Conservation efforts fail to halt the decline of the regionally endangered Natterjack toad (Epidalea calamita) in Ireland

2021 ◽  
Vol 261 ◽  
pp. 109228
Author(s):  
Marina Reyne ◽  
Aurélie Aubry ◽  
Mark Emmerson ◽  
Ferdia Marnell ◽  
Neil Reid
Keyword(s):  
Epidalea Calamita

scholarly journals Zur Bedeutung der ‚Grünbrücke Kiebitzholm‘ (Schleswig-Holstein) für Amphibien

2021 ◽  
Vol 10 ◽  
Author(s):  
Christian Winkler
Keyword(s):  
Rana Temporaria ◽  
Bufo Bufo ◽  
Rana Arvalis ◽  
Triturus Cristatus ◽  
Lissotriton Vulgaris ◽  
Epidalea Calamita

In den Jahren 2006 bis 2010 wurde die Amphibienfauna auf der Grünbrücke bei Kiebitzholm (Schleswig-Holstein, Norddeutschland), an den angrenzenden Straßensäumen beidseitig der Bundesautobahn (BAB) A21 sowie an Stillgewässern im 1,5 km Radius um die Grünbrücke untersucht. Im Untersuchungsgebiet konn- ten sieben Amphibienarten festgestellt werden, darunter Knoblauchkröte (Pelo- bates fuscus), Kreuzkröte (Epidalea calamita) und Moorfrosch (Rana arvalis), die landes- oder bundesweit als bestandsgefährdet gelten. Bei Knoblauchkröte und Moorfrosch handelt es sich zudem um bundesweit bedeutsame Zielarten für den Biotopverbund. Teichmolch (Lissotriton vulgaris), Erdkröte (Bufo bufo), Grasfrosch (Rana temporaria) und Moorfrosch wurden im Untersuchungszeitraum auf der Grünbrücke nachgewiesen. Der Kammmolch (Triturus cristatus) konnte nur auf der östlichen Rampe festgestellt werden. Die Grünbrücke diente den er- fassten Individuen offenbar in erster Linie zur Querung der BAB A21 und nur zum Teil auch als Sommerhabitat. Eine auf der östlichen Rampe angelegte Wildtränke wurde im Jahr 2010 erstmals von Teichmolch, Kammmolch und Moorfrosch als Laichgewässer genutzt. Knoblauchkröte und Kreuzkröte waren im Untersuchungsgebiet besonders selten. Sie traten in einem bzw. zwei Untersuchungsgewässern auf. Während die Kreuz- kröte auf beiden Seiten der Autobahn gefunden wurde, wurde die Knoblauchkröte nur westlich der Straße erfasst. Die übrigen festgestellten Amphibienarten traten in teilweise größeren Populationen auf beiden Seiten der BAB A21 auf. Die Funde dieser Arten auf der Grünbrücke zeigen, dass bereits ein Verbund zwischen diesem Que- rungsbauwerk und den Populationen in der Umgebung realisiert war.

Mild segregation in the breeding preferences of an invasive anuran (Discoglossus pictus) and its main native competitor (Epidalea calamita) in ephemeral ponds

2019 ◽  
Vol 40 (4) ◽  
pp. 425-435 ◽  
Author(s):  
Eudald Pujol-Buxó ◽  
Gabriel M. Riaño ◽  
Gustavo A. Llorente
Keyword(s):  
Alien Species ◽  
Native Species ◽  
Evolutionary History ◽  
Reproductive Season ◽  
Breeding Sites ◽  
Ecological Segregation ◽  
Ephemeral Ponds ◽  
Interspecific Differences ◽  
Discoglossus Pictus ◽  
Epidalea Calamita

Abstract The choice of breeding sites by pond-breeding anurans has notable consequences for the fitness of larvae. Hence, beyond pond typology and phenology, adults can also discriminate according to several other features, for instance to favour allotopy with potential competitors. However, the lack of shared evolutionary history might impede proper ecological differentiation with alien species during the first stages of invasions. Here, we studied several possible sources of ecological segregation between the invasive Discoglossus pictus and the native Epidalea calamita in ephemeral ponds, where the native toad hardly had competition before the arrival of the invasive frog. During spring of 2016, we periodically surveyed 69 ephemeral ponds in three areas with different invasion histories to detect the presence/absence of eggs and tadpoles of these species. Invasive D. pictus started breeding earlier than E. calamita, but differences were not significant. Similarly, there were not clear differences among areas with different invasion histories. However, we found for both species a mutual tendency to directly avoid larval syntopy at the end of the reproductive season. We also found interspecific differences in the features that both species use for pond choice, preferring the native species shallower and less vegetated ephemeral ponds. Globally however, co-occurrence was high, pointing at other processes as key to the coexistence between both species in these habitats.

scholarly journals Early swelling response to phytohemagglutinin is lower in older toads

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e6104 ◽  
Author(s):  
Francisco Javier Zamora-Camacho ◽  
Mar Comas
Keyword(s):  
Immune Response ◽  
Time Series ◽  
Life History ◽  
Life History Traits ◽  
Area Under The Curve ◽  
Older Individuals ◽  
Innate Response ◽  
Early Immune Response ◽  
The Individual ◽  
Epidalea Calamita

The effects of age on performance of life-history traits are diverse, but a common outcome is senescence, an irreversible deterioration of physical and physiological capabilities of older individuals. Immune response is potentially bound to senescence. However, little is known about immune response ageing in amphibians. In this work, we test the hypothesis that amphibian early immune response is reduced in older individuals. To this end, we captured adult natterjack toads (Epidalea calamita) and inoculated them with phytohemagglutinin, an innocuous protein that triggers a skin-swelling immune response whose magnitude is directly proportional to the ability of the individual to mount an immune response. We measured early swelling immune response (corresponding to an innate-response stage) hourly, for six hours, and we calculated the area under the curve (AUC) for each individual’s time series, as a measure of immune response magnitude incorporating time. We estimated toad age by means of phalanx skeletochronology. Swelling and AUC decreased with age. Therefore, in accordance with our predictions, early immune response seems subject to senescence in these toads. Reduced ability to get over infections due to senescence of immune respose might be—together with a worse functioning of other organs and systems—among the causes of lower survival of older specimens.

scholarly journals Genetic structure of natterjack toad (Epidalea calamita) populations in Flanders, Belgium, and its implications for conservation

2019 ◽  
Vol 40 (2) ◽  
pp. 193-205
Author(s):  
Joke Maes ◽  
Arend Raoul Van Oosten ◽  
Natalie Van Houtte ◽  
Erik Matthysen
Keyword(s):  
Population Structure ◽  
Genetic Structure ◽  
Habitat Management ◽  
Natural Populations ◽  
Conservation Priorities ◽  
Evolutionary Potential ◽  
Isolated Populations ◽  
Genetic Population ◽  
Wide Range ◽  
Epidalea Calamita

Abstract Unique evolutionary potential could be lost when a population goes extinct or when individuals are translocated to other existing populations. Therefore, in order to identify priorities and to predict the efficiency and consequences of conservation actions, information is needed on the genetic structure of natural populations. In the urbanized and diverse landscapes of Flanders, Belgium, natterjack toad (Epidalea calamita) populations have been declining over the last decades. Therefore, this species is subjected to a wide range of different types of conservation measures (e.g. habitat management, corridor development, translocations). However, more information is needed on its genetic population structure. In this study, we sampled egg clutches from six populations and studied their genetic structure with six microsatellite markers. In total, 184 samples from 99 different egg strings were genotyped. Observed heterozygosity was generally high, even for the small and isolated populations (overall mean HO = 0.43). The weak clustering by the Bayesian analyses (STRUCTURE, Adegenet and BAPS) does not allow us to make strong conclusions on the population structure. However, the significant ΦST values between the populations underline the importance of genetic information when conservation priorities are discussed. Unique evolutionary potential could be lost when one or more natterjack toad populations would go extinct, and translocation of individuals to other existing populations should be considered with caution.

scholarly journals Telomere attrition with age in a wild amphibian population

2020 ◽  
Vol 16 (7) ◽  
pp. 20200168
Author(s):  
Gregorio Sánchez-Montes ◽  
Íñigo Martínez-Solano ◽  
Carmen Díaz-Paniagua ◽  
Antonio Vilches ◽  
Arturo H. Ariño ◽  
...  
Keyword(s):  
Telomere Length ◽  
Breeding Population ◽  
Length Variation ◽  
Age Classes ◽  
Cross Sectional ◽  
Telomere Shortening ◽  
Amphibian Population ◽  
Telomere Attrition ◽  
Length Measurements ◽  
Epidalea Calamita

Telomere shortening with age has been documented in many organisms, but few studies have reported telomere length measurements in amphibians, and no information is available for growth after metamorphosis, nor in wild populations. We provide both cross-sectional and longitudinal evidence of net telomere attrition with age in a wild amphibian population of natterjack toads ( Epidalea calamita ). Based on age-estimation by skeletochronology and qPCR telomere length measurements in the framework of an individual-based monitoring programme, we confirmed telomere attrition in recaptured males. Our results support that toads experience telomere attrition throughout their ontogeny, and that most attrition occurs during the first 1–2 years. We did not find associations between telomere length and inbreeding or body condition. Our results on telomere length dynamics under natural conditions confirm telomere shortening with age in amphibians and provide quantification of wide telomere length variation within and among age-classes in a wild breeding population.

scholarly journals Hormonal induction of spermiation in a Eurasian bufonid (Epidalea calamita)

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Lucía Arregui ◽  
Sergio Diaz-Diaz ◽  
Elia Alonso-López ◽  
Andrew J. Kouba
Keyword(s):  
Cold Storage ◽  
Assisted Reproductive Technologies ◽  
Sperm Concentration ◽  
Hormone Treatment ◽  
Reproductive Technologies ◽  
Forward Movement ◽  
Amphibian Species ◽  
African Species ◽  
Treatment Frequency ◽  
Epidalea Calamita

Abstract Background Amphibian diversity is declining at an alarming rate due to habitat loss, invasive species, climate change and diseases. Captive assurance colonies have been established for some species at risk; however, many species do not breed well in captivity and the development of assisted reproductive technologies (ART) is critical to help sustain genetic diversity. To date, the majority of the work has been accomplished in species from the American continent and Australia, and there is a need to address similar breeding challenges in Eurasian and African species of amphibians. Methods The aim of this study was to develop a hormone protocol for stimulation of spermiation in Epidalea calamita as a model for Eurasian bufonids. Hence, the effect on sperm production and quality of three doses of chorionic gonadotropin hormone (5, 10 and 15 IU hCG/g) over time (1 to 24 h) was evaluated. In addition, cold storage (at 5 °C) of sperm for 24 and 48 h and three frequencies for hormonal treatment (weekly, biweekly and monthly) were examined. Results Hormone concentrations of 10 or 15 IU of hCG induced spermiation in 100% of males and produced sperm of comparable quality, while 5 IU hCG stimulated spermiation in only 40% of males. Total motility peaked between 1 to 4 h post-treatment with 10 IU hCG, whereas treatment with 15 IU hCG peaked between 2 to 6 h. After 24 h of cold storage total motility dropped by 20% and forward motility dropped by 10% for both the 10 and 15 IU treatments. Weekly hormone administration resulted in higher variation between trials in all motility parameters and a lower overall Total Motility and Forward Movement. Furthermore, the effect of exogenous hormone treatment overlapped between the last two trials in the weekly frequency. Sperm concentration was higher in the first trial for all frequencies but showed no differences among other trials. Conclusions Overall, these results show that hormone concentration, time after treatment, frequency of hormone treatment and cold storage should be borne in mind when developing a hormone stimulation protocol for Eurasian amphibian species.

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