total number of mature individuals

Insufficient information. Sufficient information not available on population size and trend

Criterion B – Small distribution range and decline or fluctuation

Endangered [B1ab(iii, iv) and B2ab(iii, iv)]. Small extent of occurrence (36 km²) and area of occupancy (12 km²), known to exist at only 3 locations, and apparent loss of 1 of the 3 known locations.

Criterion C – Small and declining number of mature individuals

Insufficient information. Sufficient information on population size and trend not available.

Criterion D – Very small or restricted total population

Threatened. Area of occupancy (12 km²) and number of populations are both below the thresholds, and remaining populations are vulnerable to stochastic or human habitat change that could threaten the species with extirpation in Ontario.

Criterion E – Quantitative analysis

Not applicable. No quantitative analysis available.

Rescue effect

No. Adjacent populations in Michigan are 230 km away and separated by Lake Huron (COSEWIC 2011a). Dispersal potential of the species is not well understood.

Consideration of Special Concern Status

No.

4.2 COSEWIC Evaluation results

1. Criteria satisfied in each status category

Endangered – [yes]
Threatened – [yes]
Special concern – [no]

2. Data deficiency

No.

3. Status based on COSEWIC evaluation criteria

The application of COSEWIC evaluation criteria suggests that Hungerford’s Crawling Water Beetle is Endangered in Ontario.

Part 5 - Ontario status determination

5.1 Application of COSSARO and COSEWIC criteria

COSSARO and COSEWIC criteria give the same result. Yes.

5.2 Summary of status evaluation

Hungerford’s Crawling Water Beetle is classified as Endangered in Ontario. Hungerford’s Crawling Water Beetle is a small beetle found in small to medium-sized streams with high quality, fast-flowing water, often immediately downstream from beaver dams, hydro-electric dams and culverts. It is a globally rare glacial relict that is endemic to the Great Lakes region. Its range is restricted to only 3 rivers in Bruce County, Ontario and 5 in northern Michigan, with limited potential for additional populations to be found. There is limited information on population trends, although it appears that it may have been extirpated from one of the 3 rivers in which it occurred in Ontario. Threats are not fully understood, but primary threats are believed to be hydrological changes, predation by introduced fish species and degraded water quality. The species' globally restricted range, limited number of occurrences and high conservation responsibility for Ontario, and continued threats to the aquatic environment support a designation of Endangered for this species.

Information Sources

1. Literature cited

COSEWIC. 2011a. COSEWIC status report on Hungerford’s Crawling Water Beetle (Brychius hungerfordi) in Canada. Committee on the Status of Endangered Wildlife in Canada, 2-month Interim Status Report. Ottawa. x + 44 pp.

COSEWIC, 2011b. Wildlife Species Search; Crawling Water Beetle, Hungerford’s / Wildlife Species Search; Crawling Water Beetle, Hungerford’s / Brychius hungerfordi. Last update 2010-05-06. 1 pp.

Hyde, D. and M. Smar. 2000. Special animal abstract for Brychius hungerfordi (Hungerford’s crawling water beetle), Michigan Natural Features Inventory, MI. 4 pp.

NatureServe 2011. NatureServe Explorer: an Online Encyclopedia of Life. [http://www.natureserve.org/explorer/]. Accessed May 27 2011.

Wilsmann, L.A. and R.M. Strand. 1990. A status survey of Brychius hungerfordi (Coleoptera: Haliplidae) in Michigan. Report to U.S. Fish & Wildlife Service, Fort Snelling, MN. 49 pp.

2. Community and Aboriginal traditional knowledge sources

No sources used for this report.

3. Acknowledgements

None.

Appendix 1 – Hungerford’s Crawling Water Beetle G1

Northeastern North America rank, status and decline

(NatureServe 2011)^{footnote 1[1]}

Occurs as a native species in 2 of 29 northeastern jurisdictions

SRANK or equivalent information available for 2 of 2 jurisdictions = 100 %

S1, S2, SH, or SX in 2 of 2 = 100 %