Revista de Biología Tropical ISSN Impreso: 0034-7744 ISSN electrónico: 2215-2075

The geographic bias of mammal studies: a comparison of a half a century of research on Palearctic and Neotropical mammals

Supplementary Files



geographical bias
research impact
wildlife conservation
sesgo geográfico
impacto de la investigación
conservación de la vida silvestre

How to Cite

Guerrero-Casado, J., & Monge-Nájera, J. (2021). The geographic bias of mammal studies: a comparison of a half a century of research on Palearctic and Neotropical mammals. Revista De Biología Tropical, 69(2), 391–402.


Introduction: There are no studies that specifically compare research output of Palearctic and Neotropical mammalogy; such comparison would be useful for informed decisions in conservation and management. Objective: To compare the scientific documents and citations about Palearctic and Neotropical mammals over half a century. Methods: We compared 50 years (1970-2019) of documents on 60 medium and large-sized (heavier than 1 kg) mammal species, in Scopus and the Web of Science (WoS) Core Collection, considering number of documents and four citation indicators at the species level (h-index, citation rate, total citations, and citations per year). Results: We retrieved 13 274 documents in Scopus and 12 913 in WoS. We found that Palearctic mammals have 3.77 times more documents than Neotropical species in Scopus (3.91 times in WoS), and that the documents recorded 5.95 more total citations in Scopus (6.93 times more in WoS). Palearctic documents also record more yearly citations and a higher h-index in both Scopus and WoS. Scopus retrieved more articles for Neotropical species (2 782 vs. 2 631 in WoS) and had more citations (28 120 vs. 24 977 in WoS); differences for the citation indicators between regions were marker in WoS. The h-index and total citations are greatly affected by how many studies are published, i.e. the region with more production is the one with higher values. The Neotropical articles showed a greater growth rate in the last decade, decreasing the gap between both regions. Conclusion: There is a regional bias in WoS and Scopus, which retrieve more articles and citations about Palearctic mammals than about Neotropical mammals; this bias is worse in WoS and means that an urgent increase in indexed research about Neotropical species is needed to be on par with Palearctic research.


Abramo, G., D’Angelo, C.A., & Di Costa, F. (2020). The role of geographical proximity in knowledge diffusion, measured by citations to scientific literature. Journal of Informetrics, 14, 101010. DOI: 10.1016/j.joi.2020.101010

Alberts, B. (2013). Impact factor distortions. Science, 340, 787. DOI: 10.1126/science.1240319

Allik, J., Lauk, K., & Realo, A. (2020). Factors Predicting the Scientific Wealth of Nations. Cross-Cultural Research, 54(4), 364-397. DOI: 10.1177/1069397120910982

Amori, G., & Gippoliti, S. (2000). What do mammalogists want to save? Ten years of mammalian conservation biology. Biodiversity and Conservation, 9, 785-793. DOI: 10.1023/A:1008971823774

Baquero, R.A., & Tellería, J.L. (2001). Species richness, rarity and endemicity of European mammals: A biogeographical approach. Biodiversity and Conservation, 10, 29-44. DOI: 10.1023/A:1016698921404

Borsuk, R.M., Budden, A.E., Leimu, R., Aarssen, L.W., & Lortie, C.J. (2009). The Influence of Author Gender, National Language and Number of Authors on Citation Rate in Ecology. The Open Ecology Journal, 2, 25-28. DOI: 10.2174/1874213000902010025

Brooke, Z.M., Bielby, J., Nambiar, K., & Carbone, C. (2014). Correlates of Research Effort in Carnivores: Body Size, Range Size and Diet Matter. PLoS ONE, 9, e93195. DOI: 10.1371/journal.pone.0093195

Cai, Z., Chang, Q., & Yip, P.S.F. (2020). A scientometric analysis of suicide research: 1990-2018. Journal of Affective Disorders, 266, 356-365. DOI: 10.1016/j.jad.2020.01.121

Chen, S.Y., Feng, Z., & Yi, X. (2017). A general introduction to adjustment for multiple comparisons. Journal of Thoracic Disease, 9, 1725-1729. DOI: 10.21037/jtd.2017.05.34

Chinchilla-Rodríguez, Z., Sugimoto, C.R., & Larivière, V. (2019). Follow the leader: On the relationship between leadership and scholarly impact in international collaborations. PLoS One, 14, e0218309. DOI: 10.1371/journal.pone.0218309

Christie, A.P., Amano, T., Martin, P.A., Petrovan, S.O., Shackelford, G.E., Simmons, B.I., Smith, R.K., Williams, D.R., Wordley, C.F.R., & Sutherland, W.J. (2020). The challenge of biased evidence in conservation. Conservation Biology, 0, 1-13. DOI: 10.1111/cobi.13577

Crespo-Gascón, S., Tortosa, F.S., & Guerrero-Casado, J. (2019). Producción de revistas científicas en América Latina y El Caribe en Scopus, Journal Citation Reports y Latindex en el área de los recursos naturales: su relación con variables económicas, ambientales y de inversión en investigación. Revista Española de Documentación Científica, 42, 224. DOI: 10.3989/redc.2019.1.1533

Dangles, O., Loirat, J., Freour, C., Serre, S., Vacher, J., & Le Roux, X. (2016). Research on Biodiversity and Climate Change at a Distance: Collaboration Networks between Europe and Latin America and the Caribbean. PLoS One, 11, e0157441. DOI: 10.1371/journal.pone.0157441

De Groote, S.L., & Raszewski, R. (2012). Coverage of Google Scholar, Scopus, and Web of Science: A case study of the h-index in nursing. Nursing Outlook, 60, 391-400. DOI: 10.1016/j.outlook.2012.04.007

Di Marco, M., Chapman, S., Althor, G., Kearney, S., Besancon, C., Butt, N., Maina, J., Possingham, H., von Bieberstein, K., Venter, O., & Watson, J.E.M. (2017). Changing trends and persisting biases in three decades of conservation science. Global Ecology and Conservation, 10, 32-42. DOI: 10.1016/j.gecco.2017.01.008

Di Rienzo, J.A., Casanoves, F., Balzarini, M.G., Gonzalez, L., Tablada, M., & Robledo, C.W. (2020). InfoStat (versión 2020). Universidad Nacional de Córdoba, Argentina. Recuperado de

Donaldson, M.R., Burnett, N.J., Braun, D.C., Suski, C.D., Hinch, S.G., Cooke, S.J., & Kerr, J.T. (2016). Taxonomic bias and international biodiversity conservation research. Facets, 1, 105-113. DOI: 10.1139/facets-2016-0011

dos Santos, J.W., Correia, R.A., Malhado, A.C.M., Campos-Silva, J.V., Teles, D., Jepson, P., & Ladle, R.J. (2020). Drivers of taxonomic bias in conservation research: a global analysis of terrestrial mammals. Animal Conservation (in press). DOI: 10.1111/acv.12586

Falagas, M.E., Pitsouni, E.I., Malietzis, G.A., & Pappas, G. (2008). Comparison of PubMed, Scopus, web of science, and Google scholar: strengths and weaknesses. The FASEB Journal, 22, 338-342. DOI: 10.1096/fj.07-9492LSF

Fleming, P.A., & Bateman, P.W. (2016). The good, the bad, and the ugly: which Australian terrestrial mammal species attract most research? Mammal Review, 46(4), 241-254. DOI: 10.1111/mam.12066

Guerrero-Casado, J. (2017). Producción científica latinoamericana indexada en Scopus en el área de las ciencias agropecuarias: Análisis del período 1996-2016. Idesia (Arica), 35, 27-33. DOI: 10.4067/S0718-34292017000400027

Hickisch, R., Hodgetts, T., Johnson, P.J., Sillero-Zubiri, C., Tockner, K., & Macdonald, D.W. (2019). Effects of publication bias on conservation planning. Conservation Biology, 33, 1151-1163. DOI: 10.1111/cobi.13326

Hirsch, J. E. (2005). An index to quantify an individual’s scientific research output. Proceedings of the National Academy of Sciences of the United States of America, 102(46), 16569-16572. DOI: 10.1073/pnas.0507655102

Holt, B.G., Lessard, J.P., Borregaard, M.K., Fritz, S.A., Araújo, M.B., Dimitrov, D., Fabre, P.H., Graham, C.H., Graves, G.R., Jønsson, K.A., Nogués-Bravo, D., Wang, Z., Whittaker, R.J., Fjeldså, J., & Rahbek, C. (2013). An update of Wallace’s zoogeographic regions of the world. Science, 339, 74-78. DOI: 10.1126/science.1228282

IUCN (2020). The IUCN Red List of Threatened Species (Base de datos). Recuperado de

Jarić, I., Roberts, D.L., Gessner, J., Solow, A.R., & Courchamp, F. (2017). Science responses to IUCN Red Listing. PeerJ, 2017(11), e4025. DOI: 10.7717/peerj.4025

King, D.A. (2004). The scientific impact of nations. Nature, 430, 311-316. DOI: 10.1038/430311a

Lawler, J.J., Aukema, J.E., Grant, J.B., Halpern, B.S., Kareiva, P., Nelson, C.R., Ohleth, K., Olden, J.D., Schlaepfer, M.A., Silliman, B.R., & Zaradic, P. (2006). Conservation science: a 20‐year report card. Frontiers in Ecology and the Environment, 4, 473-480.

Martin, L.J., Blossey, B., & Ellis, E. (2012). Mapping where ecologists work: biases in the global distribution of terrestrial ecological observations. Frontiers in Ecology and the Environment, 10, 195-201. DOI: 10.1890/110154

Martín-Martín, A., Orduna-Malea, E., Thelwall, M., & López-Cózar, E.D. (2018). Google Scholar, Web of Science, and Scopus: A systematic comparison of citations in 252 subject categories. Journal of Informetrics, 12(4), 1160-1177. DOI: 10.1016/j.joi.2018.09.002

Meho, L.I., & Sugimoto, C.R. (2009). Assessing the scholarly impact of information studies: A tale of two citation databases—Scopus and Web of Science. Journal of the American Society for Information Science and Technology, 60, 2499-2508. DOI: 10.1002/asi.21165

Meijaard, E., Cardillo, M., Meijaard, E.M., & Possingham, H.P. (2015). Geographic bias in citation rates of conservation research. Conservation Biology, 29(3), 920-925. DOI:

Monge-Nájera, J. (2014). La invalidez del Factor de Impacto como indicador del impacto de las revistas científicas latinoamericanas. Revista de Biología Tropical, 62, 407-412.

Monge-Nájera, J. (2017). The power of short lectures to improve support for biodiversity conservation of unpopular organisms: an experiment with worms. Cuadernos de Investigación UNED, 9(1), 145-150.

Monge-Nájera, J., & Ho, Y.S. (2018). Guatemala articles in the Science Citation Index Expanded: bibliometry of subjects, collaboration, institutions and authors. Revista de Biología Tropical, 66, 312-320. DOI: 10.15517/rbt.v66i1.29875

Mongeon, P., & Paul-Hus, A. (2016). The journal coverage of Web of Science and Scopus: a comparative analysis. Scientometrics, 106, 213-228. DOI: 10.1007/s11192-015-1765-5

Noguera-Urbano, E.A., & Escalante, T. (2017). The Neotropical region sensu the areas of endemism of terrestrial mammals. Australian Systematic Botany, 30, 470-484. DOI: 10.1071/SB16053

Padial, A.A., Nabout, J.C., Siqueira, T., Bini, L.M., & Diniz-Filho, J.A.F. (2010). Weak evidence for determinants of citation frequency in ecological articles. Scientometrics, 85, 1-12. DOI: 10.1007/s11192-010-0231-7

Pasterkamp, G., Rotmans, J.I., De Kleijn, D.V.P., & Borst, C. (2007). Citation frequency: A biased measure of research impact significantly influenced by the geographical origin of research articles. Scientometrics, 70, 153-165. DOI: 10.1007/s11192-007-0109-5

Prathap, G. (2017). Scientific wealth and inequality within nations. Scientometrics, 13, 923-928. DOI: 10.1007/s11192-017-2511-y

Pullin, A.S., Knight, T.M., Stone, D.A., & Charman, K. (2004). Do conservation managers use scientific evidence to support their decision-making? Biological Conservation, 119(2), 245-252. DOI: 10.1016/j.biocon.2003.11.007

Sitas, N., Baillie, J.E.M., & Isaac, N.J.B. (2009). What are we saving? Developing a standardized approach for conservation action. Animal Conservation, 12(3), 231-237. DOI: 10.1111/j.1469-1795.2009.00244.x

Sutherland, W.J., Taylor, N.G., MacFarlane, D., Amano, T., Christie, A.P., Dicks, L.V., Lemasson, A.J., Littlewood, N.A., Martin, P.A., Ockendon, N., Petrovan, S.O., Robertson, R.J., Rocha, R., Shackelford, G.E., Smith, R.K., Tyler, E.H.M., & Wordley, C.F.R. (2019). Building a tool to overcome barriers in research-implementation spaces: The conservation evidence database. Biological Conservation, 238, 108199. DOI: 10.1016/j.biocon.2019.108199

Reboredo, A.L., Romano, D., & Armsworth, P.R. (2020). Who studies where? Boosting tropical conservation research where it is most needed. Frontiers in Ecology and the Environment, fee.2146. DOI: 10.1002/fee.2146

Tahamtan, I., Afshar, A.S., & Ahamdzadeh, K. (2016). Factors affecting number of citations: a comprehensive review of the literature. Scientometrics, 107, 1195-1225. DOI: 10.1007/s11192-016-1889-2

Tydecks, L., Jeschke, J.M., Wolf, M., Singer, G., & Tockner, K. (2018). Spatial and topical imbalances in biodiversity research. PLOS ONE, 13(7), e0199327. DOI: 10.1371/journal.pone.0199327

Vieira, E.S., & Gomes, J.A. (2009). A comparison of Scopus and Web of Science for a typical university. Scientometrics, 81, 587. DOI: 10.1007/s11192-009-2178-0

Vinkler, P. (2018). Structure of the scientific research and science policy. Scientometrics, 114(2), 737-756. DOI: 10.1007/s11192-017-2568-7

Wen, Z., Cai, T., Feijó, A., Xia, L., Cheng, J., Ge, D., & Yang, Q. (2020). Using completeness and defaunation indices to understand nature reserve’s key attributes in preserving medium- and large-bodied mammals. Biological Conservation, 241, 108273. DOI: 10.1016/j.biocon.2019.108273

Wilson, K.A., Auerbach, N.A., Sam, K., Magini, A.G., Moss, A.S.L., Langhans, S.D., Budiharta, S., Terzano, D., & Meijaard, E. (2016). Conservation research is not happening where it is most needed. PLOS Biology, 14(3), e1002413. DOI: 10.1371/journal.pbio.1002413

Wouters, P., Sugimoto, C.R., Larivière, V., McVeigh, M.E., Pulverer, B., de Rijcke, S., & Waltman, L. (2019). Rethinking impact factors: better ways to judge a journal. Nature, 569, 621-623. DOI: 10.1038/d41586-019-01643-3



Download data is not yet available.