King Rail Evaluation

Part 1 COSSARO candidate species at risk evaluation form

June 2011
King Rail (Rallus elegans)

1.1 Current status and distribution

Current designations:

GRANK – G4 (NatureServe 2011)
NRANK Canada – N2B (NatureServe 2011)
COSEWIC – Endangered (May 2011). Endangered since 1994, most recently re-evaluated in May 2011 with no change in status.
SARA – Endangered (Schedule 1) (SARA Public Registry 2011)
ESA 2007 – Endangered
SRANK – S2B (NatureServe 2011)

Distribution in Ontario:

Patchily distributed along the southern Great Lakes shoreline from eastern Lake Ontario to Lake St. Clair, with a small number of more northern records to southern Georgian Bay and Lake Simcoe (Woodliffe 2005, COSEWIC 2011).

Distribution and status outside Ontario:

Occurs in eastern North America from southern Ontario south to interior Mexico and Cuba (COSEWIC 2011). Generally occurs in "fresh and brackish wetlands from the Gulf Coast to s. Ontario, and from the Atlantic Coast to about the l00^th meridian in the Great Plains" (Poole et al. 2005). Greatest densities in the Atlantic and Gulf Coast marshes, and the rice belts of Louisiana, Arkansas and Texas (Meanley 1969, from Zammit & Sutherland 2000).

Part 2 Eligibility for Ontario status assessment

2.1 Application of eligibility criteria

Taxonomic distinctness

Yes – Three subspecies recognized by some authorities – only one subspecies occurs in Canada (Rallus elegans elegans) (COSEWIC 2011). Closely related to Clapper Rail (R. longirostris), with which it is sometimes considered conspecific; both species are provisionally considered a superspecies (Poole et al. 2005).

Designatable units

Only one designatable unit – only one subspecies occurs in the southern Ontario range, no genetic or geographic evidence to suggest more than one DU (COSEWIC 2011).

Native status

Yes

Presence/absence

Present. Currently occurring in Ontario.

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

Not in any category. G4 (last reviewed 2002)

2. Global decline

Endangered. Long-term trend indicates a large to substantial decline (50-90%) (NatureServe 2011). Severe declines have been reported in the northern parts of its range in the U.S. (COSEWIC 2011, NatureServe 2011), and declines have been reported in all U.S. states except Florida (NatureServe 2011). Breeding Bird Survey (BBS) data indicate a significant (p<0.01) North American decline of 7.5% per year between 1966-2007 and a significant decline of 9.3% per year between 1980-2007 (COSEWIC 2011, Sauer et al. 2011), although there are limitations to the use of BBS data because of the species' low detectability. All reports appear to support an interpretation of a "generally recognized drastic population decline" globally, although there is little information on trend of populations outside of Canada and the United States.

3. Northeastern North America ranks

Endangered. Ranked as S1, S2, SH, or SX in 17 of 19 (89.5%) North American jurisdictions where it has been ranked as a breeding species. For this assessment, only breeding ranks were used.

4. Northeastern North America decline

Endangered. For 9 U.S. states near Canada where 2 breeding bird atlas projects have been completed at roughly 20 year intervals, the number of blocks where King Rails were detected decreased from 145 to 87, a 40% decrease over 20 years (data from Table 4 of COSEWIC 2011). For the Eastern Bird Region of the U.S. Fish & Wildlife Service, there was an overall decline of 5.29% per year between 1966 and 2009 (Sauer et al. 2011). Areas of "alarming" decline included the southwestern shore of Lake Erie, northwestern Iowa, Maryland, Delaware and Arkansas (Meanley 1969, NatureServe 2011). It is considered "critically imperiled" in the majority of U.S. states north of the Gulf coast (NatureServe 2011). All reports appear to support an interpretation of a "generally recognized drastic population decline" in northeastern North America.

5. Ontario occurrences

Special concern. There are 24 extant occurrences in the NHIC data base, and an additional 16 that are extirpated or historical (NHIC 2011). The species was recorded in 19 10 x 10 km squares during the most recent Ontario Breeding Bird Atlas (Woodliffe 2011). Based upon recent surveys, COSEWIC (2011) estimated that the current Ontario (Canadian) breeding population was likely between 30 and 50 pairs (60-100 mature individuals).

6. Ontario decline

Special concern. There are few data to allow an estimate of trend in Ontario, although the species was thought to be common in the marshes of Lake St. Clair, Lake Erie, and Prince Edward County in the late 1800's and early 1900's (Sandilands 2005, NHIC 2011). The wetlands of southwestern Ontario where the species was most common have experienced significant loss since historical times (COSEWIC 2011), estimated at a minimum of 52% in Prince Edward County and a maximum of 95% in Essex County (Sandilands 2005). The species is further known to have experienced drastic declines elsewhere in its northeastern North American and global range. NHIC data suggest that 33% of EOs may have been lost over time (24 extant, 16 historical or extirpated).

There was an increase from 16 to 19 in the number of 10 x 10 km atlas squares within which King Rails were recorded in the most recent Ontario Breeding Bird Atlas; however much of this increase appears to be due to survey efforts targeted on King Rail, and cannot be assumed to reflect a population increase (COSEWIC 2011, Woodliffe 2007).

7. Ontario’s conservation responsibility

Not in any category. Ontario makes up a very small proportion of the global breeding range and global population – an estimated 60-100 birds out of an estimated 70,000 birds (.06-0.14%) in Canada and the United States (COSEWIC 2011). The range proportion would be similar.

3.2 Application of secondary criteria (threats and vulnerability)

1. Population sustainability

Insufficient information. No population viability analysis has been conducted. There are very few confirmed breeding records (none in the past 2 decades [COSEWIC 2011]), however this is a secretive nesting species and this does not mean that breeding has not occurred.

2. Lack of regulatory protection for exploited wild populations

Not in any category. Currently protected as an Endangered species under the Endangered Species Act, 2007 and as a Schedule 1 Endangered species. Also protected under the federal Species at Risk Act. The Migratory Birds Hunting Regulations prohibit hunting in Canada. Incongruously, it can still be legally hunted in 13 U.S. states despite its rare status in many jurisdictions (COSEWIC 2011). As one example, Poole et al. (2005) reference Virginia where the hunting season is from Sept. 9 to Nov. 16 and the daily bag limit is 15. Ontario birds are potentially vulnerable to hunting in the U.S., although hunting pressure is estimated as very low and the King Rail harvest in the U.S. is estimated at 200-300 birds annually (Environment Canada 2010).

3. Direct threats

Threatened. Habitat loss and degradation is the primary threat through the draining, degradation and destruction of wetlands (COSEWIC 2011), and also for housing development (Environment Canada 2010). Cattail (Typha spp.) monocultures may significantly lower wetland quality for King Rails. Zammit and Sutherland (2000) estimated significant wetland loss in southern Ontario was a major factor in King Rail decline.

Other threats include collisions with man-made structures, pollutants, invasive plant species such as European Common Reed (Phragmites australis australis) and Purple Loosestrife (Lythrum salicaria), decreasing crayfish diversity and populations, and hunting in the U.S.A. (see section 2 above) (Environment Canada 2010, COSEWIC 2011). Invasive wildlife species such as Mute Swan (Cygnus olor) and Common Carp (Cyprinus carpio) are also of concern (Environment Canada 2010). West Nile Virus has been found in other rail species, and is suspected to be a concern for this species (COSEWIC 2011).

The 2010 Gulf of Mexico oil spill may be a threat, as wintering King Rails may be concentrated in the Gulf coast states; however King Rails are usually found in freshwater or brackish wetlands rather than saltwater marshes (COSEWIC 2011).

4. Specialized life history or habitat-use characteristics

Not in any category. Wetlands are increasingly rare in southern Ontario. The King Rail is a wetland specialist, but will use a wide diversity of freshwater and brackish wetland types (Poole et al. 2005). This species prefers wetlands that are shallower and with a greater cover of emergent vegetation than for wetlands favoured by most waterfowl (NatureServe 2011). The species prefers a complex of floodplain wetland habitats that include "hummocky topography and natural swales" (Poole et al. 2005).

3.3 COSSARO evaluation results (primary/secondary)

1. Criteria satisfied in each status category

• Endangered – [3/0]
• Threatened – [0/1]
• Special concern – [2/0]

Number of Ontario-specific criteria met in each status category (primary criteria numbers 5, 6 and 7)

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

2. Data deficiency

No.

3. Status based on COSSARO evaluation criteria

The application of COSSARO evaluation criteria suggests that King Rail is Threatened 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– Insufficient monitoring data, difficulty of species detectability

Criterion B – Small distribution range and decline or fluctuation

Not in any category

Criterion C – Small and declining number of mature individuals

Endangered (C2ai) - Number of mature individuals <2500 (60-100), a continuing decline inferred based upon long-term global trends and continuing habitat pressures, and no population contains more than 250 mature individuals. Note that COSEWIC (2011) did not consider this criterion to be met.

Criterion D – Very small or restricted total population

Endangered (D1) – Number of mature individuals estimated to be <250 (60-100).

Criterion E – Quantitative analysis

Insufficient information. No population viability analysis has been conducted, although the population is very small (100 individuals). Breeding has not been confirmed for more than 2 decades, although this does not mean that breeding is not occurring due to the elusive nature of the species.

Rescue effect

Unlikely. King Rail is a migratory species and breeds in neighbouring jurisdictions and therefore is potentially capable of recolonizing on its own. However it is designated as Threatened or Endangered in all adjacent U.S. states (COSEWIC 2011) and thus rescue potential from populations to the south is very limited.

Consideration of special concern status

Not applicable.

4.2 COSEWIC evaluation results

1. Criteria satisfied in each status category

Indicate whether or not a criterion is satisfied in each of the status categories.

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

2. Data deficiency

No.

3. Status based on COSEWIC evaluation criteria

The application of COSEWIC evaluation criteria suggests that King Rail 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. No

The COSSARO criteria suggest a designation of Threatened for King Rail in Ontario because the Endangered designation is not met for any Ontario-specific primary criterion or any secondary criteria. However, this is clearly a very imperiled species with 50 or fewer breeding pairs. The interpretation of a breeding pair as an extant occurrence under the "Ontario Occurrence" criterion likely overestimates the robustness of the provincial population, as a breeding pair is not analogous to a breeding population. Additionally, it is reasonable to infer under the "Ontario Decline" category that the species has declined and is absent from a greater number of documented locations than has been documented, due to the species' reclusive nature and difficulty in surveying, and the extensive loss of wetland habitat that has occurred across southern Ontario, although the actual quantitative data to support this conclusion are not available. For both of these criteria, the available data suggest a "Special Concern" designation which does not appear to adequately reflect the species' precarious status.

The COSEWIC criteria clearly support a designation of Endangered for King Rail, based upon both Criteria C (Small and Declining Number of Mature individuals) and D (very Small or Restricted Total Population). These criteria are analogous to the 2 COSSARO criteria referenced above, and in the opinion of COSSARO more accurately reflect the actual status of King Rail in Ontario. Additionally, the species is currently designated as Endangered both nationally and provincially, and there is no information to suggest that the status of the species has actually improved in recent years.

5.2 Summary of status evaluation

King Rail is classified as Endangered in Ontario.

The King Rail (Rallus elegans) is a large rail species that breeds in marsh wetland complexes in parts of eastern North America, particularly the southeast. In Canada and Ontario, it occurs only in southern Ontario, primarily in the Lake St. Clair-Walpole Island area but also elsewhere including some recently documented occurrences in the Prince Edward County area. Although ranked as G4 globally, it has declined in every Canadian and U.S. jurisdiction except for Florida, and is considered critically imperiled in many U.S. states north of the Gulf coast. Population trends are difficult to determine for Ontario, given the species' limited distribution and secretive habits; it was actually found in more 10 x 10 km atlas squares during the second Ontario Breeding Bird Atlas than during the first, but this is likely due primarily to an increased targeted effort to monitor this species. Wetland loss appears to be the primary driver for this species' declining status, although other human threats include collisions with mad-made structures, invasive plant species, and possibly declining crayfish populations and West Nile Virus. The future of this species is closely tied to the future of wetlands, particularly freshwater marshes. There is limited rescue potential, given the species' declining status, especially in immediately adjacent jurisdictions. The long-term decline, Ontario rarity, declining status in many adjacent jurisdictions and relative rarity of marsh habitats support a continued designation of Endangered for this species.

Information sources

1. Literature cited

COSEWIC. 2010. Updated COSEWIC status report on King Rail (Rallus elegans) in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. viii + 33 pp.

Environment Canada. 2010. Recovery strategy for the King Rail (Rallus elegans) in Canada [Proposed]. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. vi + 21 pp.

Meanley, B. 1969. Natural history of the King Rail. U.S. Department of the Interior, Bureau of Sport Fisheries and Wildlife: North American Fauna No. 67, Washington, D.C.

MNR, 2011. Ministry of Natural Resources. Species at Risk Website. [/page/species-risk]. Accessed May 26 2011.

NatureServe 2011. NatureServe Explorer: an Online Encyclopedia of Life. [http://www.natureserve.org/explorer/]. Accessed May 26 2011.

NHIC. 2011. Species Report for Rallus elegans (King Rail). Ontario Natural Heritage Information Centre website [/page/king-rail]. Accessed May 26 2011.

Poole, Alan F., L. R. Bevier, C. A. Marantz and Brooke Meanley. 2005. King Rail (Rallus elegans), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/003 doi:10.2173/bna.3 [link inactive]

Sandilands, A. 2005. The birds of Ontario: habitat requirements, limiting factors and status. UBC Press, Vancouver. 365 pp.

Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, D. J. Ziolkowski, Jr., and W. A. Link. 2011. The North American Breeding Bird Survey, Results and Analysis 1966–2009. Version 3.23.2011 USGS Patuxent Wildlife Research Center, Laurel, MD

Species at Risk Public Registry, 2011. [http://www.sararegistry.gc.ca/]. Accessed May 26 2011.

Wild Species, 2005. General Status Search Tool. [http://www.wildspecies.ca/wildspecies2005/search.cfm?lang=e&sec=9] [link inactive]. Accessed May 26 2011.

Woodliffe, A. 2007. King Rail – Rallus elegans. Pp. 198-99 in Atlas of the Breeding Birds of Ontario, 2001-2005. Edited by M.D. Cadman, D.A. Sutherland, G.G. Beck, D. Lepage, and A.R. Couturier. Published by Bird Studies Canada, Environment Canada, Ontario Field Ornithologists, Ontario Ministry of Natural Resources and Ontario Nature. 706 pp.

Zammit. A.E. and D.A. Sutherland 2000. COSSARO candidate V, T, E species evaluation form for King Rail (Rallus elegans). Natural Heritage Information Centre, Ontario Ministry of Natural Resources, Peterborough ON. 15 pp.

2. Community and Aboriginal traditional knowledge sources

None received

3. Acknowledgements

We would like to acknowledge the assistance of Mike Oldham and Tanya Taylor with the interpretation of NHIC data records.

Appendix 1 Northeastern North America rank, status and decline

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

Occurs as a native breeding species in 19 of 29 northeastern jurisdictions Breeding SRANK or equivalent information available for 19 of 19 jurisdictions = 100 % S1, S2, SH, or SX in 17 of 19 = 89.5 %