Introduction
The Far North region of Ontario, Canada, covers 42% of the province’s landmass, an area of 451 000 km2. This region makes up a large portion of the third-largest wetland in the world (Crins et al. Reference Crins, Gray, Uhlig and Wester2009). Like many boreal regions, few biodiversity surveys have taken place here (Potapov et al. Reference Potapov, Hansen, Laestadius, Turubanova, Yaroshenko and Thies2017), with much of the region accessible only via aircraft (Far North Science Advisory Panel 2010; Ringrose et al. Reference Ringrose, Abraham and Beresford2013). Of the few biodiversity and ecological studies, the majority have focused on charismatic vertebrates such as caribou, moose, and wolves (Poley et al. Reference Poley, Pond, Schaefer, Brown, Ray and Johnson2013), bats (Layng et al. Reference Layng, Adams, Goertz, Morrison, Pond and Phoenix2019), and birds (Abraham Reference Abraham2014). The arthropod studies that have been conducted in the Far North have focused on collembolans, odonates, dipterans, lepidopterans, hymenopterans, and some beetles (Fjellberg Reference Fjellberg1985; Danks and Foottit Reference Danks and Foottit1989; Sutherland et al. Reference Sutherland, Oldham, Jones and Pratt2005; Beresford Reference Beresford2011; Ringrose et al. Reference Ringrose, Abraham and Beresford2013, Reference Ringrose, Abraham and Beresford2014, Reference Ringrose, Langer, Fleming, Burt, Bourne, Brand and Beresford2019; Fleming and Beresford Reference Fleming and Beresford2016, Reference Fleming and Beresford2019; Jumean et al. Reference Jumean, Oldham, Fleming, Duran and Beresford2017; Gibson et al. Reference Gibson, Bennet, Brook, Langer, MacPhail and Beresford2018; Langer et al. Reference Langer, Vezsenyi, de Carle, Beresford and Kvist2018; Vezsenyi et al. Reference Vezsenyi, Beresford, Moran, Young, Locke and Crins2021). Large gaps remain in our knowledge of the diversity and distribution of insects, even though the species’ ranges represent the fundamental unit of biogeography (Lomolino et al. Reference Lomolino, Riddle and Whittaker2017).
Indeed, such baseline data are essential for understanding how impending climate change, resource extraction, and other economic activity may affect the ecology of the region. The lack of baseline information represents a serious impediment to gauging anthropogenic effects (Mihoub et al. Reference Mihoub, Henle, Titeux, Brummitt and Schmeller2017). To address this need for a better understanding of a broader range of taxa, including ground beetles, we completed extensive sampling of the region from 2009 to 2015 in partnership with the Province of Ontario and local communities.
Ground beetles are taxonomically well known, and these insects are regarded as useful and rapid responders to ecosystem changes (Thiele Reference Thiele1977; Rainio and Niemela Reference Rainio and Niemela2003; Koivula Reference Koivula2011). They are one of the largest families of insects, with more than 2000 described species in North America (Bousquet Reference Bousquet2010). Ground beetles have been collected in nearly every type of terrestrial habitat, including Arctic meadows, ice fields, forests, bogs, marshes, and agricultural fields (Lindroth Reference Lindroth1961, Reference Lindroth1963, Reference Lindroth1966, Reference Lindroth1968, Reference Lindroth1969a, Reference Lindroth1969b). Although the distribution of ground beetles is well documented in southern Ontario (Lindroth Reference Lindroth1961, Reference Lindroth1963, Reference Lindroth1966, Reference Lindroth1968, Reference Lindroth1969a, Reference Lindroth1969b; Bousquet Reference Bousquet2010, Reference Bousquet2012; Bousquet et al. Reference Bousquet, Bouchard, Davies and Sikes2013), there is a paucity of information on ground beetles in remote regions such as Ontario’s Far North.
Here, we present a summary of our bioinventory of 99 species, including one first Canadian and 11 provincial records of the family Carabidae from Ontario’s Far North region. In addition, we analyse range records of 105 species – the 99 reported in this paper and six from previous publications (Fleming and Beresford Reference Fleming and Beresford2017, Reference Fleming and Beresford2019).
Materials and methods
Study area
Ontario’s Far North is a vast region that includes two ecozones – the Ontario (Boreal) Shield and the Hudson Bay Lowlands. At a macroscale, the boreal forest in the northern portion of the province appears as a large continuous and essentially homogeneous landscape comprising mixed-wood and coniferous forests and low-lying areas of bogs and fens (Fraser and Keddy Reference Fraser and Keddy2005; Crins et al. Reference Crins, Gray, Uhlig and Wester2009). However, at the finer scale pertinent to ground beetles, the boreal forest is a patchwork of heterogeneous habitats (Rainio and Niemela Reference Rainio and Niemela2003).
Collecting methods
Specimens were collected through four different projects. The largest in scope was the Far North Biodiversity Project, followed by the Natural Heritage project, and two localised surveys – one of the Moosonee region and another that focussed on coastal regions of Attawapiskat, Burnt Point, and Peawanuck (Fleming Reference Fleming2021, Fig. 1). Across the four projects, 534 sites were surveyed (Fig. 1). Individual trapping details are provided in Table 1.
Fig. 1. Far North of Ontario, Canada. Open circles (534) represent all survey locations, 2009–2015, and filled circles (112) represent locations where ground beetles were collected. The line at approximately 50° latitude North represents the northern limit of timber harvesting in Ontario.
Table 1. Summary of trapping effort for each project. Years represent the years in which each project took place; months sampled are the months in which sampling took place (for specific dates each location was sampled, see Table 2); and trap type and trap days are the type of trap used in the different projects and the number of days the trap was set. N/A indicates that trap type was not used for that project.
The Far North Biodiversity Project was conducted at 65 sites accessed by helicopter over a two-week period at each site between 2009 and 2014. Carabidae were collected using six pitfall traps at each site, set out along bisecting transects and deployed for eight days (site sampling details provided by Goertz Reference Goertz2011), as well as by hand, in pan traps, and, for two specimens, in bottle traps.
Pitfall traps consisted of two 500-mL cups that were placed with the lip flush with the ground, one-third filled with nontoxic propylene glycol. A flat natural object, such as a piece of bark, was suspended 1.5 cm above the trap (Fleming and Beresford Reference Fleming and Beresford2019).
Pan traps consisted of shallow bowls placed in holes deep enough to allow the rim of the pan to be level with the ground (Gibson et al. Reference Gibson, Bennet, Brook, Langer, MacPhail and Beresford2018; Fleming and Beresford Reference Fleming and Beresford2019). A total of nine pans were set at each survey site, consisting of three blue, three yellow, and three white pans. The pan traps were placed in a cross formation and covered a 10-m2 sampling area (Gibson et al. Reference Gibson, Bennet, Brook, Langer, MacPhail and Beresford2018; Fleming and Beresford Reference Fleming and Beresford2019). Four pans were placed along the edge of the plot, another four pans were placed 2.25 m from the edge of the plot, and a final pan was placed in the centre, 2.25 m from the surrounding pan traps (Gibson et al. Reference Gibson, Bennet, Brook, Langer, MacPhail and Beresford2018; Fleming and Beresford Reference Fleming and Beresford2019). Pans were filled with nontoxic propylene glycol.
Specimen identification and storage
All specimens collected were stored in 70% ethanol. In January 2016, all specimens were pinned, labelled, and identified. We identified specimens using dichotomous keys (Lindroth Reference Lindroth1961, Reference Lindroth1963, Reference Lindroth1966, Reference Lindroth1968, Reference Lindroth1969a, Reference Lindroth1969b; Goulet Reference Goulet1983; Liebherr and Will Reference Liebherr and Will1996; Bousquet Reference Bousquet2010), from which we also based our taxon concept and classifications. In cases where species identifications have changed since Lindroth (Reference Lindroth1961, Reference Lindroth1963, Reference Lindroth1966, Reference Lindroth1968, Reference Lindroth1969a, Reference Lindroth1969b), we used the updated nomenclature from Bousquet (Reference Bousquet2010, Reference Bousquet2012) and Bousquet et al. (Reference Bousquet, Bouchard, Davies and Sikes2013). All specimens are housed in the entomological collection at Trent University (Peterborough, Ontario, Canada), except for a reference collection maintained by the Peawanuck First Nation community, Ontario, Canada.
Analysis
New records and range extensions were determined using publications and databases (Lindroth Reference Lindroth1961, Reference Lindroth1963, Reference Lindroth1966, Reference Lindroth1968, Reference Lindroth1969a, Reference Lindroth1969b; Goulet Reference Goulet1983; Liebherr and Will Reference Liebherr and Will1996; Bousquet Reference Bousquet2010; Bousquet et al. Reference Bousquet, Bouchard, Davies and Sikes2013; Canadian National Collection of Insects, Arachnids and Nematodes 2022; Global Biodiversity Information Facility 2022a). We denoted a range extension as any specimen more than 100 km from the closest edge of the species’ known range. We created a histogram of these distances from the range edge and the number of species that fell within each distance bin. Range maps were produced with ArcGIS 10.8.1 (Environmental Systems Research Institute 2011).
To estimate the number of species of Carabidae expected from the Far North region, we used Chao1 (Gotelli and Colwell Reference Gotelli, Colwell, Magurran and McGill2010) to produce a species rarefaction curve (Hammer et al. Reference Hammer, Harper and Ryan2001).
Results
In total, 644 specimens were collected from 112 sites across Northern Ontario (Table 2; Fig. 1; see Fleming and Beresford Reference Fleming and Beresford2017 for Carabus granulatus and Fleming and Beresford Reference Fleming and Beresford2019 for Elaphrinae). There were 335 specimens collected as part of the Far North Biodiversity Project, of which six were damaged and could not be identified. Natural Heritage surveys resulted in the collection of 68 specimens. The remaining independent projects collected 241 specimens. Six of the 644 specimens could not be identified to species: one specimen, Agonum Bonelli (Coleoptera: Carabidae), was identified to genus, and the remaining five were damaged and could not be identified further than Carabidae.
Table 2. Species of ground beetles collected in Ontario’s Far North, 2009–2015.
Φ species new to Canada;
* species new to Ontario;
• species with range extension;
§ species not native to North America. Entries represent the number of specimens. For Carabus granulatus, see Fleming and Beresford (Reference Fleming and Beresford2017) and for the five species of Elaphrinae, see Fleming and Beresford (Reference Fleming and Beresford2019).
Including specimens first reported elsewhere, Carabus granulatus (Fleming and Beresford Reference Fleming and Beresford2017), and five species of Elaphrinae (Fleming and Beresford Reference Fleming and Beresford2019), we identified 638 specimens representing 105 species from 31 genera that were collected from Ontario’s Far North. Of these 105 species, one species was new to Canada, 11 species were new to Ontario (including the species new to Canada), and 70 range extensions at least 100 km from known range limits were identified. These range extensions include the species new to Canada and Ontario and the species reported in Fleming and Beresford (Reference Fleming and Beresford2017, Reference Fleming and Beresford2019; Table 2; Fig. 2). The species new to Canada was Notiophilus nemoralis Fall (Fig. 2). The 10 species new to Ontario (excluding N. nemoralis) were Agonum simile Kirby, Amara pseudobrunnea Lindroth, Bembidion bruxellense Wesmael, Bembidion postremum Say, Bembidion rufotinctum Chaudoir, Bembidion simplex Hayward, Dicheirotrichus mannerheimii Sahlberg, Dyschirius larochellei Bousquet, Paranchus albipes (Fabricius), and Pterostichus articola (Chaudoir) (Fig. 2). Eight nonnative species were collected as part of this work. The eight species not native to North America were Agonum muelleri (Herbst), Bembidion bruxellense, Blemus discus discus (Fabricius), Carabus granulatus Linnaeus, Clivina fossor (Linnaeus), Harpalus affinis (Schrank), Paranchus albipes, and Pterostichus melanarius (Illiger) (Table 2; Fig. 3).
Fig. 2. Species locality maps of new records to Canada for Notiophilus nemoralis (N.n.) and Ontario for Agonum simile (A.s.), Bembidion bruxellense (B.b.), Bembidion postremum (B.p.), Bembidion simplex (B.s.), Dicheirotrichus mannerheimii (D.m.), Dyschirius larochellei (D.l.), and Paranchus albipes (P.a.).
Fig. 3. Collection sites of nonnative species with range extensions or gap infills in Ontario, Canada for Agonum muelleri (A.m.), Blemus discus (B.d.), Harpalus affinis (H.a.), and Pterostichus melanarius (P.m.).
We found a median range extension of 650 km, demonstrating a positive skew (Fig. 4). As well, the vast majority (66; 95%) of the 69 range extensions were in a northward direction, and only three range extensions were in a southward direction (Fig. 5).
Fig. 4. Frequency distribution of range extensions for species of ground beetles in Ontario’s Far North, Canada.
Fig. 5. Directions of range extensions of species of ground beetles collected in Ontario’s Far North, Canada. Values represent the number of species. Note: Bembidion obtusidens was excluded from this figure as the previous exact collection location was not noted (Bousquet Reference Bousquet2012). However, based on the previous collection in northwestern Ontario, we can tentatively estimate the direction to be northeastward.
From the Chao1 analysis, we surmised a total of 171 Carabidae species across the study region, 66 more species than we collected. Rarefaction analysis also indicated that our survey did not capture specimens from all species (Fig. 6).
Fig. 6. Rarefaction curve of Carabidae sampling data from 2009 to 2015 in Ontario’s Far North, Canada.
Discussion
Species new to Canada
Notiophilus nemoralis was previously recorded from the northeastern United States of America (Table 3; Bousquet Reference Bousquet2012). Notiophilus nemoralis has a restricted distribution to mountainous habitats, occurring below the timber limit (Lindroth Reference Lindroth1961). We collected a single individual from the interior of Ontario’s Far North, representing the first Canadian record of this species and a large range extension (Tables 2–3; Figs. 2, 7).
Table 3. Previously known distributions of ground beetles in Canada and the United States of America and the approximate distance for each species with range extensions. Provincial and state records and distance of range extensions were determined using Lindroth (Reference Lindroth1961, Reference Lindroth1963, Reference Lindroth1966, Reference Lindroth1968, Reference Lindroth1969a, Reference Lindroth1969b), Goulet (Reference Goulet1983), Liebherr and Will (Reference Liebherr and Will1996), Bousquet (Reference Bousquet2010), Bousquet et al. (Reference Bousquet, Bouchard, Davies and Sikes2013), Canadian National Collection of Insects, Arachnids and Nematodes (2022), and Global Biodiversity Information Facility (2022a). See the notes at the end of the table for a key to abbreviations.
Province abbreviations: AB, Alberta; BC, British Columbia; MB, Manitoba; NB, New Brunswick; NF, Newfoundland and Labrador; NS, Nova Scotia; NT, Northwest Territories; ON, Ontario; PE, Prince Edward Island; QC, Quebec; SK, Saskatchewan; YK, Yukon Territory.
State abbreviations: AK, Alaska; AL, Alabama; AR, Arkansas; AZ, Arizona; CA, California; CO, Colorado; CT, Connecticut; DC, District of Columbia; DE, Delaware; FL, Florida; GA, Georgia; IA, Iowa; ID, Idaho; IL, Illinois; IN, Indiana; KS, Kansas; KY, Kentucky; LA, Louisiana; MA, Massachusetts; MD, Maryland; ME, Maine; MI, Michigan; MN, Minnesota; MO, Missouri; MS, Mississippi; MT, Montana; NC, North Carolina; ND, North Dakota; NE, Nebraska; NH, New Hampshire; NJ, New Jersey; NM, New Mexico; NV, Nevada; NY, New York; OH, Ohio; OK, Oklahoma; OR, Oregon; PA, Pennsylvania; RI, Rhode Island; SC, South Carolina; SD, South Dakota; TN, Tennessee; TX, Texas; UT, Utah; VA, Virginia; VT, Vermont; WA, Washington; WI, Wisconsin; WY, Wyoming; WV, West Virginia.
Fig. 7. High-resolution macrophotograph of Notiophilus nemoralis (dorsal and lateral view), a new Canadian record. Photographs were taken with a Canon 5DS digital SLR camera (Canon Inc., Ota, Tokyo, Japan) with a Canon MPE-65 lens (Canon Inc.). Original photographs were processed (stacked) using Affinity Photo (Serif (Europe) Ltd. (https://affinity.serif.com/en-us/photo/).
Species new to Ontario
Eleven of the species collected were new to Ontario, including the one (N. nemoralis) mentioned above (species new to Canada; Fig. 2). Of the remaining 10 species, we documented one species in the genus Agonum: A. simile; one species of Amara Bonelli: A. pseudobrunnea; and four species of Bembidion Latreille: B. bruxellense, B. postremum, B. rufotinctum, and B. simplex. The remaining species were single representatives of their genera: Dicheirotrichus Jacquelin – D. mannerheimii; Dyschirius Bonelli – D. larochellei; Paranchus (Fabricius) – P. albipes; and Pterostichus Bonelli – P. articola. As we discuss below, A. simile, B. bruxellense, B. postremum, B. simplex, D. mannerheimii, D. larochellei, and P. albipes are of particular interest, given their previously known distributions.
Agonum simile is generally a species from the northwest of North America (Table 3; Bousquet et al. Reference Bousquet, Bouchard, Davies and Sikes2013). The species was largely restricted to the northern coniferous region from scattered locations (Table 3; Lindroth Reference Lindroth1961; Bousquet Reference Bousquet2012). We collected one specimen from Attawapiskat (Tables 2–3; Fig. 2).
Bembidion bruxellense is an exotic species in Canada, introduced from Europe. It was first discovered in Newfoundland in 1907 (Lindroth Reference Lindroth1963; Bousquet Reference Bousquet2012). Bembidion bruxellense is found in temperate and boreal climate zones (Bousquet Reference Bousquet2010). It is a habitat generalist with no documented habitat preferences (Lindroth Reference Lindroth1963) and has been documented in a variety of habitats such as open places, vacant fields, sand and gravel pits, and on the borders of marshes and ephemeral pools (Bousquet Reference Bousquet2010). Previous records for B. bruxellense were confined to eastern Canada and Maine, United States of America (Table 3; Bousquet et al. Reference Bousquet, Bouchard, Davies and Sikes2013). Our record of B. bruxellense was from the most northwestern point of Ontario (Table 3; Fig. 2).
Bembidion postremum is distributed across much of eastern North America and to the midwestern United States of America (Table 3). We collected four specimens clustered around Moosonee, Ontario near the Moose River (Table 2). This finding aligns well with the species’ habitat preferences, particularly along riverbanks and on damp ground of sandy or silty soils (Bousquet Reference Bousquet2010). Our collection of B. postremum is the first Ontario record (Table 3; Fig. 2).
Bembidion simplex is distributed across much of the eastern United States of America to the midwest, and several specimens have been collected in southern Quebec (Table 3; Lindroth Reference Lindroth1961; Bousquet Reference Bousquet2012). The origins of the two records in the Global Biodiversity Information Facility (2022b, 2022c) are uncertain. The first specimen is noted to have a “Country coordinate mismatch.” Canada is noted as the country of collection; however, the geographic coordinates place this specimen in Michigan, United States of America (Global Biodiversity Information Facility 2022b). The second specimen, collected in the Northwest Territories, Canada, was noted on the label as “might be B. simplex, if not it is planuisculum” (Global Biodiversity Information Facility 2022c). If these two records are incorrect, our collection represents the first Ontario record for B. simplex (Table 3; Fig. 2).
Dicheirotrichus mannerheimii is circumpolar in North America and Europe (Table 3; Bousquet Reference Bousquet2012). In southern locations (Colorado, United States of America), D. mannerheimii is isolated at high-altitude localities (Global Biodiversity Information Facility 2022d). Lindroth (Reference Lindroth1968) and Bousquet (Reference Bousquet2012) noted a present-day distributional gap in Ontario; however, fossil remnants of D. mannerheimii from the early Wisconsinan glacial period have been discovered in southern Ontario (Morgan and Morgan Reference Morgan and Morgan1981). Dicheirotrichus mannerheimii is a cold-hardy species, found primarily on the tundra (Lindroth Reference Lindroth1968). The southern distributional range of D. mannerheimii likely has been contracting since the last glaciation. We collected a single specimen along the northern Hudson Bay coastline, representing a new record for contemporary Ontario (Table 3; Fig. 2).
Dyschirius larochellei has a limited distribution in North America, largely confined to the eastern seaboard (Table 3; Bousquet Reference Bousquet2012; Global Biodiversity Information Facility 2022e). We collected two specimens from one locality in the Far North. This extends the known range of D. larochellei northwestwards and is the first record for Ontario (Table 3; Fig. 2).
Paranchus albipes is an adventive species that is not native to North America. It was introduced from western Europe before 1835, with the first inventoried specimen collected in Newfoundland (Bousquet Reference Bousquet2012). As well, Bousquet (Reference Bousquet2012) notes that the Canadian Museum of Nature (Ottawa, Ontario, Canada) has in its collection drawings of the insect; these drawings were created before 1834 by Philip Henry Gosse (Entomologia Terrae Novae [manuscript] https://www.biodiversitylibrary.org/bibliography/128443). Since its introduction, the species has expanded its range in Canada throughout the Maritime provinces (Table 3; Bousquet et al. Reference Bousquet, Bouchard, Davies and Sikes2013). We collected the specimens from two locations: along Moose River and along the shores of an unnamed lake in Opasquia Provincial Park (Tables 2–3; Fig. 2). Paranchus albipes generally occurs on clay soil with little to no vegetation and along the edges of aquatic ecosystems (Lindroth Reference Lindroth1968).
Range extensions and updates of nonnative species
We found eight species not native to North America, including the two nonnative species discussed above (species new to Ontario) and one, Carabus granulatus, discussed in Fleming and Beresford (Reference Fleming and Beresford2017). Of the remaining five species, three species exhibited range extensions, one species had gap infills (i.e., in the interstices of its known range), and the remaining species, Clivina fossor, was found within its known range.
Agonum muelleri is a Palaearctic species, found across much of northern Europe and Eurasia. It was initially identified in Newfoundland in 1840 and in British Columbia in 1933 (Lindroth Reference Lindroth1966; Bousquet Reference Bousquet2012). Agonum muelleri has been collected in Ontario along the north coast of Lake Superior (Lindroth Reference Lindroth1966). Our collection extends the known range northwards by 300 km (Table 3; Fig. 3). Agonum muelleri is a habitat generalist, found in a variety of open habitats (Lindroth Reference Lindroth1966).
Blemus discus discus was introduced in Canada from Europe in 1933, with the first inventoried specimen collected in Montréal, Quebec (Bousquet Reference Bousquet2012). Blemus discus discus has been collected from several eastern provinces (Table 3; Bousquet et al. Reference Bousquet, Bouchard, Davies and Sikes2013). We collected one specimen from Moosonee (Table 3; Fig. 3). Blemus discus discus prefers habitats of moist clay and peat ground, close to water (Bousquet Reference Bousquet2012).
Harpalus affinis was introduced before 1798 in Pennsylvania, United States of America, with separate western and southern introductions (Bousquet Reference Bousquet2012). The species is widely distributed in Canada, having been collected from eight provinces (Table 3; Lindroth Reference Lindroth1968; Bousquet Reference Bousquet2012). The species was previously collected in Cochrane, Ontario. Our collection of H. affinis extends the known range northwards (Table 3; Fig. 3).
Pterostichus melanarius was first introduced in Nova Scotia in 1926, originating from Europe (Bousquet Reference Bousquet2012). A second introduction was noted in Seattle, Washington, United States of America (Bousquet Reference Bousquet2012). Pterostichus melanarius is widely distributed, having been recorded from all 10 provinces (Table 3; Bousquet Reference Bousquet2012), and it was previously collected from Moosonee in Ontario (Ernst Reference Ernst2016). The specimens collected as part of this project include multiple locations near Moosonee and three locations in the interior of Ontario’s Far North. The specimens from Moosonee do not represent a range extension, but the specimens collected in the interior represent a gap infill for the province (Fig. 3).
Range extensions
In addition to the range extensions and gap infills of the nonnative species, we found range extensions for another 55 species not already discussed in previous sections (11 species) or in Fleming and Beresford (Reference Fleming and Beresford2017, Reference Fleming and Beresford2019; four species; Table 3).
In examining these range extensions, we found a median distance of 650 km (Fig. 4). This positive skew is similar to the distribution of dispersal distance among vertebrates, with most dispersers moving short distances and few species dispersing long distances (Sutherland et al. Reference Sutherland, Harestad, Price and Lertzman2000). For extensions of the distribution of ground beetles, we too found most range extensions were of short distances and few range extensions were of long distances – up to 2040 km.
We found strong directionality in these documented range extensions: three instances of southwards range extensions versus 66 instances of northwards range extensions. The three species with southwards range extensions were Agonum simile, Amara glacialis (Mannerheim), and Dicheirotrichus mannerheimii (Sahlberg) (Table 2). Range extensions for most of the species collected were in northwards directions, with 48 extensions in a northwest direction and 18 extensions in a northeast direction (Table 2; Fig. 5). We found no southwestward range extension (Table 2; Fig. 5). This tendency for northwards range extension could be due to three reasons. First, there have been few scientific studies in Ontario’s Far North: most entomological surveys and species records occur near human settlements, which, in Canada, are largely along the southern border (Potapov et al. Reference Potapov, Hansen, Laestadius, Turubanova, Yaroshenko and Thies2017). Second, latitudinal gradients in species richness (Lomolino et al. Reference Lomolino, Riddle and Whittaker2017) mean that more speciose southern assemblages serve as the source for northwards range extensions. The relative paucity of species to the north of our study region may be exacerbated by Hudson Bay, which is likely a major barrier to dispersal. Lastly, this directional skew could be the result of climatic changes that have occurred since the end of the Wisconsin glaciation: as the glaciers retreated, newly accessible areas opened up (Ball and Currie Reference Ball, Currie, Danks and Downes1997; Dyke Reference Dyke, Ehlers and Gibbard2004). The large range extensions could be due to some ground beetle species being stranded in climatic refugia as temperatures rose, which might explain the presence in Ontario’s Far North of Notiophilus nemoralis, a species previously known only from the spruce-dominated Appalachian Mountains region in the New England region of the United States of America (Lindroth Reference Lindroth1961). This is also consistent with the presence of Dicheirotrichus mannerheimii, a northern and high-elevation species. Fossilised specimens have been found across much of North America (Morgan and Morgan Reference Morgan and Morgan1981; Schwert Reference Schwert1992; Motz and Morgan Reference Motz and Morgan1997; Bousquet Reference Bousquet2012), demonstrating a more widespread earlier range.
Many of the species we collected were expected. Specifically, these were the species that had previous records from surrounding provinces (Table 3). Species that were new to Ontario and Canada are likely not new to these jurisdictions; they just probably had never been recorded. It is also possible some of these species were translocated through phoresy on migratory birds or aboard aircraft or cargo transported to the region. The Chao1 analysis indicated that our survey did not include all species, consistent with our rarefaction analysis (Fig. 6). There are still many other species present in this region, and this survey, although extensive, is incomplete. This is not surprising, given that the Far North of Ontario is a vast territory.
Nevertheless, we collected one species new to Canada, 10 species new to Ontario, and numerous range extensions and gap infills in Ontario’s boreal forest. Indeed, the documentation of species ranges is a longstanding pursuit in biology (Lomolino et al. Reference Lomolino, Riddle and Whittaker2017). Only with such knowledge are we likely to understand the biotic shifts due to climate change and an expanding industrial footprint.
Acknowledgements
The authors thank the Ontario Ministry of Natural Resources and Forestry’s Northeast Science and Information Section and Wildlife Research and Development section for coordinating the project and project logistics. In addition, the authors thank the Far North Branch, which funded the Far North Biodiversity Project, and the field crews who collected the samples used in this paper. The authors also thank the First Nations communities of Kitchenuhmaykoosib Inninuwug, Keewaywin, Fort Severn, Fort Albany, Sandy Lake, Nibinamik, Webequie, Peawanuck, Attawapiskat, Marten Falls, Moose Cree, Pickle Lake, Eabametoong, and Constance Lake, Ontario, Canada for their generosity and support for working on their traditional territory. The authors are grateful to the anonymous reviewers for their insightful comments and suggestions.
Competing interests
The authors declare no competing interests.
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