Context‐dependent dispersal determines relatedness and genetic structure in a patchy amphibian population

Dispersal is a central process in ecology and evolution with far reaching consequences for the dynamics and genetics of spatially structured populations (SSPs). Individuals can adjust their decisions to disperse according to local fitness prospects, resulting in context-dependent dispersal. By determining dispersal rate, distance, and direction, these individual-level decisions further modulate the demography, relatedness, and genetic structure of SSPs. Here, we examined how context-dependent dispersal influences the dynamics and genetics of a Great Crested Newt (Triturus cristatus) SSP. We collected capture-recapture data of 5564 individuals and genetic data of 950 individuals across a SSP in northern Germany. We added genetic data from six sites outside this SSP to assess genetic structure and gene flow at a regional level. Dispersal rates within the SSP were high but dispersal distances were short. Dispersal was context-dependent: individuals preferentially immigrated into high-quality ponds where breeding probabilities were higher. The studied SSP behaved like a patchy population, where subpopulations at each pond were demographically interdependent. High context-dependent dispersal led to weak but significant spatial genetic structure and relatedness within the SSP. At the regional level, a strong hierarchical genetic structure with very few first-generation migrants as well as low effective dispersal rates suggest the presence of independent demographic units. Overall, our study highlights the importance of habitat quality for driving context-dependent dispersal and therefore demography and genetic structure in SSPs. Limited capacity for long-distance dispersal seems to increase genetic structure within a population and leads to demographic isolation in anthropogenic landscapes.Microsatellite Genotypes: Missing values are coded "-9". Presence/Absence Data: Missing values are coded "-". Funding provided by: Deutsche ForschungsgemeinschaftCrossref Funder Registry ID: http://dx.doi.org/10.13039/501100001659Award Number: STE 1130/7-1Demographic Data (CMR and Presence/Absence Data): We surveyed 33 water bodies using mark-recapture methods for the presence, demography and reproduction of crested newts between 2012 and 2014. Newts were captured during two capture sessions (cs) per year, one early (April/May) and one late (June/July) in the breeding season. Every capture session thereby consisted of three consecutive capture events in intervals of two days. Within the context of a presence/absence analysis, all sites were surveyed for one more day in late July/early August in order to detect larvae. If a pond dried out and was therefore not surveyed during a capture session, such an event was treated as a missing observation. Newts were captured using Ortmann's funnel traps which were evenly distributed along the shoreline of a pond. The number of traps deployed per capture event varied according to pond perimeter (one trap per 10m shoreline), ranging from one to 27 traps. For individual recognition of newts during the CMR study, we used photographs of the ventral side of an individual which provides a natural marking in form of a highly variable but individually unique and stable color pattern through the time. Recaptured individuals were identified automatically by the software AmphIdent. Microsatellite Genotypes: Tissue samples were taken from seven sampling sites by puncturing the tails of captured great crested newts (Triturus cristatus) using micro haematocrit capillary tubes (Carl Roth, Ø 1.6 mm) and were then stored in 80% ethanol. Total genomic DNA was extracted using the sodium dodecyl sulfate (SDS)-proteinase K/ Phenol-Chloroform extraction method. Genomic DNA was stored in Tris-EDTA buffer (10 mM Tris-HCl, 0.1 mM EDTA, pH 8.0) and used for all subsequent reactions. Each individual sample was mugenotyped for 17 microsatellite loci. Primers were combined in three multiplex mixes (Drechsler et al., 2013). 10 µl Type-it Multiplex PCRs (Qiagen) containing 1 µl of genomic DNA were performed. The PCR profile was as follows: (1) 5 min at 95°C, (2) 30 s at 94°C, (3) 90 s at an annealing temperature of 60°C, (4) 60 s at 72°C, (5) return to step 2 for 30 times, (6) 30 min at 60°C. Obtained PCR products were diluted with 50-200 μl water depending on the strength of obtained PCR products. 1 µl of each diluted multiplex reaction was added to 20 μl of Genescan 500-LIZ size standard (Applied Biosystem) and then run on an ABI 3730 96-capillary or an ABI 3130 16-capillary automated DNA-sequencer. Allele scoring of microsatellite loci was performed using Genemarker software (SoftGenetics version 1.95)

Context‐dependent dispersal determines relatedness and genetic structure in a patchy amphibian population

Dispersal is a central process in ecology and evolution with far reaching consequences for the dynamics and genetics of spatially structured populations (SSPs). Individuals can adjust their decisions to disperse according to local fitness prospects, resulting in context-dependent dispersal. By determining dispersal rate, distance and direction, these individual-level decisions further modulate the demography, relatedness and genetic structure of SSPs. Here, we examined how context-dependent dispersal influences the dynamics and genetics of a great crested newt (Triturus cristatus) SSP. We collected capture–recapture data of 5564 individuals and genetic data of 950 individuals across an SSP in northern Germany. We added genetic data from six sites outside this SSP to assess genetic structure and gene flow at a regional level. Dispersal rates within the SSP were high but dispersal distances were short. Dispersal was context-dependent: individuals preferentially immigrated into high-quality ponds where breeding probabilities were higher. The studied SSP behaved like a patchy population, where subpopulations at each pond were demographically interdependent. High context-dependent dispersal led to weak but significant spatial genetic structure and relatedness within the SSP. At the regional level, a strong hierarchical genetic structure with very few first-generation migrants as well as low effective dispersal rates suggest the presence of independent demographic units. Overall, our study highlights the importance of habitat quality for driving context-dependent dispersal and therefore demography and genetic structure in SSPs. Limited capacity for long-distance dispersal seems to increase genetic structure within a population and leads to demographic isolation in anthropogenic landscapes

Genetic diversity and gene flow decline with elevation in the Near Eastern fire salamander (Salamandra infraimmaculata) at Mount Hermon, Golan Heights

The Near Eastern fire salamander (Salamandra infraimmaculata) reaches its southern distribution range in Israel. Although the population structure has been analysed in central Israel and at the southern distribution limit, we lack knowledge on populations in the northern area, such as along Mount Hermon. S. infraimmaculata occurs at Mt. Hermon along an altitudinal gradient and appears to be fragmented by urban and agricultural landscape. We studied the genetic structure of four populations based on microsatellite loci and the mitochondrial D-loop to determine the genetic diversity and connectivity between populations. We observed moderate gene flow at lower parts, i.e. from Tel Dan and Nimrod Castle to Banias indicating extant but limited connectivity. Genetic diversity and gene flow declined along the altitudinal gradient at Mt. Hermon, reaching rock-bottom levels in the highest located population of Nimrod Pool. The observed isolation-by-elevation gradient might induce a higher extinction risk for the highland populations of S. infraimmaculataPeer reviewe

Automatic quantification of colour proportions in dorsal black-and-yellow coloured amphibians, tested on the fire salamander ( Salamndra salamandra )

Sanchez E, Gippner S, Vences M, et al. Automatic quantification of colour proportions in dorsal black-and-yellow coloured amphibians, tested on the fire salamander ( Salamndra salamandra ). Herpetology Notes. 2018;11:73-76

EAZA Amphibian Taxon Advisory Group Best Practice Guidelines (striped) fire salamander, Salamandra salamandra (terrestris)

Bogaerts S, Lötters S, Spitzen-van der Sluijs A, et al. EAZA Amphibian Taxon Advisory Group Best Practice Guidelines (striped) fire salamander, Salamandra salamandra (terrestris). 1st ed. Amsterdam, The Netherlands: European Association of Zoos and Aquariums; 2021.EAZA Best Practice Guidelines (Striped) fire salamander, Salamandra salamandra (terrestris) is the first version of the EAZA Best Practice Guidelines for this species. This guideline has evolved out of the growing concern for extinction of local fire salamander populations due to the introduction of the invasive chytrid fungus Batrachochytrium salamandrivorans (Bsal) into Europe. Multiple populations of Salamandra salamandra terrestris have collapsed in north-western Europe. Upon the discovery of Bsal, and associated mass mortalities, a captive assurance colony was established in the Netherlands at GAIA Zoo and later also in Rotterdam Zoo. A studbook is managed in ZIMS by GAIA Zoo. In the face of continuous spreading of Bsal into new areas within Belgium and Germany, both countries aim to develop similar ex-situ programs. To ensure collaboration, shared goals and to effectively share knowledge and resources, the multidisciplinary ’Ex-situ Salamandra Group’ (ESG) was initiated by scientists, NGOs and zoos from the three bordering Bsal affected countries. Close collaboration and mutual commitment between all partners involved is the strength of this group. For this ex-situ program, it is necessary to collect available scientific knowledge on genetics, ecology and behaviour, and translate them into practical ways to keep and possibly in a later stage also breed the species. The development of a scientifically based and EAZA (European Association of Zoos and Aquaria) approved husbandry protocol for S. s. terrestris, as lies in front of you, is a first product. The complete literature list can be found at the end of this document. This document consists of two sections: • Section 1. Biology and field data: this part reflects the taxonomic information and information about the subspecies Salamandra salamandra terrestris as this subspecies has been the best studied of all subspecies and it is the focus subspecies for the ESG. It includes data on natural habitat, ecology, behaviour, diet and reproduction; • Section 2. Zoo management: this part includes suggestions about the enclosures, feeding, social structure, breeding, handling, transportation, veterinary problems of the fire salamander and recommended research to extent and improve this guideline. These Best Practice Guidelines are for current keepers who wish to expand their knowledge about this species to take care of the animals in the best possible way, but also for future keepers need for basic information. It is recommended to consult the guidelines and to contact the TAG-members for any questions or problems