COSEWIC Status Appraisal Summary on the Furbish’s Lousewort Pedicularis furbishiae in Canada
COSEWIC status appraisal summaries are working documents used in assigning the status of wildlife species suspected of being at risk in Canada. This document may be cited as follows:
COSEWIC. 2011. COSEWIC status appraisal summary on Furbish’s Lousewort Pedicularis furbishiae in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xvi pp. (Species at Risk Status Reports)
Production note: COSEWIC acknowledges Maureen Toner for writing the status appraisal summary on the Furbish’s Lousewort Pedicularis furbishiae in Canada. This status appraisal summary was overseen and edited by Erich Haber and Bruce Bennett, Co-chairs of the COSEWIC Vascular Plants Specialist Subcommittee.
For additional copies contact:
COSEWIC Secretariat c/o Canadian Wildlife Service Environment Canada Ottawa, ON K1A 0H3
Reason for designation: This plant exists at low numbers in a dynamic and restricted habitat along the Saint John River in New Brunswick. Changes to river dynamics, land clearing of buffer trees, recreational activities, and the introduction of invasive species have resulted in continuing population decline at the existing sites.
Occurrence: New Brunswick
Status history: Designated Endangered in April 1980. Status re-examined and confirmed Endangered in April 1998, May 2000, and May 2011.
Reason for designation at last assessment: Highly restricted range with natural and human-induced habitat loss and significant population decline at the three remaining sites.
Criteria applied at last assessment: B1 + 2e + 3d; C2a
Alpha-numeric criteria of 2000: 3 localities, continuing decline in number of mature individuals and fluctuating number of mature individuals and all populations <250 plants. Note: it is uncertain whether rescue of Canadian populations was taken into account when designated as Endangered since there are larger American populations upstream (85% or more of the global population). However, the species has been designated as Endangered in the U.S.
Equivalent current criteria: B1ab(v)c(iv)+2ab(v)c(iv); C2a(i)
The previous status report considered the population to be in decline. Available data suggests relative stability from 1977 to 2002 (with differences in methods limiting understanding of trends), followed by possible declines between 2001-2002 and 2008-2010.
Recommendation: Update to the status report NOT required (wildlife species’ status category remains unchanged)
Reason: sufficient information to conclude there has been no change in status category not enough additional information available to warrant a re-assessment
Evidence (indicate as applicable):
Change in eligibility, taxonomy or designatable units:
Considered one designatable unit in previous and current assessment.
Change in Extent of Occurrence (EO):
Change in Area of Occupancy (AO):
Change in number of known or inferred current locations:
Significant new survey information:
Extensive shoreline surveys conducted by the Nature Trust of New Brunswick (NTNB) and the Atlantic Canada Conservation Data Centre (AC CDC) in 2001 and 2002 resulted in the discovery of two new occurrences of Furbish’s Lousewort, bringing the number of known sites to five. However, the occurrences are all within the previously described range and therefore do not change the Extent of Occurrence. The search included all the roughly 160 km of Canadian shoreline of the St. John River from the point at which it flows into New Brunswick at the mouth of the St-François River downstream to Perth-Andover. The search was extended to appropriate habitat outside the known range (e.g. several kilometres of the northern shore of the Saint John River above Grand Falls, the lower portion of the Aroostook River), but populations beyond the previously described range were not detected.
Sites are difficult to delineate, as the plant has been found in very small areas of suitable habitat along the river. Using a 2 x 2 km grid, it is likely that the index of area of occupancy would be a maximum of 20 km2. Previously, it would have been 12 km2.
Change in number of mature individuals:
Change in total population trend:
Change in severity of population fragmentation:
Significant new survey information:
The previous status report considered the population to be in decline. Available data suggests relative stability from 1977 to 2002 (with differences in methods limiting understanding of trends), followed by possible declines between 2001-2002 and 2008-2010
Because of its dynamic habitat and poor competitive ability, local extinctions and colonization events are expected for Furbish’s Lousewort over time (Menges 1990). Thus, surveys that cover a large portion of the potential habitat are the only reliable means of assessing changes in the population. Only two such surveys have been conducted in New Brunswick, the first in the 1970s, which detected 3 occurrences for a total population estimate of 502 plants (Hinds 1997) and the second in 2001 and 2002, which detected two additional occurrences for a total population estimate of 904 plants (Nature Trust of New Brunswick 2002, Bishop 2003). Although the more recent results suggest population growth, it is not clear if differences in methodology explain a portion of the apparent increase.
Since 2003, monitoring at known sites, though restricted in scope, suggest that the population may still be in decline (Table 1.). The total count across known sites in June 2008 was 559, with particularly low numbers at three of the sites (R. Fournier, pers. comm. 2008). It should be noted that the methods differed from those of 2002. These more recent surveys were conducted early in the season, in order to take advantage of the lack of competing vegetative cover. A comparison of early versus later counts of flowering stems was not possible due to high water levels later in the season. However, a 2010 late season count of flowering plants above Grand Falls suggests that the 2008 figure was likely an underestimate for that site (NBDNRunpublished data).
Abundance estimates in the United States, where the survey effort has been more consistent, have varied from the highest estimated abundance of 18,000 (US Fish & Wildlife Service 1991) to the lower estimates of < 6000 from the 2002 and 2003 surveys (Gawler and Cameron 2003). Preliminary results from the most recent surveys (2008-2009) indicate an increase from the low counts earlier in the decade, but much of the difference can be attributed to the inclusion of new areas, or areas where survey effort had previously been less intensive (D. Cameron, pers. comm. 2010).
Furbish’s Lousewort is not considered to be severely fragmented as most of its total area of occupancy is in habitat patches that are large enough to support a viable population, and is not separated from other habitat patches by a large distance (IUCN2010).
In the previous status report the species was considered to undergo “severe fluctuations” but under current application of the criteria, the observed fluctuations are not large enough to be considered “severe” by COSEWIC definition since they do not exceed one order of magnitude.
Change in nature and/or severity of threats:
Since the last assessment, threats to Furbish’s Lousewort have been investigated through a shoreline inventory and retrospective study of aerial photographs (Nature Trust of New Brunswick 2005), as well as through monitoring of known sites (Furbish’s Lousewort Recovery Team 2006).
Dam construction, and the consequent changes in river dynamics, has been one of the most frequently cited threats to Furbish’s Lousewort (COSEWIC 2000). The lousewort currently occurs on the New Brunswick portion of the Saint John River along the head pond of the Grand Falls dam (completed in 1928), along largely free-flowing river below Grand Falls, to the upper limit of the head pond of the Beachwood dam (completed in 1958). Two major tributaries, the Tobique and the Aroostook, have also been dammed near their juncture with the Saint John River. There has been no new dam construction within the range of this species since the 1950s. While the impact of these dams on Furbish’s Lousewort is essentially undocumented, it is all but certain that habitat was lost with the filling of the reservoirs. The little information that can be gleaned from herbarium records (Stirrett 1977) suggests that Furbish’s Lousewort was once a more abundant species, whose range extended perhaps five kilometres further downstream and possibly included the lower portions of tributaries of the Saint John River. It should be noted, however, that this species persists along the Grand Falls head pond, despite predictions in the last status report that it would disappear from this portion of shoreline (Hinds 1997).
An analysis of the nature of threats to Furbish’s Lousewort across its Canadian range was conducted by The Nature Trust of New Brunswick (2005). Types of disturbance within 30 m of the high water mark were quantified through field techniques, and comparisons over time were drawn from aerial photographs available from the 1940s, 1970s and 1990s. Direct measurement of anthropogenic threats over the summer of 2004 revealed that 58% of the habitat between Grand Falls and Perth Andover remained “visibly undisturbed.” Within the 42% of disturbed habitat, shade removal (clearing of trees to the top of the bank) was the most widespread type of disturbance. The loss of shade at the top of the bank is thought to be problematic for Furbish’s Lousewort (Gawler and Cameron 2001). Road construction was the most common reason for the loss of shade, much of it having occurred in the past. Agricultural fields constituted the second most important source of and thus loss of shade, but this land use had decreased by more than 50% since the 1940s. By contrast, loss of shade increased through clearing associated with gravel pits and with residential and/or commercial development, especially since the 1970s.
Recreational activity (e.g. footpaths, marinas, picnic areas) was identified as the second most widespread type of disturbance. Alteration of the shoreline (e.g. dumping, bank stabilization) was the third most widespread disturbance. Additional measurable disturbances were establishment by invasive species and slumping attributed to clearings, affecting roughly 6% and 2% of shoreline, respectively.
Significant establishment of invasive species (patches > 5 m in length) were recorded over 6 km of shoreline, most often in association with disturbances such as shade removal (Environment Canada 2010). Three species of greatest concern are Canary Reed Grass (Phalaris arundinacea), White Sweet-clover (Melilotus albus) and Wild Angelica (Angelica sylvestris). These species were not prevalent back in 2002, but are now present and have potential to become quite dense as is the case around Fredericton and Saint John. Invasives are much more of an issue for Canadian population than US due to greater agricultural runoff and greater shoreline disturbance (Blaney, 2011).
At a smaller scale, the impacts of localized threats at the known sites of Furbish’s Lousewort have been evaluated by the Furbish’s Lousewort Recovery Team (2006). The threats of highest concern (documented for at least one site) are dumping, clearings or structures associated with recreational activity, bank slumping and erosion, ice scour and flooding, and browsing by mammals. Though considered potential threats, it is unknown to what extent Canadian populations are vulnerable to seed parasitism (Menges et al. 1986) or declines in pollinators.
Change in effective protection:
Known sites are monitored more closely, but the potential for impacts from human activity remains as high as, or higher than, believed at the time of the last assessment.
Evidence of rescue effect:
Eighty-five percent or more of the global Furbish’s Lousewort population is in Maine, and may even currently be contributing to the Canadian portion of the population, the Canadian population does extend to the US-Canada border, and there are Furbish’s Lousewort on the American side not far upstream (Gawler and Cameron 2001). However, Menges (1990) notes that seeds lack sophisticated mechanisms for wind or animal dispersal, but their loose, reticulate seed coat allows them to float for several days, perhaps accomplishing long-distance dispersal and the American population is also considered endangered. Moreover, the current threats would jeopardize establishment from these upstream sources.
Change in estimated probability of extirpation:
Menges (1990) conducted a PVA, using data from US populations (1983-6). His results suggest that individual populations are not permanent and that survival of the species depends on the viability of metapopulations. A comparison of probabilities of colonization events (3%) and extinction events (2-12%) over the period of the study suggested a negative balance. The current applicability to the Canadian population has not been examined, though the probability of extinction events was predicted to be greater for the populations at downstream sites (New Brunswick sites are downstream of Maine).
Summary and Additional Considerations:
Table 1: Summary of Survey Results for Furbish’s Lousewort
2009 NTNB with field team from Maliseet First Nation at Tobique) - May 27
2010 h - NBDNR (Aug 6) i - NTNB (with field team from Maliseet First Nation at Tobique) - June 10
118h (88/29; 1 not specified) [partial]
~ 62i [complete]
Counts of Furbish’s Lousewort from complete and partial surveys (1977-2010). Numbers in parenthesis represent the proportion of plants in flower/plants not in flower. Additional comments on completeness of survey are included in square brackets where that information is available.
Notes: *In Stirrett’s 1980 report, he indicates that his population estimates are based on the 1977 work, with revisions based on visits in 1978 and 1979. **Note: The 2008 survey methodology above Grand Falls was a departure from previous work; it involved use of a boat to visit points identified as having plants and recorded by GPS in 2001. All other surveys have been conducted by walking portions of the shore, with varying degrees of search effort (e.g. pushing vegetation aside or not to find Furbish’s Lousewort).
Brown, D.C. 1983. Summer Study of Potential Ecological Reserves (Peters River, Jolicure Boglands, Wilson Brook, Furbish’s Lousewort Sites). New Brunswick Department of Natural Resources, Fish and Wildlife Branch, Fredericton, New Brunswick.
Day, R.T. 1983. A survey and census of the endangered Furbish Lousewort, Pedicularis furbishiae, in New Brunswick. Canadian Field Naturalist 97(3): 325-327.
Drummond. 1987. The 1987 Furbish’s lousewort count. New Brunswick Department of Natural Resources and Energy. Fredericton, New Brunswick. 7 pp.
Environment Canada. 2010. Recovery Strategy for the Furbish’s Lousewort (Pedicularis furbishiae) in Canada. Species at Risk Act Recovery Strategy Series. Environment Canada, Ottawa. vi pp. + appendices.
Hinds, H. 1998. Update Status Report for Furbish’s Lousewort (Pedicularis furbishiae). Prepared for the Committee on the Status of Endangered Wildlife in Canada. Ottawa, Ontario.
O’Brien, P. 1991, 1997, 1999. Correspondence sent to Nature Trust of New Brunswick regarding George Stirrett Reserve.
Simpson, J. and C.W. Blaney. 2003. Rare Plant Surveys of the Upper St. John River with focus on Furbish’s Lousewort. The Nature Trust of New Brunswick, Inc. Fredericton, New Brunswick. 61 pp.
Stirrett, G.M. 1977. Report on the Investigations of the Flora of Northern Maine and Northern New Brunswick with particular reference to Pedicularis furbishiae and other rare plants. Contract number DACW 33-77-M-0885 with the Army Corps of Engineers. 61 pp.
Stirrett, G.M. 1980. The status of Furbish’s Lousewort, Pedicularis furbishiae S. Wats., in Canada and the United States. Second Edition. COSEWIC unpublished report. 78 pp.
Bishop, G. 2003. A floristic survey of known and potential sites of Furbish’s Lousewort (Pedicularis furbishiae). Nature Trust of New Brunswick Inc., Fredericton, NB. 104 pp.
Blaney, C.S., pers. comm. 2011. Email correspondence to B. Bennett. February, 2011. Botanist/Assistant Director, Atlantic Canada Conservation Data Centre. Sackville, NB.
Cameron, D., pers. comm. 2010. Email correspondence to M. Toner. January 29, 2010. Botanist/Ecologist, Maine Natural Areas Program, Augusta, Maine.
COSEWIC (In Press) 2000. COSEWIC assessment and update status report on the Furbish’s lousewort Pedicularis furbishiae in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vi + 7 pp.
Fournier, R., pers. comm. 2008. E-mail correspondence to M. Toner. June 17, 2008. Faculté de foresterie (FdeF), Université de Moncton - Campus d'Edmundston (UMCE), Edmundston, New Brunswick.
Furbish’s Lousewort Recovery Team. 2006. Recovery Strategy for Furbish’s Lousewort (Pedicularis furbishiae) in New Brunswick. New Brunswick Department of Natural Resources. Fredericton. NB. 28 pp.
Gawler, S.C. and D.S. Cameron. 2001. Population sizes of Furbish’s Lousewort (Pedicularis furbishiae) along the St. John river, Maine: 2001 Census Results. Report to the US Fish and Wildlife Service. Maine Natural Areas Program, Augusta, Maine. 17 pp.
Gawler, S.C. and D.S. Cameron. 2003. Population sizes of Furbish’s Lousewort (Pedicularis furbishiae) along the St. John River, Maine: 2003 Census Results. Report to the US Fish and Wildlife Service. Maine Natural Areas Program, Department of Conservation, Augusta, Maine. 14 pp.
Hinds, H. 1997. Update status report for Furbish’s Lousewort (Pedicularis furbishiae). Prepared for the Committtee on the Status of Endangered Wildlife in Canada. Ottawa. Ontario.
Menges, E.S. 1990. Population viability analysis for an endangered plant. Conservation Biology 4: 52-62
Menges, E.S., D.M. Waller and S.C. Gawler. 1986. Seed set and seed predation in Pedicularis furbishiae, a rare endemic of the Saint John River Valley, Maine. American Journal of Botany 73:1168-1177.
Nature Trust of New Brunswick. 2005. Assessing threats to the riparian flora of the Upper St. John River. Publication of the Nature Trust of New Brunswick, Inc., Fredericton, NB. 16 pp.
Simpson, J. and C.S. Blaney. 2003. Rare plant surveys of the Upper St. John River with focus on Furbish’s Lousewort. Nature Trust of New Brunswick, Inc., Fredericton, New Brunswick. 61 pp.
Stirrett, G.M. 1977. Report on the investigations of the flora of Northern Maine and Northern New Brunswick with particular reference to the Pedicularis furbishiae and other rare plants. Contract number DACW 33-77-M-0885 with the Army Corps of Engineers. Waltham, Massachusetts. 66 pp.
US Fish and Wildlife Service. 1991. Revised Furbish’s Lousewort recovery plan. Newton Corner, Massachusetts. 62 pp.
Threats (actual or imminent, to populations or habitats)
Potential for impacts from human activity remains as high as, or higher than, believed at the time of the last assessment. 1. Loss of tree cover by road construction and gravel pits, residential and commercial development 2. Recreational activity 3. Alteration of shoreline – dumping and bank stabilization 4. Effects of invasive species, particularly Reed Canary Grass
Rescue Effect (immigration from outside Canada)
Status of outside population(s)?
United States population is also considered endangered
Is immigration known or possible?
Would immigrants be adapted to survive in Canada?
Is there sufficient habitat for immigrants in Canada? There is extensive apparently suitable but unoccupied habitat between Grand Falls and Perth-Andover.
Is rescue from outside populations likely? Although 85% or more of the global Furbish’s Lousewort population is in Maine, and may even currently be contributing to the Canadian portion of the population, the United States population is also considered endangered. Moreover, the current threats would jeopardize establishment from these upstream sources.
COSEWIC : Endangered 2000 B1 + 2e + 3d; C2a
Status and Reasons for Designation
Alpha–numeric code: C2a(i)
Reasons for designation: This plant exists at low numbers in a dynamic and restricted habitat along the Saint John River in New Brunswick. Changes to river dynamics, land clearing of buffer trees, recreational activities, and the introduction of invasive species have resulted in continuing population decline at the existing sites.
Applicability of Criteria
Criterion A (Decline in Total Number of Mature Individuals): Not applicable. The extent of the decline is unknown but likely not great enough to apply.
Criterion B (Small Distribution Range and Decline or Fluctuation): Not applicable. EO<5000 km2 and IAO <500 km2though it is unclear if there are 5 locations and though there are continuing declines in area, extent and quality of habitat, and number of mature individuals, the populations do not experience extreme fluctuations.
Criterion C (Small and Declining Number of Mature Individuals): Meets Endangered C2a(i) as no population is known to contain >250 individuals and populations continue to decline.
Criterion D (Very Small or Restricted Total Population): Not applicable. Does not meet criteria for being endangered as >250 individuals are known to exist. Meets threatened D2 with <1000 individuals known.
Criterion E (Quantitative Analysis): None conducted.
The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal–Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARAestablishes COSEWIC as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.
The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.
COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non–government science members and the co–chairs of the species specialist subcommittees and the Aboriginal Traditional Knowledge subcommittee. The Committee meets to consider status reports on candidate species.
A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.
A wildlife species that no longer exists.
A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.
A wildlife species facing imminent extirpation or extinction.
A wildlife species likely to become endangered if limiting factors are not reversed.