The central focus of biospeleological research and thinking especially in North America has been those highly-adapted specialised troglobiontic animals which inhabit deep caves and subterranean waters in regions to the south of the maximum limits of the Pleistocene glaciations. Much less attention has been paid to the subterranean fauna of formerly glaciated northern regions of the continent, or to the many nonobligate species that occur in cave thresholds there and elsewhere.
The limits traditionally imposed by an emphasis on troglobionts to the exclusion of other fauna have long hindered progress in understanding hypogean fauna and ecosystems. However this is now changing. Most cave ecologists now accept the need to see subterranean communities in their entirety encompassing species at many different stages of adaptation (Gibert & Deharveng, 2002), and evolutionary cave biologists increasingly recognise the value of non-obligate cavedwellers as empirical models of natural selection and adaptation in the underground environment (e.g. Kane & Culver, 1992).
Accordingly there is now a clear need for systematic field surveys and evaluation of the cave and groundwater fauna of neglected regions of the continent, particularly Canada.
The eastern region of Canada comprising Newfoundland, the Maritime Provinces (Nova Scotia, New Brunswick, Prince Edward Island), Quebéc, and Ontario has many areas of karst, and natural dissolution caves are known from all these provinces except Prince Edward Island. However there have been almost no specific or regional biospeleological surveys. The exceptions are a detailed study of the fauna and ecology of Frenchman’s Cave, Nova Scotia (Calder & Bleakney, 1965; 1967) and a general survey of caves and mines in southern Ontario (Peck, 1988). The geographical area dealt with in the present paper, Nova Scotia and the southern part of the adjacent province of New Brunswick (Fig. 1), is the northern end of the Northern Appalachians region. The Maritime Provinces together with areas of eastern Quebéc are the Canadian part of the early French colony of Acadia; hence “Acadian” is a useful term often used in reference to this region. The area is cold-temperate, and somewhat low-lying with maximum elevations in Nova Scotia of 532m and 446m in southern New Brunswick. The whole of the present-day land area was subjected to multiple glaciations during the Pleistocene and was icecovered at the maximum of the last (Wisconsinian) glacial advance. The fauna and flora of the region is the result of immigration and recolonisation during and following the final retreat of the Wisconsinan glaciers, which is believed to have started ~21,000 years BP and to have been complete by ~11,000 years BP (King, 1996). Most species must have arrived from the south and west. Recolonisation of New Brunswick from these directions was relatively unrestricted by major physical barriers but immigration of many animals and plants into Nova Scotia is thought to have been constrained by the Tantramar Marshes, a narrow marshy isthmus which is the only land connection with New Brunswick: as a consequence the province is zoogeographically an island for many species (Fig. 1). The Strait of Canso physically further isolated Cape Breton Island until completion of the Canso Causeway in 1955 (Fig. 1). However there is evidence from present-day patterns of animal and plant distribution that some species may have recolonised Nova Scotia from the east by migration from an icefree Wisconsinian Atlantic Coastal Plain Refugium (Schmidt, 1986) or more likely from the emergent land areas which existed during the process of deglaciation (King, 1996). The existence of other late-Pleistocene refugia has also been proposed (e.g. Schmidt, 1986) but this remains highly speculative. In the historical period European contact resulted in the introduction of many exotic species through human migration and sea-borne trade.
The area has a number of exposed areas of sulphate (gypsum-anhydrite) and carbonate (limestone and dolostone) bedrock with underground drainage, springs, caves and other geomorphological karst features (Moseley, 1976; 1996: McAlpine, 1979). The southern part of mainland Nova Scotia has no significant karst but both gypsum and limestone caves are generally well-distributed throughout the rest of the region, with gypsum caves and karst predominating in Nova Scotia and limestone in New Brunswick. Dolostone karst is rare and no caves are known. Moseley (1996) gives maps showing the surface distribution of karst-forming rocks.
There are scattered notices of caves in various early geological survey reports, newspaper articles and other publications but the past forty years has seen the most intensive exploration and documentation. Approximately 50 dissolution caves are now documented in Nova Scotia and ~20 in southern New Brunswick. All explored caves are small with few exceeding 250m in length. The White Cave system (surveyed length = 515m) in New Brunswick; Hayes Cave (365m) and Point Edward Cave (293m), both in Nova Scotia, are the largest. The existence of more extensive subterranean systems is inferred from surface patterns of sinks and springs (Moseley, 1996).
Both Nova Scotia and New Brunswick have long histories of underground hardrock mining and the many abandoned mines provide ecologically cave-like habitat.
Emerton (1917) reported the Cave Spider Meta ovalis (as M. menardi) in Nova Scotia, although not from caves. Two specimens in the Canadian National Collection (CNC 3437, 3438) collected in Gays River Gold Mine, Nova Scotia, in 1963 appear to be the earliest underground record. The first published notices of cave animals in the area are of hibernating bats: the Northern Long-Eared Bat (Myotis septentrionalis) was reported by Gould (1936) in a cave in Hants County, Nova Scotia. Bleakney (1965) later found Eastern Pipistrelle (Pipistrellus subflavus) at several Nova Scotia sites as well as making the first reports of the occurrence of the common Little Brown Bat (Myotis lucifugus) in caves and mines in that province. In New Brunswick, McAlpine (1976) reported P. subflavus for the first time (from a cave) and the same author (1979) summarized underground records of this and other bats. There is one sight record of the Big Brown Bat (Eptesicus fuscus) in a cave hibernaculum in Nova Scotia (Scott & Hebda, 2004). Records of bats at underground sites in Nova Scotia have recently been collated by Moseley (in press).
There has been no systematic effort to document other vertebrates, but occasional records and observations have accumulated. North American Porcupine (Erethizon dorsatum) (Fig. 2) and their dung have been observed in most caves and a number of disused mines in southern New Brunswick and the mainland of Nova Scotia (Calder & Bleakney, 1965; 1967; McAlpine, 1979; Moseley, 1998). Porcupine did not reach Cape Breton Island until completion of the Canso Causeway. They have since become established in the east of the island (Scott & Hebda, 2004) but there are no reported sightings yet in island caves or mines.
Several other vertebrates have been sporadically recorded underground. McAlpine (1977, 1979) lists Mink (Mustela vison) scat, Smokey Shrew (Sorex fumeus), Deer Mouse (Peromyscus maniculatus) and a Beaver (Castor canadensis) den in New Brunswick. Beaver have also been seen in a Cape Breton stream cave (Sawatzky, 1986) and Raccoon (Procyon lotor) tracks were reported by Calder & Bleakney (1967) in Frenchman’s Cave. There are occurrence records of pallid Brook Trout (Salvelinus fontinalis) in limestone stream caves (Moseley, 1975; McAlpine, 1979) and Ninespine Stickleback (Pungitius pungitius) and Northern Redbelly Dace (Phoxinus eos) in Hayes Cave (Morris, 1985). Frog (Rana clamitans) tadpoles were collected in the threshold of Hayes Cave (Morris, 1985).
The first study of invertebrates was that of the terrestrial fauna of Frenchman’s Cave, Nova Scotia (Calder & Bleakney, 1965; 1967). Thirty-eight invertebrate taxa were reported from the threshold and deep threshold, the majority associated with decomposing porcupine dung accumulations. Acari were found to be numerically dominant in “poorly decomposed” dung samples, whilst Collembola became the most abundant microarthropods later in the ecological succession.
Broader, extensive rather than intensive, inventory of the regional invertebrate cave fauna began in the early 1970s with occasional sampling mostly as an adjunct to other underground work such as cave mapping, and continued through the 1980s and 1990s: a few of the records were published by the former Nova Scotia Speleological Society (Moseley, 1998 and references therein). Earthworms collected from several sites in New Brunswick were discussed by McAlpine & Reynolds (1977) and a brief summary of the composition of other New Brunswick cave fauna was provided by McAlpine (1979). During 1997, a systematic field survey of Nova Scotia cave habitats and invertebrate fauna was performed (Moseley, 1998).
A few specialised studies have been published based on the collections: Marusik & Koponen (1992); Moseley & Hebda (2001); Moseley et al. (2006); and Majka et al. (in press). Christiansen & Bellinger (1980, 1998) included records of Collembola in their comprehensive monographs on the North American collembolan fauna.
Except for a preliminary unpublished study of Hayes Cave (Moore, 1963) investigation of the cave environment and ecology started with Calder and Bleakney’s (1965, 1967) work, already referred to, in Frenchman’s Cave. This was the first report of porcupine dung as a cave habitat in the region. McAlpine (1979) suggested that plant detritus and porcupine dung were the principle energy sources in New Brunswick caves. In Nova Scotia, Hayes Cave and its environmental conditions were investigated by the provincial Museum of Natural History (Scott, 1979; Morris, 1985). The presence of porcupine dung, plant debris, and scattered bat droppings (
This paper reports the first comprehensive survey of cave fauna in Maritime Canada and the first general ecological survey of cave habitats and environmental conditions in any substantive geographical region of Canada. It also contributes to information about parietal assemblages, and adds to the very limited knowledge of the ecology of porcupine dung caves. An interim report was issued in manuscript as a museum Curatorial Report (Moseley, 1998)