Knoflookpadden in de kustduinen van Callantsoog

Discovery of common spadefoot population in coastal dunes In 2019 a single male common spadefoot (Pelobates fuscus) appeared out ofnowhere on the border of the coastal dunes of Callantsoog, Noord-Holland province. It was the first record of this species in coastal dunes in the Netherlands. A provincial road that borders the dunes on the eastside is mitigated for amphibian road kills by both fences, pitfalls and culverts. In March 2020 six more specimens were encountered in one of these pitfalls. Six night surveys in April-June 2020 revealed that the species has established a population. A total of 45 vocalizing specimens was heard and an egg string as well as 6-9 cm larvae were found. Breeding activity was registered in six waters. Also 37 unique individuals were identified in their land habitat. The total currently known distribution range contains five square kilometer grids. Since the species is naturally restricted to the eastern part of the Netherlands and is completely absent in coastal dunes, the species must have been (illegally) introduced. It is well possible that the species is more widely spread in these dunes than currently known. An additional study will likely follow in 2021. De knoflookpad (Pelobates fuscus) wordt geassocieerd met voedselrijke voortplantingswateren en goed vergraafbare, zandige grond in zijn landhabitat. Deze combinatie is van oudsher vooral te verwachten op rivierduinen in de omgeving van beek- en rivierdalen. Het gebrek aan de combinatie daarvan vormt één van de oorzaken dat de soort er landelijk niet goed voor staat en veel relictpopulaties een uiterst onzekere toekomst kennen. Een fysisch-geografische regio waar bovengenoemde randvoorwaarden tegenwoordig ruim voorhanden lijken, zijn de kustduinen. De knoflookpad ontbreekt hier in Nederland echter… of toch niet?