[MARMAM] New paper on the role of absences when modelling distributions of very high mobile animals
Dear colleagues, We are extremely pleased to share with you our new paper focusing on why using absences is not the best option when modelling the distribution of very high mobile animals like cetaceans. Use the following link to have free access to the paper until August 6th: https://authors.elsevier.com/a/1fGAo15DJ-5eza Fernandez M, Sillero, N & Yesson C. (2022).To be or not to be: the role of absences in niche modelling for highly mobile species in dynamic marine environments. Ecological Modelling, 471. Abstract Species distribution models are valuable tools for conservation management. However, there remain challenges in developing and interpreting these models in the marine environment, such as the nature of the species used for the modelling process. When working with mobile species in dynamic environments, lack of observation is usually interpreted as an observation of absence, which can result in the introduction of biases by methodological (false) absences. Here, we explore the role of absences when modelling marine megafauna distributions. To better understand how the use of absences (or equivalent) affects the niche modelling algorithms, we used a set of 20 virtual species with different relations to the habitat (generalist static, specialist static, generalist dynamic and specialist dynamic) with different encounter rates. We tested six different modelling techniques divided into three distinct groups: presence-only, presence-background and presence-absence. We compared the outputs of the models using traditional validation metrics and overlap metrics in the geographical and environmental spaces. Algorithms characterized the ecological niche for the simulated species differently. Approaches using background data generally outperformed the other methods, suggesting that the non-observation of a species in a given location and time should not be considered as an absence. A very intense (practically unrealistic) sampling schema would be required to obtain a genuine unbiased absence when working with these species and habitats. For highly mobile species, a precautionary approach would be to consider the non-observation of a species as part of the background (a sample of the conditions available in the study area) rather than an absence. A good starting point would be to use presence-background models, complemented with presence-absence and/or presence-only models, comparing outputs from the different algorithms tested in the geographic and environmental space. Improving model performance for highly mobile marine species should lead to better-informed decision making for conservation. Best, Marc Fernandez Postdoctoral fellow MARE – Marine and Environmental Sciences Centre Agência Regional para o Desenvolvimento da Investigação Tecnologia e Inovação (ARDITI) Madeira Island, Portugal ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] New paper: Modelling fine-scale cetaceans’ distributions in oceanic islands: Madeira Archipelago as a case study
Dear colleagues, We are extremely pleased to share with you our new open-access paper focusing on the fine-scale distribution of cetaceans in the Madeira archipelago using Whale Watching data: https://www.frontiersin.org/articles/10.3389/fmars.2021.688248/full Fernandez M, Alves F, Ferreira R, Fischer JC, Thake P, Nunes N, Caldeira R & Dinis A. (2021). Modelling fine-scale cetaceans’ distributions in oceanic islands: Madeira Archipelago as a case study. Front. Mar. Sci. doi: 10.3389/fmars.2021.688248. Abstract: Species distributional estimates are an essential tool to improve and implement effective conservation and management measures. Nevertheless, obtaining accurate distributional estimates remains a challenge in many cases, especially when looking at the marine environment, mainly due to the species mobility and habitat dynamism. Ecosystems surrounding oceanic islands are highly dynamic and constitute a key actor on pelagic habitats, congregating biodiversity in their vicinity. The main objective of this study was to obtain accurate fine-scale spatio-temporal distributional estimates of cetaceans in oceanic islands, such as the Madeira archipelago, using a long-term opportunistically collected dataset. Ecological Niche Models (ENM) were built using cetacean occurrence data collected on-board commercial whale watching activities and environmental data from 2003 to 2018 for 10 species with a diverse range of habitat associations. Models were built using two different datasets of environmental variables with different temporal and spatial resolutions for comparison purposes. State-of-the-art techniques were used to iterate, build and evaluate the MAXENT models constructed. Models built using the long-term opportunistic dataset successfully described distribution patterns throughout the study area for the species considered. Final models were used to produce spatial grids of species average and standard deviation suitability monthly estimates. Results provide the first fine-scale (both in the temporal and spatial dimension) cetacean distributional estimates for the Madeira archipelago and reveal seasonal/annual distributional patterns, thus providing novel insights on species ecology and quantitative data to implement better dynamic management actions. Best wishes, Marc Fernandez Postdoctoral fellow MARE - Marine and Environmental Sciences Centre / ARDITI Caminho da Penteada, Madeira Tecnopolo, 9020-105 Funchal, Portugal ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] New paper on temporal resolution for cetacean niche modelling
Dear colleagues, Following our previous paper (Fernandez et al. 2017 The importance of temporal resolution for niche modelling in dynamic marine environments. J Biogeogr. 2017;44:2816–2827), we are now pleased to share with you a second related paper published in MEPS. Here we continue investigating the effects of temporal grain variation, in this case when modelling the ecological niche of cetaceans. Hope you enjoy this new paper. Please don't hesitate to ask for a print in case you don't have a MEPS subscription. A matter of timing: how temporal scale selection influences cetacean ecological niche modelling http://www.int-res.com/abstracts/meps/v595/p217-231/ Marc Fernandez, Chris Yesson, Alexandre Gannier, Peter I Miller and José MN Azevedo ABSTRACT: Modelling in the marine environment faces unique challenges that place greater emphasis on model accuracy. The spatio-temporal variability of this environment presents challenges when trying to develop useful habitat models. We tested how different temporal scales influence model predictions for cetaceans with different ecological requirements. We used 7 years of (opportunistic) whale watching data (>16000 cetacean sightings) collected in the Azores archipelago under the MONICET platform. We modelled the distribution of 10 cetacean species with a sampling bias correction. Distribution modelling was performed at 2 spatial scales (2 and 4 km) and 2 temporal resolutions (8 d vs. monthly averages). We used a MAXENT analysis with 3 different validation procedures. Generally, the 8 d means produced better results. In some cases (e.g. baleen whales), predictions using monthly means were no better than null models. Finer temporal grains provided essential insights, especially for species influenced by dynamic variables (e.g. sea surface temperature). For species more influenced by static variables (e.g. bathymetry), differences between temporal scales were smaller. The selection of the right temporal scale can be essential when modelling the niches of cetaceans. Datasets with high temporal resolution (e.g. whale watching data) can provide an excellent basis for these analyses, allowing use of finer temporal grains. Our models showed good predictive performance; however, limitations related to the spatial coverage were found. Merging datasets with different temporal and spatial resolutions could help to improve niche estimates. Models with better predictive capacity and transferability are needed to implement more efficient protection and conservation measures. Marc Fernández Morrón MONICET project (www.monicet.net) CE3C - Centre for Ecology, Evolution and Environmental Changes GBA - Grupo de Biodiversidade dos Açores Faculdade de Ciências e Tecnologia - Universidade dos Açores ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] New paper on temporal resolution for niche modelling in dynamic environments
Dear colleagues, You may be interested in our recent methodological paper published on the Journal of Biogeography on how to select the temporal scale of environmental variables when modelling species distributions in dynamic environments, such as cetaceans: The importance of temporal resolution for niche modelling in dynamic marine environments http://onlinelibrary.wiley.com/doi/10./jbi.13080/abstract Marc Fernandez, Chris Yesson, Alexandre Gannier, Peter I Miller and José MN Azevedo Abstract: Highly dynamic ocean environments can experience dramatic changes over relatively short timeframes, affecting the spatial distribution of resources and therefore the presence or absence of highly mobile species. We use simulation studies to investigate how different temporal resolutions might affect the results of species distribution models for highly mobile species (e.g. cetaceans) in marine environments. We developed three virtual species with different habitat preferences influenced by (1) only static (topographic), (2) only dynamic (oceanographic), and (3) both dynamic and static variables. Assuming that species would reposition themselves daily according to these preferences (as has been observed for large marine foragers such as cetaceans), we used two different approaches (generalized linear model and generalized boosted model) to test the effect of using daily, weekly and monthly environmental datasets to model distributions. The results showed that the selection of different temporal scales has a very important effect on model predictions. When dynamic variables are important components of habitat preference, models based on daily or weekly timeframes performed best at reconstructing the known niche. It is important that we consider temporal resolution when applying species distribution models. Several factors (e.g. species ecology and oceanographic characteristics of the ecosystem) should be taken into consideration when selecting an adequate temporal scale for niche modelling. For fine scale applications (e.g. dynamic ocean management), highly dynamic ecosystems, and highly mobile species, our results suggest exploring temporal resolution of 7–8 days rather than coarser temporal scales. For some applications annual, seasonal or even monthly averages may produce inferior or inaccurate models. Cheers, Marc Fernandez Ph. D candidate; cE3c - Centre for Ecology, Evolution and Environmental Changes/Azorean Biodiversity Group, and Faculdade de Ciências e Tecnologia, Universidade dos Açores, Ponta Delgada, Azores, Portugal ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] New publication on calving areas and critical habitat for Risso's dolphins
Dear MARMAM colleagues, We are pleased to announce that the following paper has been made available online: Hartman K, Fernandez M, Azevedo JN (2014) Spatial segregation of calving and nursing Risso’s dolphins (Grampus griseus) in the Azores, and its conservation implications. Marine Biology: 1-10 doi 10.1007/s00227-014-2430-x ABSTRACT Calving can be a critical period for cetaceans. Areas providing security for vulnerable calves, and high food availability for lactating females can be critical habitats requiring specific conservation measures. Here, we test the hypothesis that calving and nursing habitat could be defined for Risso’s dolphins (*Grampus griseus*). We investigated the spatial and temporal preferences of this species around Pico Island, Azores, using data gathered from land-based surveys and dedicated at-sea observations between 2004 and 2007. We divided observed pods into three groups: (1) those with newborn and young calves, (2) those with older calves or juveniles and (3) those consisting only of adults or sub-adults. We analysed eco-geographical variables and incorporated them into a presence-only spatial distribution model to evaluate differences in habitat suitability among the groups. We identified 694 pods of Risso’s dolphins overall. On the 267 pods observed in the first and second groups, 136 calves or juveniles were identified, of which 22 were newborns. The peak of the calving season was between June and August. The pods with newborn calves were larger and closer to shore, whereas the other groups were more widely dispersed offshore. Our results support the definition of critical habitat areas for this species, but we suggest widening the geographical coverage for better mapping around the island and throughout the archipelago generally. Conservation measures can, nevertheless, be implemented immediately, in order to reduce human impacts on a vulnerable component of the Risso’s dolphin population. The paper can be checked at: http://link.springer.com/article/10.1007/s00227-014-2430-x?no-access=true Please do not hesitate to contact us for any question regarding our work. All the best, Marc Fernandez ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
[MARMAM] Photo-id catalogues info
Dear collegues, We have started an online photo-id catalogue mostly based on pictures taken by amateurs (see http://azoresphotoid.blogspot.com/http://webmail.uac.pt/exchweb/bin/redir.asp?URL=http://azoresphotoid.blogspot.com/). The goal is to tap on the increasing number of quality photos taken by tourists, fisherman, etc, and to put them to the service of cetacean research. We would like to know about similar projects elsewhere in the world. If you know about an online catalogue or repository of photo-id images of cetaceans, please let us know. We will post a summary of the replies. Thanks in advance for your help. Best, Marc Fernandez Research Assistant MONICET project CIRN/University of Azores ___ MARMAM mailing list MARMAM@lists.uvic.ca https://lists.uvic.ca/mailman/listinfo/marmam
