Wissenschaft ermöglicht durch Exemplardaten

Chiarenza, A. A., A. M. Waterson, D. N. Schmidt, P. J. Valdes, C. Yesson, P. A. Holroyd, M. E. Collinson, et al. 2022. 100 million years of turtle paleoniche dynamics enable the prediction of latitudinal range shifts in a warming world. Current Biology. https://doi.org/10.1016/j.cub.2022.11.056

Past responses to environmental change provide vital baseline data for estimating the potential resilience of extant taxa to future change. Here, we investigate the latitudinal range contraction that terrestrial and freshwater turtles (Testudinata) experienced from the Late Cretaceous to the Paleogene (100.5–23.03 mya) in response to major climatic changes. We apply ecological niche modeling (ENM) to reconstruct turtle niches, using ancient and modern distribution data, paleogeographic reconstructions, and the HadCM3L climate model to quantify their range shifts in the Cretaceous and late Eocene. We then use the insights provided by these models to infer their probable ecological responses to future climate scenarios at different representative concentration pathways (RCPs 4.5 and 8.5 for 2100), which project globally increased temperatures and spreading arid biomes at lower to mid-latitudes. We show that turtle ranges are predicted to expand poleward in the Northern Hemisphere, with decreased habitat suitability at lower latitudes, inverting a trend of latitudinal range contraction that has been prevalent since the Eocene. Trionychids and freshwater turtles can more easily track their niches than Testudinidae and other terrestrial groups. However, habitat destruction and fragmentation at higher latitudes will probably reduce the capability of turtles and tortoises to cope with future climate changes.

Troia, M. J. 2022. Magnitude–duration relationships of physiological sensitivity and environmental exposure improve climate change vulnerability assessments. Ecography. https://doi.org/10.1111/ecog.06217

Integrating thermal physiology with environmental temperature is essential to understanding distributions of species and vulnerability to climate change. Warming tolerance – the difference between an organism's maximum thermal tolerance (Tmax) and maximum habitat temperature (Thab) – is frequently used to integrate organismal sensitivity and environmental exposure. Traditionally, applications of warming tolerance define Tmax and Thab as invariable magnitudes, yet tolerance magnitude depends on exposure duration, and diel temperature cycles expose organisms to a range of temperature magnitudes and durations. How traditional (i.e. acute) estimates of warming tolerance compare to estimates from prolonged exposures remains poorly understood. In this study, magnitude–duration curves for tolerances of one cold‐water, two cool‐water and one warm‐water species of freshwater fish were compiled from the literature and compared to magnitude–duration exposures from 66 streams across the eastern United States. Warming tolerances were estimated for exposure durations spanning 0.01–24 h. Current acute (0.01 h) warming tolerances ranged from median 6.30°C for the cold‐water species to 9.68°C for the warm‐water species. The lowest warming tolerances corresponded to prolonged exposures lasting median 3.85–5.30 h among species and were 2.51–4.38°C lower than acute estimates. Although acute estimates remained positive in historically occupied and unoccupied streams (6.30 versus 2.33°C), estimates based on prolonged exposure were positive at occupied streams of the cold‐water species but transitioned to negative in unoccupied streams (2.19 versus −1.12°C). Acute warming tolerances for the cold‐water species also remained positive under future climate (6.29–4.23°C) but approached zero at prolonged durations (2.19–0.09°C) and transitioned to negative for 47.2% of streams. Results demonstrate that acute measures of Tmax and Thab overestimate warming tolerances and therefore underestimate climate change vulnerability. Integrating magnitude–duration relationships into warming tolerance estimates can elucidate physiological mechanisms underlying species distributions and can improve accuracy of climate change vulnerability assessments.

Inman, R. D., T. C. Esque, and K. E. Nussear. 2022. Dispersal limitations increase vulnerability under climate change for reptiles and amphibians in the southwestern United States. The Journal of Wildlife Management. https://doi.org/10.1002/jwmg.22317

Species conservation plans frequently rely on information that spans political and administrative boundaries, especially when predictions are needed of future habitat under climate change; however, most species conservation plans and their requisite predictions of future habitat are often limited in geographical scope. Moreover, dispersal constraints for species of concern are not often incorporated into distribution models, which can result in overly optimistic predictions of future habitat. We used a standard modeling approach across a suite of 23 taxa of amphibians and reptiles in the North American deserts (560,024 km2 across 13 ecoregions) to assess impacts of climate change on habitat and combined landscape population dispersal simulations with species distribution modeling to reduce the risk of predicting future habitat in areas that are not available to species given their dispersal abilities. We used 3 general circulation models and 2 representative concentration pathways (RCPs) to represent multiple scenarios of future habitat potential and assess which study species may be most vulnerable to changes forecasted under each climate scenario. Amphibians were the most vulnerable taxa, but the most vulnerable species tended to be those with the lowest dispersal ability rather than those with the most specialized niches. Under the most optimistic climate scenario considered (RCP 2.6; a stringent scenario requiring declining emissions from 2020 to near zero emissions by 2100), 76% of the study area may experience a loss of >20% of the species examined, while up to 87% of the species currently present may be lost in some areas under the most pessimistic climate scenario (RCP 8.5; a scenario wherein greenhouse gases continue to increase through 2100 based on trajectories from the mid‐century). Most areas with high losses were concentrated in the Arizona and New Mexico Plateau ecoregion, the Edwards Plateau in Texas, and the Southwestern Tablelands in New Mexico and Texas, USA. Under the most pessimistic climate scenario, all species are predicted to lose some existing habitat, with an average of 34% loss of extant habitat across all species. Even under the most optimistic scenario, we detected an average loss of 24% of extant habitat across all species, suggesting that changing climates may influence the ranges of reptiles and amphibians in the Southwest.

Lal, M. M., K. T. Brown, P. Chand, and T. D. Pickering. 2022. An assessment of the aquaculture potential of indigenous freshwater food fish of Fiji, Papua New Guinea, Vanuatu, Solomon Islands, Samoa and Tonga as alternatives to farming of tilapia. Reviews in Aquaculture. https://doi.org/10.1111/raq.12749

An important driver behind introductions for aquaculture of alien fish species into Pacific Island Countries and Territories (PICTs) is a lack of knowledge about domestication suitability and specific culture requirements of indigenous taxa. Introductions may be appropriate in some circumstances, but in other circumstances, the associated risks may outweigh the benefits, so greater understanding of indigenous species' aquaculture potential is important. This review summarises literature for indigenous freshwater food fish species from Papua New Guinea, Fiji, Vanuatu, the Solomon Islands, Samoa and Tonga, and evaluates their aquaculture potential for food security and/or small‐scale livelihoods. A species selection criteria incorporating economic, social, biological and environmental spheres was used to score 62 candidate species. Tilapia (Oreochromis mossambicus and O. niloticus) now established in PICTs were evaluated for comparison. Results show that 13 species belonging to the families Mugilidae (Mullets), Terapontidae (Grunters), Kuhliidae (Flagtails) and Scatophagidae (Scats) have the highest culture potential according to selection criteria. These feed at a relatively low trophic level (are herbivores/detritivores), have comparatively fast growth rates and overall possess characteristics most amenable for small‐scale, inland aquaculture. The four top‐ranked candidates are all mountain mullets Cestraeus spp., followed by Nile tilapia (Oreochromis niloticus). Lower ranked candidates include three other mullets (Planiliza melinoptera, P. subviridis and Mugil cephalus) and rock flagtail Kuhlia rupestris. Importantly, many species remain data deficient in aspects of their reproductive biology or culture performance. Species profiles and ranked priority species by country are provided with logistical, technological and environmental assessments of country capacities to culture each species.

Oliveira-Dalland, L. G., L. R. V. Alencar, L. R. Tambosi, P. A. Carrasco, R. M. Rautsaw, J. Sigala-Rodriguez, G. Scrocchi, and M. Martins. 2022. Conservation gaps for Neotropical vipers: Mismatches between protected areas, species richness and evolutionary distinctiveness. Biological Conservation 275: 109750. https://doi.org/10.1016/j.biocon.2022.109750

The continuous decline in biodiversity despite global efforts to create new protected areas calls into question the effectiveness of these areas in conserving biodiversity. Numerous habitats are absent from the global protected area network, and certain taxonomic groups are not being included in conservation planning. Here, we analyzed the level of protection that the current protected area system provides to viper species in the Neotropical region through a conservation gap analysis. We used distribution size and degree of threat to set species-specific conservation goals for 123 viper species in the form of minimum percentage of their distribution that should be covered by protected areas, and assessed the level of protection provided for each species by overlapping their distribution with protected areas of strict protection. Furthermore, using species richness and evolutionary distinctiveness as priority indicators, we conducted a spatial association analysis to detect areas of special concern. We found that most viper species have <1/4 of their distribution covered by protected areas, including 22 threatened species. Also, the large majority of cells containing high levels of species richness were significantly absent from protected areas, while evolutionary distinctiveness was particularly unprotected in regions with relatively low species richness, like northern Mexico and the Argentinian dry Chaco. Our results provide further evidence that vipers are largely being excluded from conservation planning, leaving them exposed to serious threats that can lead to population decline and ultimately extinction.

De Wysiecki, A., A. Irigoyen, F. Cortés, N. Bovcon, A. Milessi, N. Hozbor, M. Coller, and A. Jaureguizar. 2022. Population-scale habitat use by school sharks Galeorhinus galeus (Triakidae) in the Southwest Atlantic: insights from temporally explicit niche modelling and habitat associations. Marine Ecology Progress Series 697: 81–95. https://doi.org/10.3354/meps14146

Population-scale information on the spatial ecology of threatened mobile sharks is required to design more effective management measures. Using an exhaustive collection of presence-only records and relevant predictors, we applied temporally explicit environmental niche modelling to study habitat use by a school shark Galeorhinus galeus population in the Southwest Atlantic. As a complementary tool, we developed randomized habitat association curves to assess both the representation of data with biological information and possible intra-population variation in habitat use. Seasonal niche models supported a core area of distribution between southern Brazil and southern Argentina. Marginal seasonal variation in suitability at the northern and southern extremes of its distribution supported the hypothesis that the G. galeus population behaves to some degree as a niche shifter on an annual cycle. Habitat associations revealed regional bias in the collection of records with biological information, and suggested a complex intra-population segregation pattern between sexes and between maturity stages during the cold half of the year. Overall, results supported large-scale partial migrations (i.e. some individuals migrate while others remain resident) of the G. galeus population. This study demonstrates the significance of future regional efforts that focus on producing more and better databases to derive relevant information at a low cost for the management of threatened sharks and their relatives.

Rautsaw, R. M., G. Jiménez-Velázquez, E. P. Hofmann, L. R. V. Alencar, C. I. Grünwald, M. Martins, P. Carrasco, et al. 2022. VenomMaps: Updated species distribution maps and models for New World pitvipers (Viperidae: Crotalinae). Scientific Data 9. https://doi.org/10.1038/s41597-022-01323-4

Beyond providing critical information to biologists, species distributions are useful for naturalists, curious citizens, and applied disciplines including conservation planning and medical intervention. Venomous snakes are one group that highlight the importance of having accurate information given their cosmopolitan distribution and medical significance. Envenomation by snakebite is considered a neglected tropical disease by the World Health Organization and venomous snake distributions are used to assess vulnerability to snakebite based on species occurrence and antivenom/healthcare accessibility. However, recent studies highlighted the need for updated fine-scale distributions of venomous snakes. Pitvipers (Viperidae: Crotalinae) are responsible for >98% of snakebites in the New World. Therefore, to begin to address the need for updated fine-scale distributions, we created VenomMaps, a database and web application containing updated distribution maps and species distribution models for all species of New World pitvipers. With these distributions, biologists can better understand the biogeography and conservation status of this group, researchers can better assess vulnerability to snakebite, and medical professionals can easily discern species found in their area. Measurement(s) Species Distributions Technology Type(s) Geographic Information System • Species Distribution Model (MaxEnt/kuenm) Factor Type(s) Occurrence Records • Environmental Data Sample Characteristic - Organism Crotalinae Sample Characteristic - Location North America • South America

Gainsbury, A. M., E. G. Santos, and H. Wiederhecker. 2022. Does urbanization impact terrestrial vertebrate ectotherms across a biodiversity hotspot? Science of The Total Environment 835: 155446. https://doi.org/10.1016/j.scitotenv.2022.155446

Urbanization is increasing at an alarming rate altering biodiversity. As urban areas sprawl, it is vital to understand the effects of urbanization on biodiversity. Florida is ideal for this research; it has many reptile species and has experienced multiple anthropogenic impacts. Herein, we aim to evaluate human impacts on registered reptile richness across an urbanization gradient in Florida. The expectation is that highly urbanized areas would harbor a lower number of species. To represent urbanization, we used Venter et al. (2016) human footprint index. We downloaded georeferenced occurrence records from the Global Biodiversity Information Facility to collate species richness. We ran generalized linear regressions controlling for spatial autocorrelation structure to test the association between urbanization and reptile records across Florida. We found a positive association between urbanization and registered reptiles across Florida for total and non-native species richness; however, a lack of association occurred for native species. We performed rarefaction curves due to an inherent bias of citizen science data. The positive association was supported for non-native reptile species richness with greater species richness located at urban centers. Interestingly, total and native species richness were largest at low as well as moderate levels of urbanization. Thus, moderately urbanized areas may have the potential to harbor a similar number of reptile species compared to areas with low urbanization. Nevertheless, a difference exists in sample completeness between the urbanization categories. Thus, a more systematic monitoring of reptile species across an urbanization gradient, not only focusing on urban and wild areas but also including moderate levels of urbanization, is needed to provide informed conservation strategies for urban development planning. Advances in environmental sensors, environmental DNA, and citizen science outreach are necessary to implement if we are to effectively monitor biodiversity at the accelerated rate of urbanization.

Selvaraj, J. J., L. V. Rosero-Henao, and M. A. Cifuentes-Ossa. 2022. Projecting future changes in distributions of small-scale pelagic fisheries of the southern Colombian Pacific Ocean. Heliyon 8: e08975. https://doi.org/10.1016/j.heliyon.2022.e08975

Small-scale fisheries (SSF) contribute to nearly half of global landings and provide multiple socioeconomic benefits to coastal communities. The Pacific coast SSF represents 37% of the total fisheries landings in Colombia. Scientific literature continually shows that tropical marine habitats are mos…

Espindola, S., E. Vázquez‐Domínguez, M. Nakamura, L. Osorio‐Olvera, E. Martínez‐Meyer, E. A. Myers, I. Overcast, et al. 2022. Complex genetic patterns and distribution limits mediated by native congeners of the worldwide invasive red‐eared slider turtle. Molecular Ecology 31: 1766–1782. https://doi.org/10.1111/mec.16356

Non-native (invasive) species offer a unique opportunity to study the geographical distribution and range limits of species, wherein the evolutionary change driven by interspecific interactions between native and non-native closely related species is a key component. The red-eared slider turtle, Tra…