Skinner’s Agalinis Evaluation

Assessed by COSSARO as Endangered
February 2011

Part 1: COSSARO candidate species at risk evaluation form

Skinner’s Agalinis (Agalinis skinneriana)

Current designations:

GRANK – G3G4
NRANK Canada – N1
COSEWIC – Endangered (November 2010).
SARA – Endangered (SARA Public Registry 2011).
ESA 2007 – Endangered (OMNR 2010).
SRANK – S1 (OMNR 2011).

Distribution and status outside Ontario:

Skinner’s Agalinis is widespread through much of the midwestern and southcentral United States, reaching its northern limits in extreme southwestern Ontario. It is rare throughout its range (NatureServe 2011).

Distribution and status in Ontario

Restricted in Ontario to two areas in southwestern Ontario. During 2008 fieldwork for the Update COSEWIC Status Report Skinner’s Agalinis was observed only on Walpole Island First Nation. A population at LaSalle may persist though was not observed in 2008 (COSEWIC 2010).

Eligibility criteria

Native status

Yes. First collected in Ontario in 1904 and considered native to the province in all floristic lists.

Taxonomic distinctness

Yes. Taxonomically distinct and considered a valid species in all recent taxonomic treatments. No subspecies or varieties are recognized (COSEWIC 2010).

Designatable units

The species comprises a single designatable unit in Ontario because no infraspecific taxa are recognized and the species occurs within a very restricted geographical area within a single ecological area (Great Lakes Plains or Carolinian Zone).

Primary criteria (rarity and declines)

1. Global rank

TH. G3G4 (NatureServe 2011).

2. Global decline

Not in any category. This species has likely declined over a large portion of its range and only in Missouri (S3S4) is it locally common. "All evidence at hand suggests that loss of habitat, the degradation of habitat, and the suppression of natural disturbance regimes are the principle (sic) reasons behind the rarity of this species" (NatureServe 2010). According to NatureServe (2010) Skinner’s Agalinis has undergone a global decline of 10-30%, which is not sufficient to meet COSSARO's threshold (30%) for this criterion.

3. Northeastern North America ranks

EN. Highly ranked (S1, S2, SH or SX) in 9 of 9 (100%) northeastern jurisdictions in which it occurs as a native and is ranked.

4. Northeastern North America decline

TH. Although this species has likely declined in northeastern North America since it is ranked SH, S1, or S2 in all northeastern jurisdictions (Appendix 1), there is no quantification of this decline. In the northeast this is primarily a species of prairies, a habitat that has declined greatly in the region. Declines have been reported in several northeastern jurisdictions, including Illinois, Indiana, and Michigan (Appendix 1), suggesting that a serious regional population decline has occurred in northeastern North America. Tallgrass prairies and savannas are some of the most endangered ecological communities in Canada, with approximately one percent of their original extent remaining (Rodger 1998).

5. Ontario occurrences

EN. Known from six Ontario occurrences, one of which is likely extirpated and three others may be extirpated (COSEWIC 2010).

6. Ontario decline

TH. During 2008 fieldwork for the COSEWIC status report plants were seen at only two of six localities (COSEWIC 2010), representing a 67% decline if the other four localities are extirpated. It is difficult to be certain that populations are extirpated in this annual species, since populations may persist in the seed bank. Plants are relatively small, flower for only a short period, and numbers fluctuate, so it is possible that populations could be overlooked, particularly in years of poor flowering.

7. Ontario’s conservation responsibility

Not in any category. Ontario makes up only a small fraction of the species global range (COSEWIC 2010).

Secondary criteria (threats and vulnerability)

1. Population sustainability

Not in any category. Population size and trend information is difficult to determine in this species. Populations are known to fluctuate from year to year (COSEWIC 2010).

2. Lack of regulatory protection for exploited wild populations

Not in any category. No known harvest in Ontario.

3. Direct threats

EN. The prairie habitat occupied by this species in Ontario is threatened by a variety of factors such as lack of fire, encroachment by woody species, housing development, invasive species (White Sweet Clover), trampling, and changes in water level (COSEWIC 2010). One or more of these threats are present at all Ontario populations.

4. Specialized life history or habitat-use characteristics

EN. In Ontario Agalinis skinneriana occupies tallgrass prairie remnants. Tallgrass Prairie community types are ranked S1 in Ontario (Bakowsky 1996). Agalinis skinneriana is a hemiparasite whose host(s) were unknown (Canne-Hilliker 1988). The prairie grass, Little Bluestem (Schizachyrium scoparium), has recently been confirmed as a host plant on Walpole Island (J.M. Bowles pers. comm. Feb. 2011).

COSSARO criteria met (primary/secondary)

Endangered – 2/2
Threatened – 3/0
Special concern – 0/0

Ontario criteria met (primary 5, 6, and 7)

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

Recommended Status: Endangered.

Summary

Skinner’s Agalinis (Agalinis skinneriana) is Endangered. This globally rare (G3G4) annual species of tallgrass prairie currently occurs as two populations in Ontario, both on Walpole Island. Another population near Windsor, although not seen in 2008, may still be extant. Several populations have apparently disappeared and those remaining are threatened by a variety of factors. This plant is a hemiparasite, and Little Bluestem is one known host species. The disappearance of previously known populations and continuing threats account for the Endangered status.

Information sources

Bakowsky, W.D. 1996. Natural Heritage Resources of Ontario: Vegetation Communities of Southern Ontario. Natural Heritage Information Centre, Ontario Ministry of Natural Resources, Peterborough, Ontario. 21 pp.

Bowles, J.M. 2011. Personal communication. February 2011.

Canne-Hilliker, J.M. 1988. Status Report on the Skinner’s Purple False Foxglove Agalinis skinneriana. Committee on the Status of Endangered Wildlife In Canada (COSEWIC), Ottawa, Ontario. 26 pp.

COSEWIC. 2010. Update COSEWIC Status Report on Skinner’s Agalinis Agalinis skinneriana in Canada. Committee on the Status of Endangered Wildlife in Canada, Ottawa. Two-month Interim Report (Nov. 2010). 22 pp.

COSEWIC. 2011. Wildlife Species Search – Skinner’s Agalinis. Committee on the Status of Endangered Wildlife in Canada website. http://www.cosewic.gc.ca/eng/sct1/index_e.cfm (accessed 31 Jan. 2011).

NatureServe. 2011. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.1. NatureServe, Arlington, Virginia. Available http://www.natureserve.org/explorer. (Accessed: 31 Jan. 2011).

Oldham, M.J. 1995. COSSARO Candidate V, T, E Species Evaluation Form for Skinner’s Agalinis (Agalinis skinneriana). Ontario Ministry of Natural Resources, Peterborough, Ontario. 6 pp.

Oldham, M.J. 1999. COSSARO Candidate V, T, E Species Evaluation Form for Skinner’s Agalinis (Agalinis skinneriana). Ontario Ministry of Natural Resources, Peterborough, Ontario. 7 pp.

Ontario Ministry of Natural Resources (OMNR). 2010. Species At Risk in Ontario (SARO) list (updated September 29, 2010). http://www.mnr.gov.on.ca/en/Business/Species/2ColumnSubPage/276722.html (accessed 31 January 2011)

Ontario Ministry of Natural Resources (OMNR). 2011. Natural Heritage Information Centre (NHIC), Ontario Biodiversity Explorer website. https://www.biodiversityexplorer.mnr.gov.on.ca/nhicWEB/mainSubmit.do (accessed 31 January 2011) [link no longer active]

Rodger, L. 1998. Tallgrass Communities of Southern Ontario: A Recovery Plan. Prepared for World Wildlife Fund Canada and the Ontario Ministry of Natural Resources, February 1998. 66 pp.

Species at Risk Act (SARA) Public Registry, 2011. [http://www.sararegistry.gc.ca/default_e.cfm]. (Accessed 31 Jan. 2011).

Appendix 1

Northeastern North America rank, status and decline

Occurs as a native species in 9 of 29 northeastern jurisdictions SRANK or equivalent information available for 9 of 9 jurisdictions = (100%) S1, S2, SH, or SX in 9 of 9 = (100%)

Part 2: Ontario evaluation using COSEWIC criteria

Regional (Ontario) COSEWIC criteria assessment

Criterion A – Declining population

Insufficient information. Declines are difficult to assess due to population fluctuations. There has been a possible decline since some populations have been lost, however the documented decline is not sufficient to meet this criterion.

Criterion B – Small distribution and decline or fluctuation

EN B1ab (i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v). Index of Area of Occupancy (IAO) and Extent of Occurrence (EO) are well below Endangered thresholds. Known from <5 sites (2 sites). Not severely fragmented. Projected continuing decline in EO, IAO, habitat quality, number of individuals, populations and locations.

Criterion C – Small population size and decline

N/A. >10,000 mature individuals.

Criterion D – Very small or restricted

TH D2. Number of mature individuals is >1,000. The IAO in Canada is 20 km² (using 2X2 grid), which is the Threatened threshold. Presumably the criterion is < or = 20 km². Number of locations <5. There are identified threats.

Criterion E – Quantitative analysis

Insufficient information. No quantitative analysis available.

Rescue effect

No. Unlikely to be rescued from adjacent jurisdictions since the species is restricted to a rare habitat, is rare in adjacent jurisdictions, and separated from U.S. populations by major water bodies.