The Abundance of D. muelleri, E. ovalis, P. albonatatus
and P. fuscomaculata in Comparison to Rainfall
in the Southern Pantanal (2005-2006)
Hannah Doerrier1, Vanda Lucia Ferreira2, and Janet Buckner1
1State University of New York at Oswego, Federal University of Mato Grosso du Sul2
Objectives
Methods
-To use a database of previously collected/identified
reptiles and amphibians from pitfall traps located in the
southern Pantanal at Fazenda Nuhmirim in Mato
Grosso do Sul, Brazil in order to visualize species
abundance by age group.
-Look at the abundance patterns of four different
Anurans species, D. muelleri (Figure 1), E.ovalis
(Figure 2), P. albonatatus (Figure 3) and P.
fuscomaculata.
-Finally we wanted to compare the abundance by sex
to the amount of rainfall experienced in the area of
collection (data courtesy of Embrapa Pantanal).
For our research we used the database from nine different
expeditions to Fazenda Nhumirim (18º59´00”S/56º39´00” W)
in Mato Grosso do Sul, Brazil, from February 2005 to May
2006. The collections were carried out using pitfall traps, which
are very common in collecting small animals, including insects
and amphibians. The buckets were approximately 100 liters
and installed in environments of forest, field (native and
Brachiaria), Savannah, both in areas with and without the
presence of cattle
The database was organized by species abundance and age
group (adults, sub-adults and youth) using the rostro-anal
length (snout-cloaca) (CRA) that varied by species (Table 1)
The abundance of species was compared with the database of
rainfall from October 2004 to May 2006 from EmbrapaPantanal.This was used to find a pattern of abundance of
species by age and the volume of rain that preceeded the
period of collection. The species were grouped by biological
reproduction associated with rain. D. Muelleri and E.ovalis are
fossorial and require a greater volume of rain to start the
reproductive activity. P.albonatatus and P.fuscomaculatus do
not need much rain as they are cryptozoic. Using the data
compiled about daily rainfall and abundance of juvenilles we
looked for the period that probably led to the laying of eggs of
these individuals.
Introduction
The Pantanal is one of the most ecologically diverse
places on the earth and the largest flood plain on the
planet with an area of 140,000 km^2 (Uetanaboro et al.
2008). Due to its distinct seasons of wet and dry periods it
makes the Pantanal a great place to study amphibian
ecology.
Frogs are highly dependent on
water for reproduction and they
have adapted different strategies
in using these periods of wet/dry
(Duellman & Trueb 1994)
Physalaemus albonatatus and pleurodema fuscomaculata
(Leiuperidae) have prolonged reproduction pattern and
build foam nests as a shelter for egg development (Prado,
Uetanabaro, Haddad 2005). Dermatonotus muelleri and
Elachistocleis ovalis (Microhylidae) have explosive
reproduction patterns and tend to be opportunists,
reproducing during/directly after periods of heay rain. They
do this by laying eggs in or on top of ponds (Prado,
Uetanabaro, Haddad 2005). All these species have
development in the larval stage and the period of
metamorphosis is still unknown for the natural
environment.
Figure 1
Dermatonotas muelleri
photograph courtesy of 2003 Micro Sole
Table 1
Figure 2
Elachistocleis ovalis
Photograph courtesy of 2006 Sebastian
Lotzkat
Figure 3
Physalameus albonatatus
Photo courtesy of Wikipedia.com
Results
Daily rainfall at Fazenda Nhumirim in Mato Grosso do Sul, Brazil from Oct. 2004- Jun. 2006
Abundance of D.muelleri collected in pitfall traps at Fazenda
Nhumirim in Mato Grosso do Sul, Brazil during 2005/2006
700
Abundance of E.ovalis collected in pitfall traps at
Fazenda
Nhumirim in Mato Grosso do Sul, Brazil during
600
2005/2006
600
500
500
400
60.0
50.0
20.0
10.0
Rain
0.0
O
c
t
.
'
0
4
N
o
v
.
'
0
4
D
e
c
.
'
0
4
J
a
n
.
'
0
5
F
e
b
.
'
0
5
M
a
r
.
'
0
5
A
p
r
.
'
0
5
M
a
y
'
0
5
J
u
n
.
'
0
5
J
u
l
.
'
0
5
A
u
g
.
'
0
5
S
e
p
t
.
'
0
5
O
c
t
.
'
0
5
N
o
v
.
'
0
5
D
e
c
.
'
0
5
J
a
n
.
0
6
F
e
b
.
'
0
6
M
a
r
.
'
0
6
A
p
r
.
'
0
6
M
a
y
'
0
6
J
u
n
.
'
0
6
Time (days)
Figure 4 is showing the daily rainfall experienced at
the farm in which this collection took place. The
data was provided by Embrapa. There seems to be
a large amount of rainfall experienced from Oct ’04Feb’05 with 19 days with >20mm of rain. Between
Mar ‘05- Sept ‘05 there is little rainfall experienced
and less than 5 days with substantial rainfall
(>20mm). From Oct ’05-May ‘06 there is almost
daily rainfall, with many days of substantial rain.
400
300
Adult
Sub-adult
Juvenile
200
Adult
200
100
100
All four species of frogs are showing a direct realtionship
Jan. '05 April '05 July '05 Oct. '05 Jan. '06 April '06
to the amount of rainfall at Fazenda Nhumirim. Generally,
Month of collection
Month of collection
during/directly after months of consistent rainfall there was an
Figure 5 is showing few adults
Figure 6 is showing the most amount
increase in the abundance of frogs in these áreas. During the
except for Oct ‘05 and the most
of adult and juveniles were collected
months of March 2005 to September 2005 there was little to no
amount of juveniles (615) in Feb
during Feb ‘05 (244/490) and Mar ‘06
rainfall (Figure 4) and in turn little to no frogs found during this
‘05.
(280/345). It is also showing a period
period for any of the species (Figures 5-8). For all species more
between June ’05- Oct ‘05 were
juvenilles were captured than adults (Figures 5-8).
little/no frogs were found
D.muelleri is a terrestrial/fossorial frog, which helps to
Abundance of P.albonotatus collected in pitfall traps at
explain why in Figure 5 little to no adults were collected
Abundance of P.fuscomaculata collected in pitfall traps at
Fazenda Nhumirim in Mato Grosso do Sul, Brazil during
Fazenda Nhumirim in Mato Grosso do Sul, Brazil during
600
2005/2006
700
(Uetanaboro et al 2005).Their juvenille abundance pattern seems
2005/2006
500
600
most similar to that of E.ovalis, both showing the most amount of
500
400
juveniles in February 2005 after a long period of substantial
400
300
rainfall from October 2004 to February 2005 (Figures 4,5,6).
300
200
E.ovalis had more adults visible throughout the collection (Figure
200
100
6).
100
0
P. albonatatus and P. fuscomaculata both showed similiar
0
Oct. '04 Jan. '05 Apr. '05 Jul. '05 Oct. '05 Jan. '06 Apr. '06
Oct. '04 Jan. '05 Apr. '05
Jul. '05
Oct. '05 Jan. '06 Apr. '06
patterns of abundance. January 2006 was when the most
Month
Month of collection
Figure 8 is showing the largest amount amount of adults were present for both species (Figures 7 and
Figure 7 is showing the most amount of
adult and juveniles were collected during of adults collected in Jan ‘06 (358) and 8). P. albonatatus may have a shorter metomorphosis time, as
Feb ‘05 (244/490) and Mar ‘06 (280/345). juveniles in Mar ‘06. Fig. 5 is showing the most juveniles were seen in March 2006 (Figure 7). P.
fuscomaculata showed the most juveniles in May 2006, which is
It is also showing a period between June the most adults in Jan ’06 (268) and
four months after the most adults (Figure 8).
the most juveniles in May ‘06 (658).
’05- Oct ‘05 were little/no frogs were
Our graphs are showing a strong correlation between the
found.
amount of rainfall and the amount of frogs captured. These
species are dependent on this water and thrive when excess
rainfall accures. In order to strenghten this study it would be
beneficial to make collections every month of the year and
compare each months abundance to the amount of rainfall.
0
Oct. '04 Jan. '05 Apr. '05 Jul. '05 Oct. '05 Jan. '06 April '06
0
Oct. '04
Adult
Adult
Subadult
of collection
References
Duellman, W., Trueb, L. (1994): Biology of Amphibians . Baltimore,
The Johns Hopkins University Press.
Prado, C.P.A, Haddad, C.F.B. 2005. Size-fecundity relationships
and reproductive investment in female frogs in the pantanal, southwestern Brazil. Herpetological Journal 15: 181-189.
Prado, C.P.A., Uetanabaro, M., Haddad, C.F.B. (2005): Breeding
activity patterns, reproductive modes, and habitat use by
anurans(Amphibia) in a seasonal environment in the Pantanal,
Brazil. Amphibia-Reptilia 26: 211-221.
Thome, M.T.C, Brasileiro, C.A. 2007. Dimorfismo sexual, uuso do
ambiente e abundancia sazonal de Elachistocleis cf. ovalis (Anura:
Microhylidae) em um remanescente de Cerrado no estado de Sao
Paulo, sudeste do Brasil. Biota Neotropica 7: 27-33.
Uetanabaro, M., Prado, C.P.A., Rodrigues, D.J., Gordo, M.,
Campos, Z. (2008): Field Guide to the Anurans of the Pantanal and
Surrounding Cerrados. UFMS and UFMT.
Conclusions
300
Abundance (#)
30.0
Abundance (#)
40.0
Abundance (#)
Rainfall (mm)
70.0
Abundance (#)
80.0
Acknowledgements
Vanda L. Ferreira, PhD.
Janet Buckner