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Walk,paddle,swim,jump,cling,hold, dig,keep warm,stay cool—feetdoallthesethingsandmore.

Feetcomeinmanyshapesandsizes.Thewayfeetlookandthewaytheyworkarerelatedtowhattheydo.Butallfeetofanimalswithboneshavethesamebasicparts.

Differentanimalsrelyondifferentpartsoftheirfeetforlocomotion, or moving around. Some animals walk onthesolesoftheirfeet.Otherstravelontheirtoenails,alsoknownashooves.Andsomemovearoundontheirtoes.

Without feet, birds would never get off the ground. Without feet, gophers would never go underground. Without feet, many animals would simply not get around.

By Mary Hoff

Without feet, birds would never get off the ground. Without feet, gophers would never go underground. Without feet, many animals would simply not get around.

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Guess whose feet: Find the answers on page 38. Photographs

by: Bill Marchel (A,E,H) Allen Blake Sheldon (B,C,D,G) Dominique Braud (F).

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Frog Feet. Haveyoueverseenafrogcling-ingtoatreeorawindow?Thefeetofmanyarboreal (tree-living) frogs have pads ontheir toes that help them hang onto sur-faces.Onbarkorotherroughsurfaces,theskinfitsintotheupsanddownsofthesur-faceonwhichtheyareperchingandhelpsthemhangon.Tinyporesproducemucusthathelpsthemsticktosmoothsurfaces.

Minnesota’ssixspeciesoftruefrogsdonothavetoepads.Instead,theirhindfeethave webbed toes for swimming in theirwetlandhabitat.

Bear Feet.Youmightnotthinkyouhavealotincommonwithablackbear.Butyourfeetandthehindfeetofbearsaresimilarinoneway:Theheeltouchesthegroundfirstwhenwalking.Onebigdifference:Abear’stoenails extend almost 2 inches from theendsofitspaws.

Hoovesaremadeofkeratin,thesamestuff that makes up hair and finger-nails.Hoovesgrow,justasyourfinger-nailsgrow.Thegrowingkeratingivestheanimala freshsurfacetowalkonastheoldtoenailswearaway.

Even-toed Feet.Mammalswithtwoorfour hooves that touch the ground areeven-toed.Bisonanddeerareeven-toed.Odd-toed Feet.Mammalswithonehooforthreehoovesoneachfootareodd-toed.Theseincludehorses,zebras,andrhinos.

Sole MoversHumans,bears,frogs,andotherplantigrade animalswalkontheentiresoleoftheirfeet.

A gray treefrog (above) with sticky toe pads climbs a tree trunk. A mink frog’s toes (below) have webbing but no pads because this frog stays on the ground around wetlands.

Toenail TravelersDeer,moose,andotherunguligradeanimalswalkontheirtoenails.Thesemammalsspendalotoftimeontheirfeet,sotheyhavehardsurfacescalledhoovesthatcovertheirfeet.

Moose feet (above)and white-tailed deer feet (left) have cloven hooves with two toes that spread apart like fingers, which helps these unguligrade animals walk in mud or snow.

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Bird Feet. Most birds have four toes. Some birds, such as chickadees, havethree toes in front and one in back.Others,suchaswoodpeckers,havetwotoesinfrontandtwoinback.Owlsuse

theirtoesbothways.Sometimesanowlstandswiththreetoesinfrontandoneinback.Toperchorreachouttocap-ture prey, an owl can swing its outerfronttoetothebackforabettergrasp.

Toe WalkersWolves,bobcats,birds,andotherdigitigrade animalswalkontheirtoes.

Dog Feet. Foxes, coyotes, wolves, andother doglike animals are digitigrade.Runningonitstoesgivesadoglikeani-mal lots of “spring” in its step. Its feethavesoftbuttoughpadsonthebottom.Thepadscantake lotsofwearandtearwithoutbreakingthroughtheskin.Likeshockabsorbers,thepadshelpkeeptheforceofhittingthegroundfromhurtingtheanimal’slegbones.

Cat Feet. Lynxhavelittlesheathsattheend of their toes. When the cat tensesitslegmuscles,itsclawsstickout,readyforpouncingonprey.Butwhenrelaxed,thecattucksitsclawsinsidethesheaths.This“hiddenclaw”featurekeepsacat’sclaw from getting worn down whenwalkingaround,keepingtheclawsrazorsharpforcatchingprey.

A wolf track (above) shows claw marks. Unlike a cat, a wolf always has its claws out. Both the gray wolf and Canada lynx (below) have wide paws that act like snowshoes, so they can run quickly to catch prey without sinking in deep snow.

MITCH KEZAR, WINDIGO IMAGES

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Clockwise from top left: Harris’s sparrow, male downy woodpecker, northern hawk owl, pine grosbeak

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Cling. Some animals use their feet tograsp or cling to things. Their toes areverystrong.Oftentheyhavesharpclawsthat can dig into the surface, holdingtheminplace.Abatuses theclawsonitsfeettohangupsidedownfromroughsurfacesincavesorotherdarkplaces.

An opossum’s “thumbs” on its hindfeethelpitclimbtreesinsearchoffood.Babyopossumsusetheirthumbstoclingtotheirparents.Aperchingbirdsuchasachickadeegraspsabranchbywrappingitstoesaroundit.

Whileflying,anospreycangripfishandotherpreywithpowerfulhooksonitsclaws.

Theskinonthebottomofanosprey’sfeethas scales, which also help the bird hangtighttoitscatch.

Dig. Whenafoxdigs,itsclawsbreakupthegroundanditsfootpadsspreadapart,working likeminiatureshovels.Abad-ger’sfrontpawsareshapedlikescoopers.Amole’sfrontfeetfacesideways,whichhelpsthemolescoopsoiloutofthewayasitboresatunnelthroughtheground.

Groom. Barn owls, herons, and night-hawkshaveacomblikestructure,calledapectinate claw,oneachfoot.Theyuse

Foot ToolsManyhuman-madeobjectshaveafunctionsimilartoanimalfeet.Forexample,swimflippersworklikeduckfeet.Shovelsworklikeamole’sclawedfeet.

theclawtogroomtheirfeathers.Beavershaveasplitclawonthesecondtoe

ofeachbackfoot.Theyusethespecialclawtogroomtheirsleekfur.

Paddle. Ducks and beavers have webbedfeet. Flat pieces of skin between the fronttoesformaflatsurfacetheanimalusesasapaddletopropelitselfthroughthewater.Inducksandgeese,webbingconnectsthefront three toes. In cormorants, webbingconnectsallfourtoes.

A peregrine falcon (left) uses its feet twice to catch prey. First, it uses a closed foot to deliver a powerful punch. Then, it uses its talons to grip the prey.

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A mallard hen kicks her webbed feet (top right) as she dabbles. A bobolink’s toes (bottom) wrap securely

around a branch, its perch in a meadow.

Guess whose feet, from page 30. Foot owners: A) snowshoe hare, B) painted turtle, C) mink frog, D) spotted salamander, E) crow track, F) mallard ducks, G) gray tree frog, H) white-tailed deer.

A Note to TeachersFind links to teachers guides for this and other stories online at www.mndnr.gov/young_naturalists.

Foot WarmersImaginegoingbarefootinJanuary!Animalsdo.Theirfeethavespecialadaptationsthathelpkeepthemfromturningintotoe-sicles.

Heat Exchangers. How can a duckstand to dangle its feet in icy water?Like many birds, a duck relies on aprocess called countercurrent heat exchange inside its legs and feet. Theheartpumpswarmbloodtotheduck’stoes. The toes get warmer, but the

bloodcools.Thebloodvesselsthatre-turnbloodtotheheartrunalongsidethevesselscarryingwarmbloodfromtheheart,socoolerbloodabsorbsheatfrom the warmer blood vessels. Thisheat exchange helps keep body heatinsidetheduck.

Heating Pads. Graywolveshave webs of tiny bloodvessels on the bottom sur-face of their paws. These“heating pads” keep thetoesfromfreezing,eveninsuper-coldweather.

Fur Toes. Fur between lynxtoes works like wool socksandsnowshoes,keepingtheirfeetwarmandhelpingthemwalkonsnow.nV

Telltale TracksYoucantellalotaboutananimal’sfeetbythetracksitleavesbehind.

Crowsandravenshavethreelongtoesinfront.Themiddle toebendsslightly towardthebird’scenter. You can tell a crow’s left track from itsrighttrackbywhichwaythemiddletoegoes.

The webbed feet of a trumpeter swan arevisibleinthesetracksonthesnow.

Cat claws are always sharp because they are tucked in when the cat walks. Wolf claws (right) are blunt because they are always out. A wolf’s claws give it traction and help it dig.

ABOVE: AMERICAN CROW TRACK BY BILL MARCHELRIGHT: TRUMPETER SWAN TRACK BY DOMINIQUE BRAUD

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A mallard drake (right) is standing with both feet on the ice. A mallard hen (left) is standing on one foot.