1 23
Biological In asions
ISSN 1387-3547
Biol In asions
DOI 10.1007/s10530-019-01919-9
Di e ences in habi a use be ween he
na i e Eu asian bea e and he in asi e
No h Ame ican bea e in Finland
Riikka Alakoski, Kaa ina Kauhala &
Vesa Selonen
1 23
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ORIGINAL PAPER
Di e ences in habi a use be ween he na i e Eu asian
bea e and he in asi e No h Ame ican bea e in Finland
Riikka Alakoski .Kaa ina Kauhala .Vesa Selonen
Recei ed: 9 July 2018 / Accep ed: 14 Janua y 2019
ÓThe Au ho (s) 2019
Abs ac Habi a equi emen s la gely de e mine
he dis ibu ion and abundance o a species. An
in asi e species can he e o e h ea en he su i al
o a na i e species, i he wo species a e simila in
niche use. In Finland, he dis ibu ion o he in asi e
No h Ame ican bea e (Cas o canadensis)is
app oaching he ange o he na i e Eu asian bea e
(Cas o ibe ) possibly c ea ing a h ea o he la e .
We compa ed he habi a use o he na i e and
in asi e bea e species in Finland in he main
dis ibu ion o he species and wi hin a smalle a ea
whe e he species li e in sympa y. We compa ed he
used habi a s ( olume o bi ch and o he deciduous
ees and dis ance o ag icul u al and u ban a eas) a
bea e lodges and a andom loca ions in he a ailable
ipa ian habi a wi h (condi ional) logis ic eg ession
models. Resul s indica ed ha he na i e bea e lodges
we e loca ed close o ag icul u e han hose o he
in asi e bea e . The olume o bi ch was also sligh ly
g ea e nea he lodges o he na i e bea e han hose
o he in asi e bea e . Howe e , habi a use o bo h o
he species seemed qui e lexible, because he habi a
nea lodges did no di e much om he a ailable
habi a . We conclude ha he p obabili y ha he
No h Ame ican bea e will in ade he dis ibu ion
a ea o he Eu asian bea e in Finland depends, a leas
pa ly, on he abili y o he o me o li e in p oximi y
o ag icul u al a eas. Howe e , me hods o he han
hose ela ed o managing habi a quali y may be he
bes app oach o con olling he in asi e species.
Keywo ds Alien species Cas o ibe Cas o
canadensis Habi a use Moni o ing coun s Ci izen
science
In oduc ion
Habi a equi emen s la gely de e mine he dis ibu-
ion and abundance o species. Two e y simila
species, which sha e he same ecological niche,
seldom coexis in he same a ea o a long ime (K ebs
1972; Eh le
´n and Mo is 2015). A se ious p oblem can
de elop when an alien species is in oduced o an a ea
whe e a e y simila na i e species al eady exis s
(Ebenha d 1988). In he wo s case, he in asi e
species may ou -compe e he na i e one. In asi e
species may also ansmi diseases o pa asi es o
na i e ones (e.g. Kauhala 1996; Sainsbu y e al. 2000),
o hey may al e he habi a s o he na i e species
(Rowe and Gill 1985). They can hyb idize wi h na i e
species (e.g. Ebenha d 1988; Geno esi e al. 2009),
R. Alakoski (&)V. Selonen
Depa men o Biology, Uni e si y o Tu ku,
20014 Tu ku, Finland
e-mail: [email p o ec ed]
K. Kauhala
Na u al Resou ces Ins i u e Finland Luke, I a
¨inen
Pi ka
¨ka u 4 A, 20520 Tu ku, Finland
123
Biol In asions
h ps://doi.o g/10.1007/s10530-019-01919-9(0123456789().,- olV)(0123456789().,- olV)
and in asi e p eda o s may ha e a de imen al e ec
on na i e p ey animals (e.g. Ebenha d 1988; Kauhala
1996; Woods e al. 2003; Banks e al. 2008).
An in asi e species po en ially h ea ening a na i e
species is he No h Ame ican bea e (he ea e NA
bea e , Cas o canadensis), which is pa ly sympa ic
wi h he na i e Eu asian bea e (Cas o ibe )in
Finland (Kauhala and Tu kia 2013; Kauhala and
Ka inen 2018). The Eu asian bea e was hun ed o
ex inc ion in Finland in 1868 (G ani 1900; Lah i
1972; Lah i and Helminen 1974) bu was ein oduced
in he 1930s when 17–19 indi iduals we e b ough
om No way (e.g. Lah i and Helminen 1969;
Ha
¨ ko
¨nen 1999). Se en NA bea e s we e also in o-
duced (Lah i and Helminen 1969,1980; E mala e al.
1989), because a he ime hei s a us as a dis inc
species was no known. Bo h species we e eleased
in o se e al a eas in Finland, bu he Eu asian bea e
popula ion su i ed (only one pai ) and s a ed o
inc ease slowly only in Sa akun a in sou hwes e n
Finland, a egion whe e no NA bea e s we e in o-
duced (Fig. 1). NA bea e s lou ished especially well
in eas e n Finland (Fig. 1; E mala 1996). The ange
and popula ion size o he NA bea e inc eased as e
han ha o he Eu asian bea e , eaching an es ima ed
popula ion size o [10 000 in 2017 (Kauhala and
Ka inen 2018). The p esen ange o he NA bea e
co e s mos o eas e n and cen al Finland, and
spo adically Lapland, whe eas ha o he Eu asian
bea e is es ic ed o a smalle a ea in wes e n Finland
(mainly Sa akun a), and i s popula ion size is es i-
ma ed o be 3300–4500 (Fig. 1; Kauhala and Ka inen
2018).
The ange o he NA bea e has sp ead wes wa ds
in ecen decades and pa ly o e laps he dis ibu ion
o he Eu asian bea e in h ee a eas, i.e., in he
egions o Pi kanmaa, Pohjanmaa and Lapland
(Fig. 1; Kauhala and Tu kia 2013; Kauhala and
Ka inen 2018; Iso ou u e al., unpubl. da a). I is
possible ha he wo species ha e li ed close o each
o he o some decades in Pi kanmaa, and a p esen ,
hey e en li e in he same i e sys ems and ha e, a
leas on wo occasions, been ound nea he same
lodge (Kauhala and Ka inen 2018). Because he
Eu asian bea e did no su i e a e he o iginal
in oduc ions in a eas whe e bo h bea e species we e
p esen , i is assumed ha he sp ead o he NA bea e
is a h ea o he Eu asian bea e (Liukko e al. 2016).
The Eu asian bea e is classi ied as ‘nea h ea ened’
in Finland (Liukko e al. 2016). The NA bea e has
la ge li e s, which may be he eason o a mo e apid
g ow h a e o he popula ion and may gi e i he
ad an age when he species mee (Pa ke e al. 2012).
Bo h bea e species a e monogamous and e i o-
ial (Wilsson 1971; Nole and Rosell 1994), and he
ecological niches o hem a e ai ly simila . Bo h
species eed mainly on deciduous ees (Collen and
Gibson 2001; Danilo e al. 2011; Pa ke e al. 2017);
and in summe , e es ial and aqua ic he bs a e also
pa o hei die (Wilsson 1971; Lah i and Helminen
1974; Nole and Rosell 1994; Danilo e al. 2011). A
ma u e bea e couple builds a lodge, a bank bu ow, o
a combina ion o he wo, wi h an unde wa e en ance
(Wilsson 1971; Lah i and Helminen 1974;Mu
¨lle -
Schwa ze 2011). The c i ical wa e dep h needed o a
lodge may be abou 40 cm (Rosell and Pa ke 1996;
Baskin 2011); ha is, he lodges o he bea e s a e
always by he wa e a ea. A bea e amily can occupy
se e al lodges du ing he summe , bu only one lodge
is used du ing he win e (Lah i and Helminen 1974).
Bea e s a e cen al-place o age s (e.g. Haa be g and
Rosell 2006), and hey commonly o age wi hin a
50-me e adius om he lodge, which can be de ined
as hei co e a ea. Bea e s can, howe e , mo e up o
250 m om wa e in sea ch o good o aging ees
(Smi h e al. 1994;Mu
¨lle -Schwa ze 2011). One
amily g oup needs app oxima ely 1–2 km o sui -
able habi a along a wa e cou se o sho eline (de ined
as hei e i o y, Ha man 1994). Bea e s usually
inhabi o es ed a eas, bu may also use ag icul u al
a eas, especially a eas ha a e mosaics o ields and
o es pa ches along a i e sys em. The ange o he
Eu asian bea e in Finland co e s especially la ge
ag icul u al a eas, and hey can make dams and bank
bu ows in small di ches be ween wo ields and e en
o age in ields (Kauhala and Ka inen 2018). We
ha e also ecei ed obse a ions o bea e s in small
owns o illages om he public, which indica es ha
hey do no always a oid human p esence.
We compa ed he habi a use o he wo bea e
species wi hin hei co e a eas a ound lodges and on a
la ge e i o y scale, and compa ed he habi a use
wi h o he habi a s a ailable in he landscape (Johnson
1980). We used ci izen-science da a on bea e lodge
loca ions in he main dis ibu ion a ea o he species in
Finland. We p edic ed, based on ea lie s udies (e.g.
Lah i and Helminen 1974; Ha man 1994; Nelne and
Hood 2011), ha (1) he habi a use o he wo bea e
123
R. Alakoski e al.
species would be ai ly simila and hey would a o
habi a pa ches wi h deciduous o es s. Howe e , he e
s ill may be a di e ence be ween he species in he
amoun o bi ches and o he deciduous ees nea hei
lodges, o example, due o di e ences in he amily
s uc u e be ween he species (Pa ke e al. 2012). We
u he p edic ed (2) ha he wo bea e species would
be ound o di e in hei habi a use in ela ion o
ag icul u al and u ban a eas, because he na i e bea e
li es in an ag icul u e-domina ed landscape, whe eas
he NA bea e li es in a o es -domina ed a ea wi h a
spa se human popula ion. We discuss he possible ole
o habi a equi emen s in he conse a ion o he
Fig. 1 Map o he cu en
dis ibu ion o bea e
obse a ions in Finland and
he success ul in oduc ion
si es o he Eu asian and he
No h Ame ican bea e ,
om whe e he species
began o sp ead
(unsuccess ul in oduc ion
si es a e no included). The
s udy a ea consis ed o he
dis ibu ion a eas o bea e s,
excep Lapland (g ay a ea in
he map). Eu asian bea e s
in Lapland ha e appa en ly
dispe sed o Finland om
Sweden. The zoomed
pic u e is om he a ea in
Pi kanmaa, whe e he
species a e pa ly sympa ic
123
Di e ences in habi a use

na i e Eu asian bea e and in con olling he in asi e
NA bea e in Finland.
Me hods
S udy a ea
The s udy a ea consis ed o he dis ibu ion a eas o
bea e s in Finland, wi h he excep ion o Lapland
(Fig. 1). The landscape in Finland consis s la gely o
coni e ous and mixed o es s wi h app oxima ely 168
000 lakes wi h an a ea o a leas 500 m
2
(S a is ics
Finland 2018a) and app oxima ely 20,000 km o
i e s (Biodi e si y 2018). Fo es s co e app oxi-
ma ely 75% o he land a ea and he Sco s pine (50%;
Pinus syl es is), he No way sp uce (30%; Picea
abies) and bi ches (17%; Be ula sp.) a e he mos
common ee species (Luke 2018a). Ten pe cen o he
land co e is composed o inland wa e s, 9% o
ag icul u al a eas and 3.5% o u ban a eas, i.e.
popula ion cen e s including esiden ial, indus ial
and comme cial a eas (Biodi e si y 2018). The human
popula ion densi y is highe whe e he main dis ibu-
ion o he Eu asian bea e is, in Sa akun a in
sou hwes e n Finland, wi h 28.18 ind./km
2
, han he
human popula ion densi y o he a ea whe e he main
dis ibu ion o he No h Ame ican bea e is, in
eas e n Finland, wi h 3.66, 9.18, 10.32 and 14.71 ind./
km
2
in Kainuu, No h Ka elia, E ela
¨-Sa o and
Pohjois-Sa o, espec i ely (S a is ics Finland
2018a). Ag icul u e is mo e dominan in Sa akun a
wi h 16.7% o he a ea being ag icul u al land in 2013,
compa ed o eas e n Finland wi h 1.4, 3.9, 3.8 and
7.2% being ag icul u al land in Kainuu, No h Ka elia,
E ela
¨-Sa o and Pohjois-Sa o, espec i ely (Luke
2018b). C op cul i a ion is mo e common in Sa a-
kun a compa ed o eas e n Finland, whe e ca le
a ming is mo e common. Lakes a e mo e abundan
in eas e n Finland (also called he Lake Dis ic ) wi h
inland wa e s co e ing a minimum o 12.1% o he
a ea o Kainuu o a maximum o 25.5% o E ela
¨-Sa o,
when in Sa akun a he p opo ion is 5.3% (Ja
¨ iwiki
2018).
Da a o bea e s
Lodge si es we e ob ained om moni o ing coun s
ca ied ou by he Finnish Game and Fishe ies
Resea ch Ins i u e (Na u al Resou ces Ins i u e Fin-
land, Luke since 1.1.2015). Bea e lodge coo dina es
we e collec ed by hun e s du ing he all o 2013 and
2014 and he sp ing o 2015 (B omme e al. 2017;
cases o a si e ha ing da a o mul iple yea s we e
omi ed om he da a). The en i onmen al a iables
used in he s udy we e he same o hese yea s.
Hun e s usually know hei hun ing a eas well, and his
me hod should supply a comp ehensi e p opo ion o
lodges, bu ob iously no all lodges could be de ec ed
wi h he ci izen science app oach. Only inhabi ed
win e ing lodges we e epo ed o es ima e he numbe
o bea e amily g oups in each game managemen
dis ic . An occupied win e lodge can be ecognized
by a ood cache nea he lodge (Mu
¨lle -Schwa ze
2011). The bea e species could no be iden i ied in
he ield by a ci izen scien is collec ing he lodge-
loca ion da a. Ins ead, he iden i ica ion o bea e
species was based on he his o ic dis ibu ion o
bea e s in Finland (Fig. 1), DNA analyses om wood
chips collec ed nea bea e lodges and skull mo -
phome y om hun ed bea e s (Kauhala and Timonen
2016).
The coo dina es o 758 and 628 Eu asian bea e
and No h Ame ican bea e lodges, espec i ely, we e
analyzed in GIS (ESRI A cMap 10.2.2; ESRI 2011)
wi h land co e a iables. The geog aphic in o ma ion
o s eams 20 m (as polylines) and lakes and la ge
i e s (as polygons) we e added om he da a o he
Na ional Land Su ey o Finland ( opog aphic
map 1:100,000) (Maanmi auslai os 2/2015), and
lakes and la ge i e s we e ans o med o polylines
( om now on, all a e called wa e cou ses). We lands
we e pa ly included in hese da a, as he e a e no la ge
sepa a e we land a eas in he Finnish landscape
(excep pea bogs). Only lodges ha we e wi hin
50 m om a wa e cou se based on GIS we e included
o emo e possible e o s in coo dina es and o emo e
cases whe e lodges we e in small s eams no digi ized
in GIS. This was necessa y because he e i o y
bu e s we e gene a ed along wa e cou ses (see
below). Based on his, 328 lodges o he Eu asian
bea e and 159 lodges o he No h Ame ican bea e
we e excluded om he analysis. The Eu asian bea e
li es in a mo e ag icul u e-domina ed landscape wi h
small di ches, which is p obably why mo e o his
species’ lodges we e in undigi ized wa e cou ses. We
did no ha e a eason o suspec his emo al o he
lodges wi h unce ain loca ions would a ec ou
123
R. Alakoski e al.
analysis because he numbe o lodges o bo h species
was s ill qui e high, and he Eu asian bea e was no
o e ep esen ed in ela ion o he NA bea e . On he
con a y, some quali y checks o he lodge loca ions
p o ided by he ci izen scien is s should be done. Only
win e ing lodges should ha e been epo ed, bu
lodges we e some imes e y close o each o he .
The e o e, lodges ha we e close han one km o
ano he lodge along a wa e cou se we e coun ed as he
same amily g oup’s lodges (Ha man 1994), because
amily g oups’ home anges do no usually o e lap
(Ko belo a
´e al. 2016). Only he cen e mos lodge in a
amily g oup’s a ea was included in he analysis. In he
end, we used coo dina es o 428 lodges o he Eu asian
bea e and 466 lodges o he NA bea e ha we e
sui able o gene a ing he bu e s.
Habi a a iables in co e a eas, e i o ies
and a ailable en i onmen
The habi a a iables used in he analyses we e: he
olume o bi ches, olume o o he deciduous ees,
dis ance om u ban a eas and dis ance om ag icul-
u al a eas. The olumes o bi ches and o he decid-
uous ees (m
3
/ha) we e compu ed using he ee
olume da a om he o es in en o y da a o he
Finnish Fo es Resea ch Ins i u e in 2013 (Luke 2015).
The da a gi es he olume o bi ches (Be ula pendula,
B. pubescens and B. nana) and o he deciduous ees as
one g oup, including he Eu asian aspen (Populus
emula), alde (Alnus incana and A. glu inosa),
Eu opean moun ain ash o owan (So bus aucupa ia)
and he goa willow (Salix cap ea) (Yli alo 2013)
wi hin 16 m 916 m squa es. The dis ances om he
u ban a eas and ag icul u al a eas we e he nea es
neighbo a i hme ic dis ance om he lodge/ andom
poin . The ag icul u al a ea and u ban a ea we e added
om he 2013 Co ine land co e da a o Finland wi h
20 m 920 m squa es (SYKE 2/2015). The ag icul-
u al a ea included classes 2111–2441 (a able land,
pas u es e c.). The u ban a ea included classes
1111–1424 (u ban ab ic, indus ial uni s, dump si es
e c.) and 4122 (pea bogs in comme cial use). Roads
we e no included as possible sou ces o dis u bance,
because oads loca ed closes o lodges we e mainly
he smalles oads wi h e y low a ic.
Habi a a iables we e measu ed in wo scales:
wi hin a co e a ea a ound lodges and wi hin a e i o y.
Co e a eas we e calcula ed by bu e ing he lodges
wi h a adius o 50 m (e.g. Mu
¨lle -Schwa ze 2011).
We calcula ed he olumes o bi ches and o he
deciduous ees pe hec a e wi hin he co e a ea and
he dis ances om he lodge o he nea es ag icul u al
and u ban a eas. In he second scale, he e i o y
ex ended a maximum o 500 m om he co e a ea
along all wa e cou ses connec ed o he co e a ea and
250 m om he sho eline o he lake o om he
middle o he s eam, i.e., he maximum o aging
dis ance on land acco ding o Mu
¨lle -Schwa ze
(2011) (Fig. 2). Wi h a maximum dis ance o 500 m,
each e i o y included sho eline (on bo h sides o he
wa e cou se) wi h a mean leng h o 2050 m o he
Eu asian bea e ( ange 484–5654 m) and 2438 m o
he NA bea e ( ange 327–9746 m). We also calcu-
la ed he olumes o bi ches and o he deciduous ees
pe hec a e wi hin he e i o y. The nea es neighbo
dis ances o he e i o y om he ag icul u al and
u ban a eas we e calcula ed using he a e age a i h-
me ic dis ance o 100 andom poin s placed wi hin he
e i o y (Fig. 2).
To compa e habi a a iables wi hin co e a eas and
e i o ies wi h hose a ailable in he landscape in
habi a s close o ipa ian zone, we laid andom poin s
in he p oximi y o all wa e cou ses in he landscape.
We used andom poin s ha we e a maximum o
250 m om a wa e cou se ( om now on called a
wa e cou se a ea) and did no o e lap wi h a bea e
e i o y. Random poin s we e laid wi hin each
municipali y in Finland wi h bea e lodge coo dina es
om he 2013 municipali y di ision om he da a o
he Na ional Land Su ey (Maanmi auslai os 2/
2015). Municipali ies we e selec ed as he a ailable
landscape a eas because he sizes o he municipali ies
a e o sui able size o he bea e s o po en ially
dispe se ( he median size o a municipali y in Finland
is 750 km
2
). The numbe o andom poin s o each
municipali y was compu ed by mul iplying he wa e -
cou se a ea as hec a es (excluding bea e e i o ies)
in a municipali y wi h he highes numbe o lodges
( wo species sepa a ely) pe wa e cou se a ea ound in
all municipali ies. The numbe o andom poin s was
hen mul iplied so ha hei o al numbe s we e
app oxima ely en old compa ed o he numbe o
lodges: 4452 o he Eu asian and 4874 o he NA
bea e . We compu ed he olume o deciduous ees
(bi ches and o he deciduous ees sepa a ely) pe
hec a e a each andom poin (in e sec ing wi h a
16 m 916 m squa e wi h ee olume), and he
123
Di e ences in habi a use
sho es a i hme ic dis ances be ween andom poin s
and he nea es u ban and ag icul u al a eas.
Da a om he sympa ic Pi kanmaa a ea
A sepa a e compa ison was done o he bea e
obse a ions wi hin he egion whe e bo h species
a e sympa ic ( he egion o Pi kanmaa; Fig. 1). A
o al o 50 coo dina es, 25 o bo h species, we e used
o his analysis. Coo dina es included bea e lodges
(15 Eu asian (E); 7 NA), eeding si es (4 NA), si es
whe e d oppings we e ound (1 NA) and si es whe e
bea e s we e sho (13 E; 10 NA; ecei ed om hun e s
who sen us bea e skulls o species de e mina ion,
Kauhala and Timonen 2016) ( om now on called
ac i i y si es. Volumes o bi ch and o he deciduous
ees wi hin 250 m om each bea e ac i i y si e and
dis ances o ag icul u al and u ban a eas om 100
andom poin s in he = 250 m bu e we e calcu-
la ed. Only he 250-m bu e ( e i o y scale) was
selec ed o his analysis, because no all ac i i y si es
desc ibed he accu a e loca ion o he lodge.
Fig. 2 A GIS image o he
lodge si e, he co e a ea and
he e i o y compu ed along
he wa e cou ses. Examples
a e om wo Eu asian
bea e lodges
123
R. Alakoski e al.
S a is ical analysis
Analysis o he habi a use in co e a eas and e i o ies
o each bea e species
We compa ed he co e a eas and he e i o y bu e s
using condi ional logis ic eg ession analyses sepa-
a ely o he wo bea e species (Duchesne e al.
2010). Wi h condi ional analyses, we could ma ch he
co e a eas and e i o ies o each lodge o he analysis,
ha is, he esponse a iable was he ma ched pai o
used (co e a ea) and a ailable ( e i o y). Explana o y
a iables we e habi a cha ac e is ics, i.e., olumes o
bi ches and o he deciduous ees (m
3
/ha) and dis-
ances o ag icul u al and u ban a eas (mo e abou
condi ional analysis, see e.g. Duchesne e al. 2010).
Fo a compa ison o co e a ea/ e i o y e sus
andom poin s in he landscape, we could no o m
ma ched pai s (condi ional model). Ins ead, we buil
wo logis ic eg ession models, whe e he binomial
esponse a iable was he used habi a (1) o he co e
a ea o e i o y e sus a ailable habi a (0) in he
landscape, ep esen ed by andom poin s along he
sho e o all wa e cou ses in he municipali y. Explana-
o y a iables we e habi a cha ac e is ics, i.e., ol-
umes o bi ches and o he deciduous ees (m
3
/ha) and
dis ances o ag icul u al and u ban a eas. In addi ion,
he municipali y was included as a andom a iable in
he model.
Analysis o he di e ences in habi a use
be ween he Eu asian bea e and he No h Ame ican
bea e
To analyze whe he he habi a use di e ed be ween
he species, we combined he da a o bo h bea e s and
pe o med models simila o hose desc ibed abo e
(co e s. e i o y, co e s. landscape, e i o y s.
landscape). Condi ional logis ic eg ession was used
when compa ing he co e a ea o e i o y, and
binomial logis ic eg ession when compa ing he co e
a ea and e i o y o en i onmen . In addi ion, we
included he in e ac ion e ms be ween he class
a iable ‘species’ (1 Eu asian Bea e , 2 NA bea e )
and he habi a a iables in he models. The in e ac ion
e ms we e included sepa a ely o each habi a
a iable. Thus, we could es i habi a use di e ed
be ween he Eu asian and he NA bea e . Because his
analysis o he wise epea s he abo emen ioned
analysis, we epo only he obse ed signi ican
esul s o in e ac ion e ms.
Analysis o he habi a use in he egion whe e species
a e sympa ic
Fo he compa ison o habi a use o he in asi e and
na i e bea e s in an a ea whe e hey a e sympa ic
(Pi kanmaa), we buil a model we e species (1
Eu asian bea e , 2 NA bea e ) was he esponse
a iable. Explana o y a iables we e habi a cha ac-
e is ics, i.e. olumes o bi ches and o he deciduous
ees (m
3
/ha) and dis ances o ag icul u al and u ban
a eas. In addi ion, ype o obse a ion was included as
a class a iable in he model (ac i i y si es: 1 lodge, 2
o he ype o obse a ions). In his analysis, we
assumed ha he a ailabili y o habi a s was simila
o NA bea e s and Eu asian bea e s, because hey
we e li ing in he same a ea.
Resul s
Habi a use in co e a eas and e i o ies
Co e a eas o bo h species included s a is ically
signi ican ly mo e bi ch han did e i o ies in he
model (Table 1). The olume o o he deciduous ees
was lowe in he co e a eas han in he e i o ies o he
NA bea e (Table 1).
When compa ing co e a eas and e i o ies o
andom poin s a ailable in he ipa ian landscape,
he only s a is ically signi ican di e ence was ha he
Eu asian bea e ’s co e a eas and e i o ies we e
close o ag icul u al a eas han andom poin s we e
(Table 1). The co e a ea and he e i o y o he NA
bea e did no di e signi ican ly om he landscape
in any o he measu ed a iables (Table 1).
Di e ences in habi a use be ween he Eu asian
bea e and he No h Ame ican bea e
The dis ance om ag icul u al a eas, compa ed o he
a ailable en i onmen ( andom poin s) di e ed
be ween he na i e and in asi e bea e (in e ac ion
e m be ween bea e species and dis ance o ag icul-
u e; co e: F
1,10109
= 4.88, p= 0.03; e i o y:
F
1,10110
= 4.04, p= 0.04; Table 2); ha is, he mean
dis ances o ag icul u al a eas we e g ea e in he NA
123
Di e ences in habi a use