What is it?
Where did it come from ?
Eastern
Coyote
By Roland Kays
Curator of M ammals, Ne w York State
M useum
''I 7 110
ARE YOU ?Where did you
VV co me from?
This pair of questions greers any
newcomer, he they a new b m ily II\OV ing in down the street or a new spc cics of animal colonizing an area. A
coyote-like animal moved into Pennsylva n ia 60 years ago, but never gave
its name. It also neglected to mention
how it got here ; (rom the west or
north! On four feet or in someone's
truck ? Maybe it was always here and
we ju st neve r no t ice d ?
The fossil record answers the last
question: There is no evidence of coyotes living in Pennsylvania since it was
covered in tundra at the lasr glaciation. Instead, there were wolves runnin g aCTOSS the land sca pe , hunt ing
deer, heaver and elk , and threatening
colo nis ts' livestock. Fear made the
wolf public enemy number one, and the
government paid bounties to encourage
their persecution. Sometime in th e 1890s
the last wolf in the co mmo n wealth was
shot.
OVlT the next 60 years a scatteri ng of
wolves and coyotes were reported around
the state. Some reports turned out ro he
feral dogs , others were ret wolves. Some
were coyotes, brought into the state mistakenly - hy fox-lurnri ng clubs. Dishonest animal dealers sold coyote pups as
foxes to the d ubs, and as the pups grew to
reveal their true ldcntitv, so me were set
loose .
By the 1950s, the records of coyote-like
cre atures were becoming less of a scattering and more of a regular thing. ~1apping
out the coyote reports revealed n broad
n o rt h e rn
ban d s t re tcbing from
Pennsylvania's n, mhwcst border with Ohio
across mee-t II the co un ties adjacent to New
York. These were no longer a few escaped
pets, hut breeding populations. By the early
]980s the y had pushed so uth and co loni zed
the entire state, During the ensuing 30
years, their populations cent inucd to grow;
today they are a common, yet elu sive, spe cies in wild, rural and ur ban areas. Pennsylvania has a new top predator,
But what is this thing?
Everyone rcc ngmacd that these animals
were larger than western co yotes. Typi cal
western coyotes wei gh 25 to 30 po unds
while Pe n nsylva n ia animals were averaging 35 T!) 40 , with a few maxing o ur around
50 . They look eddifferent, too; hunters and
trapp ers were bringing back a variety of
odd-looking animals, in cluding some that
were all hlack or very pale-colored; others
had reddish fur, shaggy coats, or even Ocrman shepherd-like markings. T h e widespread assumption was that coyotes had
hvbrtdt acd with d ogs, and th e name
"covdog'' became popular.
Co vores. dogs an d wolv es are all dose
evolutlonarv co usins , all part of th e genus
Canis, and <Ill biologically able {O cross bre ed and foster fertile offspring. In the
1960s two biologists from Harvard measured rhe skulls of all three canids to compare with eastern 'co yddgs .' The sku lls of
eastern co yotes were most similar to west ern coyotes, with some resemblance to
wolves. The eastern coyote skulls had link
in common with dog skulls, or eve n with
the skulls of known coyote-dog hybrids
raised in captiv it y.
The debate co ntin ued over the next
four decades, with many theories hut lit tle
new dara. Were the easrern coyotes larger
because ofgenetics (Le. wolfhyhrid izarion)
or the environment? Western coyotes pre fer to UM' open country and eat prima rily
rabbits, mice and fruit. E astern coyotes use
all types of forests and eat more deer and
fewer mice. Maybe the abundance of food
and different environment allow, eastern
coyotes to grow Luger without any ge net ic
intluence - just like people would with
different diets and exercise regimes.
New Datil
Modern genetic techn iq ues offer biologist s a more sophisticated tool for studying
the 'What is it?' question. Instead of ju st
ranking how similar animals arc through
skull me asurements, we can a lso deduce
their origins hy tracking the evolutionary
history recorded in their DNA, Together
with two colleagues from the New York
State Museum , , explored the genertcs of
eastern coyotes to try and provide a l-etter
a nswer as to what it is and how it got here.
To do this, we e xamined <I relatively
small portion of the canid DNA across
as many coyotes as possible throughout a wide geographic regio n . Th is e nabled us to map out geographic patterns in the DNA ac ross the region.
We obtained data from al most 700
animals collected from coyote hu nters in Ohin east to New Jersey, a nd
north into Maine and sout hern Quehec. The dam set included 106 Pe nnsylvania animals from 32 differen t
counties.
T he results were simple, hut stri king. T he Northeast population of coyotes that we looked at had strong evidence of past hvbrf di aario n w ith
wolves, but almost nune for dog hvbridizarion. Approximately 20 percen t
of the eastern coyotes we tested h ad a
type of DN A typical of wolves from
eastern Canada a nd t he G rea t Lakes
regton, whileonlyone sample was doglike. This is strong evidence for a recent (last 100 years) hy bridizatio n
with wolves. Since tha t initial crossbreeding, bvbnd animals have continued to cross bac k with coyotes. wolves
and other hybrids, prod ucing what is
known as a "hyhrid swarm." All suhpopulations we examined contained a
combinauun nf wolf-l ike and coyotelike genes.
T h us, all Northeastern covores
contain a blend of wolf and coyote
genes. Because we look ed at only a
small portion of their DNA, we cannot estimate the percentage of genetic
material of individual animals that
comes from either wo lves or coyotes.
Ho weve r, eastern co yotes a rc more
similar in size and appearance to coy otes than wolves, and coyote- li ke
genotypes were more common in o ur
study. The refor e, it seems that eastern
coyotes are more like coyotes with a
dash of wolf than vic e versa.
We found only one a nima l with
dog-like DNA. We canno t rule out the
idea that there was initially more hv-
Pennsylvania Game News 2010 v81:(4)18-22
!9
This photo is of Nick Laversen, not Kays.
bridua rfon ....-uh dogs wh en coyotes
first cll l,m izl·.t nn area, hilt if rhnr was
the case, th is ~il"n t'l ic signature has
sinc e l'ecn swal1l['l.J our hy co yote and
wolf genes . The rarity (IfJog genes surpriscd us a hi t, bec ause manv of the
an imals we ana lp...J looked like wha t
you would expect from a coy-J og. The
m' lSI striking of these was a shaggy
4 7.S-r ound an imal th at took second
place at the 2008 Mosqu ito C reek coyote h um in Pennsylvania. We ni ckn amed it Bcnji for its lon g sha~..,· fur,
wh ich I've never seen in a coyote hefore. Our j.,'\'ne tic test ing showed that
its DNA was one of rhe covotc-rvres
rvpica l of the Nort heast.
The spec ific ge netic m arke r we
used . m itochondri a] DN A , is maternally inherited. Thus, ou r res t pro ves
that th is an ima l's mother was a tvptcal eastern coyote. It is r o>o.sihle th at
its father o r gra ndfat he r was a d'lg.
A nother f'tl/>..s ihility is th at new populations of covoec-wolf h vbrid animals
ha w suc h nu xed up genetics tha t oddha ll va riations like th is arc mo re likely
to appear eve n without hrel-J ing with
d'lgs. M on." de tai led gener ic tests are
needed to resolv e this question. but
IHIt resu lts shllw rhard, 'l-.'Sd iJ not cont ri bute sllt->sfa nti a lly to t h e ge ne tic
mak eup lIf mo dern easte rn covorcs .
In ad ,lil io n to an al yzing ge n e t ic
samples, we co llec ted and mea sured
196 skulls from t he N o rth east . We
co nfirmed the carlk r work, showing
lh at ea stl·rn cOyllh.' , ku lls wl'r l·larget
th an Wl'st ern coy o tes , espec ially in
l'lt·in!.: ex tra-wide. J n ad,Jit illl1, e.lste rn
coyotes :Irl' sexua lly d imo rphic, with
males hei ng larger than fem ale,. T h is
J imor ph hm is al,o ,,'l·n in wolf po puhUions, bUI n nt in Wl'stern co yotes.
Lar!.:l·r .skulls would hell' an an ima l
h unt and e:lt dl'l'r, T he increaseJ co n sumption of dl'l'r in till" C<l~t Ls one of
tlU' r rimary l'({llllJ.:ical J iffl'ren ces from
Wl'stl'rn (llylltl'S, O'llr dat a sUl-:!-:esl thar
THE AUTHOR,
above,
obtained DNA samples from
almost 700 anima ls, induding
106 from Pennsylvania and
discovered tha t our "eastern coyotes " are
largely made up of western coyotes that
hyb rid ized with wolves as they spread east.
Many coyotes exammed, like shaggy Benji.
right, exhibit dog. like appearances.
lwbridicanon with wolves allowl-J easter n
coyotes to rapid ly evolve la rge r sku lls.
wh ich made them be tter adap ted ro eas tern forests where dee r offer an abundant
food o ptio n.
\ \ 'here did it come from~
Coyotes mad e h eadl ines <1.\ rhev srrl':ld
east from thei r original r<inj,..'C in rh e G rear
Plains. The arriva l of a new hlr pred ator
does not go un noticed, and scient ists a nd
newspapers alike look nonce. Fro m rhcse
rec ords we can tr ace the ir route int o Pennsylvan ia al,m!: two st'parale front s: a ~ l l'w­
movin g fro n t co m ing east fro m Indi ana
throug h O h io , and a fast-moving front
com ing sout h from M inneso ta th rough
O ntario and New York.
Coyoles mo ving Ih ro ugh M innesota
:md O n ta rio enco unTered Wl.lf 1'It lpUlations,
and thi s seem, to I", where th e hyhridi zation occurred . Th is infl ux of wolf g~'nt",
and emlling rapid evolution inl o a br!.:er
type of coyote, hclpl,J thl' northern fw n t
mov e fi\'e tim es f:lste r than the an ima ls
moving th rou gh O hi o, which newr l'n countl'w d W ( >if ('\'pula li(lOS.
Eastern coyole ('\lpuLlIinn s lhat ori s.:inated from Ihi s nllnhem ClII'lIli::;u il'n fflln l
h a\'e a un iq ul' ge nt· t ic si!.:na ture. Firs l.
ahout 20 rercent of :m im:tls h :iw wIM-lih·
m itochund ria l l)NA. T he ir migral il,n also.l
left a seco nd uni qu e pat t ern in their genetics - very low J i\'l' rsity, with Ilnly th rc'c•
genetic tvpes present throughout the region . Typical weste rn coy ote population s
ha ve m an y dozens of gl'm' tic types. We
believe that thi s low d iversiw is the result
of a vervlirmrcd d ispersa l of coyotes from
Ontario ac ross rbe St. L awrence Rive r in to
N ew York. Pos-iblv just a han,tful l,( females
made it across. This w ry low d iw rsity is
see n in all popul ations from central New
'rork and Pennsylvania cas t th w us.:h Ne w
England and mroQucl-cc , anJ SlJ~'l~ts tha t
the spo rad ic in rroducrion of coyotes hy
h untin g clubs or per owne rs .ltd nol h ave
an influence on the colonization I,f the region by coyo tes. If th ese introduced an imal s had survived and bred thev would
have inj ec ted mo re eenenc d in·rsity in to
the populan on th a t would st ill h: eviden t
rodav.
The ge net ic panc m we observe d in
O h io \~;:;L~ much J il"ferent. with a hi gh vanely of genetic IH""'S and no wolf-like infl uences. This is lyr ical of we-t ern COYI1Il'
populat ions. and s u~ests these animals
faced no hybrid iza tion or majo r barriers to
the ir movement ,
\Vestem Pennsylvan ia and weste rn New
York are now a sort l,f cont act Zl lile between
these different rvpe s of covorcs: weste rn
coyo tes ar e spreading fro m Ohio wh ile
northeastern co yo tes . o r "coy-wolves" arc
moving in from rh e nor th and cast. How
th ese types interact is anyo ne's !.:uess. Do
th ey recogni se each other as tx'ill !.: ,Iiffl'rent? Will the y hreed am i furt he r mi x Il l'
the gen elics of easte rn coyute s? Wi ll th e
stra ins wit h a da sh of wlllf DNA , ur d w
hetter hecause th ey ;Ire IlI I lre elfie it'llt dl'l'r
REFERENCES
Fener, H. M., Ginsbe rg , J. R"
Sande rson, E,. &. Gom pper,
M. E. 200 5 . Chronology of
range ex pansion of the Coyote Canis touoos, in New York.
Canadian Field Natu ralist 119,
1-5.
Law rence, B. &. Bossert, W, H.
1969 . The cra nial evidence lor
hybridization in New Englan d
Canis. Breviora 330, 1-13 .
Kays, R., Curtis, A., &. Kirchman,
J. J. 2009 . Rapid ada ptive evolution of northeastern coyotes
via hybridization with wolves.
Biology letters.
Williams, 5. l., Mclaren, 5. B.,
&. Burgwin, M. A. 1985. Paleoarchaeological and historical
records of selected Pennsylvania mamm als . Annals o f
Carnegie Muse um 54 , 77 188.
h unt ers? Or. will the pure coyo tes survive better because they are bet te r able
to snea k arou nd and avo id confhc r
with h umans?
Last bUI nOI least - what shou ld
we call th is animal ~ Covdog seems inacc urate , because we foun d so lillie
ev idence of dug genes in the populutilIn. Covwolf migh t be more accurate,
bur may o ve rstate the amount of wo lf
influe nce . For now, I prefer 'Easte rn
Coyote ,' because it implies the anima l
is still a co yole , hUI is different than
its west ern cou sin: just as wily, n o
douht, hut even mon~ adapla ble, with
a link' h ell' from the wolve s. 0
P OPULAR FURBEARER
Sportsme n have ce rta inly noti ced the arr ival and increase in coyotes in Penn sylvania. ln 1990, acco rd ing to Game-Take and Furbear er surveys, 7,782 hunters
and tra ppers took 1,8 10 coyotes. In 2000, 28,270 hunlers and trap per s too k
10, 160 coyotes, and in 2008, ou r lalest ligures, 40,982 hunters an d trappers
took 23,699 of th e animals,
. ron"
~ ."',
....