Content uploaded by Vladimir Shakhparonov
Author content
All content in this area was uploaded by Vladimir Shakhparonov on Mar 29, 2019
Content may be subject to copyright.
1 3
J Comp Physiol A
DOI 10.1007/s00359-016-1132-x
ORIGINAL PAPER
Marsh frogs, Pelophylax ridibundus, determine migratory
direction by magnetic field
Vladimir V. Shakhparonov1 · Sergei V. Ogurtsov1
Received: 23 April 2016 / Revised: 1 November 2016 / Accepted: 12 November 2016
© Springer-Verlag Berlin Heidelberg 2016
Introduction
Orientation by global cues appears to be adaptive dur-
ing animal migrations. Celestial and magnetic compasses
are among these cues. Such compass orientation has been
demonstrated in various terrestrial vertebrates (Wiltschko
and Wiltschko 2005; Rozhok 2008; Muheim et al. 2014).
Amphibians as an evolutionary basis of terrestrial ver-
tebrates could be considered to preserve orientational
mechanisms typical for first tetrapods. A number of pub-
lications show that amphibians are able to use celestial
compass (Ferguson et al. 1968; Adler 1982; Diego-Rasilla
and Luengo 2002), though in many situations, the magnetic
cues should be considered as more appropriate, because
many amphibian species migrate during rainy nights when
celestial cues are unavailable (Shoop 1965; Grant et al.
1968; Merrell 1970; Sinsch 1990a; Marty et al. 2005).
Nowadays, magnetic orientation is more thoroughly stud-
ied in urodelious amphibians (Phillips 1986; Phillips et al.
2001, 2010; Diego-Rasilla 2003). Anuran amphibians are
still poorly investigated, and publications dealing with their
magnetic orientation are scarce.
To date, magnetic orientation of adult individuals of
anurans was tested in only one family—Bufonidae. Thus,
in toads, such as Bufo spinulosus, Bufo bufo, and Bufo
calamita magnetic bars, that were attached to a toad’s head
influenced initial orientation of the amphibians towards the
breeding pond during homing experiments (Sinsch 1987,
1988a, 1990b). It is still not clear how magnetic informa-
tion could be used by animals to determine their own posi-
tion at such short distances (within several hundred meters),
as the field gradient in this case is too small and is com-
parable with daily magnetic fluctuations (Kirschvink et al.
1985; Sinsch and Kirst 2015). The controlled magnetic
Abstract Orientation by magnetic cues appears to be
adaptive during animal migrations. Whereas the magnetic
orientation in birds, mammals, and urodele amphibians is
being investigated intensively, the data about anurans are
still scarce. This study tests whether marsh frogs could
determine migratory direction between the breeding pond
and the wintering site by magnetic cues in the laboratory.
Adult frogs (N = 32) were individually tested in the T-maze
127 cm long inside the three-axis Helmholtz coil system
(diameter 3 m). The arms of the maze were positioned par-
allel to the natural migratory route of this population when
measured in accordance with magnetic field. The frogs
were tested under two-motivational conditions mediated by
temperature/light regime: the breeding migratory state and
the wintering state. The frogs’ choice in a T-maze was evi-
dent only when analyzed in accordance with the direction
of the magnetic field: they moved along the migratory route
to the breeding pond and followed the reversion of the hori-
zontal component of the magnetic field. This preference
has been detected in both sexes only in the breeding migra-
tory state. This suggests that adult ranid frogs can obtain
directional information from the Earth’s magnetic field as
was shown earlier in urodeles and anuran larvae.
Keywords Anuran amphibians · Magnetic compass ·
Migration · Orientation · Motivation
* Vladimir V. Shakhparonov
Wshakh@yandex.ru
1 Department of Vertebrate Zoology, Faculty of Biology,
Lomonosov Moscow State University, Leninskie gory, 1,
k.12, Moscow 119234, Russia
J Comp Physiol A
1 3
field was used only in one study, where adult common
toads B. bufo were released in a circular arena 121 cm in
diameter (Landler and Gollmann 2011). According to this
publication, the mean vector of the toads’ movements in the
arena was parallel to their migratory direction at the part of
the route, where the toads were previously caught. When
the horizontal component of the magnetic field was rotated
180°, some of the animals reversed their movements. The
authors explained the fact that not all individuals reacted to
the magnetic reversal by the availability of celestial cues as
the arena being positioned in the field under the sky. They
also mentioned that the toads tended to show escape behav-
ior that interfered with realization of the orientation trials.
The latter indicates the need for searching new methods to
study amphibian magnetic orientation.
Adult individuals of other anuran species have not yet
been studied, though there are publications demonstrating
that tadpoles from Ranidae family (Lithobates catesbe-
ianus, Pelophylax perezi, and Rana temporaria) can use
a magnetic field to orient themselves along a so-called
Y-axis—an angular direction towards the nearest coastal
line (Freake et al. 2002; Freake and Phillips 2005; Diego-
Rasilla et al. 2010, 2013). In our previous research, we
managed to describe the behavior of adult individuals of
Ranidae that could be ecologically appropriate as a model
for the study of the probable magnetic orientation. Thus,
adult marsh frogs (Pelophylax ridibundus), when released
several kilometers away from their familiar breeding pond
at the time of migration, continued to follow their migra-
tory direction between the breeding place and the winter-
ing site (Shakhparonov and Ogurtsov 2008; Shakhparonov
2012). In the current study, we decided to test whether
marsh frogs could determine this migratory direction by
magnetic cues in the laboratory.
Materials and methods
Experimental animals
Experiments were conducted with marsh frogs (Pelophylax
ridibundus) caught in the vicinity of Zvenigorod biologi-
cal station of Lomonosov Moscow State University (50 km
west from Moscow) in ponds on the right side of the Mos-
cow River. Our previous field studies showed that marsh
frogs from this population undertake spring and autumn
migrations between the breeding ponds and the Moscow
River, where they hibernate. The migratory route of this
population appears to be directed south-west during breed-
ing in spring and north-east during movements to the win-
tering site in autumn (Shakhparonov and Ogurtsov 2008;
Shakhparonov 2012). Frogs were caught on September, 19
and transferred in an opaque plastic bag to Moscow (53 km
south-east from the capture site) within a day and then were
held in a laboratory at the Faculty of Biology of Lomono-
sov Moscow State University (MSU). They were tested
throughout the rest of September and October. Frogs were
kept in transparent plastic aquariums (72 × 35 × 50 cm)
half-filled with water. Experiments were repeated twice:
in 2014 (16 frogs—8 males and 8 females) and in 2015
(16 frogs—3 males and 13 females). We used only sexu-
ally matured individuals that had body length of more than
70 mm for males and of more than 72 mm for females.
Experiments were conducted in the Skobeltsyn Institute of
Nuclear Physics of MSU. After the experiments, amphib-
ians were released back to their natural wintering site.
Test apparatus
To test whether amphibians prefer to move either in
south-west or north-east directions that correspond with
their spring and autumn migratory routes, we imitated the
parameters of the natural magnetic field typical for the cap-
ture site (X = 14,920 nTl, Y = 272 nTl, Z = 50,578 nTl) by
means of three axis Helmholtz coil system “Sphera-M300”,
produced by Ryazan State Radio Engineering University
(Fig. 1a). The coil system was positioned, so that the dec-
lination of the artificial field was +45° instead of +10° of
the natural one. Coils were 3 m in diameter and provided
nearly 1 m3 of the uniform magnetic field inside. Measure-
ments of magnetic parameters were made in the field with
an accuracy of 1 nTl by means of magnetometer GI MTS-1
produced by the Pushkov Institute of Terrestrial Magnet-
ism, and Ionosphere and Radiowave Propagation of the
Russian Academy of Sciences.
To test whether frogs could distinguish between the
direction to the breeding pond “South-West” and the direc-
tion to the wintering site “North-East”, we decided to use
a simple T-maze oriented in “South-West”–“North-East”
direction of the imitated magnetic field, thus being paral-
lel to the natural migratory route of this population. We did
not use a circular arena, because it provides a large empty
space with well-defined borders. In a number of papers,
it was shown that the large open space produced animal’s
anxiety and motivation to hide near the wall (Eilam 2003;
Lebedev I et al. 2012). Well-defined borders can also stim-
ulate frogs to escape by jumping over them. This anxious
motivation could interfere with realization of orientation
behavior of anurans (Landler and Gollmann 2011). In
contrast, the T-maze provides a completely closed “cozy”
space to eliminate frog’s anxiety. More complex mazes
contain additional corners that stimulate frogs to hide near
them. That is why we prefer to use uniform corridors to test
amphibians (Ogurtsov 2005).
In the current study, the T-maze 127 cm long consisted
of tubes (10 cm in diameter) that were inconvenient for
J Comp Physiol A
1 3
frogs to stay in one place for a long time thus stimulating
them to move. The starting chamber was located over the
main corridor, thus preventing the frogs from reentering
it (Fig. 1a). Therefore, an amphibian had to move along a
uniform tube having no opportunity to hide anywhere. The
T-maze ended with black plastic bags on both sides. The
frogs tended to find escape at the dark end and fell down
into the bag. The maze was made of white plastic that
masked the surrounding visual objects but allowed the light
to come through, thus providing dim and even illumina-
tion. The presence of light could be crucial for the function
of magnetic compass based on photoreceptors, as shown
in urodelious amphibians and birds (Phillips and Borland
1992; Wiltschko and Wiltschko 2005; Phillips et al. 2010).
Testing procedure
Frogs were individually released into the start chamber of
the T-maze and were given 20 min to choose one of the
arms. The position of individuals was determined visu-
ally by slowly opening both ends of the maze. A response
was scored, if after the allotted time period, an animal was
either in one of the drop traps or reached the very end of
one of the arms of the T-maze. Frogs that stayed in the
center of the apparatus or moved half-way into the arms
were considered “unresponsive”.
We tested two frogs simultaneously in two parallel
mazes that differed in the position of the start chamber
(Fig. 1b) to minimize the influence of possible prefer-
ence for left–right turns on the direction choice that was
described in some studies with amphibians (Adler 1980).
To analyze the frogs’ orientation by magnetic cues
(magnetic axis of migration) in contrast to orientation by
other stimuli, possibly present in the room or inside the
maze, half of the individuals in the group was tested in
the “original” magnetic field (with the parameters of the
natural field at the capture site) and the other half with the
reversed one (by 180° in relation to the “original” horizon-
tal component).
Before each experiment, we controlled the horizontal
position of the mazes by means of a digital inclinometer
Bosch GLM 80. The position of the mazes in the homoge-
nous magnetic field inside the coil system was also checked
using a magnetometer (Bartington Mag658 digital three-
axis fluxgate magnetometer). To eliminate possible orienta-
tion by olfactory cues left by a previously tested individual,
the maze was washed after each trial.
Types of experiments and motivation of animals
In spite of a number of advantages of a T-maze, the appa-
ratus can perform a rather narrow range of tasks. The
T-maze describes the choice directed exactly to one of the
arms. The case of uniform distribution could not be defined
exactly as a lack of reaction to the magnetic field in gen-
eral or as a bidirectional preference for the magnetic migra-
tory axis. Such bimodal orientation is observed in a number
of orientation tests in individuals with unclear motivation
(Taylor and Adler 1973; Phillips 1987; Freake et al. 2002;
Landler and Gollmann 2011; Diego-Rasilla et al. 2013).
Thus, in the current study, we had to provide animals
with strong motivation to move in the exact direction. We
Fig. 1 T-maze in three axis Helmholtz coils system (a) and the posi-
tion of the T-maze in relation to the artificial magnetic field and “top-
ographic” bearings (geographic north) (b) Hc three axis Helmholtz
coils system, st start chamber, dt drop trap, gN geographic north,
mN magnetic north of the artificial magnetic field, bs direction to the
breeding site according to the artificial magnetic field, ws direction
to the wintering site according to the artificial magnetic field, dashed
circle—boundaries of the volume with the highest uniformity (<1%
heterogeneity) of the magnetic field
J Comp Physiol A
1 3
conducted two types of experiments with the same individ-
uals to manipulate the frogs’ motivation.
Experiment with frogs in the “breeding migratory state”
For a week, the frogs were kept under natural lighting
conditions (nearly 12 h of light daily) at a temperature of
3–5 °C. Later, for the period of 6 h, they were transferred
into a container with the temperature of 22 °C and then
tested at the same high-temperature conditions. The tem-
perature increase stimulated breeding activity of frogs:
breeding calls and grasping behavior in males. The method
of temperature-stimulated breeding behavior is widely used
for anuran amphibians (Rastogi et al. 1978). In autumn,
this effect is facilitated by rather high natural levels of sex
hormones (Polzonetti-Magni et al. 1998; Kim et al. 1998).
Experiment with frogs in the “wintering state”
For a week, the frogs were kept in dark conditions at a tem-
perature of 3–5 °C, which are supposed to simulate winter-
ing (Voituron et al. 2003; Voituron 2005). Amphibians were
transferred to the temperature of 22 °C only 5 min before
the test that lasted additional 20 min at the same temper-
ature. No calling or grasping behavior was observed in
males in such conditions.
In 2014, we conducted an experiment with frogs in the
“breeding migratory state” followed by an experiment with
the same individuals in the “wintering state”. In 2015, the
sequence of the experiments was changed: “wintering”,
followed by “breeding migratory” and then again a “win-
tering” state. The time interval between the experiments
was 7 days. It was done to test the influence of tempera-
ture-mediated breeding motivation on the frogs’ desire to
reveal migratory orientation. Otherwise, one should also
consider the role of a possible internal program that deter-
mines the time of migration and the role of consecutive tri-
als on frogs’ desire to orient themselves.
Statistical analysis
To compare the number of frogs that moved in two alter-
native directions, we used a binomial test (Lehner 1996).
“Unresponsive” individuals were not included in the analy-
sis, but the number of such animals was clearly indicated.
The same data were analyzed in three ways: (1) according
to the magnetic axis of migration; (2) according to left–right
turn preference; and (3) according to any uncontrolled stim-
uli associated with the position of the maze in a room (“top-
ographic” bearings: geographic west or geographic east). To
compare the direction choice in males and females, we used
the test of two percentages (Lehner 1996) that was calcu-
lated in Statistica 6.0 (Stat Soft Inc., 1984–2001).
Table 1 Three types of data analysis of the frogs’ scores (the data from 2014 and 2015 are summarized)
N the total number of individuals tested
* Binomial test
Experiment NNumber of “unrespon-
sive” individuals
Magnetic field Left–right turn “Topographic” bearings
Sequence Frogs’ state North-east arm (to
hibernation site in the
river)
South-west arm (to
breeding pond)
P*Left arm Right arm P*Geographic west Geographic east P*
1 Wintering 16 3 7 6 0.21 7 6 0.21 6 7 0.21
2 Breeding migra-
tory
32 8 5 19 0.003 11 13 0.15 11 13 0.15
3 Wintering 32 9 12 11 0.16 10 13 0.14 9 14 0.1
J Comp Physiol A
1 3
Results
The number of animals that made a choice (reached either
of the ends of the maze) was on average three times larger
than that of “unresponsive” animals (Table 1). In all the
experiments, the frogs did not show any significant prefer-
ence for either the right or the left arm of the maze. Nor did
they reveal any preference for “topographic” bearings asso-
ciated with the position of the maze in a room. The pref-
erence for the maze arm was evident only when analyzed
in accordance with the direction of the magnetic field. This
preference could be detected only in a particular motiva-
tional state. In the experiment with the “breeding migratory
state”, where the frogs were stimulated for mating activ-
ity, they chose the “South-West” arm of the maze relative
to the direction of the horizontal component of the artifi-
cial magnetic field (Table 1). Amphibians also preferred
this magnetic direction in the reversed field as well as in
the “original” one (Table 2). This “South-West” magnetic
direction corresponded with the migratory direction from
the wintering site to the breeding pond in the frogs’ natu-
ral habitat. The behavior of male and female frogs was the
same (Table 3).
In the experiments with the frogs in the “wintering state”
conducted before or after the stimulation for mating activ-
ity, the frogs did not show a significant preference for either
of the maze arms relatively to the artificial magnetic field
(Tables 1, 2).
Discussion
To study animal sensory abilities in a laboratory, one needs
to have an ecologically appropriate behavioral model. To
investigate a compass magnetic orientation, researchers tra-
ditionally use migrants that can maintain a compass direc-
tion in the absence of local cues (Wiltschko and Wiltschko
2005; Mouritsen 2013, 2015; Kishkinev et al. 2015). The
marsh frogs Pelophylax ridibundus undertake short dis-
tance migrations: to the breeding pond at the very begin-
ning of the mating period and to a hibernation site before
the wintering, when the frogs become inactive for the next
several months (Kuzmin 2013). In field experiments, they
can choose a unimodal migratory direction in the absence
of familiar visual and olfactory cues in these migratory
periods only (Shakhparonov and Ogurtsov 2008; Shakhp-
aronov 2012). In amphibians, the “breeding state” and the
“wintering state” can be modulated by changing light and
temperature regimes (Rastogi et al. 1978; Voituron 2005).
The transitions to both states should be accompanied by a
strong but short-lived motivation for a migratory activity.
This gives us a clue how to manipulate frogs’ motivation
in our behavioral model for studying the magnetic compass
orientation. We conducted the transition to the “breeding
state” just before the test, and the animals were considered
to be migratory active. On the contrary, the transition to the
“wintering state” occurred a week before the experiment
and the frogs were very likely to be migratory inactive.
Table 2 Frogs’ scores according to the direction of magnetic field (the “unresponsive” individuals are excluded)
The rest of the legend, as in Table 1
n.a. not available (small sample)
Experiment “Original” magnetic field Magnetic field reversed by 180° magnetic field
Sequence Frogs’ state North-east arm (to
hibernation site in the
river)
South-west arm (to
breeding pond)
P*North-east arm (to
hibernation site in the
river)
South-west arm (to
breeding pond)
P*
1 Wintering 3 2 n.a. 4 4 0.27
2 Breeding migra-
tory
3 9 0.05 2 10 0.016
3 Wintering 7 4 0.16 5 7 0.19
Table 3 Male and female scores according to the direction of the magnetic field when tested in the state of the breeding migratory activity
* The test of two percentages
Frogs’ choice Number of males Proportion between males Number of females Proportion between females P*
South-west arm (to the breeding pond) 7 0.64 12 0.57 0.73
North-east arm (to the hibernation site
in the river)
1 0.09 4 0.19 0.47
”Unresponsive” 3 0.27 5 0.24 0.83
J Comp Physiol A
1 3
Methodological approach
We were the first to use a T-maze to explore amphib-
ians’ individual responses to earth-strength magnetic fields
under controlled laboratory conditions. In our experi-
ments, the proportion of marsh frogs that made a choice
was 72–81%, which is comparable with the results of
other studies with T-mazes (e.g., studies on olfactory and
hygrotactic orientation): Bufo bufo—76%, Bufo woodhousii
fowleri—55–67%, Pseudacris clarki—29–51%, Pseu-
dacris streckeri—47–91%, and Bufo valliceps—46–74%
(Grubb 1973a, b; Reshetnikov 1996). It means that the
activity of our animals was within the normal range. In
our experiments, the frogs made equiprobable choice of
the right and left arms of the maze and of the two “topo-
graphic” sides of the experimental apparatus. It shows that
nonmagnetic factors were compensated and had no signifi-
cant effect on the results of the experiment.
Reaction to the magnetic field
We found clear differences in the preferences of the maze
arms according to the direction of the horizontal compo-
nent of the artificial magnetic field. Frogs in the breeding
migratory state preferred to move to the “South-West” arm
of the maze—that is in the direction, in which they migrate
to spawning ponds in their natural habitat. This suggests
that adult marsh frogs are able to choose a proper migra-
tory direction guided by the Earth’s magnetic field as was
shown earlier in urodeles (Phillips 1986; Phillips et al.
2001, 2010 Diego-Rasilla 2003) and the larvae of anu-
rans (Freake et al. 2002; Freake and Phillips 2005; Diego-
Rasilla et al. 2010, 2013). Frogs in the “wintering state”
distributed equally between the two arms of the maze. On
the one hand, this could be interpreted as a lack of reac-
tion to the magnetic field or disorientation. On the other
hand, equal distribution in the T-maze may reflect the case
of axial bimodal preference demonstrated in the circular
arena in a series of publications (Taylor and Adler 1973;
Phillips 1987; Freake et al. 2002; Landler and Gollmann
2011; Diego-Rasilla et al. 2013). Axial orientation could
be a result of weak motivation to choose one of the direc-
tions. In the experiments of John Phillips with Notoph-
thalmus viridescens, the switch from a bidirectional to
unimodal orientation occurred in response to an increase
of water temperature that produced a strong motivation
for an animal to orient itself in a certain direction (Phil-
lips 1987). In case with the marsh frogs, we suppose that
the first interpretation (the lack of reaction to the magnetic
field) is more appropriate. We know that in the field exper-
iments in the absence of familiar local cues, frogs show
unimodal orientation in the migratory periods and random
orientation in other times (Shakhparonov and Ogurtsov
2008; Shakhparonov 2012). In accordance with this in the
T-maze, we also observed a unimodal distribution in ani-
mals in the “breeding migratory state” and a uniform dis-
tribution in the “wintering (non-migratory) state”.
Thus, we see that the motivational conditions of an
animal influence its orientation behavior. In field homing
experiments, it was shown that the orientation behavior of
anuran species varied with the phase of an annual cycle or
with a specific physiological state (Oldham 1966; Sinsch
1988b; Shakhparonov and Ogurtsov 2008). In the labora-
tory experiments of John Phillips, the reaction of Notoph-
thalmus viridescens to the magnetic field also changed with
a season. For most part of the year, except spring, newts
kept orientation along the previously learnt Y-axis, which
corresponded to the direction between land and water in
a training tank. In the migratory period in spring, newts
shifted their movements in a circular arena to an axis that
was oriented along the direction to the home pond (Phillips
1987). In another vertebrate group, the birds, the migra-
tory orientation by magnetic cues is revealed only in indi-
viduals exhibiting migratory restlessness (Zugunruhe) that
could be activated artificially by varying the light-dark
periods (Wiltschko and Wiltschko 1972). The influence
of physiological state on motivation of orientation behav-
ior of amphibians was also described in experiments with
other sensory cues, such as olfactory ones (Grubb 1973a).
In studies on olfactory orientation, it was shown that physi-
ological state influences not only the motivation but could
also change the sensitivity of the receptors (Nakazawa et al.
2000; Nakazawa and Ishii 2000). In our study, we do not
yet know whether behavioral changes in the marsh frogs
are associated with the motivation alone or also with the
modulation of the sensitivity to the magnetic field.
In our experiments, amphibian compass reacted to the
changes in the horizontal component of the magnetic field,
while the vertical one was not altered. We cannot say what
mechanism of magnetoreception was used by the frogs at
that moment. To differentiate between inclination (Phil-
lips 1986; Wiltschko and Wiltschko 2005) and polar com-
passes (Phillips 1986; Marhold et al. 1997) or between
light-dependent (Deutschlander et al. 1999; Wiltschko
and Wiltschko 2005) and light-independent mechanisms
(Lohmann and Lohmann 1993; Schlegel 2007), further
experiments with manipulation of the vertical component
and light are needed.
Adaptive value of the magnetic compass in natural
habitat
In moderate climate marsh, frogs hibernate in rivers and
breed within several hundred meters in nearby ponds in
the flood lands (Alexandrovskaya and Bikov 1979; Lada
et al. 1995; Kuzmin 2013). One could assume that these
J Comp Physiol A
1 3
migrations seem to be too short to be guided by global
stimuli, such as Earth’s magnetic field, because the local
cues associated with the goal (for example, the pond odors
and the breeding chorus of conspecifics) seem to be more
available at this distance. Is there any adaptive value of the
magnetic orientation in this situation?
Marsh frogs become active several weeks prior to breed-
ing and migrate to the ponds as the air temperature rises
(Kuzmin 2013). The problem is that the breeding chorus
could not be used by the very first migrants, as no ani-
mals are yet present in the pond. After all, it is known that
acoustic cues are of secondary importance for those spe-
cies (including marsh frogs) that breed in permanent pools
compared to those who migrate to temporary ones (Wells
2015). The odor of the native pond is a more reliable cue.
Orientation by the pond odor is described in many species
of anuran amphibians (Sinsch 1992; Ogurtsov 2004). Nev-
ertheless, at the onset of the breeding migration, the odor
of a small pond (the goal) could presumably be masked by
the scent of a large river. This problem can be solved using
the compass orientation: whether magnetic or celestial one.
It could provide a frog with the right migratory direction
towards the breeding pond at the start of migration. Com-
ing closer to the goal, the animal could use olfactory or
other local cues to locate the breeding pond.
The use of compass orientation seems to be even more
crucial during autumn migration to the wintering site, to
the river. A long river is located at the same compass direc-
tion from a breeding pond, and the frog that follows this
direction would surely reach the wintering site. The advan-
tage of the magnetic compass over the celestial one is that
it is not influenced by weather conditions, such as visibility
of the sky on rainy nights and a fog near a river.
In the current study, we revealed that the magnetic com-
pass was used by both sexes of the marsh frogs. Accord-
ing to our observations, both sexes in the studied popula-
tion arrive at the breeding pond at the same time in spring
and thus could possess similar mechanisms of orientation.
Probably, in other species, which breed in temporary ponds
and whose males come to the breeding pool earlier than
females, the use of the same cues could be different.
Conclusion
We managed to show replicable responses of adult anuran
amphibian, the Marsh frog, to an earth-strength magnetic
field under controlled laboratory conditions. The frogs
revealed unimodal compass orientation in accordance with
the migratory route. They followed the reversion of the hor-
izontal component of the magnetic field. This suggests that
adult ranid frogs can obtain directional information from
the Earth’s magnetic field as was shown earlier in urodeles
and anuran larvae. This compass magnetic orientation was
expressed only when amphibians were motivated for breed-
ing migration. The magnetic orientation seems to be adap-
tive even for short-distance movements of anuran amphib-
ians, as it provides a compass direction for the onset of
migration that could be corrected later by local cues. The
described behavior resembles a stereotyped compass orien-
tation expressed in the period of migratory restlessness in
another vertebrate group, birds. Thus, our results indicate
the existence of common orientation mechanisms in short-
distance (amphibians) and long-distance (birds) vertebrate
migrants.
Acknowledgements We would like to thank A.V. Spassky and
V.M. Lebedev (Skobeltsyn Institute of Nuclear Physics of MSU) for
the technical assistance while working with Helmholtz coil system.
We are also thankful to A.P. Golovlev, A.S. Dubrovskaya, and E.E.
Gritsyshina for their help during the experiments. Magnetometer GI
MTS-1 was kindly provided by N.S. Chernetsov from Zoological
Institute RAS. The work of V.V. Shakhparonov was financed by Grant
mol_a 14-04-32243 from the Russian Foundation for Basic Research.
Bartington Mag658 Digital Three-Axis Fluxgate Magnetometer was
obtained with the support of the Russian Science Foundation, Grant
No. 14-50-00029 “Scientific Basis of the National Biobank—Deposi-
tory of the Living Systems”. The Helmholtz coil system was kindly
provided in accordance with the Program of Development of Lomon-
osov Moscow State University. We are grateful to two anonymous
reviewers for very useful comments that greatly improved the presen-
tation of the material and to Maria Wilding for her kind assistance in
the editing of the English language of the manuscript. All applicable
international, national, and institutional guidelines for the care and
use of animals were followed, including “Guidelines for accommoda-
tion and care of animals” of the “European Convention for the Protec-
tion of Vertebrate Animals used for Experimental and other Scientific
Purposes” (ETS No. 123) and “Guidelines for the treatment of ani-
mals in behavioral research and teaching” produced by the Associa-
tion for the Study of Animal Behavior and the Animal Behavior Soci-
ety (Animal Behavior (2012) 83:301–309). This study was conducted
in agreement with the legislation of the Russian Federation and with
the requirements of the Committee for Bio Ethics of Lomonosov
Moscow State University.
References
Adler K (1980) Individuality in the use of orientation cues
by green frogs. Anim Behav 28:413–425. doi:10.1016/
S0003-3472(80)80050-9
Adler K (1982) Sensory aspects of amphibian navigation and com-
pass orientation. Vertebr Hung 21:7–18
Alexandrovskaya T, Bikov D (1979) The distribution of green frogs in
the European part of the USSR. In: Proceedings of VII zoogeo-
graphic conference, Moscow, pp 279–281 (in Russian)
Deutschlander ME, Phillips JB, Borland SC (1999) The case for
light-dependent magnetic orientation in animals. J Exp Biol
202:891–908
Diego-Rasilla FJ (2003) Homing ability and sensitivity to the geo-
magnetic field in the alpine newt, Triturus alpestris. Ethol Ecol
Evol 15:251–259. doi:10.1080/08927014.2003.9522670
Diego-Rasilla J, Luengo R (2002) Celestial orientation in the marbled
newt (Triturus marmoratus). J Ethol 20:137–141. doi:10.1007/
s10164-002-0066-7
J Comp Physiol A
1 3
Diego-Rasilla FJ, Luengo RM, Phillips JB (2010) Light-dependent
magnetic compass in Iberian green frog tadpoles. Naturwissen-
schaften 97:1077–1088. doi:10.1007/s00114-010-0730-7
Diego-Rasilla FJ, Luengo RM, Phillips JB (2013) Use of a light-
dependent magnetic compass for Y-axis orientation in European
common frog (Rana temporaria) tadpoles. J Comp Physiol A
199:619–628. doi:10.1007/s00359-013-0811-0
Eilam D (2003) Open-field behavior withstands drastic changes
in arena size. Behav Brain Res 142:53–62. doi:10.1016/
S0166-4328(02)00382-0
Ferguson DE, McKeown JP, Bosarge OS, Landreth HF (1968)
Sun-compass orientation of bullfrogs. Copeia 1968:230.
doi:10.2307/1441746
Freake MJ, Phillips JB (2005) Light-dependent shift in bullfrog tad-
pole magnetic compass orientation: evidence for a common
magnetoreception mechanism in anuran and urodele amphibians.
Ethology 111:241–254. doi:10.1111/j.1439-0310.2004.01067.x
Freake MJ, Borland SC, Phillips JB (2002) Use of a mag-
netic compass for Y-axis orientation in larval bull-
frogs, Rana catesbeiana. Copeia 2002:466–471.
doi:10.1643/0045-8511(2002)002[0466:UOAMCF]2.0.CO;2
Grant D, Anderson O, Twitty V (1968) Homing orientation by olfac-
tion in newts (Taricha rivularis). Science 160:1354–1356.
doi:10.1126/science.160.3834.1354
Grubb JC (1973a) Olfactory orientation in breeding mexican toads,
Bufo valliceps. Copeia 1973:490. doi:10.2307/1443114
Grubb JC (1973b) Olfactory orientation in Bufo woodhousei fowleri,
Pseudacris clarki and Pseudacris streckeri. Anim Behav 21:726–
732. doi:10.1016/S0003-3472(73)80098-3
Kim JW, Im WB, Choi HH et al (1998) Seasonal fluctuations in pitui-
tary gland and plasma levels of gonadotropic hormones in Rana.
Gen Comp Endocrinol 109:13–23. doi:10.1006/gcen.1997.6992
Kirschvink JL, Jones DS, MacFadden BJ (eds) (1985) Magnetite
biomineralization and magnetoreception in organisms, 1st edn.
Springer, Boston
Kishkinev D, Chernetsov N, Pakhomov A et al (2015) Eurasian reed
warblers compensate for virtual magnetic displacement. Curr
Biol 25:R822–R824. doi:10.1016/j.cub.2015.08.012
Kuzmin SL (2013) The Amphibians of the Former Soviet Union, 2nd
edn Revised. Pensoft Publishers, Sofia – Moscow
Lada GA, Borkin LJ, Vinogradov AE (1995) Distribution, population
systems and reproductive behavior of green frogs (hybridoge-
netic Rana esculenta complex) in the Central Chernozem Terri-
tory of Russia. Russ J Herpetol 2:46–57
Landler L, Gollmann G (2011) Magnetic orientation of the common
toad: establishing an arena approach for adult anurans. Front
Zool 8:6. doi:10.1186/1742-9994-8-6
Lebedev IV, Pleskacheva MG, Anokhin KV (2012) C57BL/6 mice
open field behaviour qualitatively depends on arena size. Zhurnal
Vyss Nervn deiatelnosti Im I P Pavlov 62:485–496
Lehner PN (1996) Handbook of ethological methods, 2nd edn. Cam-
bridge University Press, Cambridge
Lohmann KJ, Lohmann CMF (1993) A light-independent mag-
netic compass in the leatherback sea turtle. Biol Bull 185:149.
doi:10.2307/1542138
Marhold S, Wiltschko W, Burda H (1997) A magnetic polarity com-
pass for direction finding in a subterranean mammal. Naturwis-
senschaften 84:421–423. doi:10.1007/s001140050422
Marty P, Angélibert S, Giani N, Joly P (2005) Directionality of pre-
and post-breeding migrations of a marbled newt population (Trit-
urus marmoratus): implications for buffer zone management.
Aquat Conserv Mar Freshw Ecosyst 15:215–225. doi:10.1002/
aqc.672
Merrell DJ (1970) Migration and gene dispersal in Rana pipiens.
Integr Comp Biol 10:47–52. doi:10.1093/icb/10.1.47
Mouritsen H (2013) The magnetic senses. In: Galizia CG, Lledo P-M
(eds) Neurosciences—from molecule to behavior: a university
textbook. Springer, Berlin, pp 427–443
Mouritsen H (2015) Magnetoreception in birds and its use for long-
distance migration. In: Scanes CG (ed) Sturkie’s avian physiol-
ogy, 6th edn. Academic Press, New York, pp 113–133
Muheim R, Boström J, Åkesson S, Liedvogel M (2014) Sensory
mechanisms of animal orientation and navigation. In: Hansson
L-A, Åkesson S (eds) Animal movement across scales. Oxford
University Press, Oxford, pp 179–194
Nakazawa H, Ishii S (2000) Changes in the oscillatory electric poten-
tial on the olfactory epithelium and in reproductive hormone lev-
els during the breeding season in the toad (Bufo japonicus). Zool
Sci 592:585–592. doi:10.2108/zsj.17.585
Nakazawa H, Kaji S, Ishii S (2000) Oscillatory electric potential on
the olfactory epithelium observed during the breeding migration
period in the japanese toad, Bufo japonicus. Zool Sci 17:293–
300. doi:10.2108/jsz.17.293
Ogurtsov SV (2004) Olfactory orientation in anuran amphibians. Russ
J Herpetol 11:35–40
Ogurtsov SV (2005) Basis of native pond fidelity in anuran amphib-
ians: the case of chemical learning. Russ J Herpetol 12:198–200
Oldham RS (1966) Spring movements in the American toad, Bufo
Americanus. Can J Zool 44:63–100. doi:10.1139/z66-006
Phillips J (1986) Two magnetoreception pathways in a migratory sala-
mander. Science 233:765–767. doi:10.1126/science.3738508
Phillips JB (1987) Laboratory studies of homing orientation in the
eastern red-spotted newt, Notophthalmus viridescens. J Exp Biol
131:215–229
Phillips JB, Borland SC (1992) Behavioural evidence for use of a
light-dependent magneto reception mechanism by a vertebrate.
Nature 359:142–144. doi:10.1038/359142a0
Phillips JB, Deutschlander ME, Freake MJ, Borland SC (2001) The
role of extraocular photoreceptors in newt magnetic compass
orientation: parallels between light-dependent magneto recep-
tion and polarized light detection in vertebrates. J Exp Biol
204:2543–2552
Phillips JB, Jorge PE, Muheim R (2010) Light-dependent magnetic
compass orientation in amphibians and insects: candidate recep-
tors and candidate molecular mechanisms. J R Soc Interface
7(Suppl 2):S241–S256. doi:10.1098/rsif.2009.0459.focus
Polzonetti-Magni AM, Mosconi G, Carnevali O et al (1998) Gonado-
tropins and reproductive function in the anuran amphibian, Rana
esculenta. Biol Reprod 58:88–93. doi:10.1095/biolreprod58.1.88
Rastogi RK, Iela L, Delrio G et al (1978) Environmental influence on
testicular activity in the green frog, Rana esculenta. J Exp Zool
206:49–63. doi:10.1002/jez.1402060106
Reshetnikov AN (1996) Hygrotactic and olfactory orientation in
juvenile common toads (Bufo bufo) during the postmetamorphic
period. Adv Amphib Res Former Sov Union 1:181–190
Rozhok A (2008) Orientation and navigation in vertebrates. Springer,
Berlin
Schlegel PA (2007) Spontaneous preferences for magnetic compass
direction in the American red-spotted newt, Notophthalmus
viridescens (Salamandridae, Urodela). J Ethol 25:177–184.
doi:10.1007/s10164-006-0016-x
Shakhparonov VV (2012) The influence of repeated experiments on
the behavior of the marsh frog (Rana ridibunda) in field experi-
ments of spatial orientation. Zool Zurnal 91:1340–1350
Shakhparonov VV, Ogurtsov SV (2008) Seasonal and geographical var-
iability of orientation behavior in the marsh frog (Rana ridibunda)
in search of its own water body. Zool Zurnal 87:1062–1076
Shoop CR (1965) Orientation of Ambystoma maculatum: movements
to and from breeding ponds. Science 149:558–559. doi:10.1126/
science.149.3683.558
J Comp Physiol A
1 3
Sinsch U (1987) Orientation behaviour of toads (Bufo bufo) displaced
from the breeding site. J Comp Physiol A 161:715–727
Sinsch U (1988a) El sapo andino Bufo spinulosus: análisis preliminar
de su orientación hacia sus lugares de reproducción. Bol Lima
57:83–92
Sinsch U (1988b) Seasonal changes in the migratory behaviour of the
toad Bufo bufo: direction and magnitude of movements. Oecolo-
gia 76:390–398. doi:10.1007/bf00377034
Sinsch U (1990a) Migration and orientation in anuran amphibians.
Ethol Ecol Evol 2:65–79. doi:10.1080/08927014.1990.9525494
Sinsch U (1990b) The orientation behaviour of three toad species
(genus Bufo) displaced from the breeding site. Fortschr Zool
38:75–83
Sinsch U (1992) Amphibians. In: Papi F (ed) Homing animal. Chap-
man & Hall, London, pp 213–233
Sinsch U, Kirst C (2015) Homeward orientation of displaced newts
(Triturus cristatus, Lissotriton vulgaris) is restricted to the range
of routine movements. Ethol Ecol Evol. doi:10.1080/03949370.2
015.1059893
Taylor DH, Adler K (1973) Spatial orientation by salamanders using
plane-polarized light. Science 181:285–287. doi:10.1126/
science.181.4096.285
Voituron Y (2005) Freezing tolerance of the European water frogs:
the good, the bad, and the ugly. AJP Regul Integr Comp Physiol
288:R1563–R1570. doi:10.1152/ajpregu.00711.2004
Voituron Y, Eugene M, Barré H (2003) Survival and metabolic
responses to freezing by the water frog (Rana ridibunda). J
Exp Zool Part A Comp Exp Biol 299A:118–126. doi:10.1002/
jez.a.10285
Wells KD (2015) The ecology and behavior of amphibians. The Uni-
versity of Chicago Press, Chicago
Wiltschko W, Wiltschko R (1972) Magnetic compass of European
robins. Science 176:62–64. doi:10.1126/science.176.4030.62
Wiltschko W, Wiltschko R (2005) Magnetic orientation and magneto
reception in birds and other animals. J Comp Physiol A 191:675–
693. doi:10.1007/s00359-005-0627-7
A preview of this full-text is provided by Springer Nature.
Content available from Journal of Comparative Physiology A
This content is subject to copyright. Terms and conditions apply.
