Atlas of the Mammalsof Ontario

Jon (Sandy) Dobbyn

Federation of Ontario Naturalists

The Atlas of the Mammals of Ontario

was generously supported by the following organizations:

Ontario Ministry of Natural Resources

Employment and Immigration Canada

Environmental Youth Corps

Ontario Heritage Foundation

Federation of Ontario Naturalists

Environment Canada

Ontario Federation of Anglers and Hunters

Canadian Wildlife Foundation

University of Waterloo

Royal Ontario Museum

Carleton University

Funding for the printing of the Atlas of the Mammals of Ontario

was provided by the Ontario Heritage Foundation.

Atlas of the Mammalsof Ontario

ii

Atlas of the Mammalsof Ontario

by Jon (Sandy) Dobbyn

with contributions from Judith Eger and Nancy Wilson

Canadian Cataloguing in Publication Data

Dobbyn, Jon Sandy, 1966-Atlas of the mammals of Ontario

Includes bibliographical references and index.ISBN 1-896059-02-3

1. Mammals - Ontario - Geographical distribution- Maps. 2. Mammals - Ontario - Geographical distribution.I. Federation of OntarioNaturalists. II. Title.

QL721.5.05D63 1994 599.09713’022’3 C94-900351-4

Published by:

Federation of Ontario Naturalists355 Lesmill Road, Don Mills, Ontario, CanadaM3B 2W8(416)444-8419 Fax: (416)444-9866

Copyright © Federation of Ontario Naturalists 1994

All rights reserved. No part of this publication may bereproduced or used in any form by any means - graphic,electronic or mechanical, including photocopying,recording, taping or information storage and retrievalsystems without written permission of the Federation ofOntario Naturalists. Critics or reviewers may quote briefpassages in connection with a review or critical articlein any media.

Proceeds from the sale of this book go to supportfurther volunteer conservation efforts.

Printed in Canada by D.W. FriesenAltona, Manitoba Canada.

cover photo: Red Fox: Michael W.P. Runtz

iv

ForewordThe presence of a balanced, functioning mammalfauna in an area is an indicator of the general healthof that environment. Monitoring mammalpopulations, particularly in habitats sensitive tohuman activities, is an important part of taking theenvironmental pulse. The Atlas of the Mammals ofOntario serves as a baseline in this regard, as didthe maps published by R.L. Peterson earlier (1966,The Mammals of Eastern Canada). Thesedocuments summarize our knowledge of thedistribution of mammals at specific periods in time.

The geographic distribution of a species is a majoraspect of its natural history, and the knowledge ofthe geographic distribution of all species within aregion provides the basis for faunal analyses orstudies of biological diversity. The Atlas of theMammals of Ontario is a compilation ofdistributional data, both historical and recent, for allwild mammals found in the province.

The distributional ranges of different species varygreatly, from those that are restricted to a relativelysmall area, such as the Eastern Mole, to those thatencompass the entire province, such as the RedFox. The reasons for this are not always clear. Insome cases ranges may be limited by geographicbarriers, but more importantly, the distribution andabundance of an individual species are governed byenvironmental factors that influence its chance tosurvive and reproduce. These factors may begrouped into four major categories:weather/climate, food, other animals and disease-causing organisms, and places in which to live.These major environmental components may act ontheir own, or, and this is probably more often thecase, they may interact.

An example of a single environmental componentbeing involved is provided by the evidence that theoccurrence of prolonged periods of cold weather inwinter is the factor that limits the northerndistribution of the Virginia Opossum. Theopossum’s spread into the north temperate regionsof North America is a relatively recent phenomenonand it is, therefore, not surprising that the specieshas not fully adapted to harsh winters.

To illustrate the more complex situation of anumber of components interacting, one couldconsider the history of the distributions of theWhite-tailed Deer and the Caribou. Habitat changesproduced by humans favoured the northwardextension of the White-tailed Deer’s range. With thedeer came a parasitic meningeal nematode which,harmless enough in its normal host, proved to bedeadly for the Caribou. The parasite, combinedwith extensive logging of old growth Boreal Foreston which the Caribou depends, played a major rolein eliminating the Caribou from most of its southernrange. Logging of the old growth forest favouredthe expansion of Moose populations. Wolf numbersincreased along with the Moose, resulting in higherpredation rates on the more vulnerable Caribou.

These few examples serve to illustrate that athorough knowledge of a species’ requirements andan understanding of how the major environmentalcomponents interact are needed to explain thedistribution and abundance of a species.Unfortunately, only a few species have beenadequately studied and there remains much to belearned about the distribution and abundance ofOntario’s mammals. One thing is certain, in thecategory “other animals”, humans loom large as afactor in the distribution and abundance of all other

Eastern Chipmunk: Ivan Foster

v

species. Humans are the most abundant largemammals in the province and their impact on theglobal environment is, as we all know, significantand pervasive. The effects of the generalenvironmental degradation of air, water, and soiland the significant loss or fragmentation of habitatsare most noticeable in southern Ontario wherehuman population densities are greatest. Althoughmany wild mammals were affected negatively,several have benefited from the human-madechanges or have adapted to them in time. Some,such as Gray Squirrels and Raccoons, have evenbecome urbanites.

In northern Ontario with nearly 90% of the landand only 10% of the human population, thesituation may seem less acute, but major problemsexist here as well. Most of these problems arecaused by extractive industries and logging. Ofparticular concern at present, is the massivedestruction of old growth boreal forests byclearcutting, which will have serious consequencesfor the distribution and abundance of species suchas Caribou and Marten. It is clear that improvingthe environment and restoring healthy ecosystemsrequires intensive management of our own species.

Biodiversity has now become a household word,like ecology before it. Most people think ofbiodiversity simply as the number of species livingin a particular area. However, there are otheraspects of biological diversity that one has to takeinto consideration when comparing different areas,

such as the relative abundances of species in acommunity, or seasonal changes in the number ofspecies present. Another aspect of biologicaldiversity is the adaptive radiation in a group. In thisrespect, mammals display greater diversity thanother vertebrates, having adapted to all climates,and to life in the water, on the land, in the soil, inthe trees, and in the air. For those interested inassessing the biodiversity of an area, the MammalAtlas provides the basic information on the numberof species present.

Not only are mammals an important part of theoverall biological diversity of the province, butmany are also keystone species in their ecologicalcommunities. For example, herbivorous mammals,such as voles, Snowshoe Hares, deer, and Moose,are important links in the food chains of terrestrialcommunities, whereas the larger carnivorousmammals function as top predators. There are alsomore subtle, but equally essential, interactionsbetween mammals and plants that sustaincommunities, such as that between the GraySquirrel and its food plants. Not only is this speciesan agent of seed dispersal for nut-bearing trees, butit also spreads the trees’ mycorrhizal symbionts, byeating the fruiting bodies of the fungi and passingthe spores, unharmed, in its droppings.

The Mammal Atlas will be a welcome and usefulreference for all those interested in Ontariomammals and is a basis for further work on theirdistribution.

C.G. van Zyll de Jong

vi

Contents

Foreword ....................................................... v

Introduction ................................................... 1

Guide to the Mammal Atlas ........................... 2

Atlas History ................................................. 3

Methods ......................................................... 4General Data Collection ....................... 4

Species .................................. 4Location ................................ 4Date ...................................... 4Evidence Codes ...................... 5

Volunteer Data Collection ..................... 8Regions and Regional

Coordinators ............... 8Special Volunteer

SurveyTechniques .................. 8

Atlas Results ................................................... 9

Features Affecting MammalDistribution ......................................... 12Physiographic Regions .......................... 12

Hudson Bay Lowland .............. 12Canadian Shield ...................... 12South and East of the

Shield .......................... 12Forest Regions ...................................... 12

Tundra .................................... 14Hudson Bay Lowland

Forest .......................... 14Boreal Forest ........................... 14Great Lakes-St.

LawrenceForest .......................... 14

Carolinian Forest ..................... 14

Species Accounts ............................................. 15

Opossums: Didelphimorphia .......................... 16Virginia Opossum ........................................... 17

Shrews and Moles: Insectivora ....................... 18Black-backed Shrew ....................................... 19Common Shrew .............................................. 20Smoky Shrew ................................................. 21Pygmy Shrew ................................................. 22Water Shrew ................................................... 23Northern Short-tailed Shrew ............................ 24Least Shrew .................................................... 25Hairy-tailed Mole ............................................ 26Eastern Mole .................................................. 27Star-nosed Mole .............................................. 28

Bats: Chiroptera ............................................. 29Eastern Small-footed Bat ................................. 30Little Brown Bat ............................................. 31Northern Long-eared Bat ................................. 32Silver-haired Bat ............................................. 33Eastern Pipistrelle ........................................... 34Big Brown Bat ............................................... 35Eastern Red Bat .............................................. 36Hoary Bat ....................................................... 37Evening Bat .................................................... 38

Rabbits and Hares: Lagomorpha .................... 39Eastern Cottontail ............................................ 40Snowshoe Hare ................................................ 41Arctic Hare ...................................................... 42European Hare ................................................. 43White-tailed Jackrabbit ..................................... 44

Rodents: Rodentia ............................................ 45Least Chipmunk ............................................... 46Eastern Chipmunk ............................................ 47Woodchuck ...................................................... 48Franklin’s Ground Squirrel ............................... 49Gray Squirrel ................................................... 50Gray Squirrel Black Phase ................................ 51Gray Squirrel Gray Phase ................................. 52

vii

Fox Squirrel .................................................. 53Red Squirrel .................................................. 54Northern Flying Squirrel ................................ 55Southern Flying Squirrel ................................ 56Beaver ........................................................... 57White-footed Mouse ....................................... 58Deer Mouse ................................................... 59Southern Red-backed Vole .............................. 60Heath Vole ..................................................... 61Rock Vole ...................................................... 62Meadow Vole ................................................. 63Woodland Vole ............................................... 64Muskrat ......................................................... 65Northern Bog Lemming .................................. 66Southern Bog Lemming .................................. 67Norway Rat ................................................... 68House Mouse ................................................. 69Meadow Jumping Mouse ................................ 70Woodland Jumping Mouse .............................. 71Porcupine ....................................................... 72

Whales: Cetacea .............................................. 73Beluga ........................................................... 74Narwhal ........................................................ 74Minke Whale ................................................. 75

Carnivores: Carnivora ................................... 76Coyote .......................................................... 77Gray Wolf ..................................................... 78Arctic Fox ..................................................... 79Red Fox ........................................................ 80Gray Fox ...................................................... 81Black Bear .................................................... 82Polar Bear ..................................................... 83Raccoon ........................................................ 84Marten .......................................................... 85Fisher ............................................................ 86Ermine .......................................................... 87Long-tailed Weasel ......................................... 88Least Weasel ................................................. 89Mink.............................................................. 90Wolverine ...................................................... 91Badger .......................................................... 92Striped Skunk ................................................ 93River Otter .................................................... 94Cougar .......................................................... 95Canada Lynx ................................................. 96Bobcat ........................................................... 97Walrus ........................................................... 98Ringed Seal .................................................... 98Harbor Seal .................................................... 99Bearded Seal ...................................................99

Deer and Bison: Artiodactyla ......................... 100Wapiti ........................................................... 101White-tailed Deer .......................................... 102Moose ........................................................... 103Caribou ......................................................... 104Bison ............................................................ 105

Exotics ............................................................ 106Black Rat ...................................................... 106Coypu ........................................................... 106Domestic Ferret ............................................. 106

Acknowledgements ......................................... 107

References ...................................................... 113

Index of common and scientificnames ................................................. 115

viii

Introduction

Naturalists, biologists, environmental consultantsand planners are but a few of the many people whowill find this book useful. By mapping the presenceof Ontario’s 86 wild mammal species, the Atlas ofthe Mammals of Ontario (Mammal Atlas) willprovide: a benchmark for future studies, an aid indetermining conservation priorities, an informationsource for status reports on rare or vulnerablespecies, and a resource for environmental impactassessments.

The Mammal Atlas makes use of informationcollected from institutions and volunteers todocument a provincial range for each wild mammalin Ontario. As such, the Mammal Atlas is a muchmore accurate record of Ontario’s mammals thancan be found in a field guide. Maps in field guidestend to be large-scale, sometimes including entirecountries or even continents in an attempt to mapthe entire range of a species. The Mammal Atlasfocuses on Ontario, mapping actual mammal

specimen records, sightings, and telltale evidence.Mammal Atlas species accounts also outline factorsknown to affect local distribution, including habitatpreferences, land-use practices and climate.

The maps in the Mammal Atlas illustrate what iscurrently known about the distribution of Ontariomammals. However, the maps are notcomprehensive. Volunteers sometimes haddifficulties finding and identifying smaller species.In some remote areas, no surveying was done at all.Consequently, some of the maps show sufficientdata to indicate specific mammal distribution whileothers indicate further study is needed to provide amore accurate distribution assessment. For mostspecies, the Mammal Atlas maps are the bestavailable representation of their Ontario range. It ishoped this book will stimulate new studies thatmight further improve our knowledge of mammaldistribution in Ontario.

Red Squirrel: Barry Kent MacKay

1

Guide to theMammal Atlas

The Atlas of the Mammals of Ontario includes tworange maps and a species account for every wildmammal found in the province. The larger rangemap (that of either southern or northern Ontario)subdivides the province into 10X10-km squareswhile the smaller all-Ontario map subdivides theprovince into 100X100-km blocks. Symbols areplotted in the centre of squares and blocks whenmammals are found to exist within their borders.Symbols include: circles (representing pre-1900records), triangles (representing records from 1900to 1969), and squares (representing records from1970 to 1993). If mammals have been observedover two or three time periods, the symbol for themost recent time period is used.

The range of a species can be determined bylooking at the configuration of the symbol-containing squares. The furthest group of symbolsin any direction is a good indication of the extent ofa particular species’ range. Unfortunately, for a fewspecies, insufficient Mammal Atlas data can create afalse impression of distribution. However, wheninadequate data misrepresent a mammal’s range, thecommonly accepted range is noted in the speciesaccount.

Occasionally, open symbols (for instance,perimeters of squares) are placed on the maps.Open symbols indicate that a mammal record can’tbe pinpointed to a single square. Usually, impreciserecord locations stem from having to adjust OntarioMinistry of Natural Resources fur harvest traplinedata to the 10X10-km square system. In suchinstances, records are assigned to the square that ismost likely the origin of the record. If data aren’tsufficient to ascertain one likely square of origin,the record is plotted as an open symbol in two,

three, or a maximum of four squares.

Mammal Atlas species accounts make use ofstandard geographic regions to facilitate rangediscussion (Figure 1).

For research or planning purposes, more specificMammal Atlas information can be obtained bycontacting the Federation of Ontario Naturalists.

2

Atlas History

Atlassing of flora and fauna originated in Britainwith the Atlas of the British Flora, published in1962. The British atlas was the first comprehensivedocument to use the 10X10-km square as the basisfor surveying and mapping species. It laid thefoundation for other atlas projects including the1976 Atlas of the Breeding Birds in Britain andIreland. The British breeding bird atlas project wasan overwhelming success, generating over 285 000records from over 10 000 contributors (Sharrock1976). Similar atlases have since been produced inmost European countries, in Africa, Australia andseveral states and provinces in North America.

In 1981, the Federation of Ontario Naturalists andthe Long Point Bird Observatory initiated theOntario Breeding Bird Atlas. Five years of fieldwork was conducted by 1 351 volunteers whocontributed over 400 000 records (Cadman et al.1987). The Atlas of the Breeding Birds of Ontario,published in 1987, quickly became the authority onthe distribution of breeding birds in the province.

By 1989, with Ontario atlas projects alreadysurveying reptiles and amphibians, butterflies, andrare vascular plants, the Ontario Ministry of NaturalResources and Ontario conservation organizationsdecided it was time to create a mammal atlas. TheAtlas of the Mammals of Ontario was launched inJanuary of 1990.

Originally, the Mammal Atlas was to be a five-yearsurvey of Ontario’s mammals similar to the Atlas ofthe Breeding Birds of Ontario. However, after oneyear of field surveys, it became apparent that acomprehensive volunteer-based Mammal Atlaswould not be feasible because of low volunteerinterest and difficulties in locating and

distinguishing some mammals. Fortunately, awealth of information on mammal distribution existsin Ontario from sources such as the OntarioMinistry of Natural Resources, the Royal OntarioMuseum, the Canadian Museum of Nature, andvarious universities. It was therefore determinedthat the Mammal Atlas would rely primarily onexisting institutional data supplemented by volunteerrecords.

The Mammal Atlas is similar to the ProvisionalAtlas of the Mammals of the British Isles, which isan ongoing project to map mammal distribution inBritain. The British atlas is a compilation of bothvolunteer and institutional data mapped using the10X10-km square system (Arnold 1978).

Although the Mammal Atlas was administered bythe Federation of Ontario Naturalists, most of theproject’s goals and policies were developed by theAtlas Management Committee. The committeeincluded representatives from the Federation ofOntario Naturalists and sponsor organizations, aswell as professional biologists.

A second committee, the Atlas of the Mammals ofOntario Technical Committee, included professionalmammalogists from Ontario universities, the RoyalOntario Museum, Ontario Hydro, and the OntarioMinistry of Natural Resources. The technicalcommittee provided methodological advice,reviewed mammal records, and assisted in theproduction of instructional materials.

Committee members were all volunteers. Theirexperience, knowledge and advice were crucial tothe project’s success. See the acknowledgements fora complete list of committee members.

Long-tailed Weasel: Linda Shaw

3

Methods

Methods used to collect and process data for theMammal Atlas were suggested by the Atlas of theMammals of Ontario Technical Committee anddeveloped by atlas staff. For more detailedinformation on Mammal Atlas methods, contact theFederation of Ontario Naturalists for copies of theAtlas of the Mammals of Ontario Participant’sManual numbers 1 and 2.

Mammal Atlas data were obtained from institutionsand volunteers. Data-contributing organizationsincluded the Ontario Ministry of Natural Resources,the Royal Ontario Museum, the Canadian Museumof Nature and several universities (see theAcknowledgements for a complete list). Volunteerdata came from interested naturalists, hunters, andresearchers.

General Data Collection

Species

Data were collected on all wild mammals includingindigenous species, non-indigenous (released)species that have developed a sustainablepopulation, and any escaped mammals thought to bereproducing in the wild. For a complete species list,consult the table of contents, or the species index atthe back of the book. Common and scientific namesused in the Mammal Atlas were decided upon bythe nomenclature sub-committee of the Atlas of theMammals of Ontario Technical Committee.

Location

To ensure geographic accuracy, mammal locationswere recorded using the Universal Transverse

Mercator-Grid (UTM) coordinate system. The10X10-km square, a unit of the UTM grid, waschosen as the basic unit for Mammal Atlassurveying.

Instructions for determining the UTM of a locationare provided in the right margin of all topographicmaps under the heading “ONE THOUSANDMETRE UNIVERSAL TRANSVERSEMERCATOR GRID”. Figure 2 shows the UTMzones and 100X100-km blocks of Ontario andindicates how the blocks are further subdivided into10X10-km squares. Figures 3 and 4 illustrate,respectively, northern and southern Ontario,including larger cities, towns, and lakes. UTM gridlines plotted over Figures 3 and 4 will help readersdetermine the location of specific squares on thespecies maps.

Whenever possible, records from volunteers andinstitutions were assigned a UTM coordinate towithin a 100X100-m site. However, when data werenot sufficient to allow such precision, records wereassigned to a 10X10-km square in southern Ontarioor a 100X100-km block in northern Ontario.

Date

The dates of most mammal observations wererecorded to the day. However, sometimes dateswere accepted precise to the month, year, or “ten-year period” (for instance, 1980-1989).

For common mammals, only one record per squareper ten-year period was required. But for lesscommon species, called “Provincial PrioritySpecies” (as denoted by a + in the species index),all available records were collected.

Meadow Vole: Linda Shaw

4

Evidence Codes

A voucher specimen or photograph provides thebest evidence of a mammal observation. However,many species are rarely seen in the wild. Mammalsdo often leave telltale signs of their presence,though, including tracks, scat, and homes. TheMammal Atlas made use of such evidence todocument mammal presence. A series of evidencecodes was developed and grouped into threecategories based on the nature of evidence.

l. Voucher specimen or photograph

VS Voucher Specimen - skin and skull,skeleton, or other distinctive part collected,or whole animal pickled or frozen andplaced in a collection or museum

PH Photograph clearly showing distinguishingcharacteristics

5

6

2. Actual observation in whole or part but notretained or photographed

OB Observed live mammalTR Trapped, netted, or hand-captured mammalCA Carcass of mammal seen and identifiedBO Bones, especially skulls, antlers or teethRE Remains in scat or raptor pelletHA HairQU QuillsDP Other distinctive part found

3. Distinctive signs observed

DA Dam (e.g., Beaver)DE Den (e.g., Black Bear)BU Burrow (e.g., Woodchuck)HO House (e.g., Muskrat)NE Nest (e.g., Gray Squirrel)FC Food cache (e.g., Red Squirrel)OD Odour (e.g., Striped Skunk)PD Plant damage (e.g., Porcupine chewing)RT Radio-tracking (for use by scientists)SC Scat (e.g., White-tailed Deer)TK Tracks (e.g., Virginia Opossum)VO Vocalization (e.g., Gray Wolf)

7

Volunteer Data Collection

Two main data forms were used by volunteers: theData Report Form for submitting personal historicaldata and casual observations, and the Square SurveyForm for surveying a particular 10X10-km square.Volunteer surveys were conducted during 1992 and1993.

Volunteers who submitted a record of a difficult-to-identify or Provincial Priority Species (as denotedby * and +, respectively, in the species index) werealso asked to forward detailed documentation on anUnusual Species Report Form. On these forms, thevolunteers provided information stating: the time ofthe observation; the distance between mammal andobserver; distinctive features of the mammal; and adetailed explanation of what characteristics led thevolunteer to believe the record to be of a particularspecies and not any other similar species. TheUnusual Species Report Forms were reviewed bythe Atlas of the Mammals of Ontario TechnicalCommittee. Acceptable records were incorporatedinto the data base.

Regions and Regional Coordinators

The coordination of hundreds of volunteerssurveying an area the size of Ontario couldn’t behandled from one central office. Volunteersrequired survey information, encouragement, and asteady supply of data forms. To best assistvolunteers, Ontario was divided into a series ofregions, each with a volunteer RegionalCoordinator. Southern Ontario was broken into 40regions and northern Ontario was divided into 10regions. Regional Coordinators played an importantrole in directing the compilation of local historicalrecords and in coordinating field data collection.See the Acknowledgements for a complete list ofvolunteers who acted as Regional Coordinatorsduring the Mammal Atlas.

Special Volunteer Survey Techniques

Surveying by passive observation alone was notsufficient to obtain data on all species. Two specialsurvey techniques were adopted by the MammalAtlas: live-trapping and the use of bat detectors.

1. Live-trappingA pilot program of live small mammal trapping wasconducted to assess trapping effectiveness in thedetermination of small mammal distribution.Trapping was conducted in eight regions throughoutOntario (Essex, Niagara, Bruce, Lanark/SouthRenfrew, Ottawa-Carleton, Manitoulin, Nipissing,and Chapleau). Sherman-type live traps capturedmammals ranging in size from shrews to flyingsquirrels and weasels. The pilot project met withvarying degrees of success. Some volunteers did notcontinue trapping long enough to obtain the skilland knowledge necessary to obtain high capturerates. In other cases, volunteers contributed usefulinformation on some difficult-to-find mammals.

2. Bat DetectorsBats were the most challenging group of mammalsto survey. Fortunately, bat detectors can be used toidentify certain bats based on characteristics of theirecholocation calls. Bat detectors are small,transistor radio-sized electronic devices equippedwith an ultrasonic microphone. The detectorconverts bat calls into a pulse which is heardthrough the bat detector speaker. Different speciesof bats are heard at different frequencies and someproduce distinctive patterns in their calls which canbe distinguished by a trained listener.

Volunteers borrowed bat detectors in exchange forany data collected. Some groups and individualseven purchased bat detectors. Volunteers who hadbeen trained to use bat detectors could positivelyidentify Eastern Red Bats and Hoary Bats.Identification of Big Brown Bats was also possible,although sometimes they can be hard to distinguishfrom Silver-haired Bats. Bats of the genus Myotiscould be identified but distinguishing between theEastern Small-footed, Northern Long-eared, andLittle Brown bats was impossible with basic batdetectors. With increased experience, identifying theEastern Pipistrelle was also possible.

8

Atlas Results

The Mammal Atlas sought to collect institutionalinformation on mammal distribution in Ontario andsupplement it with a volunteer survey program. Assuch, the Mammal Atlas was quite successful. Formost species, Mammal Atlas range maps provide anexcellent indication of overall range within theprovince and many also provide a decent indicationof local distribution.

Twenty-one institutions and 444 volunteerscontributed data to the Mammal Atlas. In all,164 697 records were contributed, 137 106 frominstitutions and 27 591 from volunteers. Table 1outlines the number of records obtained per species.

Mammal Atlas maps should be interpretedcarefully. The number of mammal records does notalways correlate with the actual abundance of aspecies.

Vastly different numbers of historical data wereavailable for different species. The largest singlesource of data for the Mammal Atlas was theOntario Ministry of Natural Resources. The OMNRcontributed records on big game and furbearers anda few less common species such as Caribou. TheOMNR does not keep significant quantities of dataon other species. Consequently, big game andfurbearers can misleadingly appear to be morecommon than other species.

Some species were particularly difficult to surveybecause of their small size, behaviour, secretivenature, or more obscure distinguishingcharacteristics. Fewer records were obtained forsuch species, even though they could actually bequite common. Examples of difficult-to-surveymammals include: shrews and voles (very small and

live within the leaf litter or grass layer); GrayWolves (very secretive); flying squirrels and bats(nocturnal).

Some specific regions exist where Mammal Atlasdata require careful interpretation. On MammalAtlas maps, for example, Algonquin ProvincialPark mistakenly appears to be devoid of somemammals. Because there exists only a localizedharvest of furbearers or big game mammals fromthe park, data were generated almost exclusivelyfrom volunteers. Unfortunately, Algonquin has alarge area and very few resident atlassers. Ashortage of volunteers affected data accumulation insparsely-populated areas of northern Ontario aswell. Infrequent northern records of Woodchuckand Porcupine (species for which no harvest recordsare kept), for example, reflect a lack of volunteersin the north, not necessarily fewer mammals.

Figure 5 illustrates the number of species obtainedfor each 100X100-km block in Ontario (5A) andeach l0X10-km square in southern Ontario (5B).The average number of species obtained per squarein southern Ontario was 14.7 (maximum 46),whereas the average number of species per blockfor the province was 26.6 (maximum 61).

Although 444 volunteers contributed data to theMammal Atlas, the number falls short of the 1 351who contributed to the Atlas of the Breeding Birdsof Ontario. The difference in volunteer support forthe two atlases can likely be attributed to the highernumber of birders in the province, and difficultiesin locating and identifying mammals.

A comprehensive all-biota inventory in Hamiltonsuggested that more survey time results in a higher

Red Squirrel: Ivan Foster

9

number of species being found per 10X10-kmsquare. So, to increase the number of speciesfound, future studies might consider longer, more

localized surveys and/or surveys of fewer species.A more focused study would also ease coordinationproblems and help maintain volunteer involvement.

Table 1: The number of records per species

Virginia OpossumBlack-backed ShrewCommon ShrewSmoky ShrewPygmy ShrewWater ShrewNorthern Short-tailed ShrewLeast ShrewHairy-tailed MoleEastern MoleStar-nosed MoleEastern Small-footed BatLittle Brown BatNorthern Long-eared BatSilver-haired BatEastern PipistrelleBig Brown BatEastern Red Bat .Hoary BatEvening BatEastern CottontailSnowshoe HareArctic HareEuropean HareWhite-tailed JackrabbitLeast ChipmunkEastern ChipmunkWoodchuckFranklin’s Ground SquirrelGray SquirrelGray Squirrel Black PhaseGray Squirrel Gray PhaseFox SquirrelRed SquirrelNorthern Flying SquirrelSouthern Flying SquirrelBeaverWhite-footed MouseDeer MouseSouthern Red-backed VoleHeath VoleRock VoleMeadow VoleWoodland Vole

940192

1901525254317

18902

26952

556141

179324813591

1878264167

111331464

1356

3558

26962053

16165386643056

4056373163

3885248931701772107273

266943

MuskratNorthern Bog LemmingSouthern Bog LemmingNorway RatBlack RatHouse MouseMeadow Jumping MouseWoodland Jumping MousePorcupineCoypuBelugaNarwhalMinke WhaleCoyoteGray WolfArctic FoxRed FoxGray FoxBlack BearPolar BearRaccoonMartenFisherErmineLong-tailed WeaselDomestic FerretLeast WeaselMinkWolverineBadgerStriped SkunkRiver OtterCougarCanada LynxBobcatWalrusRinged SealBearded SealHarbor SealWapitiWhite-tailed DeerMooseCaribouBison

380323

288370

4361985697

12028

7311

19413564

657058

2341294575666118681635492325145

97342

52.18

38892369678

11491775118171

8328373438462522

1

10

Figure 5: Number of species recorded in (A)each block in all of Ontario, and(B) each square in southern Ontario

(A)

(B)

11

Features AffectingMammal Distribution

Mammal range is influenced by many factors,including: climate, land-use patterns, physiographicregions, and forest types. Two of these factors,physiographic regions and forest types, areparticularly helpful in understanding mammaldistribution.

Physiographic RegionsThere are three physiographic regions withinOntario: the Hudson Bay Lowland, the CanadianShield, and areas to the south and east of theCanadian Shield in southern Ontario (Figure 6).The following descriptions of the physiographicregions have been summarized from Cadman et al.(1987).

Hudson Bay Lowland

The Hudson Bay Lowland is found within 150 to300 km of the shorelines of James and Hudsonbays, immediately northeast of the Canadian Shield.The area is underlain with sedimentary bedrock andcharacterized by flat, poorly-drained lands withnumerous small, shallow lakes and ponds. Most ofthe Hudson Bay Lowland is covered by the HudsonBay Lowland Forest.

Canadian Shield

The Canadian Shield is the largest physiographicregion in Ontario, extending from the Hudson BayLowland to southern Ontario. The southern extentof the shield is called the Frontenac Axis, whichcrosses the St. Lawrence River northeast ofKingston. The Canadian Shield is underlain withigneous and metamorphic bedrock and covered by a

thin layer of relatively infertile soil and thousandsof lakes. The primary forest regions of the shieldare the Boreal Forest and the Great Lakes-St.Lawrence Forest. Significant Canadian Shield landfeatures include the Little and Great Clay Beltswhich extend, respectively, from Haileybury toEnglehart, and from Timmins to north of Cochraneand west of Kapuskasing. The clay belts are formedby the former bed of Lake Ojibway-Barlow, and arecharacterized by deep, fertile soils capable ofsupporting agriculture.

South and East of the Shield

The areas to the south and east of the CanadianShield in southern Ontario are underlain withsedimentary rock and covered with deeper, morefertile soils. Relatively flat topography and richsoils make the areas south and east of the shield theprovince’s most suitable region for agriculture.Significant land features in this region include theNiagara Escarpment and the Oak Ridges Moraine.The Niagara Escarpment extends from NiagaraFalls to the tip of the Bruce Peninsula and acrossManitoulin Island, and is characterized by largecliffs and heavily-wooded forests. The Oak RidgesMoraine extends westward from Presqu’ileProvincial Park to the Niagara Escarpment nearOrangeville. The moraine features deep rolling hillswith well-drained soil and large tracts of forest.

Forest Regions

Five main forest regions are found within Ontario:the Tundra, the Hudson Bay Lowland Forest, theBoreal Forest, the Great-Lakes-St. LawrenceForest, and the Carolinian Forest (Figure 6).

12

13

The following descriptions of the forest regionshave been summarized from Rowe (1972).

Tundra

The Tundra, characterized by permafrost, is anarrow strip of land along the shore of Hudson andnorthern James bays. Features include dry uplandswith lichens and heath plants, low-lying fens withgrasses and sedges, and uplifted beach ridges withnumerous ponds and lakes. Dwarf willows andbirches occur in sheltered areas. Stunted sprucesgrow singly or in patches along riverbanks andoccur with increasing frequency inland toward thetransition with the Hudson Bay Lowland Forest atthe tree line.

Hudson Bay Lowland Forest

The Hudson Bay Lowland Forest extends inlandfrom the Tundra. It stretches south to the northernedge of the Canadian Shield. The Hudson BayLowland Forest is characterized by flat topographyand poor drainage, numerous open fens and bogs,and treed fens and bogs of black spruce andtamarack. Ground cover consists of lichen in dryareas and sphagnum in wet areas. Forests of whitespruce, balsam fir, trembling aspen, balsam poplar,and white birch are all common in well-drainedareas. The southern parts of the Hudson BayLowland Forest are heavily forested, whereas thenorthwestern sections are dominated by lakes andwetlands.

Boreal Forest

The Boreal Forest is the largest forest region inOntario. It is underlain by the Canadian Shield. Theregion is dominated by thousands of lakes andconiferous forests of black spruce, white spruce,balsam fir, jack pine, and tamarack with occasionalwhite birch, trembling aspen and balsam poplar.Towards the southern extent of the Boreal Forest,the forest becomes transitional, exhibitingcharacteristics of both the Boreal and Great Lakes-St. Lawrence Forest regions.

Great Lakes-St. Lawrence Forest

The Great Lakes-St. Lawrence Forest is the primaryforest region of southern Ontario. It is characterizedby a mixture of coniferous and deciduous treesincluding sugar maple, yellow birch, easternhemlock, white and red pine, red maple, basswood,white elm, white cedar, beech, red oak, and whiteash.

The northern portion of the Great Lakes-St.Lawrence Forest overlies the Canadian Shield whilethe southern and eastern portions are located oversedimentary rock. Most of the Great Lakes-St.Lawrence Forest region that is not located on theCanadian Shield has been cleared for agriculture,leaving only small pockets of forest cover.

The Great Lakes-St. Lawrence Forest region isdivided into several forest sections, including theTimagami Forest and the Algonquin HighlandsForest sections. The Timagami Forest section is thetransition area between the Boreal and Great Lakes-St. Lawrence Forest regions and features a highproportion of Boreal tree species. The AlgonquinHighlands forest section, which is almost entirelycontained within Algonquin Provincial Park, alsocontains a large proportion of Boreal tree species.

Carolinian Forest

The Carolinian or Eastern Deciduous Forest isrestricted to the southern part of the province alonglakes Erie and Ontario. Typical of eastern USforests, the Carolinian Forest is dominated bybroad-leaved trees such as beech, sugar maple,basswood, red maple, black walnut, sycamore,swamp white oak, shagbark hickory, butternut,butternut hickory, rock elm, blue beech, and red,white, and bur oak. The Carolinian Forest alsofeatures a number of typically southern species suchas tulip tree, black cherry; Kentucky coffee-tree,and sassafras. This forest region has been highlymodified by settlement and agriculture.Consequently, few large woodlots remain,especially in southwestern Ontario.

14

Species Accounts

Eastern Cottontail: Barry Kent MacXay

15