Species at risk classifications and rationales (November 2011 and May 2012 meetings)

Results of the November 2011 and May 2012 COSSARO meetings

Rationale

Amphibians

The Northern Dusky Salamander (Desmognathus fuscus) is a medium-sized member of the family Plethodontidae (lungless salamanders). Adults are usually brownish with a thin, dark, dorsal stripe that continues onto the first portion of the tail. The body is sparsely covered with dark spots concentrated on the sides and is white or cream on the underside. Old individuals tend to be uniformly dark brown or black. The Northern Dusky Salamander inhabits springs, seepages, and small tributaries of clear headwater streams in forested habitats and is distributed throughout the mountainous regions of eastern North America. The Ontario distribution accounts for less than 1% of the global range and occupies only a single, tiny stream in the Niagara Gorge. There are no data on abundance or population trends, but the total number of adults is likely much fewer than 250. Threats include the effects of small population size including inbreeding and environmental and demographic stochasticity, erosion from flooding and runoff, impairment of water quality from surface contamination and disturbance from hikers. Given its limited range, numbers and numerous ongoing threats the Northern Dusky Salamander is assessed as Endangered in Ontario.

Birds

The Buff-breasted Sandpiper (Tryngites subruficollis) is a medium-sized, shorebird with buffy underparts, and black speckling on its back and top of head. It is the only North American shorebird that breeds in leks. The species suffered severe declines from market- hunting in the late 1800s and early 1900s. There is some evidence for recent population decline resulting from loss of its specialized grassland habitat on its wintering grounds in South America and along its migration routes; this is believed to pose the most significant threats. This sandpiper breeds in northern Alaska and the western Canadian Arctic with the nearest breeding area more than 1000 km from Ontario. Ontario lies east of its main migration route through the prairies. It is an uncommon, but regular migrant along the Hudson - James Bay coast in autumn and rare regular fall transient and irregular, very rare spring transient in southern Ontario. Records of occurrence are too infrequent or widespread to make any conclusions about extent of occurrence, population size, threats, or trends, particularly along Ontario's Hudson and James Bay coast. As a result the species is designated as Data Deficient in Ontario.

A small insectivorous bird, the Hooded Warbler (Setophaga citrina) breeds throughout much of the eastern United States. It remains uncommon in Ontario and is still restricted to the southern portion of the province, and particularly the Carolinian forest region. However, it continues to expand its range in southern Ontario, now occurring in at least 15 counties, and extending north to the Midland Peninsula and east to the Kingston region. It breeds in patches of dense saplings and shrubs in mature deciduous or mixed forest. Substantial increases in numbers of breeding pairs have occurred over the past two decades. Recent estimates suggest that there are more than 500 to 1000 breeding pairs in Ontario. Hooded Warblers are classified as Not at Risk (formerly Special Concern) because their population in Ontario is recovering strongly and the species is more abundant now than previously recorded in historical times.

The Peregrine Falcon (Falco peregrinus) is a cosmopolitan mid-sized falcon that underwent a dramatic decrease in distribution and abundance across its North American, Canadian and Ontario ranges in the mid-20^th century. It was lost as a breeding species in Ontario from the mid-1960s until the mid-1980s. Prohibition on DDT use in North America, and sustained recovery efforts such as the release of captive-reared young in Ontario and elsewhere have resulted in increasing populations across North America. The Ontario population has expanded from 0 in 1985 to a minimum of 119 territories in 2010, with 50 territories producing young. At least 140 young were fledged in 2010, the highest productivity ever recorded. Considerable historical cliff-nesting habitat in northern Ontario has been reoccupied, and new habitat has been colonized in urban southern Ontario. The vast majority (94%) of the historically documented cliff-nesting sites in Ontario remain unoccupied, most of which are in central and southeastern Ontario. There are ongoing concerns about threats including the effects of chemicals in the environment and potential effects of USA harvest for falconry. The species’ status in Ontario was downlisted from Endangered to Threatened in 2006. Given persistent threats, the relatively small Ontario population, and the large proportion of its historical range that remains uncolonized, a status of Special Concern is appropriate.

The Yellow-breasted Chat (Icteria virens) is a shrub-thicket specialist that occurs at the northern edge of its range in Canada. One subspecies (I. v. virens) occurs only in southern Ontario and has a localized and very small population. Since the last status report in 2000, significant declines have occurred in the Ontario population, owing to habitat loss and fragmentation. A range retraction also appears to have occurred. Major threats include natural loss of habitat due to forest succession, human-mediated habitat loss due to agricultural intensification and urban expansion, habitat fragmentation and subsequent socially-facilitated population reduction, and Brown-headed Cowbird parasitism. The potential for rescue effect from neighbouring has also been dramatically reduced during this time, because population declines are evident across most of its eastern range. The Ontario population is clearly very small, declining, and at risk of extirpation. A designation of Endangered is appropriate for Yellow-breasted Chat in Ontario.

Fishes

The Blackstripe Topminnow (Fundulus notatus) occurs in lowland areas of the southern Great Lakes, throughout much of the Mississippi basin, and along the lower coastal plain from Texas to Alabama and is native to 16 US states (not listed special concern in any state). The Blackstripe Topminnow prefers turbid waters and is tolerant to warm low oxygenated waters and appears dependent on aquatic vegetation and bank cover. Ontario Blackstripe Topminnow populations appear stable; however a lack of quantitative demographic and reproductive data make population size and declines difficult to assess. The species in Canada is restricted to a small range in a highly developed drainage system, and thus may be susceptible to habitat disturbance and loss. The Blackstripe Topminnow is of Special Concern in Ontario due to their small and isolated distribution, coupled with the highly developed nature of their range. Both quantitative demographic data and, to a lesser extent, genetic data are identified as deficient.

Adult Chestnut Lampreys (Ichthyomyzon castaneus) parasitize other fish. They then migrate up steams to spawn at the end of their lives. They live up to six years as larval ammocoetes in soft sediments of clean streams with stable flows. The ammocoetes of the three species of Ichthyomyzon occurring in Ontario are nearly impossible to distinguish, complicating the estimation of population size and trends. Chestnut Lampreys range from southern Ontario and adjacent Quebec west to southern Saskatchewan and Manitoba south through the Mississippi drainage of the central US. The Great Lakes – Upper St. Lawrence River population occupies most of Ontario and western Quebec. There are only one or two records from any location and most result from surveys targeting Sea Lamprey. Population trends are unknown. Threats to the Chestnut Lamprey in this population include lampricide, which may have extirpated the species from at least one river, and dams which restrict migration between lakes and breeding areas. Limited Ontario records, difficulty of identifying the ammocoetes, and lack of targeted surveys make distribution and status of this species unclear. Until more information becomes available, the Great Lakes – Upper St. Lawrence River population of this species is best assessed as Data Deficient.

The main range of the Northwestern Ontario population of the Chestnut Lamprey (Ichthyomyzon castaneus) occurs predominately in Manitoba but extends into the Lake of the Woods area of Ontario. There is only a single record of Chestnut Lamprey for this population in Ontario and consequently there are no population trends. The species is likely susceptible to construction of dams which would restrict its ability to migrate between lakes and breeding areas. Because there is only a single Ontario record for this population, physical similarity with two other species of lamprey, difficulty of distinguishing the ammocoetes of these species, and a lack of targeted surveys, the true distribution and status of this species is not clear. It is possible that it is more widespread and abundant than the record indicates. Until such time as more definitive population and distribution information becomes available, the Northwestern Ontario population of this species is best assessed as Data Deficient.

The Northern Madtom (Noturus stigmosus) is a small member of the catfish family that forages mostly at night. It has a mottled colour pattern, four pairs of barbels on the head, and venomous spines in dorsal and pectoral fins. This fish appears to be declining in much of its global range. In the United States, the Northern Madtom is found in the Ohio River, western Lake Erie, and the Lake St. Clair basins. In Canada, it is known only from the Detroit River, St. Clair River, Lake St. Clair, and the Thames River. It is likely extirpated from the Sydenham River where it was last recorded in 1975. Despite its rarity and limited range, the species occupies a wide range of habitats from small creeks to the shores of the Great Lakes. The maximum age for the species is three years. Potential threats to Northern Madtom include siltation of its habitat, excessive turbidity and nutrient loading, exotic species, toxic compounds, and habitat loss or degradation. Most of these threats relate to agricultural and urban land uses that dominate the species range. The Northern Madtom is considered Endangered in Ontario and imperiled or critically imperiled in most of its US range.

The Pugnose Minnow (Opsopoeodus emiliae) is a small (64 mm maximum) fish in the family Cyprinidae (shiners, chubs, dace, minnows). Courtship and mating involves swimming in figure- eight patterns, raising and lowering the dorsal fin, and depositing the eggs under a flat rock. With its small, upturned mouth, it feeds on algae and small organisms (insects, crustaceans, larval fish and fish eggs) on the surface or in the water column. Habitat is shallow, slow-moving water near wetlands and other near-shore areas in lakes and rivers. The species is globally common, with a centre of abundance in the Mississippi drainage in the USA. It is not at risk in most of its range, but, owing to reduced abundance in the north, it is considered to be at risk or rare in 54% of the jurisdictions in northeastern North America. Data suggest it has always been rare in Ontario, at the northern edge of its range, where it is known from only 9 sites in the extreme southwest. The main threats to the species include nutrient and sediment loading, deterioration of water quality, and habitat loss due to dredging and shoreline alterations. The species is protected under the federal Fisheries Act and is not a legal baitfish in Ontario. Owing to its rarity in Ontario and adjacent jurisdictions, the Pugnose Minnow is classified as Threatened in Ontario.

Silver Chub (Macrhybopsis storeriana) is a large minnow that occurs throughout rivers and lakes of eastern and central North America. In Ontario, it appears to be restricted to Lake Erie. It was once an abundant forage fish in Lake Erie, but experienced drastic population declines in response to poor water quality in the 1960s and 1970s. Silver Chub began to recover through the 1980s and 1990s and then declined rapidly in the early 2000s. Trawl surveys demonstrate that this short-lived fish has extreme population fluctuations. Numbers declined by 71% from 1996 to 2005, and while the population has increased by 25% over the last 5 years, it is still much lower than historic levels. The primary threat to this species is the recent declines in Lake Erie water quality. Silver Chub is Threatened in Ontario because populations have significantly declined over the last 10 years, and recent changes in the condition of Lake Erie may further impair habitat and the recovery of this species.

The Silver Lamprey (Ichthyomyzon unicuspis) is a parasite on other fish (as an adult), and then migrates up streams to spawn at the end of its life. It lives up to 6 years as a larval ammocoete in soft sediments of streams. The ammocoetes are nearly impossible to distinguish among the various species of Ichthyomyzon. The Silver Lamprey occurs primarily in northeastern North America from Quebec and Manitoba south to Tennessee. The Great Lakes – Upper St. Lawrence River Population occurs in Quebec, Ontario and the Great Lakes states. In Ontario, members of this population occur in a number of streams that flow into all the Great Lakes as well as the St. Lawrence and Ottawa Rivers. The species has shown no recent declines and may have increased in Lake St. Clair. Surveys since 1989 have recorded the species at most historical locations, therefore the area of occurrence has only declined slightly since the 1930s. Threats to Silver Lamprey include treatment of occupied streams with lampricides to control Sea Lampreys, installation of dams which restrict the lamprey’s ability to migrate between lakes and breeding areas, and chemical pollution particularly by Atrazine. This population comprises about 20% of the global range of the species and is classified as Special Concern.

The Northwestern Ontario population of the Silver Lamprey (Ichthyomyzon unicuspis) occurs in the Lake of the Woods area of Ontario. The population of Silver Lamprey in northwestern Ontario is poorly known and there are insufficient population data to determine the species’ status. Specific threats have not been identified but may include dams that restrict the lamprey’s ability to migrate between lakes and breeding areas. This population is classified as Data Deficient.

Insects

American Burying Beetle (Nicrophorus americanus) is a large (25 to 35 mm), black beetle with distinctive orange markings. It is a habitat generalist, but prefers undisturbed deciduous forest. This genus is unusual among insects in that both parents care for the young by burying carrion and building a brood chamber, which the parents guard from competitors and predators. Both parents feed the developing young. American Burying Beetle was formerly distributed across most of the eastern US and adjacent Ontario but has declined precipitously and is now restricted to less than 10% of its former range. In Ontario, it occurred north of lakes Erie and Ontario from Windsor to Toronto, but it was last seen in 1972. Threats are unknown but probably include habitat alteration, extinction of the Passenger Pigeon (which provided abundant carrion), attraction to artificial lights, road kill, and increased predation and competition from Raccoons and domestic dogs and cats. American Burying Beetle is classified as Extirpated in Ontario because it has not been recorded in 39 years despite extensive survey effort throughout its former Ontario range.

Mammals

Until recently, the Little Brown Myotis (Myotis lucifugus) (formerly Little Brown Bat) has been common throughout much of Canada and the United States. Feeding primarily at night on insects caught in the air, members of this species roost in trees and human structures during the summer and hibernate during winter months in cool, damp caves and abandoned mines. White Nose Syndrome (WNS), a disease caused by a cold-loving fungus Geomyces destructans, has caused dramatic declines at hibernacula of this species in northeastern North America since it was first recorded 6 years ago (February 2006) in a cave near Albany, New York. It has spread at a rate of approx. 200-400 km per year, reaching Ontario and Quebec in 2010, and New Brunswick and Nova Scotia in 2011. WNS is not yet known to be present west of Wawa, Ontario, but declines in all 8 caves that have been monitored in infected areas of Ontario before and after WNS have averaged >90%. Lack of monitoring attention and baseline knowledge about population numbers pre-WNS precludes any precise estimate of impact to the population at large, but evidence of WNS mortality events in New Brunswick, New England and New York is a cause of profound concern for the continued persistence of this species in Ontario. The Little Brown Myotis is classified as Endangered in Ontario.

Until recently, the Northern Myotis (Myotis septentrionalis) (formerly Northern Long-eared Bat) has been a widespread insect-eating bat found throughout forest regions of a large portion Canada and the United States. Usually found with or near groups of Little Brown Myotis, this species is never as common and is difficult for all but experienced fieldworkers to identify.

Feeding primarily at night on aerial insects, members of this species roost in trees during the summer and hibernate during winter months in cool, damp caves and abandoned mines. White Nose Syndrome, a disease caused by a cold-loving fungus Geomyces destructans, has caused dramatic declines at hibernacula of this species in Northeastern North America since it was first recorded 6 years ago (February 2006) in a cave near Albany, New York. It has spread at a rate of approx. 200-400 km per year, reaching Ontario and Quebec in 2010, and New Brunswick and Nova Scotia in 2011. In Ontario, WNS is not yet known to be present west of Wawa, but declines in all 8 caves that have been monitored in infected areas of Ontario before and after WNS have averaged >90%. An unknown proportion of these bats are Northern Myotis, but confirmed mortalities for this species elsewhere have exceeded 90%. Lack of monitoring attention and baseline knowledge about population numbers pre-WNS precludes any precise estimate of impact to the population at large, but evidence of WNS mortality events in New Brunswick, New England and New York is a cause of profound concern for the continued persistence of this species in Ontario. The Northern Myotis is considered Endangered in Ontario.

Molluscs

The Snuffbox (Epioblasma triquetra) is a small freshwater mussel and is the most widely distributed member of the genus Epioblasma and is morphologically distinct from any other mussel in Canada. Historically known from 208 streams and lakes in 18 states plus Ontario, it is currently found in only 74 streams, representing a 65% decline. Remaining populations are small and geographically isolated. In Ontario, there were 31 known historical records for Snuffbox from Lake Erie, Lake St. Clair, and the Ausable, Sydenham, Thames, Grand, and Niagara rivers. It is now restricted to a few sites in the Sydenham and Ausable Rivers. It occupies shallow riffles in clean, clear, swift-flowing rivers with firm gravel/sand, silt-free substrates. Current population trends are unknown, but reproduction is still occurring. Impoundment and diversion of rivers likely destroyed much of this species’ habitat during the last century. Major current threats to Snuffbox are siltation, pollution habitat perturbation, loss of riffle habitat, invasive dreissenid mussels, and loss of glochidial hosts. Dreissenid mussels have made Snuffbox habitat unsuitable throughout a large portion of its former range. The two remaining populations are in areas of intensive farming and subject to siltation and pollution. Small remaining populations, restricted distribution, and ongoing threats qualify Snuffbox as Endangered in Ontario.

Mosses

Incurved Grizzled Moss (Ptychomitrium incurvum) has been accepted as a legitimate member of the Ontario and Canadian moss flora in all floras, checklists, and other related bryological publications (COSEWIC 2012), indicating that bryologists have universally accepted the Drummond collection as having come from Canada. Even with many more years of intense bryological surveys one could not be absolutely certain that a moss species is extirpated from Ontario. However, in this case there is good circumstantial evidence suggesting Ptychomitrium incurvum is extirpated.

1. Almost 200 years have passed since the only Ontario specimen was collected and natural habitats in the Niagara Falls area have been extensively altered in that time.
2. Although it is a small moss, Ptychomitrium incurvum is easily distinguishable in the field and the Niagara Falls area has been more extensively botanized bryologically than other parts of Ontario.
3. The Niagara Falls area is one of the most heavily visited locations in North America and habitats near the Falls, where the species was recorded in 1828, have been greatly altered by human impacts. A recent vascular plant survey of the Niagara Falls area (Varga and Kor 1993) concluded that 141 (64%) of the historically-documented rare vascular plant flora had been extirpated.

Therefore, the Incurved Grizzled Moss is assessed as Extirpated in Ontario.

Reptiles

The Blue Racer (Coluber constrictor foxii) is one of Ontario’s largest snakes. A fast-moving constrictor, it is harmless to humans. In Ontario, the Blue Racer formerly had a restricted distribution on the mainland in areas near the shores of lakes Huron, St. Clair and Erie and on Pelee Island in extreme southwestern Ontario. All mainland populations in Ontario are now extirpated and only a small population (<250 mature individuals) remains on Pelee Island. On Pelee Island, the Blue Racer occurs in: Chinquapin Oak - Nodding Onion Treed Alvar Grassland a provincial rare community type (S1), savanna, old fields and other types of open and semi- open habitat. The Blue Racer is at risk on Pelee Island due to a number of anthropogenic threats. A major threat is road mortality and this threat is increasing as the volume of seasonal traffic continues to rise. Although Pelee Island is still largely rural, pressures from development are ongoing and threaten to reduce further the quantity and quality of Blue Racer habitat available, although recent purchases of land parcels to maintain habitat may alleviate this decline. Blue Racer is designated Endangered under both COSSARO and COSEWIC criteria.

Vascular Plants

Bluehearts (Buchnera americana) is an attractive, herbaceous vascular plant that is extirpated or at risk throughout much of its eastern North American range, including the states immediately adjacent to Ontario. In Ontario its habitat is restricted to rare coastal marshes on moist soils in open woods and intertidal dunes along the Lake Huron shoreline. Bluehearts is a facultative parasite obtaining some nutrients from roots of trees, where trees are present. In Canada, it occurs only within a 10 km stretch of the Lake Huron shoreline in southwestern Ontario, disjunct from the rest of the global range in the southeastern United States. There are only three extant populations in Ontario; four others are considered extirpated. Primary human threats are habitat-related. Only one Ontario population is considered relatively secure; a second may be facing habitat disruption and a third is not considered viable in the long-term. The species still appears to be declining in Ontario due to habitat disruption, although the rate of decline may be decreasing. Due to the small number of Ontario occurrences, limited distribution, its imperiled status throughout much of the northeastern United States, threats of further habitat disruption, and its specialized life history, Bluehearts is considered Endangered in Ontario.

False Hop Sedge (Carex lupuliformis) is an herbaceous perennial that grows 50 to 130 cm tall. It grows in tufts of up to 30 stems. It is distinguished from Hop Sedge (Carex lupulina), a closely-related species, by the prominent knobs on the achenes. False Hop Sedge grows primarily in forest pools, small ponds, and marshes in the Carolinian Zone of southwestern Ontario. These pools are all subject to periodic flooding. The global distribution extends from southern Quebec west to Wisconsin, Iowa, Missouri and Oklahoma, and south to Florida, Louisiana, and Texas. In Ontario, it occurs at seven locations in Middlesex and Elgin Counties. There is also a historical record from Galt (1902) and a recently extirpated site at Amherstburg. It is rare and declining in most of its range. Threats include altered drainage that interferes with periodic flooding; spread of invasive species, such as Common Buckthorn (Rhamnus cathartica) and Reed Canary Grass (Phalaris arundinacea); and habitat succession. False Hop Sedge is classified as Endangered in Ontario due to its declining numbers and small range.

Heart-leaved Plantain (Plantago cordata) is an early spring flowering perennial, herbaceous, semi-aquatic plant 20-50 cm tall with a basal rosette of large, heart-shaped leaves. It is adapted to temporarily flooded habitat, owing to massive, fleshy roots that anchor the adult plants. Its short-lived seeds disperse in water and germinate on bare soil. Habitat in northeastern North America has been described variously as along intermittent streams flowing through silver maple swamps; clear, shallow streams and seepages in mature woods; streams flowing over limestone or dolomitic rock; gravelly or rocky beds of shallow, clear streams or springs; sandstone rubble; and silt-laden water of tidal flats. It occurs only in eastern North America, and reaches the northern edge of its range in Ontario. It is ranked as extirpated, presumed extirpated, imperiled, or critically imperiled in 91% of 11 northeastern jurisdictions. Five historical sites known in Ontario are no longer occupied, and it has declined 47% over 22-26 years at the 2 extant sites near the southernmost point of Lake Huron. The species’ decline since the 1990s, occurrence at only 2 sites over a small area, and status as imperiled or extirpated in other jurisdictions in northeastern North America suggest Heart-leaved Plantain qualifies for Endangered status in Ontario.

Hoary Mountain-mint (Pycnanthemum incanum) is a fragrant, perennial, herbaceous plant that can attain 1 m tall and may be long-lived. It occurs in eastern North America and reaches the northern edge of its range in Ontario. Records from the Hamilton-Burlington area exist from 1880-1900, but the species was not seen for decades until rediscovered in 1981. It now occurs in 2 populations of fewer than 1,000 plants on steep, unstable slopes along the Hamilton- Burlington bluffs. Elsewhere within its range in northeastern North America it occupies disturbed areas such as “thickets and pastures” as well as roadsides and rights-of-way, and is secure or “not at risk” in 72% of the jurisdictions, including neighboring New York State, Pennsylvania, and Ohio. However, the Ontario plants are >115 km from the nearest population in the USA. In Ontario, the open sites preferred by Hoary Mountain-mint are vulnerable to encroachment by competing, invasive species, and shading by woody shrubs. Recovery actions have helped reduce the threats, but the control of competing plants will require constant management. One erosion event on these unstable slopes could eliminate a large proportion of the small Ontario population. Because Hoary Mountain-mint populations are small, confined to 2 unstable sites, and subject to competition from invasive plants, the species has been classified as Endangered in Ontario.

Large Whorled Pogonia (Isotria verticillata) is a moderately-tall orchid whose flower has greenish-yellow petals, a white and crimson-purple lip, and three long, dark purple sepals. In the United States, Large Whorled Pogonia occurs from New England and Michigan south to Texas and Georgia. In southwestern Ontario, this species grows in acidic soils in moist deciduous or mixed woods in the Carolinian Zone. This orchid has been found at four locations in Middlesex, Oxford, and Norfolk Counties: at one location, it has not seen since 1879, at two others it hasn’t been seen since 1990, and at the fourth site, it was last seen in 1996. Large Whorled Pogonia is known for its tendency to enter dormancy lasting several years during which time no plants appear above ground. Thus, the species may still occur at former sites even though it has not been seen for many years. Threats to the species in Ontario include habitat loss and degradation; spread of invasive species, such as exotic earthworms and Garlic Mustard; flooding by beavers; and logging. Due to the small number of locations and the very low population recorded in recent years, Large Whorled Pogonia is classed as Endangered in Ontario.