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Intrapopulation variation in the diet of franciscana dolphin (Pontoporia blainvillei) off southern Brazil

Published online by Cambridge University Press:  25 June 2021

Manuela Bassoi Open the ORCID record for Manuela Bassoi [Opens in a new window] ,
Eduardo R. Secchi ,
Daniel Danilewicz ,
Ignacio B. Moreno ,
Roberta A. Santos  and
John G. Shepherd
Manuela Bassoi*
Affiliation:
Laboratório de Ecologia e Conservação da Megafauna Marinha (EcoMega), Universidade Federal do Rio Grande-FURG, Avenida Italia km8 s/n, 96203-900, Rio Grande, RS, Brazil
Eduardo R. Secchi
Affiliation:
Laboratório de Ecologia e Conservação da Megafauna Marinha (EcoMega), Universidade Federal do Rio Grande-FURG, Avenida Italia km8 s/n, 96203-900, Rio Grande, RS, Brazil
Daniel Danilewicz
Affiliation:
Grupo de Estudos de Mamíferos Aquáticos (GEMARS), Rua Felipe Neri 382/203, 90440-150, Porto Alegre, RS, Brazil
Ignacio B. Moreno
Affiliation:
Centro de Estudos Costeiros, Limnológicos e Marinhos (CECLIMAR/UFRGS), Campus Litoral Norte, Universidade Federal do Rio Grande do Sul, Avenida Tramandaí, 976, 95625-000, Imbé, RS, Brazil Programa de Pós-Graduação em Biologia Animal, Departamento de Zoologia, Universidade Federal do Rio Grande do Sul, 91540-000, Porto Alegre, Brazil
Roberta A. Santos
Affiliation:
Instituto Chico Mendes de Conservação da Biodiversidade (ICMBio), Centro Nacional de Pesquisa e Conservação da Biodiversidade Marinha do Sudeste e Sul (CEPSUL), 88301-445, Itajaí, SC, Brazil
John G. Shepherd
Affiliation:
School of Ocean and Earth Science, National Oceanography Centre, Southampton SO14 3ZH, UK
*
Author for correspondence: Manuela Bassoi, E-mail: [email protected]
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Abstract

The franciscana dolphin (Pontoporia blainvillei) is a coastal dolphin endemic to the western South Atlantic Ocean. The dolphin is listed as vulnerable in the IUCN Red List, with incidental catches in gillnet fisheries the greatest conservation concern for this species. Insights into the feeding habits of this dolphin are essential to understand its distribution, movements and use of habitat, which are fundamental for effective management of the species. The feeding habits of franciscana dolphins were investigated from analyses of stomach contents of animals incidentally caught by two fishing operations from southern and northern regions of the southern Brazilian coast. In this study we investigate the existence of intrapopulation (sexual maturity and sex-related) variation in the diet of the franciscana dolphin, evaluating the spatial (northern and southern geographic areas) and seasonal influences. The analyses were based on Linear and Generalized Linear Models (LM and GLM). The majority of identified prey species were bottom-dwelling teleosts and the squid Doryteuthis sanpaulensis. The most important prey differed spatially and seasonally between northern and southern regions of the study area, and our results revealed significant differences between sexes and sexual maturity stages, mainly related to prey species sizes. This variation might indicate differences in prey selection, availability or habitat use patterns among these groups. In any case, these dietary differences are likely to minimize intraspecific competition for food resources, and/or indicate spatio-temporal variation in prey availability.

Keywords

Feeding ecologyLa Plata river dolphinstomach contentsWestern South Atlantic
Type
Research Article
Information
Journal of the Marine Biological Association of the United Kingdom , Volume 101 , Issue 3 , May 2021 , pp. 621 - 637
Copyright
Copyright © The Author(s), 2021. Published by Cambridge University Press on behalf of Marine Biological Association of the United Kingdom

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References

Amaral, KB, Danilewicz, D, Zerbini, A, Di Beneditto, AP, Andriolo, A, Alvares, DJ, Secchi, E, Ferreira, E, Sucunza, F, Borges-Martins, M and de Oliveira Santos, MC (2018) Reassessment of the franciscana Pontoporia blainvillei (Gervais & d'Orbigny, 1844) distribution and niche characteristics in Brazil. Journal of Experimental Marine Biology and Ecology 508, 1–12.CrossRefGoogle Scholar
Andriguetto, JM Jr and Haimovici, M (1991) Abundance and distribution of Loligo sanpaulensis Brakoniecki, 1984 (Cephalopoda, Loliginidae) in southern Brazil. Scientia Marina 55, 611–618.Google Scholar
Barros, NB and Wells, RS (1998) Prey and feeding patterns of resident bottlenose dolphins (Tursiops truncatus) in Sarasota Bay, Florida. Journal of Mammalogy 79, 1045–1059.CrossRefGoogle Scholar
Bassoi, M (1997) Feeding of Franciscana, Pontoporia blainvillei (Gervais & D'Orbigny, 1844), Accidentally Caught in Coastal Gillneting in Southern Brazil (Graduation dissertation). Universidade do Rio Grande, Rio Grande, Brazil.Google Scholar
Bassoi, M and Secchi, ER (2000) Temporal variation in the diet of franciscana Pontoporia blainvillei (Cetacea, Pontoporiidae) as a consequence of fish stocks depletion off southern Brazil. IV Workshop para a Coordenação da Pesquisa e Conservação da Franciscana, Pontoporia blainvillei, no Atlântico Sul Ocidental, Brazil.Google Scholar
Bassoi, M, Shepherd, JG, Secchi, ER, Moreno, IB and Danilewicz, D (2020) Oceanographic processes driving the feeding ecology of franciscana dolphin off Southern Brazilian coast. Continental Shelf Research 201, 104124.CrossRefGoogle Scholar
Bastida, R, Rodríguez, D, Moreno, V, Pérez, A, Marcovecchio, J and Gerpe, M (1992) Varamientos de pequeños cetáceos durante el período 1984–1988 en el área de Mar del Plata (Provincia de Buenos Aires, Argentina). Anales III Reunión de Trabajo de Especialistas en Mamíferos Marinos Acuáticos de América del Sur. Montevideo.Google Scholar
Bearhop, S, Adams, CE, Waldron, S, Fuller, RA and MacLeod, H (2004) Determining trophic niche width: a novel approach using stable isotope analysis. Journal of Animal Ecology 73, 1007–1012.CrossRefGoogle Scholar
Bittar, VT and Di Benedito, APM (2009) Diet and potential feeding overlap between Trichiurus lepturus (Osteichthyes: Perciformes) and Pontoporia blainvillei (Mammalia: Cetacea) in northern Rio de Janeiro, Brazil. Zoologia 26, 374–378.CrossRefGoogle Scholar
Boffo, MS and Reis, EG (2003) Atividade pesqueira da frota de média escala no extremo sul do Brasil. Atlântica 25, 171–178.Google Scholar
Bordino, P, Siciliano, S, Bastida, R and Cremer, M (2002) Report of the working group on distribution and behavior. Latin American Journal of Aquatic Mammals 1, 21–23.CrossRefGoogle Scholar
Bordino, P, Wells, RS and Stamper, MA (2008) Satellite tracking of franciscana dolphins Pontoporia blainvillei in Argentina: preliminary information on ranging, diving and social patterns. In International Whaling Commission Scientific Committee Meeting SC60/SM14.Google Scholar
Botta, S, Secchi, ER, Muelbert, MM, Danilewicz, D, Negri, MF, Cappozzo, HL and Hohn, A (2010) Age and growth of franciscana dolphins, Pontoporia blainvillei (Cetacea: Pontoporiidae) incidentally caught off southern Brazil and northern Argentina. Journal of the Marine Biological Association of the United Kingdom 90, 1493–1500.CrossRefGoogle Scholar
Brownell, RL Jr (1975) Progress report on the biology of the franciscana dolphin, Pontoporia blainvillei, in Uruguayan waters. Journal of the Fisheries Board of Canada 32, 1073–1078.CrossRefGoogle Scholar
Campos, LB, Lopes, XM, da Silva, E and Santos, MCO (2020) Feeding habits of the franciscana dolphin (Pontoporia blainvillei) in south-eastern Brazil. Journal of the Marine Biological Association of the United Kingdom 100, 301–313.CrossRefGoogle Scholar
Caon, G and Kucharski, LCR (2000) Dados preliminares sobre a análise das reservas energéticas em Franciscanas (Pontoporia blainvillei) no litoral norte do Rio Grande do Sul. IV Workshop para a Coordenação da Pesquisa e Conservação da Franciscana, Pontoporia blainvillei, no Atlântico Sul Ocidental, Brazil.Google Scholar
Capítoli, RR (1997) Continental shelf benthos. In Seeliger UB, Odebrecht C and Castello JP (eds), Subtropical Convergence Environments: The Coast and Sea in the Southwestern Atlantic. Berlin: Springer, pp. 117–123.Google Scholar
Clarke, MR (1997) The role of cephalopods in the world's oceans. Oceanographic Literature Review 4, 353.Google Scholar
Crawley, MJ (2012) The R Book. Chichester: Wiley.CrossRefGoogle Scholar
Cremer, MJ, Pinheiro, PC and Simões-Lopes, PC (2012) Prey consumed by Guiana dolphin Sotalia guianensis (Cetacea, Delphinidae) and franciscana dolphin Pontoporia blainvillei (Cetacea, Pontoporiidae) in an estuarine environment in southern Brazil. Iheringia. Série Zoologia 102, 131–137.CrossRefGoogle Scholar
Crespo, EA (2009) Franciscana Pontoporia blainvillei. In Perrin, WF, Würsig, B and Thewissen, JGM (eds), Encyclopedia of Marine Mammals, 2nd Edn. Amsterdam: Elsevier, pp. 466–469.CrossRefGoogle Scholar
Crespo, EA, Harris, G and Gonzalez, R (1998) Group size and distributional range of the franciscana, Pontoporia blainvillei. Marine Mammal Science 14, 845–848.CrossRefGoogle Scholar
Crespo, EA, Pedraza, SN, Grandi, MF, Dans, SL and Garaffo, GV (2010) Abundance and distribution of endangered franciscana dolphins in Argentine waters and conservation implications. Marine Mammal Science 26, 17–35.CrossRefGoogle Scholar
Dall, WH, Hill, BJ, Rothlisberg, PC and Sharples, DJ (1990) Predation on penaeids. In Blaxter JHS and Southward AJ (eds), Advances in Marine Biology: The Biology of the Penaeidae, vol. 27. London: Academic Press, pp. 357–377.Google Scholar
Danilewicz, DS, Secchi, ER, Ott, PH and Moreno, IM (2000) Analysis of the age at sexual maturity and reproductive rates of franciscana (Pontoporia blainvillei) from Rio Grande do Sul, southern Brazil. Comunicações do Museu de Ciências e Tecnologia, PUCRS 13, 89–98.Google Scholar
Danilewicz, D, Rosas, F, Bastida, R, Marigo, J, Muelbert, M, Rodríguez, D, Lailson-Brito, J, Ruoppolo, V, Ramos, R, Bassoi, M, Ott, PH, Caon, G, Da Rocha, AM, Catão-Dias, JL and Secchi, ER (2002) Report of the working group on biology and ecology. Latin American Journal of Aquatic Mammals 1, 25–42.CrossRefGoogle Scholar
Danilewicz, D, Zerbini, A, Andriolo, A, Secchi, ER, Sucunza, F, Ferreira, E, Denuncio, P and Flores, PAC (2012) Abundance and distribution of an isolated population of franciscana dolphins (Pontoporia blainvillei) in southeastern Brazil: red alert for FMA I? International Whaling Commission Working Paper SC/64/SM17.Google Scholar
Denuncio, P, Viola, MN, Machovsky-Capuska, GE, Raubenheimer, D, Blasina, G, Machado, R, Polizzi, P, Gerpe, M, Cappozzo, HL and Rodriguez, DH (2017) Population variance in prey, diets and their macronutrient composition in an endangered marine predator, the Franciscana dolphin. Journal of Sea Research 129, 70–79.CrossRefGoogle Scholar
Di Beneditto, APM (2000) Ecologia Alimentar de Pontoporia blainvillei e Sotalia fluviatilis (Cetacea) na Costa Norte do Estado do Rio de Janeiro, Brasil (Doctoral dissertation). Universidade Estadual Norte Fluminense, Campo dos Goytacazes, Brazil.Google Scholar
Di Beneditto, APM, dos Santos, MVB and Vidal, MV (2009) Comparison between the diet of two dolphins from south-eastern Brazil: proximate-composition and caloric value of prey species. Journal of the Marine Biological Association of the United Kingdom 89, 903–905.CrossRefGoogle Scholar
Frainer, G, Huggenberger, S and Moreno, IB (2015) Postnatal development of franciscana's (Pontoporia blainvillei) biosonar relevant structures with potential implications for function, life history, and bycatch. Marine Mammal Science 31, 1193–1212.CrossRefGoogle Scholar
Gomez, JJ and Cassini, MH (2015) Environmental predictors of habitat suitability and biogeographical range of franciscana dolphins (Pontoporia blainvillei). Global Ecology and Conservation 1, 90–99.CrossRefGoogle Scholar
Graphen, A and Hails, R (2002) Modern Statistics for the Life Sciences. Oxford: Oxford University Press.Google Scholar
Haimovici, M (1997 a) Demersal fisheries off south Brazilian region. Technical report, Environmental Ministery (MMA) and Interdisciplinary Commission for Sea Resources.Google Scholar
Haimovici, M (1997 b) Cephalopods. In Subtropical Convergence Environments: The Coast and Sea in the Southwestern Atlantic. Berlin: Springer, p. 308.Google Scholar
Haimovici, M and Perez, J (1991) Coastal cephalopod fauna of southern Brazil. Bulletin of Marine Science 49, 221–230.Google Scholar
Haimovici, M, Martins, AS and Vieira, PC (1996) Distribuição e abundância de peixes teleósteos demersais sobre a plataforma continental do sul do Brasil. Revista Brasileira de Biologia 56, 27–50.Google Scholar
Henning, B, de Sa Carvalho, B, Pires, MM, Bassoi, M, Marigo, J, Bertozzi, C and Araújo, MS (2017) Geographical and intrapopulation variation in the diet of a threatened marine predator, Pontoporia blainvillei (Cetacea). Biotropica 50, 157–168.CrossRefGoogle Scholar
Hin, V, Harwood, J and de Roos, AM (2019) Bio-energetic modeling of medium-sized cetaceans shows high sensitivity to disturbance in seasons of low resource supply. Ecological Applications 29, e01903.CrossRefGoogle ScholarPubMed
Keast, A (1977) Mechanisms expanding niche width and minimizing intraspecific competition in two centrarchid fishes. Evolutionary Biology 10, 333–395.Google Scholar
Kindt, R and Coe, R (2005) Tree Diversity Analysis. A Manual and Software for Common Statistical Methods and Biodiversity Studies. Nairobi: World Agroforestry Centre, ICRAF.Google Scholar
Machado, R, de Oliveira, LR, Ott, PH, Haimovici, M, Cardoso, LG, Milmann, L, Romero, MA, dos Santos, RA and Borges-Martins, M (2020) Trophic overlap between marine mammals and fisheries in subtropical waters in the western South Atlantic. Marine Ecology Progress Series 639, 215–232.CrossRefGoogle Scholar
Maiorana, VC (1978) An explanation of ecological and developmental constants. Nature 273, 375–377.CrossRefGoogle Scholar
Martins, AS and Haimovici, M (1997) Distribution, abundance and biological interactions of the cutlassfish Trichiurus lepturus in the southern Brazil subtropical convergence ecosystem. Fisheries Research 30, 217–227.CrossRefGoogle Scholar
Martins, AS and Haimovici, M (2016) Seasonal mesoscale shifts of demersal nekton assemblages in the subtropical South-western Atlantic. Marine Biology Research 13, 88–97.CrossRefGoogle Scholar
McCabe, EJB, Gannon, DP, Barros, NB and Wells, RS (2010) Prey selection by resident common bottlenose dolphins (Tursiops truncatus) in Sarasota Bay, Florida. Marine Biology 157, 931–942.CrossRefGoogle Scholar
Möller, OO, Piola, AR, Freitas, AC and Campos, EJD (2008) The effects of river discharge and seasonal winds on the shelf off southeastern South America. Continental Shelf Research 28, 1607–1624.CrossRefGoogle Scholar
Moreno, IB, Ott, PH and Danilewicz, DS (1997) Análise preliminar do impacto da pesca artesanal costeira sobre Pontoporia blainvillei no litoral norte do Rio Grande do Sul, sul do Brasil. Proceedings of the Second Workshop for the Research Coordination and Conservation of the Franciscana (Pontoporia blainvillei) in the Southwestern Atlantic, Florianópolis, Brazil.Google Scholar
Moreno, IB, Tavares, M, Danilewicz, D, Ott, PH and Machado, R (2018) Descrição da pesca costeira de média escala no litoral norte do Rio Grande do Sul: comunidades pesqueiras de Imbé/Tramandaí e Passo de Torres/Torres. Boletim do Instituto de Pesca 35, 129–140.Google Scholar
Nikolsky, G (1963) The Ecology of Fishes. London: Academic Press.Google Scholar
Oksanen, J, Blanchet, FG, Friendly, M, Kindt, R, Legendre, P, McGlinn, D, Minchin, PR, O'Hara, RB, Simpson, GL, Solymos, P, Stevens, MHH, Szoecs, E and Wagner, H (2019) Community Ecology Package. Package “Vegan”. R Core Team.Google Scholar
Oliveira, MR, Pinheiro, PC and Rosas, FCW (1998) Ecologia alimentar de Sotalia fluviatilis e Pontoporia blainvillei acidentalmente capturados no litoral do Paraná. In VIII Reunião de Trabalhos de Especialistas em Mamíferos Aquáticos da América do Sul, Recife, Brazil.Google Scholar
Ott, PH (1994) Estudo da ecologia alimentar de Pontoporia blainvillei (Gervais & D'Orbigny, 1844) (Cetacea, Pontoporiidae) no litoral norte do Rio Grande do Sul, sul do Brasil (Graduation dissertation). Universidade do Rio Grande do Sul, Porto Alegre, Brazil.Google Scholar
Paso-Viola, MN, Denuncio, P, Negri, MF, Rodríguez, D, Bastida, R and Cappozzo, HL (2014) Diet composition of franciscana dolphin Pontoporia blainvillei from southern Buenos Aires, Argentina and its interaction with fisheries. Revista de Biología Marina y Oceanografía 49 393–400. http://dx.doi.org/10.4067/S0718-19572014000200019.CrossRefGoogle Scholar
Phillips, RA, Silk, JRD, Phalan, B, Catry, P and Croxall, JP (2004) Seasonal sexual segregation in two Thalassarche albatross species: competitive exclusion, reproductive role specialization or foraging niche divergence? Proceedings of the Royal Society of London. Series B: Biological Sciences 271, 1283–1291.CrossRefGoogle ScholarPubMed
Pinedo, MC (1982) Análise dos conteúdos estomacais de Pontoporia blainvillei (Gervais e D'Orbigny, 1844) e Tursiops gephyreus (Lahille, 1908) (Cetacea, Platanistidae e Delphinidae) na zona estuarial e costeira de Rio Grande, Brasil (Master's thesis). Universidade do Rio Grande, Rio Grande, Brazil.Google Scholar
Pinedo, MC, Praderi, R and Brownell, RLJ (1989) Biology and Conservation of the River Dolphins, Chapter Review of the Biology and Status of the franciscana Pontoporia blainvillei (Gervais e D'Orbigny, 1844). IUCN Species Survival Commission, Occasional Paper No. 5.Google Scholar
Pinkas, L, Oliphant, MS and Iverson, ILK (1971) Food habitats of albacore, bluefin tuna and bonito in Californian waters. California Fish Game 152, 1–105.Google Scholar
Pio, VM, Pezzuto, PR and Wahrlich, R (2016) Only two fisheries? Characteristics of the industrial bottom gillnet fisheries in southeastern and southern Brazil and their implications for management. Latin American Journal of Aquatic Research 44, 882–898.Google Scholar
Piola, AR, Campos, EJD, Möller, OO, Charo, M and Martinez, C (2000) Subtropical shelf front off eastern South America. Journal of Geometry and Physics 105, 2156–2202.Google Scholar
Polis, GA (1984) Age structure component of niche width and intraspecific resource partitioning: can age groups function as ecological species? American Naturalist 123, 541–564.CrossRefGoogle Scholar
Prado, JHF, Kinas, PG and Secchi, ER (2013) Mark-recapture of the endangered franciscana dolphin (Pontoporia blainvillei) killed in gillnet fisheries to estimate past bycatch from time series of stranded carcasses in southern Brazil. Ecological Indicators 32, 35–41.CrossRefGoogle Scholar
Prado, JHF, Mattos, PH, Silva, KG and Secchi, ER (2016) Long-term seasonal and interannual patterns of marine mammal strandings in subtropical eastern South Atlantic. PLoS ONE 11, e0146339.CrossRefGoogle Scholar
Prado, JHF, Kinas, PG, Pennino, MG, Seyboth, E, Silveira, FRG, Ferreira, EC and Secchi, ER (2021) Definition of no-fishing zones and fishing effort limits to reduce franciscana bycatch to sustainable levels in southern Brazil. Animal Conservation. doi: 10.1111/acv.12679CrossRefGoogle Scholar
Rivero, L, Bastida, R and Rodriguez, D (2000) Ecologia trófica de la franciscana (Pontoporia blainvillei) en areas estuariales y marinas del norte de Argentina. IV Workshop para a Coordenação da Pesquisa e Conservação da Franciscana, Pontoporia blainvillei, no Atlântico Sul Ocidental, Brazil.Google Scholar
Rodríguez, D, Rivero, L and Bastida, R (2002) Feeding ecology of the franciscana (Pontoporia blainvillei) in marine and estuarine waters of Argentina. Latin American Journal of Aquatic Mammals 1, 77–94.CrossRefGoogle Scholar
Rupil, GM, Barbosa, L, Marcondes, MCC, de Carvalho, BM and Farro, APC (2019) Franciscana dolphin (Pontoporia blainvillei) diet from Northern Espírito Santo State coast, Brazil. Revista Biotemas 32, 2.Google Scholar
Santos, RA (1999) Cefalópodes nas relações tróficas do sul do Brasil (Doctoral dissertation). Universidade do Rio Grande, Rio Grande, Brazil.Google Scholar
Santos, RA and Haimovici, M (2001) Cephalopods in the diet of marine mammals stranded or incidentally caught along southeastern and southern Brazil (21–34oS). Fisheries Research 52, 99–112.CrossRefGoogle Scholar
Secchi, ER (2010) Life history and ecology of franciscana, Pontoporia blainvillei (Cetacea, Pontoporiidae). In Ruiz Garcia, M and Shostell, JM (eds), Biology, Evolution and Conservation of River Dolphins Within South America and Asia. Wildlife Protection, Destruction and Extinction Series. Hauppange: Nova Science Publishers, pp. 301–321.Google Scholar
Secchi, ER (2014) Family Pontoporiidae (franciscana). In Wilson, DE and Mittermeier, RA (eds), Handbook of the Mammals of the World, vol. 4. Sea Mammals. Barcelona: Lynx Edicions, pp. 386–393.Google Scholar
Secchi, ER and Fletcher, D (2004) Estimating survival rates of franciscana by fitting the Siler model to data on age-at death of beachcast and bycatch and by a modeling approach using life tables of similar species: a comparison. International Whaling Commission Scientific Committee Paper SC/56/SM16.Google Scholar
Secchi, ER, Danilewicz, D and Ott, PH (2003) Applying the phylogeographic concept to identify franciscana dolphin stocks: implications to meet management objectives. Journal of Cetacean Research Management 5, 61–68.Google Scholar
Shine, R (1989) Ecological causes for the evolution of sexual dimorphism: a review of the evidence. Quarterly Review of Biology 64, 419–461.CrossRefGoogle Scholar
Siciliano, S, Di Beneditto, AP and Ramos, R (2002) A toninha, Pontoporia blainvillei (Gervais & d'Orbigny, 1844) (Mammalia, Cetacea, Pontoporidae), nos estados do Rio de Janeiro e Espírito Santo, costa sudeste do Brasil: caracterização dos hábitats e fatores de isolamento das populações. Boletim do Museu Nacional 476, 1–15.Google Scholar
Smith, RJ and Read, AJ (1992) Consumption of euphasiids by harbour porpoise (Phocoena phocoena) calves in the Bay of Fundy. Canadian Journal of Zoology 70, 629–632.CrossRefGoogle Scholar
Teixeira, CR, Botta, S, Daura-Jorge, FG, Pereira, LB, Newsome, SD and Simões-Lopes, PC (2020) Niche overlap and diet composition of three sympatric coastal dolphin species in the southwest Atlantic Ocean. Marine Mammal Science 37, 111–126.CrossRefGoogle Scholar
Tellechea, JS, Perez, W, Olsson, D, Lima, M and Norbis, W (2017) Feeding habits of franciscana dolphins (Pontoporia blainvillei): echolocation or passive listening? Aquatic Mammals 43, 440–448.CrossRefGoogle Scholar
Troina, G, Botta, S, Secchi, ER and Dehairs, F (2016) Ontogenetic and sexual characterization of the feeding habits of franciscanas, Pontoporia blainvillei, based on tooth dentin carbon and nitrogen stable isotopes. Marine Mammal Science 32, 1115–1137.CrossRefGoogle Scholar
Venables, WN and Dichmont, CM (2004) GLMs, GAMs and GLMMs: an overview of theory for applications in fisheries research. Fisheries Research 70, 319–337.CrossRefGoogle Scholar
Wrona, FJ, Davies, RW and Linton, L (1979) Analysis of the food niche of Glossiphonia complanata (Hirudinoidea: Glossiphoniidae). Canadian Journal of Zoology 57, 2136–2142.CrossRefGoogle Scholar
Zerbini, AN, Secchi, ER, Crespo, EA, Danilewicz, D and Reeves, R (2017) Pontoporia blainvillei (errata version published in 2018). The IUCN Red List of Threatened Species 2017: e.T17978A123792204. doi: https://dx.doi.org/10.2305/IUCN.UK.2017-3.RLTS.T17978A50371075.en.CrossRefGoogle Scholar