Abs ac
This s udy desc ibes he mo emen pa hs —in si ua ion o s ess— o i e anu an species
(Aly es obs e icans, Peloba es cul ipes, Bu o bu o, Bu o calami a and Bu o i idis balea-
icus) by ajec ome ic analysis. Di e en expe imen al ea men s (a i icial s. na u al)
and seasonal a ia ions we e s udied. The pa h s uc u e e lec s speci ic (phyogene ic)
cons ain s. Each species showed a cha ac e is ic pa e n o locomo ion o di e en expe-
imen al si ua ions and seasons.
Key wo ds: Anu ans, Beha iou , S ess, T ajec ome y.
Resum. T ajec ome ia en anu s
L’es udi desc iu els desplaçamen s —en si uació d’es ès— de cinc espècies d’anu s (Aly es
obs e icans, Peloba es cul ipes, Bu o bu o, Bu o calami a i Bu o i idis balea icus) mi -
jançan una anàlisi ajec omè ic. Es an es udia en di e en s si uacions expe imen als
(a i icials i na u als) i en di e en s èpoques de l’any. L’es uc u a del desplaçamen e lec-
eix les p essions adap a i es especí iques ( ilogenè iques). Cada espècie mos a un pa ó
de locomoció ca ac e ís ic i dependen de la si uació expe imen al i de l’època de l’any.
Pa aules clau: anu s, compo amen , es ès, ajec ome ia.
O sis 13, 1998 55-65
Analysis o he displacemen o i e ibe ian
anu an species in s ess condi ions
Del í Sanuy Cas ells
Uni e si a de Lleida. ETSEAL. Depa amen de P oducció Animal
A inguda Ro i a Rou e, 177. 25006 Lleida. Spain
Manusc ip ecei ed on No embe 1997
In oduc ion
The amphibians, show s ong cons ain s in ela ion o dampness (dehyd a ion
—Shoemake e al., 1992— and ep oduc ion- Pough e al., 1992), g a idi y (loco-
mo ion), and ai ( espi a ion Bou ilie e al., 1992). Anu ans ha e in he o de o
amphibians, a g ea e au onomy ega ding hose cons ain s, and wi hin hem,
he e is also a di e si ica ion in species ela i ely dependen on aqua ic media and
o he s ha can be quali ied as animals o e es ial habi s.
Any beha iou al desc ip ion equi es p ecise measu es o i s componen s
(Hun ing o d, 1984). The pa hs ollowed by di e en anu an species in di e en
expe imen al egimes ha e been quan i ied o compa e hei displacemen s.
Buy endijk (1918) was a pionee in s udying he locomo i e beha iou in se e al
species o Anu a; he de ined se e al a iables o cha ac e ize quan i a i ely he
pa hs ha a e cu en ly used. In spi e o many wo ks conce ning o he o ien a ion,
mig a o y pa hs and mo emen a ia ion du ing he ep oduc i e season in se e al
Bu o species (Able, 1981; Adle , 1982; Bide , 1968; Moo e, 1954; Oldham, 1966),
ha e been done, no da a a e a ailable on he de ailed s uc u e o mo emen pa hs.
The s udies made by Sinsch (1987a, 1987b, 1988, 1990a, 1990b, 1991) on com-
pa a i e locomo o y beha iou among oad species we e pe o med especially
unde he scope o mig a o y beha iou .
The e a e ew wo ks ha s udy he s uc u e o he displacemen s in e eb a-
es, usually ela ed o sea ch o ood (Bo e and Benhamou, 1988; Benhamou and
Bo e , 1989; K ebs and Da ies, 1981; Pyke, 1984; Smi h, 1974a, 1974b; Sanuy
and Bo e , 1997).
The locomo ion ype is a beha iou which can e lec di e en le els o adap-
a ion o he e es ial en i onmen (Dingle, 1980; Pough e al., 1992). The e o e,
di e en species can be expec ed o show dis inc mo emen pa e ns. Also, i is
known ha habi a luc ua ions h oughou he yea can bea upon he exp ession
o he beha iou (Eibl-Eibes eld , 1974). Ou aim in his wo k is o conside he
in luence o speci ic and ecological condi ions on he s uc u e o he locomo i e
pa hs o di e en anu a; we add ess he ollowing ques ions: a) A e he e loco-
mo o y speci ic di e ences among species? (phylogene ic componen ); b) A e
he e di e ences due o dis inc expe imen al si ua ions, in ime and space? (eco-
logical componen ).
Ma e ials and me hods
The pa hs o 1449 specimens belonging o i e species o Anu ans we e moni o-
ed (Table 1). The indi iduals o each species we e om he same popula ion. The
56 O sis 13, 1998 Del í Sanuy Cas ells
Table 1. Species s udied, numbe o animals, species size and geog aphical and ecological
p ocedence.
No. Specie O igin
Specie subjec s size (mm) locali y Ecological si e
Aly es 237 40-50 Py enees Ca icion nig ae and
obs e icans Adenos ylo-Vale iane um-
py enaicae
Peloba es cul ipes 276 70-100 Moneg os* Ag opy o-lygeion
Bu o bu o 430 70-110 Py enees Que ce um o undi oliae
Bu o calami a 285 50-90 Py enees Buxo-Que e um Pubescens
Bu o i idis 221 70-90 Majo ca Apie um nodi lo i
ssp. balea icus
*Si ed in A agón (no h Spain).
obse a ions we e pe o med ew days a e collec ing he animals. In he labo a-
o y, he animals we e kep in cap i i y in indi idual cages wi h high humidi y
and ed wi h ali e p ey. A e es ing, animals we e eleased a hei o iginals bio-
opes. The es s moni o ed he pa h o each animal a e i s elease om he cen-
e o es a ena. The s udy was pe o med du ing wo hou s a e sun ise and wo
hou s be o e he sunse ; he du a ion o each obse a ion was 30 minu es. A g id
con ibu ed o loca e he animal and made possible o ans e he pa h obse ed
on o a ske ch; along wi h he pe o med pa h, o he ea u es ha allowed o iden-
i y and de ine each o he mo emen s we e no ed. The obse e emained hidden
o i i was no possible, a a long dis ance in o de no o dis u b he animals. The
pa h o he s udied species was a succession o mo emen s and s ops. Each s op
du a ion was measu ed; hese we e no always in places whe e he animal could
s ay hidden ( ege a ion, s ones…). The isual ho izon o he expe imen al ani-
mals was assumed o be di e se, wi h mul iple shapes and in ensi ies o ligh and
da k.
The «i ine a y» o pa h includes all aspec s o an animal’s ip om i s elease
un il i s exi om he es a ena o du ing he 30 minu es ial pe iod. We consi-
de ed a «s op» when he animal was s ill o mo e han wo seconds. Di e en
a iables quan i y he pa e n o ac i i y and non-ac i i y o each i ine a y.
—Ini ial ime (IT). Elapsed ime (seconds) om an animal’s elease in he cen e
o he a ena un il he i s mo emen .
—T ajec ime (DT). The o al (seconds) ime o ac ual mo emen , excluding IT
and he s ops be ween successi e mo emen phases.
—Numbe o mo emen phases (NS). Numbe o po ions o he i ine a y deli-
mi ed by s ops. S ops did no coincide wi h shel e s and we e a he ypical o
he pa h s uc u e o hese animals.
— Leng h (L). Whole dis ance a elled (cm) in an i ine a y.
—Veloci y o Dis ance o ajec ime o (V = L/DT). This a iable, epo ed on
he o al speed o mo emen , including he ime o pe manence in each s op.
—Mean du a ion o mo emen phases (DT/NS). The a e age ime o pe manen-
ce in each o he s ops pe o med by he animal. Ac ually, he animal spen
almos 90 % o he ime quie in one o hese s ops. Thus his a iable in o -
med abou he ime he animal keeps s ill along he ip.
—S aigh ness (S). Dis ance in a s aigh line om he ini ial o he inal poin
di ided in o he o al leng h. (Ba schele , 1981; Sinsch, 1988; Bo e , 1983).
The s aigh ness was no compa ed be ween expe imen because pa h leng hs
di e owing o di e en sizes o es a enas.
—Numbe o mo emen phases o uni leng h (NS/L). I de ines he a e age
leng h o he mo emen phases.
—Jumping (J). Numbe o s e ches in which some jump we e pe o med di i-
ded in o he o al numbe o s e ches.
The expe imen al a eas we e loca ed nea Jaca (Huesca, Spain) and in p o ec-
ed a eas belonging o he Py enean Cen e o Ecology (CSIC). The es s we e
T ajec ome y in anu ans O sis 13, 1998 57
ca ied ou in h ee expe imen al si ua ions, conside ing 12-16 eplica es o each
ype o expe imen and ime:
—Expe imen 1 (ST-1). Closed Room. The es s we e ca ied ou in a 60-squa e-
me e s oom. A 9-squa e-me e s g id was d awn on he loo . The animals
mo ed h oughou his su ace. A es ended ei he when he animal wen
beyond he ma ked space o when ime exceeded 30 minu es. The en i on-
men al condi ions we e s able du ing he whole pe iod o es s. Tes s we e pe -
o med du ing ep oduc ion pe iod. Du ing he obse a ion, he esea che
emained hidden a a dis ance o 4 me e s. The expe imen s we e ca ied ou a
nigh , unde dim ed ligh (0.03 lux a g ound le el) —see Sanuy and Bo e
1997.
— Expe imen 2 (ST-2). Bushes. Tes s we e pe o med in an open a ea —aban-
doned ennis cou , wi h g ound su ace— o 1500 squa e me e s close o a
building; es s we e done in sp ing and a he beginning o summe . Vege a ion
consis ed o he baceous bushes (mainly composi es and leguminosae) and
g asses, which did no allow animals o shel e . The animal was placed in he
cen e o a g id (30 x 50 m); he mo emen was obse ed ei he o 30 minu-
es o un il he animal wen o e he ield limi s.
—Expe imen 3 (ST-3). Meadow. Obse a ions we e pe o med in a meadow
belonging o he domain o he Que cion obo i-py enaicae, a 800 m o al i-
ude; he he baceous and sh ub-like ege a ion was e y abundan . The size o
ege a ion allowed he animals o shel e . The space was signalled wi h s akes
and he obse e no ed he mo emen o he animal om a dis ance o 6-8
me e s. In his expe imen al si ua ion, es s we e pe o med in h ee di e en
imes o he yea : be o e (ST-3A), du ing (ST-3B) and a e (ST-3C) he
pe iod o se ing and his o each o he species. ST-3A also includes he
pe iod o mig a ions owa ds he place o spawning, and ST-3C es s we e
ca ied ou in summe . The empo al limi was he only one conside ed o
inish he es in his expe imen al si ua ion. The e a e no enough es s o da a
o Aly es obs e icans in ST-3C and o Bu o i idis in ST-3A. The numbe
o pa hs o each species and expe imen al si ua ion is speci ied in able 3.
S a is ical analysis: The da a we e es ed wi h an analysis o a iance (Rouane
and Lépine, 1970, 1977) o each o he a iables. This analysis includes a pos -
hoc Tukey es and loga i hmic ans o ma ion o da a when hey we e no no -
mally dis ibu ed. S aigh ness was a csine ans o med. To s udy he in luence o
he en i onmen ( ield s. labo a o y) a design o 5 species x 3 expe imen al si ua-
ions (ST-1, ST-2, ST-3B) was pe o med; he es s we e all pe o med du ing he
spawning season o he species. To emphasize he in luence o he ime o he
yea , a design o 3 species (Peloba es cul ipes, Bu o bu o and Bu o calami a) x 3
imes o he yea (ST-3A, ST-3B, ST-3C) was pe o med.
Simila i ies among da a om ST-3B (na u al habi a ) we e assessed wi h a
clus e analysis (CSS-S a is ica, 1991) on mean alues (s anda ised da a) using
Euclidean dis ances and he single linkage me hod.
58 O sis 13, 1998 Del í Sanuy Cas ells
Resul s
Table 2 shows he alues o he means and s anda d de ia ion o each species and
expe imen al si ua ion. Tables 3 and 5 show he esul o he analysis o a iance
o he a iables used and o bo h expe imen al designs. Rele an compa isons
among expe imen al si ua ions o each species and among species o each expe-
imen al si ua ion we e pe o med wi hin each o he analyses. Figu e 1 shows a
g aphical summa y o he deg ee o simila i y o each species o he di e en
indexes o a iables o able 2, and o he expe imen al si ua ion ST-3B.
T ajec ome y in anu ans O sis 13, 1998 59
Table 2. Mean alues and s anda d de ia ion o each species and expe imen al si ua ion.
IT: Ini ial ime; S: S aigh ness; V: Veloci y; DT/NS: Mean du a ion o s op; NS/L: Numbe
o mo emen phases o uni leng h; J: Jumping (see ex o a iable de ini ion and uni s).
nº: sample size. AO: Aly es obs e icans; PC: Peloba es cul ipes; BB: Bu o bu o; BC: Bu o
calami a; BV: Bu o i idis balea icus.
IT S V DT/NS NS/L J No.
X
–sd X
–sd X
–sd X
–sd X
–sd X
–sd
AO ST-1 498 321 0.54 0.29 0.94 0.54 29.07 21.71 12.12 7.24 0.58 0.33 81
ST-2 372 250 0.75 0.35 0.70 0.47 24.48 17.67 5.53 3.28 0.37 0.21 57
ST-3A 302 201 0.70 0.35 1.49 1.05 34.23 24.43 4.16 1.63 0.90 0.42 49
ST-3B 133 79 0.65 0.30 1.89 1.26 25.78 17.27 3.75 1.35 0.83 0.41 50
PC ST-1 426 307 0.45 0.21 0.98 0.64 85.29 45.43 4.72 1.98 0.15 0.07 50
ST-2 151 72 0.81 0.51 1.41 1.17 79.92 47.25 3.18 1.61 0.25 0.11 77
ST-3A 322 160 0.64 0.31 1.77 1.23 57.48 35.83 2.19 1.13 0.45 0.27 50
ST-3B 129 92 0.61 0.27 2.39 1.71 42.34 27.38 2.16 0.95 0.67 0.39 49
ST-3C 172 121 0.59 0.48 1.82 1.24 25.02 17.18 2.87 1.57 0.57 0.31 50
BB ST-1 815 621 0.57 0.25 0.71 0.47 98.54 62.92 6.30 3.23 0.00 – 54
ST-2 399 279 0.77 0.31 1.65 1.21 86.83 55.47 4.24 1.92 0.28 3.20 210
ST-3A 505 394 0.69 0.27 2.47 2.11 83.44 51.73 0.76 0.28 0.00 – 50
ST-3B 163 75 0.68 0.29 6.01 5.08 63.52 27.34 0.39 0.15 0.00 – 48
ST-3C 173 140 0.62 0.33 2.61 1.69 64.54 25.54 1.09 0.75 0.18 6.06 68
BC ST-1 271 150 0.75 0.39 2.82 2.06 23.65 12.27 5.40 3.34 0.00 – 74
ST-2 200 110 0.57 0.21 2.55 1.56 31.92 16.60 5.71 3.12 0.00 – 62
ST-3A 755 521 0.68 0.31 1.82 0.93 61.29 29.36 1.87 0.96 0.00 – 49
ST-3B 128 96 0.67 0.29 3.08 2.36 50.13 21.19 1.52 1.16 0.00 – 50
ST-3C 175 125 0.64 0.21 2.62 1.22 43.40 17.35 1.76 1.24 0.00 – 50
BV ST-1 19 8 0.78 0.45 4.26 3.48 11.98 6.51 4.84 2.30 0.67 0.31 48
ST-2 51 19 0.84 0.61 4.49 4.19 9.60 6.03 2.50 1.65 0.47 0.24 75
ST-3B 70 27 0.66 0.52 5.34 4.77 10.04 6.21 2.72 1.19 0.96 0.46 49
ST-3C 22 11 0.68 0.49 3.70 3.24 11.51 8.14 3.27 2.08 0.75 0.38 49

60 O sis 13, 1998 Del í Sanuy Cas ells
Table 3. Analysis o a iance. p<0.05 in all es s. F: Values o F. dl: deg ees o eedom.
Design analyzed: i e (5) species and h ee (3) expe imen al si ua ions (ST-1, ST-2 and ST-
3B, see ex ). IT: Ini ial ime; V: Veloci y; DT/NS: Mean du a ion o s op ; NS/L: Numbe
o mo emen phases o uni leng h; J: Jumping (see ex o a iable de ini ion and uni s).
Sou ce IT V DT/NS NS/L J
Species F 25.9 88.9 15.7 107.2 92.6
dl (40, 1015) (4, 961) (4, 961) (4, 961) (4, 961)
Exp, Si , F 26.9 42.6 0.9 284.5 21.9
dl (2, 1015) (2, 961) (2, 961) (2, 961) (2, 961)
In e ac ion F 18.1 43.5 7.3 121.5 32.9
dl (14, 1015) (14, 961) (14, 961) (14, 961) (14, 961)
Table 4. S a is ical signi icance (+: p<0.05) o di e ences be ween species o ST3-B. IT:
Ini ial ime; S: S aigh ness; V: Veloci y; DT/NS: Mean du a ion o s op; NS/L: Numbe
o mo emen phases o uni leng h; J: Jumping (see ex o a iable de ini ion and uni s).
AO: Aly es obs e icans; PC: Peloba es cul ipes; BB: Bu o bu o; BC: Bu o calami a;
BV: Bu o i idis balea icus.
IT V DT/NS NS/L J
BV-AO + + + + –
BV-PC + + + + +
BV-BB + + + + +
BV-BC + + + + +
AO-PC – + + + +
AO-BC – + + + +
AO-BB – + + + +
PC-BC – + – + +
PC-BB – + – + +
BC-BB – + – + –
Table 5. Analysis o a iance. p<0.05 in all es s. F: Values o F. d : deg ees o eedom.
Design analyzed: h ee (3) species (Peloba es cul ipes, Bu o bu o and Bu o calami a) and
h ee (3) expe imen al si ua ions (ST-3A, ST-3B and ST-3C see ex ). IT: Ini ial ime;
S: S aigh ness; L/DT: Dis ance o ajec ime; DT/NS: Mean du a ion o s op; NS/L:
Numbe o mo emen phases o uni leng h; J: Jumping (see ex o a iable de ini ion
and uni s).
Sou ce IT S V DT/NS NS/L J
Species F 30.7 13.1 37.3 3.8 136.5 13.0
dl (4, 972) (4, 908) (4, 908) (4, 908) (4, 908) (4, 908)
Exp, Si , F 9.0 3.9 28.2 12.2 27.0 140.2
dl (14, 972) (14, 908) (14, 908) (14, 908) (14, 908) (14, 908)
In e ac ion F 13.8 16.3 22.3 4.1 54.6 30.6
dl (14, 972) (14, 908) (14, 908) (14, 908) (14, 908) (14, 908)
A. Compa isons o i e species in h ee di e en expe imen al si ua ions (Closed
Room (ST-1), Bushes (ST-2) and Meadow (ST-3B)). Tes e ec ed du ing he
spawning season.
The analysis o a iance con i med ha species we e di e en and his
happens o all he a iables wi h he excep ion o DT/NS (see Table 3).
Bu o i idis was he species wi h he sho es ini ial ime (IT) and mean
du a ion o he s e ches (DT/NS) and acco dingly mo ed a he highes elo-
ci y. Fu he mo e i was he species wi h he g ea e numbe o jumps (J) and
he mos s aigh pa hs.
Aly es obs e icans. The a e o s e ches (NS/L) pe o med by his species
is he highes in each expe imen al si ua ion. I was he second species ha
jumped he mos a e Bu o i idis. This species needed a long ime o lea e
he elease poin and on many occasions in ST-2 and ST-3 i did no mo e
du ing he ial pe iod (IT>30 minu es). Besides, i appea s as he slowe spe-
cies. This was mainly due o he high numbe o s ops and he ime o pe ma-
nence in each o hem.
Bu o bu o. The ini ial ime (IT) is e y high in ST-1 because o high num-
be o immobili y sco es (IT>30 minu es). This species makes ew s ops bu
i emains a subs an ial ime in each o hem. I ca ied ou he pa hs a he hig-
hes speed a e Bu o i idis, bu he a e o s e ches in a uni o leng h (NS/L)
is he smalles .
Bu o calami a. Due o he cha ac e is ics o i s ajec o ies, his species was
somewha simila o Bu o bu o and Peloba es cul ipes. Like Bu o bu o, his
species was cha ac e ised by he small numbe o jumps (only in a 0.6 % o
he analysed s e ches), bu i mo ed quicke and spending less ime in he
s ops han Bu o bu o.
Peloba es cul ipes shows mean alues ha can be conside ed in e media-
e among Bu o bu o, Bu o calami a and o he species.
Table 4 shows ha all species a e di e en acco ding o some a iables,
om wo (Bu o calami a - Bu o bu o) o i e (Bu o i idis -Peloba es cul i-
T ajec ome y in anu ans O sis 13, 1998 61
Figu e 1. Single linkage clus e dend og am o simila i ies be ween he
i e Anu an species (da a om able 3, s anda ized). Only alues om
he na u al expe imen al si ua ion (ST-3B) we e used.
10 201
(Dlink/Dmax) x 100
40 50 60 70 80 90 100
A. obs e icans
P. cul ipes
B. bu o
B. calami a
B. i idis
30
pes, and Bu o bu o - Bu o calami a). Veloci y (V) and he a e age leng h o
s e ches (NS/L) a e use ul o cha ac e ise and di e en ia e each species in he
mos na u al expe imen al si ua ion.
B. In luence o season (e ec ed in Meadow: be o e (ST-3A), du ing (ST-3B) and
a e ST-3C). Tes ealised by Peloba es cul ipes, Bu o bu o and Bu o cala-
mi a.
Analysis we e done wi h he aim o es ing possible di e ences in he dis-
placemen s among h ee species (Peloba es cul ipes, Bu o bu o and Bu o cala-
mi a) a di e en seasons. Resul s o he a iance analysis (Tables 5 and 6)
shows ha he season has a ma ked in luence on he pa h s uc u e. Du ing he
season p eceding he onse o ep oduc ion (ST-3A) all species ook conside-
ably mo e ime o s a mo emen when placed on he ini ial poin o he pa h.
They spen also mo e ime on in e media e s ops and hei speed o he mo e-
men was lowe . Du ing ep oduc ion (ST-3B) all h ee species showed a ma -
ked inc ease in speed and he ini ial ime and s ep numbe o o al leng h was
he smalles o he h ee seasons.
In summe (ST-3C), when ege a ion d ying-up and he animals we e ou
o he ep oduc i e season (mig a ion and spawning), he ime o ini ia e he
mo emen is sligh ly highe ha in ST-3B, he speed dec eases and he numbe
o s e ches inc eases; his, o all o he species. Peloba es cul ipes made a
small numbe o jumps in his si ua ion; his was also obse ed wi h he o he
wo species, hough wi h a le el o signi icance o p < 0.1.
F om able 2 i can be seen ha a ia ion in he dis inc a iables o
he species PC, BC and BB, when conside ing he e ec o season (ST-3A,
ST-3B and ST-3C), shows pe sis en di e ences among species and ha hey
show simila endencies along he ime o season.
Discussion
Pa h s uc u e was analysed in i e species o oads in di e en en i onmen s and/o
in di e en seasons in he same bio ope. The species s udied showed a di e en
pa h s uc u e ha is consis en in each o he expe imen al si ua ion (Table 6); This
62 O sis 13, 1998 Del í Sanuy Cas ells
Table 6. S a is ical signi icance (+: p<0.05) o di e ences be ween expe imen al si ua ions,
o i e (5) species and h ee (3) expe imen al si ua ions. IT: Ini ial ime; S: S aigh ness;
V: Veloci y; DT/NS: Mean s op du a ion; NS/L: S ep numbe / o al leng h; J: Jumping (see
ex o a iable de ini ion and uni s).
IT S V DT/NS NS/L J
ST-3A/ST-3B + + – – – –
ST-3A/ST-3C + + + – + +
ST-3B/ST-3C – + + – + –
may be in e p e ed as a phylogene ic componen in he locomo i e beha iou . I can
be no ed specially ha mo emen ea u es o Bu o i idis balea icus di e s ongly
om he o he species in all he si ua ions s udied. This is no su p ising as his
subspecies has ma ked aqua ic habi s (Vi es e al., 1987) and e en has mo pholo-
gical ea u es (in e digi al memb ane, long legs: Vi es e al., 1987, Pough and
Magnusson, 1992; body p opo ions: Dob owolska, 1973 and Eme son 1988) clo-
se o o he aqua ic Anu ans. Among he species s udied, his species can be consi-
de ed as he leas e es ial, conce ning he pa h s uc u e. The highe p opo ion
o jumps clea ly sepa a es Bu o i idis om o he ep esen a i es o he genus Bu o.
I is wo h men ioning ha Bu o calami a is mo phologically and phylogene ically
he closes species o Bu o i idis ou o he ones s udied (Duellman and T ueb,
1986). Zug, 1972a, 1972b and Eme son 1988, sugges ed ha jumps do no b ing so
many ad an ages o a e es ial animal, bu hey do o one o aqua ic habi s.
The mo emen s pe o med by Aly es obs e icans (sho s e ches, sinuous
pa h, small eloci y) may be ela ed o he smalle size o his species. Du ing he
es s, i was obse ed ha he indi iduals o his species used shel e s (small bus-
hes, holes be ween s ones, e c.) ha we e no used by o he species.
Peloba es cul ipes is a highly specialised species li ing on so and sandy
soils. This imposes s ic limi s o i s dis ibu ion (Vi es e al., 1987 and Llo en e
e al., 1996). A ma ked endency o bu y i sel was obse ed (and no o hide i sel
nea ege a ion o s ones).
This s udy shows ha each species beha es di e en ly in each o he expe i-
men al si ua ions. This could be expec ed o ST-1 due o he absolu e a i iciali y
(absence o ege a ion ha d subs a e) and spa ial limi s imposed on he animals.
The i ine a ies pe o med in ST-2 show in e media e alues be ween ST-1 and ST-
3B, bu a e mo e simila o he o me . This could be due o he absence o ege-
a ion o ST-1, he almos absence —only sho g asses— o ST-2, and he
spa ial limi s ha unca ed he pa hs.
The es s pe o med in ST-3 we e done in di e en seasons (ST-3A, ST-3B
and ST-3C) o h ee species. Be o e he spawning season he ege a ion was a -
he poo ly de eloped bu he empe a u e and dampness we e op imal o he h ee
species. This could explain he long ime needed o ini ia e he mo emen and
spend on each s op in spi e o he absence o e uges and e e ences. The mo e-
men pa hs o hese animals a e s ongly in luenced by he p esence o ege a ion
and i s ege a i e s a e. Sc ubs and bushes p o ide shel e s and p o ec ion agains
clima ic ac o s. Pa hs in his season a e mo e ec ilinea . The smalle olume o
ege a ion, wi h he consequen educ ion o shel e s, and he clima ic cons ain s,
may be he cause. This is in ag eemen wi h Sinsch (1988) who sugges ed he
s aigh ness o he pa hs o Bu o bu o s eadily dec eases h oughou he yea ,
being smalle in summe .
The di e ence wi hin phyllogene ically close species iz. Bu o calami a and
Bu o i idis (Llo en e e al., 1996), shows ha ecological componen a e mo e
in luen ial han phylogene ic componen s in he design o a pa h.
Physiological ac o s (ho monal balance wi h he mig a ion and/o ep oduc-
ion phase) canno be uled ou and could be also in ol ed in he exp ession o he
T ajec ome y in anu ans O sis 13, 1998 63