[MARMAM] New publication on South American fur seals individual variation in habitat and resource use
On behalf of my co-authors, I am pleased to announce the publication of our research article "Individual foraging specialization and sexual niche segregation in South American fur seals". Lima, R.C., Franco-Trecu, V., Vales, D.G., Inchausti, P., Secchi, E.R., and Botta, S. Individual foraging specialization and sexual niche segregation in South American fur seals. https://doi.org/10.1007/s00227-019-3480-x Abstract Individual variation in habitat and resource use has been reported for many top predators. This variation becomes important when comparing individuals taking into account sex, size, or age classes, since it can influence population dynamics and stability. We evaluated the individual variation and sexual/geographical isotopic niche overlap of the South American fur seal (SAFS) from the western South Atlantic. Whiskers of adult individuals from Brazil (n = 19), Uruguay (n = 29), and Argentina (n = 5) collected between 2005 and 2016 were serially sampled, resulting in 1001 samples, and their carbon and nitrogen isotopic ratios were analyzed longitudinally. According to its length, time integrated by whiskers ranged between 1.4 and 5.6 years. Males had δ13C (− 14.5 ± 0.6‰) and δ15N (18.9 ± 1.2‰) values significantly higher than females (δ13C = − 15.2 ± 0.5‰, δ15N = 17.8 ± 1.2‰). Females from Uruguay and Brazil were isotopically similar, displaying a large isotopic niche overlap (65.2–84%). Contrary, moderate isotopic niche overlaps were observed between males from Uruguay and Brazil (40.1–48.4%), and Uruguay and Patagonia (22.3–27.8%), indicating the use of different prey and/or feeding grounds. The WIC/TNW index of individual specialization pointed a significant specialization in males (0.38 for δ15N and 0.39 for δ13C). Females, on the other hand, are more generalists compared to males (0.53 and 0.71, for δ15N and δ13C, respectively). Differences in the ecological opportunity between sexes can account for these variations. Our study points out that trophic generalist populations of SAFS are composed of specialist and generalist individuals. The article is available in: https://link.springer.com/article/10.1007%2Fs00227-019-3480-x You can also request a free pdf copy in my e-mail: renan...@gmail.com Best regards, Renan --- MSc Renan Costa de Lima Doutorando do Programa de Pós-Graduação em Oceanografia Biológica Laboratório de Ecologia e Conservação da Megafauna Marinha - EcoMega Instituto de Oceanografia Universidade Federal do Rio Grande (FURG) Fone: (53) 99718994 ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] New publication on dolphins mixed-species associations in Brazil
On behalf of my co-authors, I am pleased to announce the publication of our new research article on the current issue of Aquatic Mammals: Lima, RC, Di Tullio JC, Secchi ER, Castro FR, and Troina, GC. Delphinid mixed-species associations in the oceanic waters of the Western South Atlantic. https://doi.org/10.1578/AM.47.1.2021.53 Abstract Dolphins are highly social animals usually reported in large groups comprised of individuals of a single species, although they are often reported associating with other species as well. The drivers for the formation of these mixed-species associations (MSAs) are poorly understood, and records in Brazilian waters are scarce. To better understand their occurrence in the region, we assessed seasonal and spatial distribution of MSAs in waters over the outer continental shelf and slope off Brazil (22 to 33° S). Data were collected during spring and autumn between 2009 and 2014. >From a total of 187 Delphinidae sightings, 28 consisted of MSAs. Tursiops truncatus was the most frequently sighted species in an MSA (n = 22 sightings) and was mostly found in lower numbers than its associated counterparts: Globicephala melas, Stenella frontalis, Grampus griseus, and Pseudorca crassidens. MSAs between Stenella attenuata and Stenella longirostris or Delphinus delphis and S. frontalis were also reported. Our data did not show any seasonal or spatial trends in overall MSA frequency; nevertheless, the widely distributed T. truncatus appears to shift its associates according to their local abundance (e.g., associating with G. melas in the southern region of the study area and with S. frontalis in the southeastern region). Although a lot remains to be investigated regarding the ecological drivers for such associations between sympatric dolphins in Brazilian waters, this was the first effort to describe their occurrence and distribution patterns using cetacean dedicated surveys. The article is available at https://www.aquaticmammalsjournal.org/index.php?option=com_content&view=article&id=2114:delphinid-mixed-species-associations-in-the-oceanic-waters-of-the-western-south-atlantic&catid=199&Itemid=326 Please feel free to contact me via email (renan...@gmail.com) for any questions or a pdf copy of the paper. Best regards, Renan Lima -- MSc Renan Costa de Lima Doutorando do Programa de Pós-Graduação em Oceanografia Biológica Laboratório de Ecologia e Conservação da Megafauna Marinha - EcoMega Instituto de Oceanografia Universidade Federal do Rio Grande (FURG) Fone: +55(53)99718994 ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] New publication on foraging ecology of South American fur seals
Dear MARMAM community, On behalf of my co-authors, I am pleased to announce that our newest paper in Aquatic Ecology is now online: "Segregation of diets by sex and individual in South American fur seals" RC de Lima, V Franco-Trecu, TS Carrasco, P Inchausti, ER Secchi, S Botta https://link.springer.com/article/10.1007/s10452-021-09915-9 Abstract Trophic niche width and individual specialization among marine predators are often subjected to seasonal constraints. Differences are expected to arise for sexually dimorphic species exposed to distinct ecological opportunities, as well as intrinsic differences in physiological abilities or energetic requirements. We assess seasonal and sexual differences in isotopic niche overlap and width and analyze inter-individual foraging variation throughout the year of the South American fur seal (Arctocephalus australis). We obtained chronologically ordered δ13C and δ15N data from vibrissae of 25 males and 24 females from southern Brazil and Uruguay. There were significant differences between sexes for both isotopes with males showing higher values (δ13C = − 14.5 ± 0.5‰; δ15N = 18.9 ± 1.2‰) than females (δ13C = − 15.2 ± 0.5‰; δ15N = 17.8 ± 1.2‰), but not among seasons or years. A very small isotopic niche overlap found between sexes (1.1–9.5%), with limited seasonal variation, likely resulted from differences in prey consumption and foraging habitats. Compared to other seasons, females had a wider isotopic niche in spring. While males showed seasonal stability in the foraging niche, females showed some small variation, which is probably influenced by central place foraging. Both sexes had considerable interindividual variation in estimated dietary composition and had different proportions of potential prey contribution at the population level. These findings enlighten the knowledge of South American fur seal trophic ecology, and how they may seasonally and spatially shift their foraging strategies according to their distinct life histories. It ultimately reflects in a small niche partitioning and possibly low intraspecific competition at the species northernmost area of occurrence in the western South Atlantic. Please feel free to contact me via email (renan...@gmail.com) for any questions or a pdf copy of the paper. Best regards, Renan Lima -- MSc Renan Costa de Lima Doutorando do Programa de Pós-Graduação em Oceanografia Biológica Laboratório de Ecologia e Conservação da Megafauna Marinha - EcoMega Instituto de Oceanografia Universidade Federal do Rio Grande (FURG) Fone: +55(53)99718994 ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] New paper: Ecosystem shifts inferred from Antarctic fur seals stable isotopes
Dear MARMAM community, On behalf of my coauthors, I'm happy to share our new paper: "Ecosystem shifts inferred from long-term stable isotope analysis of male Antarctic fur seal *Arctocephalus gazella* teeth" which was recently published in the Marine Ecology Progress Series. de Lima RC, Cebuhar JD, Negrete J, Ferreira A, Secchi ER, Botta S (2022) Ecosystem shifts inferred from long-term stable isotope analysis of male Antarctic fur seal *Arctocephalus gazella* teeth. Mar Ecol Prog Ser 695:203-216. https://doi.org/10.3354/meps14112 ABSTRACT: The Atlantic sector of the Southern Ocean has been rapidly changing over the last century. Many of those changes are driven by climate anomalies such as the El Niño−Southern Oscillation and the Southern Annular Mode, which affect biological processes that scale up the food web. We used δ13C and δ15N time series of dentine growth layer groups (as a proxy of individual foraging history from multiple years, n = 41 teeth) to assess temporal shifts in foraging habits of subadult/adult male Antarctic fur seals *Arctocephalus gazella* (AFSs) in 2 areas of high concentration of Antarctic krill *Euphausia superba*: the South Shetland Islands and the South Orkney Islands. Our analyses, which represent the first long-term isotopic assessment of male AFS sampled in Antarctic waters, revealed a significant decrease of δ13C (0.04‰ yr−1) from 1974 to 2015 and a decrease of δ15N after the late 1990s. The observed changes are likely driven by shifts in latitudinal and longitudinal distribution of krill and increased incorporation of 15Nenriched sources (higher trophic level prey and/or feeding in different areas) in the most recent period for reasons that are not yet clear. We were able to trace ecosystem changes through isotopic bio-archives of Antarctic fur seals, highlighting the role of this species as an ecosystem indicator of the trophic cascade effects caused by climate change in the Southern Ocean. <https://doi.org/10.3354/meps14112>Please contact me (renan...@gmail.com) for a copy or any questions. Kind regards Renan Lima --- *Renan Costa de Lima, MSc* Doutorando do Programa de Pós-Graduação em Oceanografia Biológica Laboratório de Ecologia e Conservação da Megafauna Marinha - EcoMega Instituto de Oceanografia Universidade Federal do Rio Grande (FURG) COMNAP Antarctic Fellow 2021 Fone: +55(53)99718994 | e-mail: renan...@gmail.com www.researchgate.net/profile/Renan-Lima-2 ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] Short Note: South American sea lion twins
Dear MARMAM community, On behalf of my coauthors, I'm happy to share our new research note reporting a rare case of twinning in South American sea lions: Lima RC, Cebuhar J, Martí L, Franco-Trecu V, Oliveira L, Botta S (2022) FIRST RECORD OF TWIN FETUSES OF SOUTH AMERICAN SEA LION ON THE SOUTHERN BRAZILIAN COAST. Oecologia Australis, vol. 26, no 3, https://doi.org/10.4257/oeco.2022.2603.09 Abstract: We report the first known occurrence of South American sea lion (Otaria flavescens) twins on the South American coast. In January 2021 a female pregnant with dizygotic male and female fetuses was found dead in southern Brazil. The timing of the stranding event suggests that the pregnancy was near-term. However, the total body length and weight of fetuses suggested poor development and growth, which could be due to the advanced age of the mother and/or poor nutrition of the individual during pregnancy. The female fetus was larger and heavier than the male and could have been implanted and developed earlier. The note is open access and is available on the following link: https://revistas.ufrj.br/index.php/oa/article/view/45742 Best regards, Renan Lima --- *Renan Costa de Lima, MSc* Doutorando do Programa de Pós-Graduação em Oceanografia Biológica Laboratório de Ecologia e Conservação da Megafauna Marinha - EcoMega Instituto de Oceanografia Universidade Federal do Rio Grande (FURG) COMNAP Antarctic Fellow 2021 Fone: +55(53)99718994 | e-mail: renan...@gmail.com www.researchgate.net/profile/Renan-Lima-2 ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] New paper on fur seals' feeding habits in the South Atlantic
Dear MARMAM community, On behalf of my co-authors, I'm pleased to announce the publication of our new paper in Marine Mammal Science: Feeding habits of South American and sub-Antarctic fur seals during their nonbreeding season in the southwestern Atlantic Ocean de Lima RC, de Albernaz TL, ER Secchi, JD Cebuhar, S Botta https://onlinelibrary.wiley.com/doi/abs/10./mms.13049 Abstract: Stomach contents of South American (*Arctocephalus australis*) (n = 219) (SAFS) and sub-Antarctic (*A. tropicalis*) (n = 37) (SFS) fur seals were opportunistically sampled from 1980 to 2021 to examine their feeding habits and resource partitioning in southern Brazil while in their nonreproductive periods. SAFSs mainly consumed abundant coastal pelagic species, such as Anchoa marinii and *Doryteuthis sanpaulensis*, resulting in high sexual trophic niche overlap. The frequency of occurrence (%FO) of fish prey, especially the overexploited *Micropogonias furnieri*, decreased between 1980–1992 and 2007–2021, while squid increased. For SFSs, offshore squids such as *Ommastrephes bartramii* and *Illex argentinus* were the most important prey considering both sexes in the long-term. The interspecific trophic niche overlap was low, but it is likely underestimated since it increased with the inclusion of scat samples from SFSs. This sample-size effect was also observed in Shannon's diversity index, which was lower for underrepresented SFSs. Marine debris ingestion was detected in both species (SAFS %FO = 2.7; SFS %FO = 8.3), with only flexible plastic material found. This study brings novel information on feeding habits of fur seal species in the extreme south of Brazil and unprecedented information about their ecology during the nonreproductive period. If you can't access the paper through the link, please contact one of my co-authors, Julieta (jucebu...@gmail.com). Kind regards, Renan -- *Renan C. de Lima, PhD* Postdoctoral fellow Laboratório de Ecologia e Conservação da Megafauna Marinha - EcoMega Instituto de Oceanografia Universidade Federal do Rio Grande (FURG) Association of Polar Early Career Scientists - Brazilian Committee (APECS Brazil) - National Representative *Phone*: +55(53)99718994 | *e-mail*: renan...@gmail.com *RG:* www.researchgate.net/profile/Renan-Lima-2 *ORCID*: https://orcid.org/-0002-9311-7085 ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] New publication on niche partitioning among odontocetes in the western South Atlantic
Dear MARMAM community, My co-authors and I are pleased to share our recent publication: Tatsch, A.C., de Lima, R.C., Secchi, E.R., Botta, S. 2024. Niche partitioning among odontocetes in a marine biogeographic transition zone of the western South Atlantic Ocean. Marine Biology 171, 38. https://link.springer.com/article/10.1007/s00227-023-04359-1 ABSTRACT: Toothed cetaceans represent a diverse and important component in poorly studied pelagic food webs. We used the variation in δ13C and δ15N values in tooth dentin and bone collagen sampled from 185 specimens of 23 species (families Delphinidae, Physeteridae, Kogiidae, Phocoenidae, and Ziphiidae) stranded in the western South Atlantic Ocean (WSAO) to estimate the isotopic niche width and assess the interspecific isotopic niche overlap. Two gradients of increasing δ13C values among species were evidenced: ocean-coast and high-to-low latitudes. Variation in δ13C and δ15N values indicated the existence of at least four trophic and habitat-related guilds: neritic high trophic-level predators (*Pseudorca crassidens*, *Tursiops truncatus gephyreus*, *T. truncatus truncatus* and *Phocoena spinnipinis*); oceanic intermediate trophic-level predators (*Orcinus orca*, *Steno bredanensis*, *Kogia breviceps*, *Lagenodelphis hosei*, *Physeter macrocephalus*, *Delphinus delphis* and *Stenella frontalis*), oceanic low trophic-level predators (*Grampus griseus*, *P. crassidens*—mass stranded group,* Mesoplodon grayi*,* M. densirostris,* *Ziphius cavirostris*, *Globicephala melas*, *S. coeruleoalba*, and *K. sima*), all from the subtropics, and a temperate/polar grouping of neritic/oceanic low trophic-level predators (*Berardius arnuxii*, *M. layardii*, *M. hectori *and *P. dioptrica*). Furthermore, our results also suggest the occurrence of putative ecotypes of *O. orca* and *P. crassidens*. The isotopic niche width was highly variable among species, with high niche overlap among several oceanic taxa. The results of the present study suggest a wide variation in trophic position, habitat and, therefore, the ecological role of different odontocete species in the WSAO ecosystems. All the best, Renan -- *Renan C. de Lima, PhD* Postdoctoral fellow Laboratório de Ecologia e Conservação da Megafauna Marinha - EcoMega Instituto de Oceanografia Universidade Federal do Rio Grande (FURG) Association of Polar Early Career Scientists - Brazilian Committee (APECS Brazil) - National Representative *Phone*: +55(53)99718994 | *e-mail*: renan...@gmail.com *RG:* www.researchgate.net/profile/Renan-Lima-2 *ORCID*: https://orcid.org/-0002-9311-7085 ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] Avian influenza outbreak among pinnipeds in southern Brazil
Dear MARMAM community, On behalf of my co-authors, I am excited to announce the publication of our new short note in Marine Mammal Science: Impacts and Lessons Learned from the First Highly Pathogenic Avian Influenza (H5N1) Outbreak in South American Pinnipeds along the Southern Brazilian Coast Authors: Renan C. de Lima, Sérgio C. Estima, Maurício Tavares, Paula L. Canabarro, Silvina Botta, Liane A. Dias, Andrine P. da Silva, Derek B. de Amorim, Larissa R. de Oliveira Abstract: Last year, a significant outbreak of highly pathogenic avian influenza impacted the Atlantic coast following mass mortalities recorded in the Pacific. Our study details the first outbreak of this virus in South American pinnipeds along the southern coast of Brazil. We also discuss the lessons learned from managing this crisis and suggest standard practices, and areas of priority in advance of potential future outbreaks For those interested, the full text is available at: https://onlinelibrary.wiley.com/doi/full/10./mms.13163 Please feel free to email me at renan...@gmail.com if you would like a copy. Kind regards, Renan -- *Renan C. de Lima, PhD* Postdoctoral fellow Laboratório de Ecologia e Conservação da Megafauna Marinha - EcoMega Instituto de Oceanografia Universidade Federal do Rio Grande (FURG) Association of Polar Early Career Scientists - Brazilian Committee (APECS Brazil) - National Representative *Phone*: +55(53)99718994 | *e-mail*: renan...@gmail.com *RG:* www.researchgate.net/profile/Renan-Lima-2 *ORCID*: https://orcid.org/-0002-9311-7085 ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] New Publication: Report of an extra-limit pregnant subantarctic fur seal
Dear MARMAM community, I’m pleased to share our new publication in Polar Biology, a brief report on the occurrence of a pregnant subantarctic fur seal (*Arctocephalus tropicalis*) recorded in Brazil, approximately 3,800 km from the species' nearest breeding colony. *de Lima, R.C., de Oliveira, L.R., Drehmer, C.J., Botta, S.* *Longest known foraging journey of a pregnant subantarctic fur seal* https://doi.org/10.1007/s00300-025-03383-9 Please feel free to reach out if you’re interested but are unable to access the article through the link. Best regards, Renan -- *Renan C. de Lima, PhD* Postdoctoral fellow Laboratório de Ecologia e Conservação da Megafauna Marinha - EcoMega Instituto de Oceanografia Universidade Federal do Rio Grande (FURG) *Phone*: +55(53)99718994 | *e-mail*: renan...@gmail.com *RG:* www.researchgate.net/profile/Renan-Lima-2 *ORCID*: https://orcid.org/-0002-9311-7085 ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
