Anthropogenic activities have highly impacted aquatic ecosystems. The developments of urbanization like dams, channels, industries taking oil and gas has greatly affected river systems. This paper of “Patterns of genetic divergence in the Rio Grande cooter (pseudemys gorzugi), a riverine turtle inhabiting an arid and anthropogenically modified system” caught my attention because it talks about urbanization impacts on wildlife genetics. Especially how a well-known persistent long-lived turtle such as the Rio Grande Cooter (pseudemys gorzugi) is even experiencing conservation concerns. Genetics is interesting to look at when thinking about being able to adapt to new challenges and the population’s fitness in survivability.

This study was conducted in the Southwest region of the United States. Specifically, looking at the river systems of the Rio Grande and Pecos River. Methods consisted of sample collection, DNA preparation, sequencing, mapping, population structure, genetic diversity measurements, migration inference, and demographic inferences. Either tissue or blood was collected and surveyed through snorkeling or hoop-net traps. The DNA was collected using QIAGEN DNest Blood and Tissue Kit. There was the process of determining which cross-reference genome to map and address genotype uncertainty using ANGSD 0.94. Population structure was done by using the NGSadmix that estimated “admixture proportions of individuals”. For genetic diversity measurements the data was split in 5 groups: Pecos River North/South, Black River, Devils River, and the Rio Grande. Migration inference was analyzed through pairwise genetic distances and used EEMS for migration surfaces in locating corridors and barriers to gene flow. There were plenty of other resources used to visualize the data better and account for errors, but the above are the main points.

The author’s findings found that there was lower heterozygosity, diminished nucleotide diversity, and a reduced effective population (Ne). The modified river confluences have caused challenges in the migration patterns that have caused isolations in the original population. Which has created two distinct populations discovered through population genetic analysis one residing in the Pecos and the other in the Black Rivers of New Mexico. The population in New Mexico was found to have a greater decline and harder bounce back then Texas’ population. These findings were done with 150 samples that had fit analysis criteria and 141 were sequenced.

I like how the study mentioned other effects on chelonians since turtles have survived many extinctions. Yet are being detrimentally impacted by the Anthropocene. The other studies mentioned in the paper have found loss in connectivity, reduced gene flow in the Rio Grande endemic Trachemys gaigeae in New Mexico and Texas populations. Then other freshwater turtle species: Terrapene caohulia, Trachemys taylori, and Apalone atra in Coahulia, Mexico have suffered reduced genetic diversity, connectivity, and isolation from drying environments. This emphasizes how urbanization has deeply affected even the most known enduring animal. Highlighting the urgency for understanding conservation needs and implementation plans.

Although the study was well-developed and looked at many variables, I would suggest a few things that I think could have been considered. Additional variables that should have been added are having gone the extra mile and gone ahead to inflate the number of singletons. The data analysis could improve in having been able to observe more sites such as the Rio Grande tributaries that had not been permitted to do so but maybe in the future. The discussion of findings in my opinion is well-rounded it emphasizes how Rio Grande cooter (pseudemys gorzugi may not receive attention for federal protection but aids in how that should be re-evaluated with the new findings and then moves on to be more general on the climate change and urbanization effects on freshwater turtles. The future research directions are to utilize the findings to aid in conservation efforts and re-establishing populations of Rio Grande Cooter (pseudemys gorzugi). There is still a gap to identify the distinctive demands for the two populations.

Citation: Michael W Vandewege, Javier Gutierrez, Drew R Davis, Michael R J Forstner, Ivana Mali, Patterns of genetic divergence in the Rio Grande cooter (Pseudemys gorzugi), a riverine turtle inhabiting an arid and anthropogenically modified system, Journal of Heredity, Volume 115, Issue 3, May 2024, Pages 253–261, https://doi.org/10.1093/jhered/esae011

Link: Reptiles in danger: Implications of road mortality in wetlands of South America | Request PDF (researchgate.net)

The paper “Reptiles in danger: Implications of road mortality in wetlands of South America” does a great job at comparing different sites in the Parana River floodplain roads in relation to seasons, species diversity, abundance, and hotspots. There relationships of magnitude, timings, and locations were able to be pooled together through the researcher’s analysis of intrinsic (habitat use), extrinsic (temperature, precipitation, hydrometric levels) and anthropogenic factors (traffic volume) The visualization did a good job at illustrating the results, especially Fig.3 with relation to seasons and number of reptiles roadkill’s at the three sites. This helps to realize that there are so many factors that can be considered. Along with other papers the results bring more attention to placing more emphasis on conservation management to be geared on amphibians and reptiles that are the highest susceptible subjects to road mortality rates in wetlands. It was found that species richness had a significant increase as altitude decreases due to rising temperatures. Hence, the North region had higher richness of reptile species, but lowest abundance of reptile roadkill’s. The habit for this region consisted of the highest spatial heterogeneity of forest and wetland structure that aided in microhabitats for snakes.

This paper caught my attention due to the fact that it looks at road mortality specifically in relation to wetlands of South America. Since I work at an urban forest that has a wetland area with a wild population of different species of turtles. This paper calls to me because of the emphasis on higher vulnerability to reptiles due to thermoregulation and slow movement. Moreover, with the knowledge that each individual has their own home range while one goes out way farther some stay in their usual area. In the past year outside of my working area I have come across two turtles in the road that I have moved that would have otherwise been hit by another incoming car. Then, at my internship in Massachusetts one summer I would see so many turtles that would be moved off the roads. Hence, why this topic intrigues me and not just on turtles but also other species such as snakes that people especially don’t really care about swerving around.

I believe that the researchers could improve their data analysis of the environmental conditions’ variables. Such as providing more accurate precipitation readings by collecting days using Kestrels instead of just noting the average precipitation of the last three days. Moreover, there could have been more visits to the roads to include more data. It is stated that the data of GLMM showed that precipitation had no effect on reptile roadkill abundance. This raises an even higher concern that data could have been collected better for more accurate precipitation readings. This is due to the fact that it is widely known that reptiles often become more active after a precipitation event. These events could have been missed due to the short sampling period of taking the environmental condition measurements. However, it is a good point that the researchers did state that seasons were part of the additional variables which took part in the significant variations seen in the GLM abundance of reptile roadkill’s. It was found that Autumn had the highest species abundance compared to spring, winter, and summer. Additionally, spring has a higher number of roadkill’s compared to winter. This is important in creating modified mitigation strategies for each season that calls for different levels of risks to wildlife.

Other additional variables that should be considered are zones such as school, residentials, and industries, in relation to the differing speed limits to show if there is a correlation between the speed limits and roadkill. This could help in shifting conservation attention to zones that have lower or higher levels of speed limits to consider altering the levels for better visibility. Especially when overlapping with the sections North (NS), Centre (CS), and South (SS) of Parana River that were observed to have higher numbers of roadkill and compare those zones. I might have done a number of days for overall data collection differently in that increasing the field visits to have had the different regions of NS, CS, and SS meet the minimum number required for Autumn Optimized Hot Spot Analysis. This would have helped to have greater data on hotspots not just for region SS but for the others.

I appreciate how in the paper’s discussion two plausible reasons were given for how in the study a large proportion of reptile roadkill were snakes One that there is just a greater snake species richness in the area and second that people intentionally run over snakes. Additionally, how factors such as size of the snakes affect home range and movement frequencies when looking at factors such as foraging and being ectothermic animals. This builds onto the later elaboration on how pregnant snake females use the roads for thermoregulation which find themselves at higher risks of people just killing them by hand or by vehicles even in protected areas. This helps the readers to understand how even people’s perspectives on certain species a variable in species survivorship rates is also. Moreover, the highest world-wide threatened reptile species are those that live in freshwater environments that are not subject to negative effects from human activities. Future research directions are looking at study designs of roadkill’s in terms of reproductive seasons, exposure levels, and human population densities.

Link: https://resjournals-onlinelibrary-wiley-com.prox.lib.ncsu.edu/doi/10.1111/icad.12481

Light pollution is an increasing threat to firefly populations. Due to the aspect of sexual attraction in the process of this species mating behavior. Although fireflies are also harmed by habitat loss and urbanization, light pollution is hard to mitigate. This paper is interesting in that it compares the damage from different sources that implement harm on firefly’s to highlight the most alarming threat. Moreover, I remember as a kid there would be so many fireflies outside at night that my friends and I would catch with our hands and admire how they could produce light. This article modeled the possible distribution of the tracker ghost firefly Amydetes fastigiata and determined the rate of growth for light pollution, urbanization, and deforestation in the Atlantic Forest.


This study was conducted in the Atlantic Forest. The light pollution data was collected by analyzing a data set on harmonized global nighttime light observations from 1992-2018.Then the urbanization and forest cover trends data were collected by using MapBioMas Collect 5 to analyze the distribution of the ghost firefly from 1992-2018. To compare the first and last 5-year time frames of this data set the researchers calculated mean values and other statistical analysis to find the percentage of land cover, pixel numbers, etc. The researchers performed the Cramer’s V test to find associations between the split data set. I believe that the data analysis could have included some self-observations from the researchers of at least a year’s worth of data to add it to the analysis of the data set from 1992-2018. However, the researchers did compile entomological collections, literature, and field work data. Therefore, with the understanding that research has limitations based on funds, the self-observations for at least a year would not have been a priority; it would have just added another year of data collection.

The authors’ findings showed that light pollution had the greatest rate of growth in the study site. Approximately 1,4000 km2 of dark areas were found to be impacted by artificial light. It was emphasized that the main reason that light pollution outdoes the other threats in the speed of growing concern is that it is difficult to cut off the light’s reach. Unlike how protected spaces allow there to be a buffer between urbanization and deforestation. Light pollution is a challenging matter especially to nocturnal insects that are most vulnerable to the changes it implies. The discussion does a great job in explaining the different vulnerabilities to fireflies. For instance, to the males using the light signaling to detect females. The activity of the light flashes are reduced lowering reproductive opportunities. Furthermore, larvae are left with both decreased defense mechanisms and effectiveness as predators. Since, larvae use aposematic signals under bioluminescent communication. Additional variable that should be considered is that given that more than 60% Brazil’s population lives within the Atlantic Forest that the visits from the growing number of people to the areas that the fireflies reside on may be damaging the larvae, capturing fireflies for entertainment purposes, etc.

This study brings attention to artificial light being the top stressor to fireflies and the challenges of mitigating it. In addition, to the need for adapting regional conservation policies and locations of protected areas. The framework that the research created can help future research pinpoint areas of improvement for vulnerable populations of species. The study found that deforestation had the greatest extent of effect on firefly’s however, pointing out that light pollution was found to be an emerging concern which directs future research. It is important to know that further growth of light pollution comes from habitat loss for new developments that changes the land use.