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The worldwide decline of amphibian populations calls for studies concerning their ecological role within eco-systems and only knowledge about amphibian species' diets may facilitate the identification of their respective position in trophic cascades. Frog consumption by humans has recently increased to a considerable extent in some parts of West Af-rica. We analyse herein the diet of the most commonly consumed frog species, Hoplobatrachus occipitalis (Dicroglossidae), in Malanville, northern Benin. In order to determine its prey spectrum we investigated stomachs of frogs obtained from frog hunters, and stomach-flushed frogs caught by ourselves. Overall, we investigated the gut contents of 291 individuals (83 flushed, 208 dissected), 21% of which had empty stomachs. We identified Coleoptera, Lepidoptera and Formicidae as the most important prey categories in flushed frogs and Pisces, Coleoptera and Araneae in collected frog stomachs. Accord-ing to these data, H. occipitalis is an opportunistic forager, able to predate on terrestrial as well as on aquatic taxa. The prey spectrum revealed by the two different sampling methods differed only slightly. In contrast, the frequency of particular prey categories (e.g., fish) differed strongly. These differences were most probably method-based, rather than reflecting different prey availability among capture sites.
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Diet of Hoplobatrachus occipitalis
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© 2011 Deutsche Gesellscha für Herpetologie und Terrarienkunde e.V. (DGHT), Rheinbach, Germany
SALAMANDRA 47(3) 125–132 20 August 2011 ISSN 0036–3375
e diet of the African Tiger Frog, Hoplobatrachus occipitalis,
in northern Benin
M H  M-O R
Museum für Naturkunde, Leibniz Institute for Research on Evolution and Biodiversity at the Humboldt University Berlin,
Invalidenstr. 43, 10115 Berlin, Germany
Corresponding author: M-O R, e-mail:
Manuscript received: 27 May 2011
Abstract. e worldwide decline of amphibian populations calls for studies concerning their ecological role within eco-
systems and only knowledge about amphibian species’ diets may facilitate the identication of their respective position in
trophic cascades. Frog consumption by humans has recently increased to a considerable extent in some parts of West Af-
rica. We analyse herein the diet of the most commonly consumed frog species, Hoplobatrachus occipitalis (Dicroglossidae),
in Malanville, northern Benin. In order to determine its prey spectrum we investigated stomachs of frogs obtained from
frog hunters, and stomach-ushed frogs caught by ourselves. Overall, we investigated the gut contents of  individuals (
ushed,  dissected),  of which had empty stomachs. We identied Coleoptera, Lepidoptera and Formicidae as the
most important prey categories in ushed frogs and Pisces, Coleoptera and Araneae in collected frog stomachs. Accord-
ing to these data, H. occipitalis is an opportunistic forager, able to predate on terrestrial as well as on aquatic taxa. e prey
spectrum revealed by the two dierent sampling methods diered only slightly. In contrast, the frequency of particular prey
categories (e.g., sh) diered strongly. ese dierences were most probably method-based, rather than reecting dierent
prey availability among capture sites.
Key words. Amphibia, Anura, Dicroglossidae, diet, savanna, stomach ushing, West Africa.
In addition to climate change (B et al. ),
habitat degradation and conversion (C ,
E et al. ), and diseases (D et al. ),
the overharvesting by humans may play a major role in
the decline of amphibian populations (S et al.
, W et al. ). Since amphibians are im-
portant components in trophic cascades, vanishing popu-
lations may have crucial eects on ecosystem function-
ing (H , M  R ). How-
ever, only detailed ecological and biological data, such as
diet, can facilitate estimating these eects (D ,
W et al. ).
Anuran larvae are mostly grazers or suspension feeders
(R et al. , A et al. ), whereas adults
predominantly prey on various invertebrates and, in re-
lation to their sizes, sometimes vertebrates. Studies con-
cerning the diet of adult amphibians have been conducted
for various species in almost all regions of the World; e.g.,
the Neotropics (W  D , Let
al. ), Asia (H  M b, Y et al. ),
Australia (L  S ), temperate Amer-
ica (M J , H et al. ), and
Europe (BS, Kovács et al. ).
Although studies on African anurans are comparatively
rarer, the diets of several species have been studied (I-
  M , H , B  M
, K et al. ).
e large aquatic African Tiger Frog, Hoplobatrachus
occipitalis (G, ) inhabits savannas in sub-
Saharan Africa. It is known to be consumed by humans
in several countries (e.g., Benin, Burkina Faso, Ghana,
Guinea, Ivory Coast, Nigeria). e intensity of exploita-
tion of this species as human food varies among regions as
well as between dierent ethnic groups (M et al.
). e focus of our study was the town of Malanville
in northern Benin, where the collection of H. occipitalis
for local and regional food markets is especially intense,
i.e., a group of  Nigerian frog hunters collected approxi-
mately  frogs within two months (M et al.
). is intense exploitation seems to be unsustainable
and may lead to the local decline of H. occipitalis. is
could have ecological consequences. An Asian Hoploba-
trachus species, H. tigerinus is known to ingest as much
as  of its own weight in insects per day (A
). In India, the collection of frogs’ legs resulted in the
survival of tonnage of insects, including disease-carrying
mosquitoes and agricultural pests (O ). Larval H.
occipitalis are opportunistic carnivores and mainly feed
on other tadpoles and mosquito larvae in temporary sa-
vanna ponds (S  L , R ).
Detailed knowledge about the amount and composition
of the adults’ diet is so far limited to two studies from Sen-
egal (L ) and Ivory Coast (T ). e
aim of our study was to a) identify the diet of H. occipitalis
in northern Benin, as well as to b) evaluate the eciency
and accuracy of stomach ushing versus dissection.
M H  M-O R
Material and methods
Study site and period
e study took place in northern Benin, close to the bor-
ders of Burkina Faso, Niger and Nigeria. All specimens
were collected in close proximity to the river Niger, near
Karimama (N °.’; E °.’) and Malanville
(N °.’; E °.’). is region is characterized
by a dry Sudan savanna with an annual precipitation of ap-
proximately  mm (Faoclim  – worldwide agroclimatic
data base,/fao-world-
climate-data). First rainfalls normally occur in late June
and last until mid-September. Our data were collected at
the end of the dry season (May and June) in .
Stomach contents
ere are various approaches to investigating the diet of
amphibians. Individuals can be directly observed (mostly
very dicult) or faeces can be collected (many prey items
may be completely digested or unrecognisable). However,
the two most common methods are dissection and stom-
ach ushing. ere are only a few studies comparing these
both methods directly (L  C , W et
al. ). We applied both methods. No frog was killed for
this study.
Stomach ushing. Adult Hoplobatrachus occipitalis were
captured during the night ( to  h) in ooded rice
paddies, at riversides and temporary ponds, and immedi-
ately (within one hour aer capturing) stomach ushed on
site, as described in S et al. (). We recorded weight
(spring scale:  to  g, accuracy: ± . g), snout–vent
length (digital dial calliper:  to  mm, accuracy: ± .
mm), and sex of each frog. For ushing, we used two types
of exible PVC tubes with diameters of  mm for larger and
 mm for smaller frogs. e tube was attached to a syringe,
which was lled with pond or river water (according to the
respective capture site). Regurgitated items were stored in
formalin () and later transferred to ethanol (). At the
beginning of our study, we kept  ushed frogs in plastic
containers for three days to check for potential complica-
tions due to the stomach ushing (e.g., injuries, death). All
these frogs survived unharmed. All other individuals were
immediately released aer ushing.
Stomach sampling. Stomachs of H. occipitalis were
collected in the rice paddies of Malanville on three dierent
days. e respective frogs had been killed by Nigerian frog
hunters during the preceding nights (sampling time: 
to  h) by beating the frogs to death with long wooden
sticks (M et al. ). e hunters gutted the
frogs in the early morning and allowed us to separate the
stomachs from the remaining innards. Each of these frogs
was weighed with a spring scale (details see above) before
they were disembowelled by the hunters. e stomachs
were xed in formalin ().
Diet analyses
e stomach content of each frog was examined individ-
ually. e collected stomachs were sliced lengthwise to
extract the entire stomach content. All items were trans-
ferred into ethanol () for subsequent identication.
Prey items were counted, identied to a particular taxo-
nomic category (mostly order level), and length, width and
depth were measured (to the nearest . mm) with a dig-
ital calliper under a dissecting microscope. e volume of
completely preserved food items was calculated using the
formula of a prolate ellipsoid V = /π (½ × length) × (½
× width)². e original volumes of partly digested Formi-
cidae were calculated with the regression method as de-
scribed by H & M (a).
In order to characterize the diet of H. occipitalis in gen-
eral, several indices, adopted from diet studies in sh and
amphibians, were used (e.g. P et al. , G et
al. , D et al. ). Each calculation was done for
stomach ushing and sampling, respectively. e number
of stomachs containing a particular prey category was eval-
uated as the frequency of occurrence (FOi) and the propor-
tion of FOi [FOi = (FOi/nstomachs with diet) × ]. For each
prey category, we calculated the total volume as the sum
of all prey items of category i (Vi) as well the proportion of
Vi relative to the total volume of all measured food items
[Vi = (Vi/ΣVi...n) × ]. e importance of each prey cat-
egory related to the entire range of food items in all sam-
ples was identied via the index of relative importance
IRIi = (Ni + Vi) × FOi (P et al. ). We used
the Mann-Whitney U-test to search for potential prey dif-
ferences in relation to the frogs’ sizes, weights and sex and
to compare the two methods. e χ²-test was chosen to
compare frequencies. For correlative analyses, we applied
the Spearman-Rank correlation. All statistical analyses
were conducted with R .. (
Investigated animals
 frogs were ushed and the stomachs of  individuals
were collected. e weight of the frogs ranged between 
and  g (mean ± SD: . ± . g, n = ), with ushed
frogs being slightly lighter (stomach sampling: range –
 g, . ± . g, n = ; stomach ushing: range –
g, . ± . g, n = ). However, this dierence was
not signicant (Mann-Whitney U-test: W = , p= .,
nsampling = , nushing = ). Snout–vent length was only
measured in ushed individuals (range .–.mm;
mean ± SD: . ± . mm, n = ). Since size and
weight were tightly correlated (Spearman-Rank correla-
tion: rs = ., p < ., n = ), we used only weight for
subsequent analysis. Due to the killing method of the frog
hunters (see M et al. ), heads were damaged
and vocal sacs of male frogs were oen not recognizable.
Sex was thus only identied in ushed frogs (nmales = ,
nfemales = , two frogs were too young for sexing). In ushed
frogs, the sexes diered neither in size (Mann-Whitney
U-test: W = , p= ., nmales = , nfemales = ) nor in
weight (W = ., p = ., nmales = , nfemales = ).
Stomach lling
In total, . (sampling: .; ushing: .) of the
frogs had empty stomachs. e proportion of stomachs
Diet of Hoplobatrachus occipitalis
containing prey items did not dier between the two meth-
ods (χ²-test: χ² = ., df = , p = ., nstomach sampling = ,
nstomach ushing = ). Whether a stomach contained prey items
or not was independent from weight (all samples: Mann-
Whitney U-test: W = ., p = ., n = , stomach
sampling: W = , p = ., n = ; stomach ushing:
W= , p = ., n = ), size (stomach ushing only:
W = ., p = ., n = ), as well as from sex (stomach
ushing only: χ²-test: χ² = ., df = , p = ., nmales = ,
nfemales = ).
Overall, we recorded  prey items,  were gathered
by stomach sampling and  by stomach ushing. e
number of items ranged between one and  per stomach
(. ± ., n = , sampling range: –, . ± ., n=;
ushing range: –, . ± ., n = ). ere was no dif-
ference in the number of items found per stomach re-
lated to sex (stomach ushing only: W = ., p = .,
n=), nor to sampling method (Mann-Whitney U-test:
W=., p = ., n = ). We detected no correlation
between the number of food items and the weight of the
frogs (rs = -., p = ., n = ).
Volume of food items
Stomach contents at a more advanced stage of digestion
became increasingly dicult to identify both taxonomi-
cally as well as in volume. In order to avoid wrong catego-
rizations and misestimates in body sizes of the prey items
we included solely feebly digested or nearly intact items
for the content analysis. erefore, no volume calculations
were carried out in . of the prey items in the ushed
and in . in the collected stomachs. Flushed, single prey
items were signicantly smaller in size than those collect-
ed through dissection (sampling range: .–. mm³,
. ± .; ushing range: .–. mm³, .
± .; Mann-Whitney U-test: W = , p < .,
nsampling = , nushing = ; Figure ). When testing all frogs
or those that had been collected by the frog hunters only,
the mean size of prey was not correlated to the frogs’ weight
(Spearman-Rank correlation: all frogs: rs = ., p = .,
n = ; frog hunters samples: rs = ., p = ., n = ).
Prey size was weakly negatively correlated to the weights of
the ushed frogs (rs = -., p < ., n = ).
e volume of stomach contents (sum of all measured
preys items in one stomach) ranged between . and
. mm³ (. ± . mm³, n = ). Stomachs of
frogs that had been collected by the frog hunters contained
signicantly more prey volume than ushed frogs (stomach
ushing: range .–. mm³, . ± .mm³,
n= ; stomach sampling: range .–.mm³, .
± . mm³, n = ; Mann-Whitney U-test: W= ,
p < ., n = ). e volume of stomach contents was
positively correlated to the H. occipitalis weight, irrespec-
tive of the method (Spearman Rank correlation: rs= .,
p < ., n = ).
Prey composition
Most prey items were arthropods such as spiders or insects,
but vertebrates, i.e., sh and amphibians, were also com-
mon. e most common prey of ushed frogs were ter-
mites, whereas beetles, due to their frequency of occur-
rence and greater individual size, were the most important
prey animals. Ants and adult moths also had a high index
of relative importance in the ushed frogs. In the collected
stomachs, sh were the most common and most important
Figure 1. Volume of Hoplobatrachus occipitalis prey. Given are the calculated volumes of all measured food items in mm³ of collected
and ushed frog stomachs. e scale on the Y-axis is logarithmic; nsampling = 465, nushing = 430.
Volume of prey items [mm³]
. stomach ushing stomach sampling
M H  M-O R
Table 1. Stomach contents of Hoplobatrachus occipitalis. N = number of prey items, Nm = number of measured items used for volume
calculations, N% = percentage of N, FO = frequency of occurrence, FO% = percentage of FO, V = sum of volume of prey items in
mm³, V% = percentage of V, IRI = index of relative importance, prey categories comprising several stages are divided in adults (a),
larvae (l) and egg (e); the three most important prey categories are highlighted; number of stomachs containing prey items: stomach
ushing = 65, stomach sampling = 166.
stomach ushing Prey animals N NmN% FO FO% V V% IRI
Oligochaeta 1 1 0.19 1 1.54 111.17 0.44 0.96
Araneae 28 25 5.18 12 18.46 283.14 1.12 116.25
Decapoda 2 0 0.37 2 3.08 na na na
Amphipoda 1 1 0.19 1 1.54 20.70 0.08 0.41
Blattodea 1 1 0.19 1 1.54 51.69 0.21 0.60
Coleoptera (a) 75 55 13.86 29 44.61 5819.27 23.04 1646.61
Coleoptera (l) 2 2 0.37 2 3.08 61.02 0.24 1.88
Dermaptera 7 6 1.29 6 9.23 679.16 2.69 36.77
Diptera (a) 9 9 1.66 4 6.15 30.34 0.12 10.98
Diptera (l) 3 3 0.56 1 1.54 69.40 0.28 1.28
Hemiptera 5 5 0.92 5 7.69 102.33 0.41 10.23
Formicidae 38 38 7.02 12 18.46 304.55 1.21 151.94
others 5 3 0.92 3 4.62 145.64 0.58 6.93
Isoptera 91 87 16.821 5 7.69 325.48 1.29 139.30
Lepidoptera (a) 62 29 11.46 19 29.23 3853.58 15.26 781.05
Lepidoptera (l) 6 6 1.11 6 9.23 234.01 0.93 18.79
Odonata (a) 2 1 0.37 2 3.08 298.01 1.18 4.77
Odonata (l) 1 1 0.19 1 1.54 117.67 0.47 1.00
Orthoptera 9 7 1.66 6 9.23 982.44 3.89 51.27
Phasmatodea 6 5 1.11 5 7.69 164.67 0.65 13.55
unidentied (a) 29 0 5.36 24 36.92 na na na
unidentied (e) 55 55 10.17 1 1.54 8.40 0.03 15.69
Diplopoda 2 2 0.37 2 3.08 998.98 3.96 13.31
Bivalvia 1 1 0.19 1 1.54 88.31 0.35 0.82
Gastropoda 1 1 0.19 1 1.54 58.50 0.23 0.64
Anura (a) 2 2 0.37 2 3.08 7081.62 28.04 87.42
Anura (l) 82 82 15.16 1 1.54 1320.87 5.23 31.37
Mammalia 1 0 0.19 1 1.54 na na na
Pisces 11 2 2.03 9 13.85 2042.34 8.09 140.13
unidentied 3 0 0.56 3 4.66 na na na
TOTAL 541 430 100 168 258.46 25253.31 100 3283.94
Diet of Hoplobatrachus occipitalis
prey animals. ey were present in . of stomachs and
the index of relative importance (IRI = .) was almost
seven times higher than the second most important prey
category beetles (IRI = .). Furthermore, spiders were
frequently found in the frogs collected by the frog hunters.
Table  summarizes the spectrum of recorded prey items.
Although most prey types were found in both collected
and ushed stomachs, the relative occurrence of each cat-
stomach sampling Prey animals N NmN% FO FO% V V% IRI
Araneae 54 45 7.52 35 21.08 2179.03 1.580 191.89
Collembola 1 1 0.14 1 21.08 9.29 0.007 0.088
Decapoda 2 1 0.28 2 1.21 0.24 0 0.34
Blattodea 2 2 0.28 2 1.21 277.34 0.201 0.58
Coleoptera (a) 72 45 10.03 45 27.11 5564.73 4.035 381.22
Coleoptera (l) 3 3 0.42 3 1.81 9.11 0.007 0.77
Dermaptera 1 1 0.14 1 0.60 0.35 0 0.08
Diptera (a) 27 19 3.76 19 11.45 254.42 0.184 45.15
Diptera (l) 18 16 2.51 10 6.02 337.02 0.244 16.57
Hemiptera 32 23 4.46 26 15.66 3615.40 2.622 110.87
Formicidae 49 49 6.83 19 11.45 293.47 0.213 80.55
others 8 6 1.11 8 4.82 133.43 0.097 5.84
Isoptera 58 41 8.08 8 4.82 459.18 0.333 40.54
Lepidoptera (a) 19 17 2.65 18 10.84 1140.28 0.827 37.66
Lepidoptera (l) 26 25 3.62 19 11.45 2133.17 1.547 59.15
Mecoptera 1 1 0.14 1 0.60 15.18 0.011 0.09
Mantodea 3 1 0.42 3 1.81 530.74 0.385 1.45
Odonata (a) 8 4 1.11 8 4.82 1554.47 1.127 10.80
Odonata (l) 4 2 0.56 4 2.41 330.88 0.240 1.92
Orthoptera 36 20 5.01 29 17.47 4553.92 3.302 145.28
Phasmatodea 14 8 1.95 13 7.83 205.07 0.149 16.43
unidentied (a) 74 0 10.31 52 31.33 na na na
unidentied (l) 2 0 0.28 2 1.21 na na na
unidentied (e) 16 16 2.23 7 4.22 46.52 0.034 9.54
Chilopoda 1 1 0.14 1 0.60 102.87 0.075 0.13
Gastropoda 9 9 1.25 8 4.82 1978.51 1.435 12.96
Anura (a) 9 7 1.25 8 4.82 26379.25 19.128 98.22
Mammalia 2 1 0.28 2 1.21 6010.64 4.358 5.59
Pisces 150 101 20.89 56 33.74 79794.02 57.860 2656.68
Squamata 1 0 0.14 1 0.60 na na na
unidentied 16 0 2.23 16 9.64 na na na
TOTAL 771 509 100 461 277.71 140078.24 100 4122.18
Table 1 continued
M H  M-O R
egory diered signicantly with the method used (χ²-test:
χ² = ., df = , p < ., n = ). Gravel, vegetation
and rice grains were also frequent in the investigated stom-
achs, with the latter being the most common non-food item
(–grains per stomach, . ± ., n = ). Vegetation was
gathered from  stomachs and  contained grains of grav-
We analysed the dietary composition of Hoplobatrachus oc-
cipitalis in rice paddies and small rivers close to the river
Niger around the end of the dry season of . We iden-
tied sh, beetles, moths and ants as the most important
prey. Our data on overall prey composition thus partly dif-
fered from other studies on H. occipitalis. In a Senegalese
population, L () found predominantly beetles,
ants and spiders by dissection. In southern Ivory Coast, Hy-
menoptera (including ants) were the most important prey
category of dissected H. occipitalis, followed by beetles and
amphibians (T ). It is known that many anurans
change their feeding habits according to the seasons; e.g.,
T () found dietary dierences according to the re-
spective supply in Peru, and I & M () report-
ed a seasonal dietary change in various Central African an-
uran species. In contrast, three of four analysed Hyperolius
species did not show any change between the dry and wet
seasons in Nigeria (L et al. ). Dierences in diet
composition may be based upon prey availability, varying
between seasons and/or habitats (K et al. ). Both
factors may explain dierences between our study, con-
ducted in a dry savanna around the end of the dry season,
and other populations (L , T ). Grav-
el, rice grains, and plant matter within the stomachs have
most likely been accidentally ingested (A et al. ,
K et al. ). On the other hand, some frog species
are known to feed on plants (D ,  S   B-
-P ) and gravel could aid the digestion of the
diet (E  L ). To clarify if these “prey items”
are deliberately ingested, direct observations are necessary.
e type of frogs’ prey items is oen associated with a
specic foraging mode. Active feeders may predate upon
large numbers of smaller prey that oen occurs in aggrega-
tions. T () called these frogs “ant-specialists”. Sol-
itary prey like beetles or spiders are preferred by “sit and
wait” feeders, which have been dened as “non-ant special-
ists” (T , L et al. ). Ants were consumed by
H. occipitalis in dierent quantities. L () found
them in . of the analysed stomachs (. of all ingest-
ed prey items). T () did not distinguish between
members of Hymenoptera. However,  of the investigat-
ed stomachs contained individuals of this insect order. is
group, probably mostly ants, made up  of all ingested
prey items in his analysis. In our study, ants occurred in
. of the collected and . of the ushed stomachs and
amounted to . and . of all identied categories, re-
spectively. us, ants were not avoided in northern Benin,
but played a less dominant role in comparison to other diet
components. Termites, which represent another aggrega-
tion taxa, are generally of less importance (L ,
this study) in, or even absent (T ) from, the diet of
H. occipitalis. e dietary composition of our H. occipitalis
populations speaks in favour of these frogs behaving as op-
portunistic “sit and wait” predators (G et al. ).
Terrestrial invertebrates usually dominate the diet of
anurans, even in aquatic or semiaquatic species (H 
M b, M  J ). Likewise, most
of the prey ingested by H. occipitalis was made up by ter-
restrial species. However, aquatic animals like tadpoles,
water bugs, and especially sh occurred as well (L
, T ; this study). A very high proportion of col-
lected stomachs (N = .) contained sh. is suggests
that H. occipitalis is capable of capturing prey above as well
as under the water surface as has been reported for only a
few other frog species such as Aubria subsigillata (K-
 ), Lithobates catesbeianus (H et al. ),
or Xenopus laevis (I  M ).
e high proportion of sh was surprising, particularly
since in the study of T (), sh accounted for only
. of the prey, even though he studied a H. occipitalis
population at a sh farm, whereas our frogs predominantly
originated from rice paddies. e sh species in our sam-
ples (cichlids, cyprinids and catsh) cannot persist in tem-
porary waters and thus likely migrated into the rice paddies
when these were ooded.
While qualitative prey composition was similar between
both methods applied, quantitative results were dierent.
We identied beetles, moths and ants as the most impor-
tant prey categories in ushed frogs, and sh, beetles and
spiders in collected frog stomachs. Prey size was signi-
cantly smaller in the ushed frogs, potentially indicating
that not all large food items may have been ushed out.
Since sh were by far the largest prey items, this would ex-
plain why they were seemingly so rare in the ushed ani-
mals. Generally, altered abundance of particular prey items
might be related to site, prey availability varying between
habitats (H  M ), as well as between natural
and human-dominated landscapes (S et al. ). For
instance, a large aquatic African rainforest frog, Aubria sub-
sigillata, was reported to mainly predate upon sh in Ga-
bon ( of all individuals investigated had ingested sh,
K ), whereas frogs from Ghana did not con-
tain any sh (H ). We captured our frogs within
rice paddies (as did the frog hunters), in shallow branches
of rivers, as well as in temporary ponds and near a well of a
village. However, we found sh in nine ushed individuals:
three captured in the paddy elds, six from the riverside,
and one from a temporary pond. It therefore seems unlikely
that our observed dierences in sh abundance were habi-
tat-specic. Most probably, the dierences can be ascribed
to the sampling approach. Stomach ushing might be less
eective in terms of larger food items like sh.
e reliability of stomach ushing data was evaluated in
various taxa. In penguins e.g., the eectiveness is relatively
high, but decreases with ingestion time (G ). In a
study on the diet of shes, the ecacy of ushing also var-
ied with the type of prey in combination with time aer
ingestion (P O’H ). F ()
concluded in his methodical comparison of diet analyses
in crocodiles, that problems will always occur with regard
to prey item size. In contrast, L & C ()
dissected some ushed frogs and found that less than  of
the total volume had remained in their stomachs. W et al.
Diet of Hoplobatrachus occipitalis
() likewise found that nearly  of the total volume
and prey item number could be recovered through ush-
ing. Unfortunately, we cannot provide such data since we
were not permitted to ush the animals before they were
killed by the Nigerian frog collectors and abstained from
killing the frogs we caught. Hence, it remains unclear if
some of the larger and/or a certain part of ingested items
remained in the stomachs aer ushing.
Many authors have reported that size of prey is relat-
ed to the snout–vent length and mouth width of anurans
(H , T , D et al. ) and/or that
diet preferences change with age (L M ,
H , B  M ). We could not
nd any correlation between prey size and frog weight in
our study (however, only subadult to adult frogs were ex-
amined), although the prey covered a broad spectrum con-
cerning weight and size. Most of the examined frogs had
well-lled stomachs. e volume of all ingested items in
one frog adds up to a maximum of , mm³ and was
found in a medium-sized individual. e potentially enor-
mous quantity of daily consumption underlines the poten-
tially important position of H. occipitalis within its ecosys-
tems, especially where the species is very abundant such as
on river banks in the dry season, in swamps or rice pad-
dies. Since the consumption of H. occipitalis by West Af-
ricans is locally dramatically increasing (M et al.
), notable eects on the ecosystem of the species’ po-
tential decline are not unlikely. Regardless of the methodo-
logical approach, our data, based on nearly  individu-
als, very probably provide a representative picture of the
species’ diet, at least in this particular region (rice pad-
dies and Sudanese savanna near a large river) and season
(dry season). It is known that H. occipitalis migrates from
river sites (occupied in the dry season) to newly formed
savanna ponds in the wet season (S  L
). is switching of habitats may be also reected in a
change of prey items. Furthermore, H. occipitalis tadpoles
are known to be very ecient predators of, e.g., other tad-
poles and mosquito larvae (R , ). A decline
of adult frogs will consequently result in smaller numbers
of tadpoles. In the wake of unsustainable harvesting of
frogs, a dramatic increase of pest insect populations was
reported from India (A , O ). It would
therefore be interesting to investigate the diet of H. occipi-
talis during the wet season in their breeding habitats, far
from the rice paddies and riversides, as well as the exact
composition and quantities of the tadpoles’ prey.
We thank B S, as well as the respective authorities in
Benin for their support and the necessary research permits. We
are very thankful to M M, A T and
N A for their help during planning and conduct-
ing the eldwork. is study is part of the BIOLOG program of
the German Ministry of Education and Science (BMB+F; Project
BIOTA-West III, amphibian projects, LCJ).
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... A cet effet, plusieurs études portant sur les paramètres morphologiques et les habitudes alimentaires de H. occipitalis ont été conduites en Afrique de l'Ouest notamment en Côte d'Ivoire et au Nigéria. Au Bénin, des travaux sur ces aspects sont assez rares hormis le travail de [6] limitée au nord du Bénin. Etant donné que les modèles de croissance et la composition du régime alimentaire des grenouilles varient en en fonction de la situation géographique, du type de milieu et de la saison, il est encore nécessaire que des recherches supplémentaires soient entreprises pour mieux connaitre le régime alimentaire de cette espèce dans ses principales zones d'occurrence au Bénin. ...
... La référence [15] a également observé un dimorphisme sexuel chez les amphibiens du Cameroun, les femelles étant plus grandes avec une longueur museau-cloaque variant de 11 à 13,5 cm, contre 6,8 à 11 cm chez les mâles. Les auteurs de la référence [6] qui ont travaillé sur la même espèce dans le bassin du Niger au Bénin ont également rapporté des poids individuels variant de 35 à 48 g (soit 73,1±29,0 g en moyenne) et de longueurs museau-cloaque variant de 6,78±10,8 cm (soit en moyenne 8,38±1,04 cm). Comme dans notre cas, ces mêmes auteurs n'ont pas observé de différences significatives de taille ni de poids entre les mâles et les femelles de H. occipitalis dans le bassin du Niger au Bénin. ...
... La variation des aliments consommés par H. occipitalis d'un bassin à un autre pourrait être due à la disponibilité des ressources alimentaires qui elles aussi peuvent varier selon les saisons et/ou les habitats ( [23], [19], [24]). Contrairement à nos résultats, [6] ont observé que les poissons étaient les proies les plus courantes et les plus importantes dans les estomacs de H. occipitalis capturés dans le bassin du Niger. Ils les ont observés dans 33,8% des estomacs examinés et leur indice d'importance relative (IRI = 2646,7) était presque sept fois plus élevé que celui des Coléoptères qui représentaient la deuxième catégorie de proies en importance (IRI = 381,22). ...
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This study deals with the morphological features and diet of the frog Hoplobatrachus occipitalis in Benin. Specimens were caught in the River basins of Ouémé, Mono and Niger using the light fishing technique. Morphometric data were taken on 180 individuals while diet data were collected on 90 specimens per hydrographic basin. The mean values of individual weight, total length and snout-cloaca length of H. occipitalis in the Niger River basin are significantly lower compared to the other two basins (p<0.05) where the values of the three parameters are statistically similar (p>0.05). Compared to males, females displayed higher values of these parameters and most of the differences are significant in the Ouémé and Mono River basins (p<0.05). The overall emptiness index is 29.9%, the highest and lowest values being obtained in the Niger River basin (43.3 ± 2.4%) and Ouémé River basin (13.6 ± 2.5%), respectively (p<0.05). The diversity of prey in the stomachs of frogs from the Niger River basin (Insects, plant debris and grains of sand) is low compared to the Ouémé River basin (Insects, plant debris, Arachnids, Molluscs, Fish and grains of sand) and the Mono basin (Insects, plant debris, Fish and grains of sand). Insects are the most frequent, the most numerically abundant and the most weight-representative in the three River basins. They are the main food in the diet of H. occipitalis in the Ouémé and Niger River basins while in the Mono River basin, they are with the plant debris of secondary foods. All other prey encountered are incidental in the diet of H. occipitalis. These biological data are useful for the breeding of H. occipitalis in Benin. RESUME: La présente étude traite de la morphologie et du régime alimentaire de la grenouille Hoplobatrachus occipitalis au Bénin. Les spécimens ont été capturés dans les bassins fluviaux de l'Ouémé, du Mono et du Niger en utilisant la technique de pêche à la lumière. Les mesures morphométriques ont été prises sur 180 sujets par bassin alors que les données sur le régime alimentaire ont été collectées sur 90 spécimens par bassin. Les valeurs moyennes du poids individuel, de la longueur totale et de la longueur museau-cloaque de H. occipitalis dans le bassin du Niger sont significativement plus faibles en comparaison aux deux autres bassins (p<0,05) où les valeurs des trois paramètres sont statistiquement similaires (p>0,05). Comparées aux mâles, les femelles présentent des valeurs plus élevées de ces paramètres et la plupart des différences sont significatives dans le bassin de l'Ouémé et celui du Mono (p<0,05). L'indice de vacuité est globalement de 29,9%, la plus forte et la plus faible valeur étant obtenues respectivement dans le bassin Niger (43,3 ± 2,4%) et celui de l'Ouémé (13,6 ± 2,5%) (p<0,05). La diversité de Morphologie et régime alimentaire de la grenouille Hoplobatrachus occipitalis (Gunther, 1858) au Bénin: Un pas essentiel vers son élevage ISSN : 2351-8014 Vol. 58 No. 1, Dec. 2021 84 proies dans les estomacs des grenouilles provenant du bassin du Niger (Insectes, débris végétaux et grains de sable) est faible comparativement au bassin de l'Ouémé (Insectes, débris végétaux, Arachnides, Mollusques, Poissons et grains de sable) et celui du Mono (Insectes, débris végétaux, Poissons et grains de sable). Les Insectes sont les plus fréquents, les plus numériquement abondants et les plus pondéralement représentatifs dans les trois bassins. Ils constituent le principal aliment dans le régime de cette espèce dans les bassins de l'Ouémé et du Niger alors que dans le Mono, ils sont avec les débris végétaux des aliments secondaires. Toutes les autres proies sont accessoires dans le régime alimentaire. Ces données sont utiles pour l'élevage de H. occipitalis au Bénin.
... Understanding the reasons for decreasing amphibian populations worldwide requires detailed research on their ecological role in ecosystems. To this aim, feeding biology is one of the first aspects that must be investigated to fully understand the ecology of a species (Hirschfeld & Rödel 2011). Amphibians are generally carnivores and they feed on various vertebrate or invertebrate animals (Duellman & Trueb 1986). ...
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The food composition of Pelophylax bedriagae was studied in the province of Muğla, southwestern Anatolia. The food contents of 32 individuals (16 males, 16 females) were collected by using the stomach-flushing method. A total of 128 different food items were detected and identified to the lowest possible taxa. Class Insecta was the most dominant prey category, 60% in number, 87% in frequency and 33% in volume. Among orders, Diptera was the highest prey group in both number (27%) and frequency (53%) whereas Coleoptera was the highest in volume (17%). Similarly, Culicidae was the highest prey group in both number (20%) and frequency (33%) among families while Scarabaeidae was the highest in volume (17%). There was no difference between the number of preys consumed by females and males.
... Toft, 1985;Vignoli & Luiselli, 2012). Investigations on the role of anurans in tropical and subtropical natural amphibian communities have been undertaken in South America (Toft, 1980(Toft, , 1981Parmelee, 1999;Piatti & Souza, 2011;Talione Sabagh et al., 2012;Moreno-Barbosa & Hoyos-Hoyos, 2014;Huckembeck et al., 2018, Brandão et al., 2020 and West Africa (Barbault, 1974;Eniang et al., 2003;Akani et al., 2011;Hirschfeld & Rödel, 2011;Onadeko, 2011;Enabulele & Aisien, 2012;Tohé et al., 2015;Ofori et al., 2021). Whilst studies on urban anurans have typically addressed species richness, population density and habitat availability (e.g. ...
Suitable habitats for anurans can be found in the ever-growing tropical urban environments but anurans’ adaptations to urban conditions, including their trophic ecology remain largely unknown. We studied the food habits of two generalist, widespread West African Sclerophrys adult toads: African common (S. regularis) and Hallowell's toad (S. maculata). The first was studied in Lomé (Togo), Cotonou (Benin) and Ikeja (Nigeria), and the second in Port Harcourt and Ikeja (both Nigeria); the latter city represents the only studied sympatric occurrence. Mean dietary overlap between population pairs was relatively high, and diet composition of the two species when sympatric did not differ significantly. Food niche width was significantly positively correlated with local rainfall in both species, and diet composition changed significantly between the dry and wet seasons. Diversity metrics revealed that females had a more diversified diet, with higher evenness and lower dominance index values than males. The diet of both species was not correlated to prey type availability, in both the wet and dry season. Both toad species targeted specific food items rather than opportunistically consume prey as observed in most anurans which may be a response to high anuran diversity typically found in the tropics or an adjustment to urban habitats.
... Insects were predominant in the diet composition of S. fuscovarius as observed for many anuran species in different regions (Hirai & Matsui 1999, Rodrigues et al. 2004, Hirschfeld & Rödel 2011, Kittel & Solé 2015. Regarding foraging strategy, it is suggested that S. fuscovarius displays a "sit and wait" type of foraging behavior, with fast moving prey present in most stomachs, such as Araneae, Blattaria, Coleoptera, Hymenoptera, Lepidoptera and Orthoptera arthropods. ...
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Amphibians control the population size of various invertebrate species and are food sources for other predators. Their diets can be influenced by characteristics that facilitate prey discovery according to foraging strategies that vary between anuran species. The diets of seventy-five Scinax fuscovarius specimens collected through active nocturnal searches at the Estância Mimosa farm, in the municipality of Bonito, Mato Grosso do Sul, Brazil were assessed. Thirty-nine of the stomachs (52%) contained food items, comprising 94 items and 28 prey categories, divided into three groups (insects, arachnids and crustaceans). Orthoptera was the most frequent prey item, while Araneae was the most abundant prey and Hemiptera Cicadellidae was the most voluminous prey category. The results indicate that S. fuscovarius is a generalist and opportunistic predator, using a "sit and wait" foraging strategy. Prey volume was not associated with individual size, but the number of preys per individuals was related to frog size. Variation in diet composition throughout the different life stages along with reproductive activity may explain the low similarity found in the diets of male, female and juvenile individuals.
... This may be due to their active foraging strategy. Studies on amphibian foraging in other parts of the world such as Africa, South America and the Indian subcontinent indicate that amphibians with a sit-and -wait foraging strategy have a narrow niche breadth in comparison to active foragers, which feed on a wide range of prey items (Das 1996;Ferreira and Teixeira 2009;Hirschfeld and Rödel 2011;Caldart et al. 2012;Rebouças and Solé 2015). Although no direct observations have been made on the foraging strategy of U. rohani, the lowstandardised niche breadth value indicates that U. rohani could be a sit-and-wait forager. ...
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Understanding the conditions under which interacting species can persist is a major goal in ecology. Dietary partitioning is one of the major strategies that enables ecologically similar species to coexist in communities. In this study, we examined the dietary patterns of a selected group of amphibians in an amphibian community in northern Sri Lanka to understand differential resource use by coexisting species. The stomach flushing method was used to examine the diet of amphibians to study the niche breadth and pairwise species dietary niche overlap. Seventeen different prey categories were identified from the diet of six species of amphibians in the community. The most frequently used prey category by all amphibians was hymenoptera. Among the amphibians, some consumed several different prey categories (8–9 prey categories), while some were more specialised (e.g. Uperodon rohani fed only on ants), consuming only one or two different prey categories. The average niche overlap among the species in the community was 0.392 indicating low trophic niche overlap. This study indicates a low level of dietary niche overlap between the selected amphibian species and hence, a high degree of dietary niche partitioning. The findings also provide valuable insights into the dietary ecology of these amphibians, which will be invaluable for the formulation of conservation strategies.
... Apart from the predatory impact of the larval stage, adults of the genus may impact native biodiversity similarly to H. tigerinus (e.g. predation of native vertebrates, Table 1; Hirschfeld and Rödel 2011;Pili et al. 2019). Similarities in the invasion process of Hoplobatrachus to the well-studied model species Lithobates catesbeianus (130 publications on its non-native populations; Ficetola et al. 2007a;van Wilgen et al. 2018) belonging to the same ''invasion syndrome'', should be leveraged to frame hypotheses and inform management (Novoa et al. 2020). ...
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Invasive amphibians have considerable ecological and socio-economic impact. However, strong taxonomic biases in the existing literature necessitate synthesizing knowledge on emerging invaders. The Indian bullfrog, Hoplobatrachus tigerinus, a large dicroglossid frog (snout to vent length: up to 160 mm), is native to the Indian sub-continent. Despite the high likelihood of invasion success for H. tigerinus, based on the species’ natural history traits and human use, the status of its non-native populations and global invasion potential has not yet been assessed. In this paper, we provide a profile of H. tigerinus as an invasive species to aid in risk analyses and management of existing populations. We review the available knowledge on non-native populations of H. tigerinus and model its potential distribution in the non-native range and globally; finally, we evaluate its ecological and socio-economic impact using standard impact classification schemes. We confirm successful invasions on the Andaman archipelago and Madagascar. The ensemble species distribution model, with ‘good’ predictive ability and transferability, predicts tropical regions of the world to be climatically suitable for the species. Considering potential for propagule pressure, we predict the climatically suitable Mascarene Islands, Malaysia and Indonesia, and East Africa to likely be recipients of bridgehead invasions. We assign the species two impact scores: both socio-economic and environmental scores were ‘moderate’ with ‘medium’ confidence levels in our assessment. Finally, this synthesis outlines the invasion process of the genus Hoplobatrachus, which is an emerging group of amphibian invaders.
... However, there is a lack of information on the artificial reproduction and ontogeny of H. occipitalis. Major research works on H. occipitalis focused on its biological diversity and feeding habits (Rödel and Spieller 2000;Rödel and Branch 2002;Rödel 2003;Rödel and Ernest 2004;Assemian et al. 2006;Hirschfeld and Rödel 2011). The purpose of this study was to reproduce H. occipitalis in captivity by the spawning agent Ovaprim Ò and to document the different stages of its embryonic development. ...
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The objective of this study was to investigate the embryonic development of the frog Hoplobatrachus occipitalis after their artificial reproduction with the Ovaprim®, a combination of gonadotropin releasing hormone analogue and dopamine antagonist domperidone. Male and female H. occipitalis were collected from the wild and were intramuscularly injected with Ovaprim® at doses of 6 µL/g and 8 µL/g body weight, respectively. The eggs were laid 6 h after hormone injection. The numbers of eggs laid by each female frog were 1726 ± 5.4 (SD) with 94.4% and 88.2% mean fecundity and hatching rate, respectively. The diameter of the eggs at laying was 2.73 ± 0.33 mm while it was 5.04 ± 0.05 mm just before hatching. The stages of embryonic development starting from fertilization to tadpoles’ formation took 27 h to complete at 26.4 ± 0.3 °C. The average height of the tadpoles after hatching was 5.1 mm. Circular tadpole movement in the chorion with an irregular respiratory movement was observed at 21 h after egg-laying. In summary, the study shows that H. occipitalis could reproduce in controlled environment by hormonal induction; the reproductive structures have no significant effect on egg-laying; and the embryonic development time of H. occipitalis differs from that other Anuran species.
... were added to enclosed experimental rice fields, and the addition of frogs also improved yields (Teng et al., 2016). Several rice field amphibians are also generalist predators that feed on a diversity of taxa including insects, arachnids, gastropods, and even some vertebrates (Burghelea et al., 2010;Hirai and Masafumi, 1995;Hirschfeld and Rödel, 2011). Generalists can provide effective control of invertebrate rice pests if they do not consume a disproportionate number of predators; Symondson et al. (2002) observed that the addition of invertebrate generalist predators significantly reduced pest numbers in 75% of manipulative field studies across a variety of crops. ...
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Irrigated rice cropping systems serve the dual role of providing an essential food crop to the world’s most populous regions and functioning as man-made wetlands that harbor wildlife. Amphibians utilize irrigated rice fields throughout multiple life history stages to develop, forage and reproduce. However, routine exposure to pesticides can negatively affect amphibians and the ecosystem services they provide. My dissertation addresses this concern by examining how pesticide exposure affects amphibians that occupy rice fields at multiple scales, spanning physiology, behavior, and ecology. Through a series of experiments and surveys, I also explore the ecosystem services of rice field amphibians as indicators of endocrine disruption and providers of natural pest control. First, I conducted a quantitative meta-analysis where I found that across 39 papers and 23 different chemicals, sub-lethal pesticide exposure consistently affects critical behaviors (swimming speed and activity level) of aquatic vertebrates. Next, I conducted a series of three experiments to test whether exposure to butachlor, one of the most popular herbicides used in rice, affects development, behavior, and competitive interactions between a native and invasive species. My results provide evidence that environmentally relevant concentrations of butachlor disrupt thyroid hormone mediated development, and demonstrates that important species interactions such as competition can be affected by pesticide exposure in aquatic ecosystems. Last, I examined the diet composition of native Luzon wart frogs and invasive cane toads over two seasons, and found that the native frog may provide effective pest control services and thereby reduce the need for insecticide use, but that non-native cane toads may indirectly damage rice crops by consuming a disproportionate number of beneficial predators. Taken together, this research provides evidence to encourage sustainable management of rice that prioritizes reducing pesticide inputs and promoting native species, such as the Luzon wart frog, in order to safeguard biodiversity while simultaneously improving yields.
... The aquatic African Tiger Frog (H. occipitalis) inhabits riversides, swamps and temporary ponds or depressions that are filled with water, it feeds on terestrial insects and spiders (Hirschfeld and Rödel, 2011) and ecologically, they occupy important positions in the food chain as they serve as food for both aquatic and terrestrial predators (Ezemonye and Enuneku, 2012). E. senegalensis (rough mudfish) and H. africana (smooth mudfish) belongs to the family Eleotridae and are carnivorous fish that lives in burrows at the bottom of the subtidal zone of the river (Idodo-Umeh, 2003), combined with their benthic feeding habit makes them a valid representative of the state of the sediment which acts as a sink for heavy metals in the river. ...
In this study, Periophthalmus papilio (mudskipper), Eleotris senegalensis (rough mudfish), Hannoichthys africana (smooth mudfish) and Hoplobatracchus occipitalis (aquatic tiger frog) were selected to assess the water quality of Benin River at Koko, from December 2014 to July 2015 using three sampling stations (Obialegbe, Beach, and Ajalugbeti). The morphometric characteristics were determined using standard methods while spatial variations in heavy metal (Cadmium, Chromium, Copper, Iron, Lead, Manganese, Nickel, Vanadium and Zinc) concentrations were determined using Atomic Absorption Spectrophotometer. The heavy metals concentrations for E. senegalensis, H. africana and P. papilio in decreasing order were Fe > Zn > Mn > Cu > Pb > Cr > Cd, while concentrations for H. occipitalis were Fe > Zn > Mn > Cu > Cr > Pb > Cd > V > Ni. There was no significant difference (P > 0.05) in morphometric characteristics and heavy metal levels in species across sampling stations. Fe, Mn and Zn concentrations in fish and frog were above the recommended permissible limits by FAO/ WHO, while Cd, Cr, Cu, Ni, Pb and V were within recommended limits. However, all sampled fish were in good condition (k > 1) and under no form of stress in Benin River.
Murree Hills Frog, Nanorana vicina, is one of the under studied anuran species of South Asia. We hypothesized that the diet of Murree Hills Frog differed during breeding and non-breeding seasons. We found that the geographic range of the species in Pakistan is narrower than reported. It occurs in Tehsil Murree (District Rawalpindi, Province Punjab), District Abbotoabad (Province Khyber Pakhtunkhwa) and Districts Poonch and Bagh (Azad Jammu and Kashmir). We recovered 12 taxa from stomach contents during the breeding season. The most frequent food items included Coleopterans (60%, constant) and Hymenopterans (40%, secondary). The food items from order Coleoptera contributed the most in the stomach content volume (ml) 0.06, followed by Hymenoptera 0.05, and Isoptera 0.05. The frogs showed secondary degree of food preference for Coleopterans and occasional for other food items. We recorded ten food items during non-breeding season. The most frequent food items included Coleopterans (45%, secondary), Hymenopterans (40%, secondary) and Orthopterans (35%, secondary). The food items from order Coleoptera contributed the most in the stomach content volume (ml) 0.12, followed by Orthoptera 0.11. The species showed secondary degree of food preference for Coleopterans, Hymenopterans and Orthopterans and occasional for other food items. The food item taxa during breeding and non-breeding seasons did not differ significantly. We have reported major threats to the species and suggested research, conservation and management options.
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The diet of the banded newt, Triturus vittatus ophryticus, from 3 different sites in northern Turkey was studied based on stomach contents from 180 samples (104 males + 76 females). The banded newt was found to forage on wide variety of prey organisms in the aquatic phase. Benthic invertebrates consistently made the greatest contribution to the diet, both numerically and volumetrically. Nektonic prey also appeared to be of importance in terms of volume but constituted few items. Terrestrial invertebrates contributed very little to the diet. In addition to invertebrates, a few amphibian prey items were found in the stomachs. The number of major prey taxa in the diet was significantly correlated with the seasons (Kruskal-Wallis test, P < 0.01). There were proportionally more Ostracods and Chironomids (larvae and pupae) in the diets of banded newts in spring, whereas Daphnia sp. were largely consumed in late summer and autumn. Differences in the size of newts seem to cause a corresponding significant difference in the selection of large and small prey (rmax, = -0.247, P < 0.05). We also found that Triturus vittatus ophryticus consumed similar prey taxa among sites, but that the frequency of the major prey taxa in the diet was significantly different (Tukey's test: P < 0.05) due to ecological conditions.
We studied the diet of two syntopic and morphologically very similar leaf litter frogs, Phrynobatrachus ghanensis and P. phyllophilus, in Banco National Park, south-eastern Ivory Coast. We determined the prey composition of females of both species to understand the potential avoidance of competition for food. Insects dominated (> 80%) the general diet of both species. We determined insect prey items down to the level of the order. At this level the diet of both species differed, however not significantly. Whereas P. ghanensis preyed mainly on hymenoptera (65.6%, mostly ants); P. phyllophilus mainly preyed on coleoptera (56.8%). With respect to seasons these differences were even larger, although again not statistically significant. Hence, there seem to be some differences in the food preference of the two species. However, the large overlap in prey can be taken as a hint that competition for food does not play a major role between these two frogs. The slightly different diets are more likely the result of so far undetected differences in habitat preferences and / or activity patterns. © 2008 Deutsche Gesellschaft für Herpetologie und Terrarienkundee. V.(DGHT).
In Gaboon, the frog Aubria subsigillata, at least at certain periods of the year, eats fishes of the genus Epiplatys. The fish are caught when they jump out of the water to escape their aquatic predators, or to look for different surroundings.
Etude comparative de 3 methodes de lavage d'estomac chez le caiman pour etudier le regime alimentaire. La methode proposee est celle du tuyau d'arrosage avec des mouvements de Heimlich (hose with Heimlich maneuvers).
Rana nigromaculata was found to consume a wide variety of prey organisms in rice fields of Kyoto, Japan. Arthropods constituted the bulk of its diet both numerically and volumetrically. Frequencies of the major prey taxa fluctuated seasonally and were significantly correlated with the prey availability estimated by a sweeping method. This result suggests that this frog feeds opportunistically depending on encounter rates with prey. A significant correlation between individual frog SVL and prey size suggests frogs consume larger prey as they grow. However, considerable dietary overlap among three different body-size groups suggests only weak food resource partitioning among them. These results indicate that the diet of R. nigromaculata is more strongly influenced by prey availability than by prey selectivity and that this anuran is a generalist predator.