Les articles de Dilara Arslan

Contrasting effects of agriculture and urbanisation on bird and reptile communities in a Mediterranean delta (Gediz Delta, Türkiye)

Wed, 4 Jun 2025 15:53:31

de Dilara Arslan, Elie Gaget, Kerim Cicek, Anthony Olivier, Thomas Galewski, Ömer Döndüren, Anis Guelmami, Lisa Ernoul, Arnaud Béchet
In BMC Ecology and Evolution, 25(1) (June, 2025), 58
En ligne : doi.org[...]

Wetlands have been some of the most destroyed ecosystems over the last century, with important land-use changes resulting from agricultural, industrial, and urban development. Gediz Delta is a large wetland on the Aegean coast of Western Türkiye with natural areas affected by conversion to agriculture and urban developments from the Izmir metropolis. We assessed the effects of landscape type (natural, agricultural, and urban) on the composition of breeding bird (90 species) and reptile (14 species) communities in the Gediz Delta between 2019 and 2021. We used generalized linear models to estimate the effect of landscape types on community indexes and joint species distribution models to assess how species-specific habitat preferences explained their responses to landscape type.

Domestic water buffaloes: an unexpected basking support for two sympatric freshwater turtles, Emys orbicularis (Linnaeus, 1758) and Mauremys rivulata (Valenciennes, 1833) in Türkiye

Fri, 5 Sep 2025 15:54:17

de Ömral Ünsal Özkoç, Cem Akın, Anthony Olivier, Dilara Arslan
In Herpetology Notes, 18 (2025), 839-843
En ligne : figshare.com[...]

This study aims to present new data on the relationships between domestic water buffaloes and reptiles.

Conservation of more evolutionary unique amphibian communities in Türkiye: The role of protected areas

Wed, 21 Aug 2024 14:29:06

de Dilara Arslan, Anthony Olivier, Süreyya Cevat İsfendiyaroğlu, Yanina Benedetti, Burak Akdağ, Kerim Cicek, Federico Morelli
In Journal of Environmental Management, 368 (September, 2024), 122001
En ligne : www.sciencedirect.com[...]

The alarming decline of amphibians, sometimes marked by sudden extinctions, underlines the urgent need for increased conservation efforts. Conservationists recognize that more action, particularly the setting of national targets, is needed to ensure the future persistence and recovery of species and habitats. Protecting habitats that harbor evolutionarily diverse species preserves divergent genetic information within ecosystems. Türkiye holds 36 amphibian species at the intersection of two continents, creating three biodiversity hotspots and phylogenetic transitional areas. In this study, we aimed to determine the hotspot regions and to evaluate the effectiveness of the protected areas in Türkiye in preserving amphibian populations. First, we estimated four community indexes (species richness and three evolutionary distinctiveness measures) for amphibian communities in Türkiye divided into 371 grid cells with a ca 50 × 50 km size. Then, the spatial extent of protected areas is evaluated from two perspectives: current (has a protection status) and candidate protected areas (Key Biodiversity Areas, not protected) coverage in those grid cells. Finally, these two approaches' effectiveness in protecting areas was assessed by modeling four diversity metrics using GLS models. Current protected areas protect about 6% of the total amphibian distribution in Türkiye, while Key Biodiversity Areas would cover 30% if declared protected areas. We estimated that the coastal areas of Türkiye are identified as hotspots based on the four measured amphibian community indexes. Our study also highlights that Key Biodiversity Areas (KBAs) can contribute to conserving high levels of amphibian richness and evolutionary distinctiveness of species across Türkiye. However, existing protected areas (PAs) networks were insufficient to protect amphibians.

An extensive database on the traits and occurrences of amphibian species in Turkey

Fri, 15 Mar 2024 09:34:40

de Dilara Arslan, Burak Akdağ, Çağdaş Yaşar, Anthony Olivier, Yanina Benedetti, Federico Morelli, Kerim Cicek
In Scientific Data, 11(1) (March, 2024), 292
En ligne : www.nature.com[...]

Amphibians are the most endangered taxa among vertebrates, and they face many threats during their complex life cycles. The species’ life history traits and occurrence database help understand species responses against ecological factors. Consequently, the species-level-trait database has gained more prominence in recent years as a useful tool for understanding the dimensions of communities, assembly processes of communities, and conserving biodiversity at the ecosystem level against environmental changes. However, in Turkey, there are deficiencies in the knowledge of the ecological traits of amphibians compared to other vertebrate taxa, as most studies have focused on their distribution or taxonomic status. Consequently, there is a need to create such a database for future research on all known extant amphibians in Turkey. We compiled a species-level data set of species traits and occurrences for all amphibians in Turkey using 436 literature sources. We completed 36 trait categories with 5611 occurrence data for 37 amphibian species in Turkey. This study provides an open, useful, and comprehensive database for macroecological and conservation studies on amphibians in Turkey.

Where will Lycian salamanders, genus Lyciasalamandra, be in the near future in southwestern Anatolia, Turkey?

Thu, 13 Apr 2023 10:35:48

de Seyyed Saeed Hosseinian Yousefkhani, Burak Akdağ, Dilara Arslan, Kerim Cicek
In Herpetology Notes, 16 (April, 2023), 241-251
En ligne : www.biotaxa.org[...]

Lycian salamanders, genus Lyciasalamandra, are a group of seven allopatric, endangered species restricted to the Mediterranean coast of Anatolia, Turkey and certain adjacent Aegean islands. In this study, we created maps to prediction the potential ranges for six of these species using a maximum-entropy algorithm to identify the most significant environmental factors that shape their distribution. These projections were created under current climate conditions and for three future periods (2011–2040, 2041–2070, and 2071–2100), using two shared socioeconomic pathways (SSPs), middle-of-the-road (SSP370) and pessimistic (SSP585). We found that temperature and precipitation are the most important factors influencing the distribution of these salamanders in southwestern Turkey. Under both SSP scenarios, we found that five Lyciasalamandra species are likely to shift or reduce their ranges in the near future, while one species (L. antalyana) was predicted to expand its range. For the five negatively affected species, whose ranges are already highly ranges, this predicts that climate change combined with high anthropogenic pressure poses a serious risk of extinction. Significant population declines are predicted, particularly for L. billae and L. luschani. We hope that our findings can serve as a resource for the long-term conservation of these species and aid decision-makers in the development of effective management strategies.

Using literature and expert knowledge to determine changes in the bird community over a century in a Turkish wetland

Thu, 27 Oct 2022 17:35:55

de Dilara Arslan, Lisa Ernoul, Arnaud Béchet, Ömer Döndüren, Mehmet Sıkı, Thomas Galewski, Dilara Arslan, Lisa Ernoul, Arnaud Béchet, Ömer Döndüren, et al.
In Marine and Freshwater Research, Online (October, 2022)
En ligne : www.publish.csiro.au[...]

Bird species have been studied and documented abundantly in the past decades and are good indicators of ecosystem conditions, providing useful information of the changes in the ecological state of wetlands over time. However, monitoring data for birds in wetland sites are often disparate and not homogeneous over time and among species, which complicates the interpretation of trends.
We examined historical literature from 1835 to 2019, complemented by an expert knowledge survey and citizen-science databases to estimate the abundance of species, and evaluated changes in the structure and composition by average bird abundances.Key results Our results suggested that land-cover and land-use changes have shaped the local bird community, with a decline in agricultural and grassland bird species as a result of changes in agricultural practices. Coastal wetland and marine birds have increased in abundance, most probably linked to the extension of saltpans and successful conservation measures.
hese trends in bird communities demonstrate the impacts of different land management strategies on biodiversity.Implications This methodology can be replicated in other Ramsar and wetland sites around the world to raise new conservation issues and improve site conservation.

A comparative study of biodiversity between natural, urban and agriculture environments in the Gediz Delta, Turkey (2022)

Mon, 30 May 2022 16:18:28

de Dilara Arslan
[S.l.] : Avignon Université, 2022, 162

Economic growth, demographic pressures, and lack of enforcement of environmental laws and protections have caused important levels of land-use changes and habitat destruction, threatening wetlands and their biodiversity around the world. Land-use changes have been the most important driving force on species composition changes in the last century. Mediterranean wetlands have been transformed by human activities over last the century and one-third of their surface area has been lost in the last decades. Understanding and quantifying the community-level responses to the land-use cover changes is essential for creating sustainable conservation management to protect species and ecosystems. The Gediz Delta is located in the Mediterranean basin of Turkey and offers the opportunity to understand better how agriculture and urbanization affect biodiversity with a good potential for generalization in other wetlands in the Mediterranean basin. This study's main objective is to better understand how land cover affects bird and reptile community assembly processes and which habitats in the Gediz Delta need special conservation attention. The study is divided into 3 components: First, we (a) evaluated the avian biodiversity changes in Gediz Delta from the 1980s-2019, and (b) compared bird and reptile communities in natural, agricultural, and urban environments. Finally, we (c) made a threat analysis and identified possible conservation actions for future management to reduce the effects of threats and improve the sustainable management of the delta.

Threat Ranking to Improve Conservation Planning: An Example from the Gediz Delta, Turkey

Wed, 15 Dec 2021 16:21:19

de Dilara Arslan, Kerim Cicek, Ömer Döndüren, Lisa Ernoul
In Land, 10(12) (December, 2021), 16
En ligne : www.mdpi.com[...]

Mediterranean wetlands are among the most threatened natural areas. The needs and demands of an increasing human population are modifying land use and converting natural habitats into artificial areas. In order to combat these trends, effective conservation planning needs to provide clear, systematic identification of threats to find sustainable conservation strategies. In this case study, we evaluated current threats in the Gediz Delta (Turkey) using a multi-method approach. First, we did a comprehensive literature review and stakeholder interviews to identify existing threats. We then did a complete survey of the Delta through intensive fieldwork. The threats were coded and ranked using the conservation standards. We used the threat ranking and field survey to map the most vulnerable areas of the Delta. The most commonly observed threats in the field were pollution and agriculture and aquaculture activities. According to the threat ranking, the most important threats are climate change and residential and commercial development. The habitats that are most at risk are agricultural grassland habitats. The results indicate a need to extend conservation actions in the inner part of the Delta. In addition, the multi-method threat ranking approach could serve as a model to improve conservation planning in other sites worldwide.

Demography, distribution, and threat assessment of the Spur-thighed Tortoise (Testudo graeca) in the Gediz Delta, Turkey (Reptilia: Testudines)

Wed, 26 May 2021 10:39:17

de Dilara Arslan, Anthony Olivier, Lisa Ernoul, Arnaud Béchet, Kerim Cicek
In Zoology in the Middle East, 67(3) (July, 2021), 1-12
En ligne : www.tandfonline.com[...]

The Spur-thighed tortoise (Testudo graeca) is listed as vulnerable on the IUCN Red List, with small and fragmented populations located around the Mediterranean basin. In Turkey, this species has remained poorly studied which hampers solid assessment of threats and conservation measures. We studied the spatial distribution, habitat use, and demography of the species in the Gediz Delta (Aegean coast of Turkey) between 2015 and 2017 with a specific capture-mark-recapture survey made in the Sazlıgöl marshes. A total of 114 individuals (20 juveniles, 62 males and 32 females) were captured and released in that period. Carapace length of adult females was on average higher (205.2±3.2 mm) than in adult males (190.9±2.3 mm). Sex ratio was biased with 1.94 males per female. Based on the capture-recapture histories of 65 individuals (3 juveniles, 37 males and 25 females) marked in 2015, we estimated the population size of the Sazlıgöl marsh population to be 137±23 individuals, which corresponds to a density of 5.7 individuals per ha. The main threats detected were agricultural activities, urbanisation and captures for the pet trade.

Assessing population status and conservation of endangered Marmaris salamander, Lycisalamandra flavimembris (Mutz and Steinfartz, 1995), in southwestern Turkey

Wed, 1 Jul 2020 13:57:34

de Dilara Arslan, Çağdaş Yaşar, Akın İzgin, Kerim Cicek
In Herpetology Notes, 13 (June, 2020), 531-541
En ligne : www.biotaxa.org[...]

The Marmaris salamander is an endemic and endangered amphibian species in Southwestern Anatolia. Here, we estimated some population parameters of the Marmaris salamander by conducting a total of 40 days of intensive sampling across 5 different sites. We marked 323 salamanders with visible implant elastomer between 2017 and 2019 and recaptured 46 of them. The population consists of 36% juveniles, 27.9 % males, and 35.9% females with a female-biased sex ratio (m: f= 0.77) was observed. We estimated population density per site to be between 10 and 42 indiv./ha. The capture probability ranged from 0.15 to 0.54 and the survival rate ranged from 0.53 to 0.86 among the populations. Based purely on models of habitat suitability, the geographic distribution of the Marmaris salamander is likely to shrink by 9–62% in the next 30-50 years. The most important threats are land use conversion, climate change, and forest fires. If no action is taken some populations of the species might go extinct.

Distribution and current status of herpetofauna in the Gediz Delta (Western Anatolia, Turkey)

Thu, 11 Jan 2018 11:31:45

de Dilara Arslan, Anthony Olivier, Çağdaş Yaşar, İlhan Bayryam Ismail, Ömer Döndüren, Lisa Ernoul, Nicolas Beck, Kerim Cicek
In Herpetology Notes, 11(0) (2018), 1-15
En ligne : www.biotaxa.org[...]

In this study, we implemented an inventory of amphibians and reptiles between 2013 and 2016 in the Gediz Delta (İzmir, Turkey). The field results were then combined with existing records. According to the data obtained, a total of 35 herptile species, comprising 7 amphibians (2 urodeles, 5 anurans) and 28 reptiles (6 chelonians, 10 lizards and 12 snakes) live in the region. Five species (Lissotriton vulgaris, Triturus ivanbureschi, Heremites auratus, Platyceps collaris and Telecopus fallax) were recorded for the first time in the Gediz Delta during the study. A chorotype classification and potential threats of the species are also discussed.

Another case of facultative paedomorphism in Smooth newts, Lissotriton vulgaris (Caudata: Salamandridae) from Turkey

Thu, 6 Oct 2016 17:25:33

de D. Kizil, I.B., Ismail, Anthony Olivier, K. Cicek
In Amphibians and Reptiles Conservations, 10(1) (June 2016), pp. 28-33
En ligne : amphibian-reptile-conservation.org[...]

A report of the occurrence of a dimorphic population of Smooth Newts in Lake Sazlı (Izmir, Western Anatolia, Turkey). During fieldwork on March 2015, 29 aquatic individuals (seven males, 22 females) were captured and of these individuals, five were paedomorphic (four males, one female). The metamorphic (83%) and paedomorphic (17%) ratio of the population is skewed to metamorphic. The mean snout-vent length (SVL) was 28.30 mm (range = 26.00−30.41), and total length (TL) was 57.66 mm (53.35−61.40) in paedomorphs. The average exterior gill length was 4.12 mm (2.64–4.71). The SVL was 39.99 mm (range = 33.44−39.93), and TL was 69.06 mm (66.19−79.17) in metamorphs. The possible reasons for the presence of facultative paedomorphosis in the population are discussed, with the dimorphic paedomorph hypothesis supported