Research Article |
Corresponding author: Diego José Santana ( santanadiegojose@yahoo.com ) Academic editor: Günter Gollmann
© 2019 Diego José Santana, Vanessa Gonçalves Ferreira, Gabriel Nassif Crestani, Matheus Oliveira Neves.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Santana DJ, Ferreira VG, Crestani GN, Neves MO (2019) Diet of the Rufous Frog Leptodactylus fuscus (Anura, Leptodactylidae) from two contrasting environments. Herpetozoa 32: 1-6. https://doi.org/10.3897/herpetozoa.32.e35623
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The impact of urbanization on amphibians has received some attention in the conservation literature. Despite the various impacts on animal life, some species can persist along the cities structures by adjusting their natural histories. Leptodactylus fuscus is a common anuran species occurring in South America, which can commonly be found in urban environments. Herein, we compare the diet of L. fuscus between an urban and a wild environment. We collected 57 individuals of L. fuscus and analysed their diet, which differed significantly between the two sites. In the urban environment, Coleoptera were the prevalent prey items, whereas specimens from the wild site had a more diverse diet.
anthropic changes, anthropization, Cerrado, resources, trophic ecology
Urbanization processes lead to several changes in biological communities (
The majority of anurans are considered generalist predators and feed mostly on invertebrates (
The Rufous Frog Leptodactylus fuscus (Schneider, 1799) is a common species occurring in savannas from Panama throughout South America, east of the Andes, south to southern Brazil, Bolivia, Paraguay, and northern Argentina (
We collected data from contrasting sites in the municipality of Campo Grande, state of Mato Grosso do Sul, Brazil (Fig.
We collected adult L. fuscus through nocturnal active searches by “Visual Encounter Surveys” (
To evaluate the diet, we removed the stomachs of each specimen through a small abdominal incision and extracted their contents. We identified each prey item with a stereoscope microscope to the order level and measured the length and width of the prey with a Mitutoyo digital calliper (0.01 mm precision). Prey items in advanced stages of digestion were considered as unidentifiable.
For the diet analysis, we first identified prey to the lowest possible taxonomic level (usually order). The volume of each prey item was then calculated using an ellipsoid formula: (
We performed a PERMANOVA analysis to test if diet composition varies between the two site types, with euclidian distance, using the prey volume, and then we executed a Principal Component Analysis (PCA) to check which prey category most contributed for the differentiation. All statistical analyses were conducted in the R software v.3.4.2 (
We collected 57 individuals of Leptodactylus fuscus, 31 in the urban site (27 males and four females), and 26 in the wild site (12 males and 14 females). Among the analyzed stomachs (n = 57), only two were empty. We found 236 preys belonging to 16 categories as follow by alphabetical order: Araneae, Blattaria, Chilopoda, Coleoptera, Dermaptera, Diptera, Hymenoptera, Hemiptera, Isopoda, Isoptera, Lepidoptera, Orthoptera, Plant Material, Pulmonata, Scorpiones and unidentifiable (Table
Diet composition differs between the wild and urban site types (F=7.77; df=53; P<0.001; Fig.
Principal components analysis to evaluate the differences in the diet of Leptodactylus fuscus sample in the urban and wild sites in the municipality of Campo Grande, state of Mato Grosso do Sul, Brazil. Black dots indicate individuals from the urban site, and red dots indicate individuals from the wild site. Arrows indicate the contribution in the ordination of each prey item.
Comparison of the diet of Leptodactylus fuscus between urban and wild sites in the municipality of Campo Grande, state of Mato Grosso do Sul, Brazil. V = volume, N = number, F = frequency, IRI = important relative index.
Urban environment | Wild environment | |||||||
Prey category | V% | N% | F% | IRI | V% | N% | F% | IRI |
Araneae | 0.87 | 4.65 | 5.43 | 30 | - | - | - | - |
Blattaria | 0.17 | 0.58 | 1.09 | 0.81 | 2.93 | 1.56 | 2.44 | 10.96 |
Chilopoda | - | 0.58 | 1.09 | 0.63 | - | - | - | - |
Coleoptera | 26.36 | 34.88 | 25.00 | 1531.11 | 1.72 | 4.69 | 7.32 | 46.91 |
Dermaptera | 4.67 | 4.65 | 6.52 | 60.78 | 2.32 | 3.13 | 4.88 | 26.54 |
Diptera | 0.27 | 1.16 | 1.09 | 1.56 | 0.64 | 9.38 | 4.88 | 48.87 |
Hemiptera | 1.18 | 6.98 | 9.78 | 79.76 | 0.89 | 3.13 | 2.44 | 9.79 |
Hymenoptera | 11.31 | 21.51 | 10.87 | 356.73 | 0.43 | 25.00 | 12.2 | 310.14 |
Isopoda | 1.36 | 4.07 | 2.17 | 11.8 | - | - | - | - |
Isoptera | - | - | - | - | 0.47 | 3.13 | 2.44 | 8.78 |
Lepidoptera | 4.66 | 2.33 | 3.26 | 22.79 | 27.05 | 15.63 | 9.76 | 416.34 |
Not Identified | 40.21 | 11.05 | 20.65 | 1058.5 | 46.3 | 20.31 | 34.15 | 2274.62 |
Orthoptera | 1.18 | 2.33 | 4.35 | 15.23 | 0.28 | 1.56 | 2.44 | 4.5 |
Pulmonata | 4.16 | 0.58 | 1.09 | 5.16 | - | - | - | - |
Scorpiones | - | - | - | - | - | 4.69 | 4.88 | 22.87 |
Vegetal | 3.62 | 4.65 | 7.61 | 62.9 | 16.95 | 7.81 | 12.2 | 301.94 |
Diet of Leptodactylus fuscus in the urban and wild sites in the municipality of Campo Grande, state of Mato Grosso do Sul, Brazil. Bars represent Index of Relative Importance (IRI) (
In this study, we report differences in the diet composition of L. fuscus between urban and wild sites. Differences between urban and wild environments have been reported for other vertebrates such as birds (
All previous diet studies of L. fuscus reported different prey as the most important in the species diet. We also highlight that each study was conducted in different ecoregions. Firstly, a population from a Cerrado area was studied, and the most important prey item was Coleoptera (
The changes from urban to wild environments provide a gradient in the composition of insect communities (
Leptodactylus fuscus is a common and abundant species, inhabiting many environments (
We are grateful to two anonymous reviewers for their critical revision. To Vinícius de Avelar São Pedro for his revision and comments in a previous version of the manuscript. To the Use Animal Ethics Committee of the Federal University of Mato Grosso do Sul for their approval of the project that predated this experiment (protocol 810/2016). The collection license was provided by Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio 49080-1). We thank “Dona” Marina e “Seu” João for the study permits in the area of Santa Fé Farm in “Projeto Brejo Bonito”. VGF and MON thank Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for their scholarship (financial code 001). DJS thanks Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for his research fellowship (311492/2017-7).