Table 1. Documented effects of roads and traffic on animal abundance.

Species or Species Group Direction of Road
or Traffic Effect
Reference(s)
Invertebrates
  invertebrate order diversity neutralLuce and Crowe (2001)
  butterfly species richness negative
neutral
White and Kerr (2007)
Munguira and Thomas (1992)
  butterfly total abundance neutralMunguira and Thomas (1992)
  carabid species richness negativeKoivula and Vermeulen (2005)
  carabid total abundance negativeKoivula and Vermeulen (2005)
  Calathus micropterus negativeKoivula and Vermeulen (2005)
  Carabus nemoralis neutralKoivula and Vermeulen (2005)
  Pterostichus melanarius neutralKoivula and Vermeulen (2005)
Herptiles
  herptile species richness negativeFindlay and Bourdages (2000)
Amphibians
  amphibian species richness negative


neutral
Findlay and Houlahan (1997)
Parris (2006)
Houlahan and Findlay (2003)
Loehle et al. (2005)
  amphibian total abundance negativeHoulahan and Findlay (2003)
  anuran species richness negativeEigenbrod et al. (2008a)
  anuran total abundance negative
neutral
Fahrig et al. (1995)
Fahrig et al. (1995)
  salamander relative species richness negativePorej et al. (2004)
  salamander total abundance negativeSemlitsch et al. (2007)
deMaynadier and Hunter (2000)
  American toad (Bufo americanus) negativeEigenbrod et al. (2008a)
Trenham et al. (2003)
  treefrog (Hyla arborea) negativePellet et al. (2004a, b)
  Cope's gray tree frog (Hyla chrysoscelis) neutralTrenham et al. (2003)
  gray treefrog (Hyla versicolor) negative
neutral
Houlahan and Findlay (2003)
Eigenbrod et al. (2008a)
Trenham et al. (2003)
  spadefoot toad (Pelobates fuscus) negative
neutral
Nyström et al. (2007)
Nyström et al. (2002)
  spring peeper (Pseudacris crucifer) negative
neutral
Houlahan and Findlay (2003)
Eigenbrod et al. (2008a)
Trenham et al. (2003)
  western chorus frog (Pseudacris triseriata) neutralTrenham et al. (2003)
  moor frog (Rana arvalis) negativeVos and Chardon (1998)
  green frog (Rana clamitans) negative
neutral
Houlahan and Findlay (2003)
Eigenbrod et al. (2008a)
Trenham et al. (2003)
Carr and Fahrig (2001)
  leopard frog (Rana pipiens) negative

neutral
Eigenbrod et al. (2008a)
Carr and Fahrig (2001)
Trenham et al. (2003)
  mink frog (Rana septentrionalis) negativeHoulahan and Findlay (2003)
  wood frog (Rana sylvatica) negative
neutral


positive
Houlahan and Findlay (2003)
Eigenbrod et al. (2008a)
Porej et al. (2004)
Skidds et al. (2007)
Trenham et al. (2003)
  spotted salamander (Ambystoma
    maculatum
)
neutralPorej et al. (2004)
Skidds et al. (2007)
  smallmouth salamander (Ambystoma
    texanum
)
neutralPorej et al. (2004)
  Jefferson's salamander (Ambystoma
    jeffersonianum
)
neutralPorej et al. (2004)
  tiger salamander (Ambystoma tigrinum
    tigrinum
)
negativePorej et al. (2004)
  blue-spotted salamander (Ambystoma
    laterale
)
negativeHoulahan and Findlay (2003)
  Appalachian seal salamander (Desmognathus
    monticola
)
negativeWard et al. (2008)
  mountain dusky salamander (Desmognathus
    ochrophaeus
)
negativeWard et al. (2008)
  northern two-lined salamander (Eurycea
    bislineata
)
positiveWard et al. (2008)
  southern gray-cheeked salamander
    (Plethodon metcalfi)
negativeSemlitsch et al. (2007)
  red-spotted newt (Notophthalmus
    viridescens viridescens
)
negativePorej et al. (2004)
Reptiles
  reptile species richness neutralLoehle et al. (2005)
  snake total abundance negative
neutral
Rudolph et al. (1999)
Sullivan (2000)
  turtle total abundance negativeGibbs and Shriver (2002)
  large-bodied turtle total abundance negativeGibbs and Shriver (2002)
  small-bodied turtle total abundance neutralGibbs and Shriver (2002)
  eastern diamondback rattlesnake (Crotalus
    adamanteus
)
positiveSteen et al. (2007)
  timber rattlesnake (Crotalus horridus) negativeSteen et al. (2007)
  black ratsnake (Elaphe obsoleta) negativeRow et al. (2007)
  Galápagos lava lizard (Microlophus
    albemarlensis
)
negativeTanner and Perry (2007)
  painted turtle (Chrysemys picta bellii) negativeFowle (1990)
  desert tortoise (Gopherus agassizii) negativeBoarman and Sazaki (2006)
Birds
  bird species richness negativeFindlay and Bourdages (2000)
Findlay and Houlahan (1997)
Small birds
  small bird summed density negativeReijnen et al. (1996)
  grassland bird presence negativeForman et al. (2002)
  grassland passerines total abundance neutralWarner (1992)
  Yellow Thornbill (Acanthiza nana) positive*Pocock and Lawrence (2005)
  Skylark (Alauda arvensis) negativeReijnen et al. (1996)
  Meadow Pipit (Anthus pratensis) negativeReijnen et al. (1996)
  Florida Scrub Jay (Aphelocoma
    coerulescens
)
negativeMumme et al. (2000)
  Linnet (Carduelis cannabina) negativePeris and Pescador (2004)
  Goldfinch (Carduelis carduelis) neutralPeris and Pescador (2004)
  Greenfinch (Carduelis chloris) neutralPeris and Pescador (2004)
  Short-toed Treecreeper (Certhia
    brachydactyla
)
neutralPeris and Pescador (2004)
  Bobolink (Delichonyx oryzivorus) negativeForman et al. (2002)
  Galah (Eolophus roseicapillus) negative*Pocock and Lawrence (2005)
  Pied Flycatcher (Ficedula hypoleuca) negativeKuitunen et al. (2003)
  Chafffinch (Fringilla coelebs) neutralPeris and Pescador (2004)
  Crested Lark (Galerida cristata) neutralPeris and Pescador (2004)
  Oystercatcher (Haematopus ostralegus) negative
neutral
Reijnen et al. (1996)
van der Zande et al. (1980)
  Woodchat Shrike (Lanius senator) negativePeris and Pescador (2004)
  Yellow-Tufted Honeyeater (Lichenostomus
    melanops
)
negative*Pocock and Lawrence (2005)
  Fuscous Honeyeater (Lichenostomus fuscus) negative*Pocock and Lawrence (2005)
  Black-tailed Godwit (Limosa limosa) negativeReijnen et al. (1996)
van der Zande et al. (1980)
  Woodlark (Lullula arborea) negativePeris and Pescador (2004)
  Superb Fairy-Wren (Malurus cyaneus) positive*Pocock and Lawrence (2005)
  Corn Bunting (Miliaria calandra) positivePeris and Pescador (2004)
  Yellow Wagtail (Motacilla flava) neutral/negativeReijnen et al. (1996)
  Wheatear (Oenanthe oenanthe) negativePeris and Pescador (2004)
  Striated Pardalote (Pardalotus striatus) negative*Pocock and Lawrence (2005)
  Blue Tit (Parus caeruleus) neutralPeris and Pescador (2004)
  Great Tit (Parus major) neutralPeris and Pescador (2004)
  House Sparrow (Passer domesticus) positivePeris and Pescador (2004)
  Rock Sparrow (Passer petronia) positivePeris and Pescador (2004)
  Black Redstart (Phoenicurus ochrurus) neutralPeris and Pescador (2004)
  Iberian Chiffchaff (Phylloscopus brehmii) negativePeris and Pescador (2004)
  Serin (Serinus serinus) neutralPeris and Pescador (2004)
  Nuthatch (Sitta europaea) neutralPeris and Pescador (2004)
  Eastern Meadowlark (Sturnella magna) negativeForman et al. (2002)
  Starling (Sturnus unicolor) neutralPeris and Pescador (2004)
  Blackbird (Turdus merula) negativePeris and Pescador (2004)
  Lapwing (Vanellus vanellus) negativeReijnen et al. (1996)
van der Zande et al. (1980)
Large birds
  Shoveler (Anas clypeata) negativeReijnen et al. (1996)
  Mallard (Anas platyrhynchos) neutral/negativeReijnen et al. (1996)
  Tufted Duck (Aythya fuligula) neutral/negativeReijnen et al. (1996)
  Turkey Vulture (Cathartes aura) positiveColeman and Fraser (1989)
  Black Vulture (Coragyps atratus) positiveColeman and Fraser (1989)
  Mute Swan (Cygnus olor) neutral/negativeReijnen et al. (1996)
  Coot (Fulica atra) negativeReijnen et al. (1996)
  Sandhill Crane (Grus canadensis) negativeNorling et al. (1992)
  Bald Eagle (Haliaeetus leucocephalus) negativeAnthongy and Isaacs (1989)
Paruk (1987)
  Redshank (Tringa tetanus) neutral/negativeReijnen et al. (1996)
Mammals
  mammal species richness neutral/negativeFindlay and Houlahan (1997)
Small mammals
  small mammal species richness neutralGarland and Bradley (1984)
  small mammal total abundance neutral
positive*
Garland and Bradley (1984)
Rosa and Bissonette (2007)
Adams and Geis (1983)
  white-tailed antelope squirrel (Ammospermo-
    philus leucurus
)
neutralGarland and Bradley (1984)
  black-tailed prairie dog (Cynomys
    ludovicianus
)
positiveJohnson and Collinge (2004)
  Merriam's kangaroo rat (Dipodomys
    merriami
)
neutralGarland and Bradley (1984)
  kangaroo rat (Dipodomys microps) positive*Rosa and Bissonette (2007)
  prairie vole (Microtus ochrogaster) neutral/positiveAdams and Geis (1983)
  California vole (Microtus californicus) neutral/positiveAdams and Geis (1983)
  house mouse (Mus musculus) positiveGarland and Bradley (1984)
  woodrat (Notoma lepida) neutralGarland and Bradley (1984)
  golden mouse (Ochrotomys nuttalli) neutral/positiveAdams and Geis (1983)
  long-tailed pocket mouse (Perognathus
    formosus
)
neutralGarland and Bradley (1984)
  brush mouse (Peromyscus boylii) neutral/negative*Rosa and Bissonette (2007)
  white-footed mouse (Peromyscus leucopus) neutral
neutral/positive
positive
McGregor et al. (2008)
Adams and Geis (1983)
Rytwinski and Fahrig (2007)
  deer mouse (Peromyscus maniculatus) neutral/positiveAdams and Geis (1983)
  ship rat (Rattus rattus) neutralGarland and Bradley (1984)
  eastern chipmunk (Tamias striatus) positiveMcGregor et al. (2008)
Medium-sized mammals
  chacoan peccary (Catagonus wagneri) negativeAltrichter and Boaglio (2004)
  hedgehog (Erinaceus europaeus) negativeHuijser and Bergers (2000)
  brown hare (Lepus europaeus) negativeRoedenbeck and Voser (2008)
  American marten (Martes americana) neutralMowat (2006)
  badger (Meles meles) negativevan der Zee et al. (1992)
Roedenbeck and Köhler (2006)
  koala (Phascolarctos cinereus) negativeMcAlpine et al. (2006)
  white-lipped peccary (Tayassu pecari) neutralAltrichter and Boaglio (2004)
  collared peccary (Tayassu tajacu) neutralAltrichter and Boaglio (2004)
  red fox (Vulpes vulpes) negativeRoedenbeck and Köhler (2006)
Large mammals
  impala (Aepyceros melampus) neutralNewmark et al. (1996)
  moose (Alces alces) neutralKunkel and Pletscher (2000)
  wolf (Canis lupus) negative



Fuller (1989)
Mech et al. )1988)
Thiel (1985)
Jedrzejewski et al. (2004)
Karlsson et al. (2007)
  eastern timber wolf (Canis lupus lycaon) negativeJensen et al. (1986)
Mladenoff et al. (1995)
  black-backed jackal (Canis mesomelas) negativeNewmark et al. (1996)
  roe deer (Capreolus capreolus) negativeRoedenbeck and Köhler (2006)
  elk (Cervus canadensis) negativeRost and Bailey (1979)
  wildebeest (Connochaetes taurinus) neutral/negativeNewmark et al. (1996)
  zebra (Equus quagga) neutral/negativeNewmark et al. (1996)
  giraffe (Giraffa camelopardalis) neutralNewmark et al. (1996)
  African elephant (Loxondonta africana) negativeNewmark et al. (1996)
Barnes et al. (1991)
  bobcat (Lynx rufus) negativeLovallo and Anderson (1996)
  Eurasian lynx (Lynx lynx) negativeNiedziałkowska et al. (2006)
  Iberian lynx (Lynx pardinus) negativePalma et al. (1999)
  Mule Deer (Odocoileus hemionus) negativeRost and Bailey (1979)
  Amur tiger (Panthera tigris altaica) negativeKerley et al. (2002)
  warthog (Phacochoerus africanus) neutralNewmark et al. (1996)
  cougar (Puma concolor) negativevan Dyke et al. (1986)
Dickson and Beier (2002)
  woodland caribou (Rangifer tarandus
    caribou
)
negativeDyer et al. (2001)
  bohor reedbuck (Redunca redunca) negativeNewmark et al. (1996)
  wild boar (Sus scrofa) negativeRoedenbeck and Köhler (2006)
  eland (Taurotragus oryx) negativeNewmark et al. (1996)
  brown bear (Ursus arctos) negativeSuring et al. (2006)
  grizzly bear (Ursus arctos horribilis) negativeCiarniello et al. (2007)
Mace et al. (1996)
McLellan and Shackleton (1988)
*based on our analyses of data presented in paper