Browsing by Author "Peksen, Cigdem Akin"

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Conservation Genetics of the European Fallow Deer: A Reply to Marchesini et al.
(2021) Baker, Karis H.; Gray, Howard W. I.; Peksen, Cigdem Akin; Hoelzel, A. Rus; 0000-0001-5736-3062
In this letter, we revisit a study we published in 2017, following comment in a paper by Marchesini et al. published in this volume. We provide some further analyses that help us to reinforce the original conclusions of our earlier paper, and to address the points raised by Marchesini et al. We conclude that the concerns raised in their review do not alter the inference we presented earlier, and we identify issues with analyses presented by Marchesini et al. that limit their utility. The key points of inference remain that this species in Europe shows remarkably low levels of diversity within populations and strong structure among populations which can be explained by a combination of natural and anthropogenic processes.
Extremely low mitochondrial DNA diversity in a near threatened species, the Cinereous Vulture Aegypius monachus in Turkey
(2019) Cakmak, Emel; Peksen, Cigdem Akin; Kirazli, Cihangir; Yamac, Elif; Bilgin, C.Can; ABC-7273-2020
The Cinereous Vulture Aegypius monachus is a near threatened raptor that occurs in isolated populations across its range. The only comprehensive genetic study performed so far excluded samples from Turkey, although this area forms a significant part of the species' range. In this study, we used 311 bp long sequences of the mitochondrial cytochrome b gene from 58 Turkish individuals to assess genetic diversity and phylogeny, and to determine if any signals for population expansion exist. Our phylogenetic analyses indicate that the Turkish birds hold, along with those from the Caucasus, an intermediate position between European (Balkan and Iberian) and North Asian (Mongolian) lineages. Our findings also demonstrate extremely low mitochondrial diversity and suggest no population expansion. Despite the low genetic diversity found in this study, other mtDNA gene regions and other nuclear markers should be evaluated together with the current results, before any kind of conservation action plan of this species is applied.
Genetic diversity is retained in a bottlenecked Cinereous Vulture population in Turkey
(2019) Cakmak, Emel; Peksen, Cigdem Akin; Kirazli, Cihangir; Yamac, Elif; Bensch, Staftan; Bilgin, Cemal Can; ABC-7273-2020
Vulture populations worldwide have suffered precipitous declines in recent decades. The Cinereous Vulture Aegypius monachus, a highly philopatric scavenger distributed across southern Europe and the central Asian plateau, is threatened in many parts of its range. Turkey holds the second largest population of this species in the Western Palaearctic, but there has been no research on its genetic structure and the possible implications of this structure for the future of the species. Here we report nuclear diversity and relatedness determined by short tandem repeat genotyping of 81 individuals from the four largest colonies. Our results demonstrated no significant genetic structuring, suggesting a single panmictic metapopulation connected by frequent dispersal. Furthermore, we show that the study population has retained moderate levels of genetic diversity, despite passing through a recent demographic bottleneck. We estimated the effective population size to be 112 individuals (95% confidence interval 74-201). Our results imply that the observed lack of increase in population size since the 1990s has not been caused by lowered fitness due to genetic inbreeding but rather by increased mortality via demographic processes. In the short term, we suggest that conservation efforts should treat the Turkish subpopulations as a single management unit and aim to increase population size through effective protection, especially during the breeding season.
Unsustainable harvest of water frogs in southern Turkey for the European market
(2021) Cicek, Kerim; Ayaz, Dincer; Afsar, Murat; Bayrakci, Yusuf; Peksen, Cigdem Akin; Cumhuriyet, Oguzkan; Ismail, Ilhan Bayram; Yenmis, Melodi; Ustundag, Erdal; Tok, Cemal Varol; Bilgin, C. Can; Akcakaya, H. Resit; ABC-7273-2020
Frogs have been harvested from the wild for the last 40 years in Turkey. We analysed the population dynamics of Anatolian water frogs (Pelophylax spp.) in the Seyhan and Ceyhan Deltas during 2013-2015. We marked a total of 13,811 individuals during 3 years, estimated population sizes, simulated the dynamics of a harvested population over 50 years, and collated frog harvest and export statistics from the region and for Turkey as a whole. Our capture estimates indicated a population reduction of c. 20% per year, and our population modelling showed that, if overharvesting continues at current rates, the harvested populations will decline rapidly. Simulations with a model of harvested population dynamics resulted in a risk of extinction of > 90% within 50 years, with extinction likely in c. 2032. Our interviews with harvesters revealed their economic dependence on the frog harvest. However, our results also showed that reducing harvest rates would not only ensure the viability of these frog populations but would also provide a source of income that is sustainable in the long term. Our study provides insights into the position of Turkey in the 'extinction domino' line, in which harvest pressure shifts among countries as frog populations are depleted and harvest bans are effected. We recommend that harvesting of wild frogs should be banned during the mating season, hunting and exporting of frogs < 30 g should be banned, and harvesters should be trained on species knowledge and awareness of regulations.
Weak population-genetic structure of a widely distributed nematode parasite of frogs in the western Palearctic
(2021) Mikulicek, Peter; Meskova, Michaela; Cyprich, Martin; Jablonski, Daniel; Papezik, Petr; Hamdi, Diyar; Peksen, Cigdem Akin; Voros, Judit; Herczeg, David; Benovics, Michal
The genetic structure of parasite populations is affected by various factors such as host-parasite interactions, life-history strategies, and the evolutionary histories of both interacting organisms. In this study, we investigated the distribution, prevalence, and population-genetic structure of Icosiella neglecta (Spirurida, Onchocercidae), a nematode parasite found in Ranidae frogs. We reported this parasite from eight species of water frogs (genus Pelophylax) in Europe, the Middle East, and Central Asia. Its prevalence across investigated localities varied from 3.03% to 95.83%. Based on nucleotide variation in a 28S ribosomal RNA gene, all investigated I. neglecta sequences formed a well-supported phylogenetic clade and were placed in the sister position to the genus Ochoterenella. Despite the substantial genetic variability in a mitochondrial cytochrome c oxidase subunit I (COI) fragment (33 unique haplotypes recognized among 91 sequences), we found only weak population-genetic structure across the study area. There was no obvious association of COI haplotypes with geography, except haplotypes from eastern Turkey, Lebanon, and Iraq which formed a homogeneous, albeit only weakly differentiated group. The historical demographic analyses suggest that the species underwent a sudden and relatively recent population expansion. According to our results, we assume that the population-genetic structure of I. neglecta might be linked to the evolutionary history and dispersal of its dipteran vectors than water frog hosts.