Research Article |
Corresponding author: Wellington Hannibal ( wellingtonhannibal@gmail.com ) Academic editor: Ana Maria Leal-Zanchet
© 2019 Wellington Hannibal, Polla Renon, Valquiria Vilalba Figueiredo, Roniel Freitas Oliveira, Antonio Eduardo Moreno, Romari Alejandra Martinez.
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:
Hannibal W, Renon P, Figueiredo VV, Oliveira RF, Moreno AE, Martinez RA (2019) Trends and biases in scientific literature about marmosets, genus Callithrix (Primates, Callitrichidae): biodiversity and conservation perspectives. Neotropical Biology and Conservation 14(4): 529-538. https://doi.org/10.3897/neotropical.14.e49077
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Marmosets of the genus Callithrix are small-bodied platyrrhines, endemic to Brazil. In the last 30 years, there has been a constant interest in studying their biology, ecology and conservation. In this study, we compiled a systematic review to evaluate the trends and advances of marmoset research, from biodiversity and conservation perspectives. We searched for articles published in peer-reviewed journals within the main academic search engines, using the keywords “marmoset” OR “sagui” OR “Callithrix”. We found 68 published articles with a focus on biodiversity and conservation. The number of articles has increased over the years, most of them consisting of research from the Atlantic Forest biome. Callithrix penicillata (26 articles) and C. jacchus (21) were the most studied species. The number of studies was associated with the species’ geographical distribution. From a conservation perspective, the most threatened species showed the narrowest geographical distribution, a lower number of studies and, on average, a smaller protected area size. We concluded that trends and biases in biodiversity and conservation scientific literature of Callithrix are directly and indirectly associated with its geographical distribution. Species with wide geographical distribution are more studied, better known and protected. We highlight that the major effort of studies must be towards marmoset populations from the transition region of the Atlantic Forest-Cerrado and Caatinga biomes, and on threatened species within narrow geographical ranges.
Saguis do gênero Callithrix são platyrrhines de corpo pequeno, endêmicos para o Brasil. Nos últimos 30 anos, tem havido um interesse constante em estudar sua biologia, ecologia e conservação. Neste estudo, compilamos uma revisão sistemática para avaliar as tendências e avanços da pesquisa de saguis, a partir de uma perspectiva de biodiversidade e conservação. Procuramos artigos publicados em periódicos revisados por pares dentro dos principais mecanismos de busca acadêmicos, utilizando as palavras-chave “marmoset” OU “sagui” OU “Callithrix”. Encontramos 68 artigos publicados com foco na biodiversidade e conservação. O número de artigos aumentou ao longo dos anos, a maioria deles tendo sido realizada no domínio da Mata Atlântica. Callithrix penicillata (26 artigos) e C. jacchus (21) foram as espécies mais estudadas. O número de estudos esteve associado à distribuição geográfica das espécies. Do ponto de vista da conservação, as espécies mais ameaçadas apresentaram distribuição geográfica mais estreita, menor número de estudos e, em média, menor tamanho de área protegida. Concluímos que tendências e vieses na literatura científica sobre os estudos de biodiversidade e conservação de Callithrix estão direta e indiretamente associados à sua distribuição geográfica. Espécies com ampla distribuição geográfica são mais estudadas, mais conhecidas e protegidas. Ressaltamos que o maior esforço de estudos deve estar voltado para populações de saguis na região de transição de Mata Atlântica-Cerrado e Caatinga, e espécies ameaçadas com distribuição geográfica restrita.
Atlantic Forest, Callithrix flaviceps, Callithrix penicillata, geographic distribution, scientometrics
Callithrix flaviceps, Callithrix penicillata, cienciometria, distribuição geográfica, Mata Atlântica
It has been proposed that two scientific milestones explain a considerable increase in the number of Neotropical Primate species in the past 30 years: A shift towards the phylogenetic species concept and the inclusion of cytogenetic and molecular analyses in taxonomy and systematics (
Marmosets use plant exudates as an important component of their diet (
We searched for articles about Callithrix in Google Scholar (https://scholar.google.com.br), Scielo (https://www.scielo.org), Scopus (https://www.scopus.com) and Web of Science (WoS, https://apps.webofknowledge.com) databases for the whole time series available in each database. The following keywords were used: “Callithrix” OR “marmoset” OR “sagui” in the articles’ titles, abstracts and keywords. Later, we manually checked this result to select articles in biodiversity and conservation, ranging within the following areas: animal behavior, conservation, ecology and zoology. We considered only articles using the current Callithrix taxonomy as presented on the Annotated Checklist of Brazilian Mammals (
Regarding Callithrix conservation, we searched for previously published Red List assessments to show changes in each species’ conservation category. We also visited the conservation action sub-session on the IUCN home page to verify the number and average size of protected areas for each marmoset species (
For trends and biases of Callithrix studies, we associated the number of articles with: year of publication, biomes, Callithrix species and Callithrix geographical distribution. We tested the relationship between the number of articles (response variable) with the year of publication and the geographical distribution – km2 (predictive variable) using the Pearson correlation test. To test the association between the average size of protected areas (response variable) with any given marmoset species (explanatory variable), we used the analysis of variance (ANOVA) through the ‘aov’ function and a Tukey post-hoc test through the ‘tukeyHSD’ function to compare differences between each Callithrix species. Previously, the size of protected area was log (x + 1) transformed to standardize the great variance of the data. Normality and homogeneity were tested using the Shapiro-Wilk normality test through the ‘shapiro.test’ function (W = 0.983, P = 0.412) and Levene’s test for homogeneity of variance through ‘leveneTest’ function (F = 0.513, P = 0.764) executed by ‘car’ package (
We found 68 articles (Suppl. material
Callithrix penicillata and C. jacchus have the broadest geographical distribution, occurring in the Atlantic Forest, Caatinga and Cerrado (Suppl. material
The past 30 years have shown an increase in articles written on Callithrix studies, approximately 15 years after the first study. Since 2006, the number of articles has more than doubled in each passing year. The temporal trends of the number of articles published have been reported for different groups, i.e. Euphorbiaceae (
The relation between the number of articles and marmoset species also responds directly and indirectly to geographical distribution. Callithrix penicillata and C. jacchus, which have the largest geographical ranges of the genus (
Shifts on the Red List assessments have also affected protection for Callithrix species. Until 1994, four Callithrix species were considered threatened. Currently, only C. flaviceps and C. aurita are endangered and vulnerable, respectively, with decreasing population trends driven by areas of extreme forest fragmentation through agriculture, cattle ranching, tree monocultures (Eucalyptus), urbanization, mining, and pet hunting (
The analysis of scientific production was important to reveal a broad range of studies on the genus Callithrix. We also found the need for further research in the Caatinga and Cerrado biomes, although there is an important volume of knowledge for certain populations of C. jacchus and C. penicillata. Some species endemic to the Atlantic Forest, such as C. flaviceps and C. kuhlii, need more attention, considering their IUCN status. The trends observed can be justified not by the species distribution, abundance or conservation importance, but by the distribution of the main research groups and graduate programs in Brazil, concentrated on the southeastern Atlantic Forest (
Our thanks go to colleagues of the Laboratório de Ecologia e Biogeografia de Mamíferos of the Universidade Estadual de Goiás for the discussion about marmoset studies. We thank the two anonymous reviewers of the Neotropical Biology and Conservation.
Figure S1. Map showing the geographical distribution of Callithrix species according to International Union for Conservation of Nature (
Data type: occurrence
Table S2. List of articles approaching biodiversity and/or conservation of Callithrix species
Data type: reference data