Species at risk classifications and rationales (May and December 2014 meetings)

Meeting location and dates

The Committee held meetings on May 27-29, 2014 in Thunder Bay and on December 9-10, 2014 in Toronto. At the meetings, 11 Ontario species/populations were assessed and classified. A special meeting was held in March 2014 in Toronto to discuss the criteria used by the committee.

Results of the May and December 2014 COSSARO meetings

Classifications^{footnote *[*]}

Change in species classification from one population to two populations

Change in species classification from geographically defined areas to entire province

Name changes

Rationale for Conservation status classifications of species in 2014

Classification summary:

Cutlip Minnow (Exoglossum maxillingua)

The Cutlip Minnow is a small cyprinid identifiable by its distinctive tri-lobed lower jaw. It is found across the Atlantic drainages of North America, with Ontario and Quebec being its northern- most extent. In Ontario they occur in four water bodies (historically seven). This minnow prefers clear streams with moderate flow and rocky or gravel substrates, and is sometimes found in lakes. The Ontario Cutlip Minnow is not well studied, and most biological data comes from U.S. populations. Age of maturation is likely 2-3 years and fecundity is between 300 and 1200 eggs laid into nests prepared by the males. Ontario Cutlip Minnows have a small index of area of occupancy and are in decline based on historic locations they are no longer found at. Turbidity and invasive species pose likely threats. While globally secure (G5), the Cutlip Minnow has been previously listed as Threatened by COSSARO and as Special Concern by COSEWIC (2013). The species meets COSSARO criteria (B1 & B2) for Endangered due to small distribution range and decline. However, there is the potential for dispersal from more robust populations (Quebec & New York). Considering the potential for rescue effect, the Cutlip Minnow is classified as Threatened in Ontario.

Flooded Jellyskin (Leptogium rivulare)

The Flooded Jellyskin is a semi-aquatic lichen requiring periodic inundation by water to reproduce. When wet, its lobes swell and become jelly-like, giving it the name “jellyskin". Its habit of developing low on the trunks of trees and shrubs below the water line in small woodland pools or along the margins of rivers or lakeshores that are periodically flooded makes it relatively obscure. The species was first identified in Ontario in 1946 and was known at only 5 sites up to 2004. It is widely distributed in Europe. Recent surveys by OMNR staff have resulted in 165 observations spread across 11 counties in Ontario from the far north to the south. The success rate of targeted searches has been high, suggesting that the Flooded Jellyskin is much more common and widespread than previously thought, and that more searches in appropriate calcium-rich habitat would yield more populations. OMNR surveys revealed that the species uses primarily the bark of young and older trees from a wide variety of species of trees and shrubs as a substrate, suggesting that habitat supply is not limiting the species in Ontario. Based on the new information on abundance, distribution, and population size, the Flooded Jellyskin has been assessed as Not at Risk in Ontario.

Grasshopper Sparrow (Ammodramus savannarum)

The Grasshopper Sparrow is a small dull-coloured song bird of grassland habitats and hayfields. It prefers fields with low sparse vegetation such as on poor soils, alvars and sandy areas. Within Ontario it occurs mainly south of the Canadian Shield. A very small population occurs in the Lake of the Woods area of northwestern Ontario. It is a migratory species that arrives on breeding ground in May and has one or two broods per year. Grasshopper Sparrow feeds largely on seeds and insects, especially grasshoppers.

Breeding Bird Survey data showed a continual annual decline of 1.5% since the 1970s or a 46% decline over 40 years and a non-significant decline of 13% in the 10 year period of 2002 to 2012. The populations in the Carolinian portion of Ontario have suffered most with a 48% decline between the two Ontario Breeding Bird Atlases between the 1980s and 2000s. The chief threats appear to be habitat loss through intensification of agricultural land use practices and the hay cutting regime which presumably results in elevated nesting mortality for those that breed in hayfields.

The Grasshopper Sparrow has been assessed by COSSARO as a Special Concern species because of a continual long-term decline and a land use trend that continues to reduce the amount of suitable habitat for the species. The species is experiencing even greater annual declines in adjacent provinces and states.

Gypsy Cuckoo Bumble Bee (Bombus bohemicus)

The Gypsy Cuckoo Bumble Bee is one of six cuckoo bumble bees (subgenus Psithyrus) occurring in North America. Both sexes are medium-sized (12 – 18 mm length), with a white- tipped abdomen and similar colour pattern. The Gypsy Cuckoo Bumble Bee is a nest parasite of bumble bees of the subgenus Bombus in North America. Host species are the Rusty-patched Bumble Bee (B. affinis) (assessed Endangered by COSEWIC) and the Yellow-banded Bumble Bee (B. terricola) in Ontario. Females lack corbiculae (‘pollen baskets’) due to their parasitic life history.

The Gypsy Cuckoo Bumble Bee also occurs throughout most of Europe and parts of north and central Asia (COSEWIC 2014). In Canada, the Gypsy Cuckoo Bumble Bee has been recorded in every province and territory except Nunavut. Historically it occurred throughout most of Ontario in various habitat types. The species distribution is likely determined primarily by the distribution and abundance of its hosts. Despite high search effort 2001-2014 (n>6000 bumble bees) only one individual has been observed in Ontario (Pinery Provincial Park 2008). The primary threat to this species is the decline of its two hosts, possibly due to pathogen spillover from managed bumble bees. Other threats such as pesticide use and habitat loss may affect the species locally.

This species is assessed as Endangered using criterion A2abce. Despite having one of the largest historic ranges of all bumble bee species, declines in this species have exceeded 50% in 10 years. This has been observed with high recent search effort in southern Ontario and inferred from findings in other jurisdictions. The last record in Ontario (and in Canada) for this species was in 2008 at Pinery Provincial Park.

Loggerhead Shrike (Lanius ludovicianus)

The Loggerhead Shrike (Lanius ludovicianus) is a medium-sized, migratory songbird that inhabits open habitat containing isolated trees for nesting and elevated perches from which it hunts for prey such as insects and small rodents, snakes, amphibians, and birds. In Ontario, it has been observed using a variety of habitats including alvars, active and idle pastures, cultivated and native grasslands. The Shrike may impale (and temporarily cache) its prey on thorny trees or shrubs or barbed wire fences where available. It regularly occupies a narrow band of Ontario extending from the Bruce Peninsula in the west to Smith’s Falls in the east, and has been recorded periodically in northwestern Ontario. The Loggerhead Shrike is widely distributed in North America, and 11 subspecies have been named. Recent genetic analysis suggests the birds nesting in southern Ontario and adjacent Quebec may be genetically distinct enough to qualify as a separate subspecies (Lanius ludovicianus ssp.) that has not been named yet. The Ontario Breeding Bird Atlas suggests a decline of 63% in the probability of occurrence between the two atlas periods (1981-85 and 2001-05). Targeted surveys in Ontario suggest a decline in the number of mature adults of 26% from 1992-2013 and 13% from 2003-2013. The rate of decline in nesting pairs may have slowed as a result of recovery efforts underway since 1997, but the population of breeding birds is now critically low. The total number of breeding pairs is estimated to be 50-100 adults in Ontario and 10 or fewer birds in Quebec. A 2014 survey for the shrike revealed 16 pairs and 11 single birds for a total of 43 birds in Ontario.

A population viability analysis conducted by Environment Canada suggests the most important factor limiting recovery of the Loggerhead Shrike is overwinter survival of adults and juveniles, which directly influences potential recruitment into the breeding population. Birds from Ontario are thought to overwinter in the southeastern US. More information is needed on key factors that may affect the species on its wintering range.

The Loggerhead Shrike (Lanius ludovicianas) is classified as Endangered in Ontario on the basis of a very small number of adults, ongoing threats and continued population decline (COSSARO criteria met: C2a(i), D1).

Piping Plover (Charadrius melodus)

The Piping Plover is a small shorebird that nests on sandy or gravelly beaches just above the high water mark. Only one subspecies Charadrius melodus circumcinctus occurs in Ontario. In Ontario they nest primarily along the coasts and shorelines of large waterbodies such as the Great Lakes and Lake of the Woods. In the most recent census in 2011 it was estimated that there were 8100 breeding birds in a global population of 12,000-13,000. They were not historically common in Ontario, with the historical population estimated to be 70-90 pairs. The major causes of past declines were habitat (shoreline) disruption and recreational disturbance, augmented by increased predation and high water levels and/or wave action; these remain the most significant threats today. The breeding population in southern Ontario was extirpated in the 1970s, although a small breeding population remained in Lake of the Woods. National and provincial recovery strategies are in place, and extensive recovery efforts have been underway in both Canada and the United States. Nesting was once again initiated in southern Ontario (Sauble Beach) in 2007, and since that time 4-7 pairs have nested annually at four sites in Lake Huron. The Lake of the Woods population has remained at low levels, with 0-2 pairs nesting annually. The Piping Plover is considered vulnerable globally, and is also considered imperilled in most adjacent jurisdictions, providing little potential for rescue effect. The species meets Endangered under criterion D1 for very small or restricted population and criterion E1 for quantitative analysis indicating low probability of persisting population in Ontario. The Piping Plover (circumcinctus subspecies) is classified as Endangered in Ontario.

Round Pigtoe (Pleurobema sintoxia)

The Round Pigtoe is a freshwater mussel that reaches up to 13 cm in length. Adults have a thick, mahogany-coloured shell with dark bands. In Canada, Round Pigtoe are found in southwestern Ontario in the St. Clair River delta and the Sydenham River with small populations in the Grand and Thames rivers. It may be extirpated from Lake Erie and the Niagara River, however, further surveys are required to confirm this.The Round Pigtoe uses a variety of habitats including rivers and lakes with deep water and sandy, rocky, or mud bottoms. Like all freshwater mussels, it feeds on algae and bacteria that it filters out of the water. Mussel larvae are parasitic and must attach to a fish host, where they consume nutrients from the host until they transform into juvenile mussels and drop off. Hosts of the Round Pigtoe include: Spotfin Shiner, Northern Redbelly Dace, Bluntnose Minnow and Bluegill. Round Pigtoe is Endangered in Ontario. It only occurs at a few locations and the number of sites has continued to decline over the past 10 years due to invasive Zebra Mussels (COSSARO criteria A2, B1 & B2). The greatest threats to the Round Pigtoe are invasive species and run-off from agricultural lands.

Small-mouthed Salamander (Ambystoma texanum)

The Small-mouthed Salamander is a mole salamander (family Ambystomatidae). Adults are typically 11-18 cm in length, and black or dark brown in colour with light-grey or silver flecking, or grey blotching. Males are usually smaller than females. Small-mouthed Salamanders are nocturnal and often subterranean, preferring moist habitats near permanent bodies of water. They eat small invertebrates such as insects, slugs, and earthworms. Breeding occurs in the spring, and females can lay up to 700 eggs, which they attach in small clumps of up to 30 eggs to substrate under the water. The larvae are just over one centimetre in length when they hatch, and they develop into adult salamanders by midsummer.

In Canada the Small-mouthed Salamander is found only on Pelee Island, the largest island in Lake Erie, where only three known breeding sites remain. Precise population numbers are unknown, but extensive surveys have left no doubt that the total population size is small. Threats to Small-mouthed Salamanders on Pelee Island are thought to come from the recently introduced wild turkeys, which alter habitat and are known to prey on salamanders. Low water levels in at least one of the sites (Mosquito Point Woods) may also be a threat in years of low rainfall (COSEWIC, 2014). Small population size, potential ongoing threats, and the limited distribution of small-mouthed salamanders meant that this species was designated as Endangered in Canada in 2004 and 2014 (COSEWIC 2004, 2014). The Small-mouthed Salamander was designated as Endangered in Ontario in 2014 by COSSARO because of its small distribution and the predicted decline in the quality of its habitat [criteria B1 (a)(biii) and B2 (a)(biii)].

Wolverine (Gulo gulo)

Wolverine is a furbearer and member of the weasel family with a legendary reputation for strength and ferocity. Wolverines were once found throughout most of Ontario, but their range receded north and west between the 1800s and mid-1900s. They are now mostly confined to the boreal forest north of about 50°N latitude and west of about 85°W, although individuals often wander to the south and east. They require large home ranges and travel great distances seeking prey and carrion. Wolverines have low reproductive potential compared to other carnivores, with females maturing at 2 to 3 years, bearing only 2 young, and having litters every 2 to 3 years. Habitat loss and fragmentation contributed to the historical decline in Ontario and is a continuing threat at the southern edge of their range. Numbers killed by trapping are unknown, but their wide-ranging habits put them at higher risk of encountering traps and being killed by vehicles than more sedentary species. Although protected from non-native trapping, their low density, attraction to baited traps, and low reproductive potential put populations at risk of increased trapping mortality where roads push into formerly inaccessible parts of the range.

Although there is recent evidence suggesting that Ontario’s Wolverine population may be growing as the species expands east to reoccupy parts of its former range, the population remains small (estimated at between 458 and 645 animals) and it meets the threshold for Threatened under Criterion D1. Wolverine is classified as Threatened in Ontario.