Species at risks classifications and rationales (June 2010 meeting)

Cucumber tree (Magnolia acuminata)

This forest canopy tree can attain a height of about 30 m. It prefers rich, moist sites, often within a mosaic of swamp and upland. It occurs in eastern North America from New York in the north to northern Florida, Louisiana and Arkansas in the south. In Canada, it is native to the Carolinian region of Ontario and is restricted to two disjunct areas: Norfolk County and the Niagara Region. There are 18 extant populations known, of which only 4 contain more than 10 individuals. Lone trees will set a few seeds, but seed production is much higher where cross-pollinations can occur. Recruitment has not been observed in 8 sites in 10 years. The main threat may be inadvertent logging particularly on private land. Most populations appear to be stable, but habitat loss has occurred throughout the Carolinian region in Ontario and decline in habitat quality through fragmentation and invasive species is continuing in most sites. This species is Endangered in Ontario.

Dense blazing star (Liatris spicata)

Dense Blazing Star is a rare and declining species in Ontario that depends on provincially- imperiled prairie and savannah habitats. The species is threatened because of its restricted distribution, continued decline in the number and quality of extant occurrences, and the loss of habitat due to agriculture, urban development and fire suppression. Other identified threats include invasive species (particularly Common Reed, Phragmites australis australis), management practices (mowing, site alteration), trampling, wildflower picking, erosion from ship wakes, herbicides, and genetic contamination from adventive hybrids. However the species still occurs in 10 to 12 Ontario sites, some of which are in protected areas, and there are still an estimated 60,000 to 70,000 mature individuals in the province. This species is Threatened in Ontario.

Eastern prickly pear cactus (Opuntia humifusa)

There has been little change in status to this species since 1985 when it was first assessed as Endangered. While it has a widespread distribution in eastern North America, it is of conservation concern in several jurisdictions. There is no reason to believe that species is not native to Ontario or a recent arrival, but some populations have been introduced. Two extant native locations are present in Ontario, both occurring in the same ecodistrict. There is one Designatable Unit. Suitable habitat appears to be in decline and habitat loss arises from successional processes and control of habitats. This species is subject to imminent or projected habitat changes. This species is Endangered in Ontario.

Four-leaved milkweed (Asclepias quadrifolia)

Four-leaved Milkweed is widespread in eastern North American and known in Canada from two small populations near the eastern end of Lake Ontario. Historically the species was also present at several populations where there are no records in more than 50 years from this area. It occurs in open Bur Oak (Quercusmacrocarpa) – Shagbark Hickory (Carya oxata) woodland on shallow soil over limestone, a provincially rare habitat type, where it is threatened by increased shading due to habitat succession and invasive species. Fewer than 200 mature individuals are known in Ontario. This species is Endangered in Ontario.

Northern riffleshell (Epioblasma torulosa rangiana)

This species is currently confined to well-oxygenated riffle runs on two rivers in southwestern Ontario. These are two of four extant populations in North America The population is currently stable on one river, but there is evidence of recent declines on the other. Sedimentation, declining water quality, and the rapid spread of invasive mussels are the main threats in the intensively cultivated watersheds. The species has already disappeared from several areas in its former range, largely because of the spread of invasive Zebra Mussel (Dreissena polymorpha) and Quagga Mussel (Dreissena rostriformis bugensis). Because of the small area of occupancy and continuing declines in population and quality of habitat, this species is Endangered in Ontario.

Rayed bean (Villosa fabalis)

This is a small freshwater mussel with a limited northeastern North American distribution. In Ontario, it now occurs only in two rivers, and it has been extirpated from a large portion of its former range. The population in the one river appears relatively abundant and stable, whereas the other population is much smaller. With only 9 elemental occurrences in 2 river systems, this species is extremely vulnerable to environmental perturbations. Primary threats include the deterioration of water quality due to siltation, urbanization, nutrient enrichment from intensive agriculture, contaminants, thermal effects from the loss of riparian zones, and the detrimental effects of invasive species such as Zebra Mussel, Quagga Mussel and Round Goby (Neogobius melanostomus). There is little potential for rescue effect. This species is Endangered in Ontario.

Wavy-rayed lampmussel (Lampsilis fasciola)

This mussel was formerly widespread in southwestern Ontario where it now persists in only five river systems. They live in clear streams and are filter feeders. Their motile juvenile stage require fish hosts Smallmouth Bass (Micropterus dolomieu), Largemouth Bass (Micropterus salmoides), and perhaps also sculpins and sticklebacks. Some populations show evidence of recovery and there are large populations in three river systems. The area of occupancy has increased since the last status report. There is, however, a methodological problem used to estimate populations. Earlier surveys involved visual searches for the mussels and more recent ones also involved digging. Digging exposes younger animals and more animals so the apparent increase in population could be an artifact of sampling. Direct threats affecting streams and streambeds include contaminated runoff associated with agriculture and sedimentation Zebra Mussels are established downstream in some of these rivers and could pose a significant problem if they spread upstream. This species is Threatened in Ontario.

Bogbean buckmoth (Hemileuca sp.)

This is a black and white, day-flying, giant silkworm moth (Saturnidae). Although it has not yet been described as a new species, or possibly subspecies, it is distinguished from other similar moths by habitat, preferred food plant, and attributes of the larvae. Bogbean Buckmoth is found only in eastern Ontario and upper New York State and is the only buckmoth occurring in Ontario. The larvae feed primarily on Bogbean (Menyanthes trifoliata) in fens. Adults emerge in September, mate, and die within a few days. The primary threat to this species is invasive plant species including Common Reed (Phragmites australis autralis), Glossy Buckthorn (Rhamnus frangula), and Narrow-leaved Cattail (Typha angustifolia) that occur in or near all Ontario sites and threaten to crowd out Bogbean or otherwise alter the fen habitat. This species is Endangered in Ontario.

Frosted elfin (Callophrys irus)

Known historically in Ontario only from a single site in remnant oak savannah in Norfolk County. It has not been seen at this or any other site in the province since 1988, despite repeated searches of the historical site of occurrence and other sites supporting Wild Lupine (Lupinus perennis), the species’ larval host. The historical site has repeatedly been visited by several experienced entomologists at the appropriate season but there has been no sign of this species there. The data indicate that the species has been Extirpated from Ontario.

Karner blue (Lycaeides melissa samuelis)

Known historically in Ontario from remnant oak savannahs at 5 sites. It has not been reliably reported at any site in the province since 1988, despite repeated searches of the historical sites of occurrence and other sites supporting populations of Wild Lupine, the species’ larval host. In spite of continued sampling there are no new records of the species. This species has been Extirpated from Ontario.

Laura’s clubtail (Stylurus laurae)

This is a medium sized dragonfly inhabiting clean, sandy streams in eastern North America from Ontario, south to Florida and Texas. Its Ontario range includes sections of the north shore of Lake Erie. The larvae burrow in the silt and sand in the stream bed for 2 years or more. The adults emerge in July or early August and disperse to the surrounding forest until they return to the stream to breed. Laura`s Clubtail was discovered in Ontario in 1999 and population trends are unknown. Threats include aquatic habitat degradation through pollution, water removal for irrigation, and the invasive Round Goby. Given its small population size, limited distribution, and declines in habitat quality, this species is Endangered in Ontario.

Macropis cuckoo bee (Epeoloides pilosula)

This is a rarely collected species with a very specialized life history that involves a host species that is also very rare. With so few specimen records and no concrete information about nest sites or population trends it is difficult to say whether the species has declined or is declining, although some bee experts consider the species to have become increasingly rare.

This species is Data deficient in Ontario.

Rusty-patched bumble bee (Bombus affinis)

This species was once common in southern Ontario, but has undergone a well-documented and precipitous decline throughout its range over the past 30 years. Pesticides and pathogens (infections in domestic bees spreading into wild populations) along with habitat fragmentation have been suggested as possible causes of the decline. At the same time, while some Bombus species have become much more common others, such as B. fervidus, have become less common. We have an excellent baseline from which to work in the form of extensive collections, and publications in the 1970s. Recent surveys up to 2008 used the same sites studied in the 1970s, and have documented complete disappearance from most locations where it formerly occurred. This species is Endangered in Ontario.

Fowler’s toad (Anaxyrus fowleri)

This species occurs in most U.S. states south and east of the Great Lakes. In Canada, it is confined to portions of the Lake Erie shoreline, rarely occurring more than 500 m inland. Over the past few decades, it has declined with several populations disappearing. The species is severely limited by the amount of available habitat. Threats to the species are numerous as its beach habitat is under great and increasing pressure for recreation and housing. Major threats include manipulation of beach habitat, loss of beaches, dunes and temporary breeding ponds, decreased connectivity among occupied habitats, impact of invasive species especially Common Reed and Zebra Mussels, and increased levels of toxins including pesticides, industrial waste and botulism. A Population Viability Analysis based on a long-term population study indicates that the species has a high probability of extirpation from Ontario within the next 20 years. This species is Endangered in Ontario.

Spring salamander (Gyrinophilus porphyriticus)

The Spring Salamander is reliably known in Ontario only from an old (1877) specimen record from the Niagara River area. Repeated searches by people knowledgeable on the species and its habitat have not rediscovered it anywhere in Ontario, and it is reasonable to assume that the species has been Extirpated from Ontario.

Queensnake (Regina septemvittata)

This species is quite widespread in eastern North America but in Canada only occurs in Ontario. It shows a global decline in distribution and population. In Ontario, it appears to have been extirpated from 9 of 29 reported locations, and has not been observed in 15 of these 29 locations in the past 20 years despite targeted searches. It is a highly specialized species that requires the narrow riparian habitat of healthy streams as well as freshly moulted crayfish as its prey. It is limited by these requirements and threatened by loss and degradation of the riparian habitat, decline of water quality from pollution, siltation and water removal, and by declines in their crayfish prey. Native crayfish are themselves threatened by habitat degradation and by introduced crayfish. It is not known if Queensnakes eat introduced crayfish so it is not clear if their survival is threatened by invasive crayfish species. The species is further threatened by severe fragmentation into small isolated populations and the small size of its total Ontario population (<2500 individuals). This species is Endangered in Ontario.

Acadian flycatcher (Empidonax virescens)

The Acadian Flycatcher is a small, olive-green medium- to long-distance Neotropical migrant songbird. In Canada, the species breeds only in southwestern Ontario where it is typically found either in large patches of mature deciduous forest or in mature, forested ravine settings. Although the preferred habitat of these birds has diminished by as much as 90% since European settlement, there is no indication that this species was ever particularly abundant in Ontario. Within the core of its range south of the Great Lakes, this species has existed at stable population levels over the past several decades, with some increasing trends in New England states in tandem with reforestation. The Ontario population appears to have been relatively stable over the past 10-20 years. Nevertheless, it is a small population of no more than 35-50 pairs, which is very likely not sustainable except through immigration from U.S. populations. In the agriculture-dominated landscapes of southwestern Ontario, forests remain highly fragmented.

Forest pests that are killing preferred nest trees are increasing in northeastern United States, and that threaten to enter Canada, impose imminent threats to nesting habitat. This species is Endangered in Ontario.

Barn owl (Tyto alba)

One of the two Canadian populations occurs in Ontario (consisting of ~20 adult birds), the other is in British Columbia. Although this species has high reproductive potential because they lay large clutches and may reproduce at any time of the year, adults live less than 3 years. Even though in British Columbia and elsewhere in their range these birds regularly use nest boxes, this has not happened in Ontario. In Ontario, birds have suffered from loss of nesting sites (old barns and silos) and foraging habitat (due to the spread of agriculture and succession). There has been no change in the population in Ontario since the last assessment. Changes in land use and farming practices are the main threats to the population in Ontario. This species is Endangered in Ontario.

Bobolink (Dolichonyx oryzivorus)

This wide-ranging native species occurs in Canada from Newfoundland and Labrador to British Columbia and winters in southern South America. The Bobolink originally occurred mainly in tallgrass prairie of central North America and was less common in Ontario in presettlement times. The birds switched to hayfields with the spread of agriculture in its range. Breeding Bird Survey data indicate long term declines of 5.2% per year in the past 40 years or an 88% decline between 1968 and 2008 in Ontario. In the past 10 years (1998 to 2008) it declined by 38%. In Ontario the current breeding population is estimated at 400,000 pairs, but continual population declines as well as decreases in the extent of occurrence identify Bobolink as a species at risk. Ontario now supports about 45% of the Canadian population and therefore has a greater responsibility for protection of the species than it did historically. The main causes of mortality are associated with the timing of mowing of hayfields. One study has shown that early mowing directly destroys 51% of nests and young, and that the mortality increases to 94% as a result of nest abandonment, predation and baling. Hayfields are now mowed, on average, two weeks earlier than in the 1950s coinciding with the peak of the nesting season. Loss of habitat is associated with a change of land use, from hay to intensive crops and alfalfa, and with pesticide use on both summer and winter habitat. Rescue effect is possible from immigrants from the US. This species is Threatened in Ontario.

Eskimo curlew (Numenius borealis)

This is one of the world’s most endangered birds and is likely already extinct. There have been no fully substantiated records of the species anywhere since 1963, though there are still occasional sightings reported, including one from Ontario in 1976. The species never bred in Ontario but was once a regular and common transient in fall along the Hudson and upper James Bay coasts. The species is Extirpated in Ontario.

Greater prairie-chicken (Tympanuchus cupido)

This species originally occurred in southwestern Ontario, temporarily expanded its range east to Lake Simcoe, but had disappeared from southwestern Ontario in 1920s. It also occurred in Lake of the Woods area and on Manitoulin Island, where it persisted until about 1970.

Extirpation resulted from habitat loss and hybridization with Sharp-tailed Grouse. It was considered extirpated in Canada in 1978. The bird still persists in some states of the American Great Plains. The population adjacent to northwestern Ontario does not provide a likely rescue effect because large areas of suitable habitat are required for the species to persist. The species is Extirpated in Ontario.