Distribution review, habitat suitability and conservation of the endangered and endemic Moroccan spadefoot toad (Pelobates varaldii)

Abstract

The Moroccan spadefoot toad (Pelobates varaldii) has received little scientific attention since its discovery. Currently, P. varaldii is listed as Endangered on the IUCN Red List due to a multitude of threats, while its distribution is partially unknown and fragmented. The current study addresses distribution, threats and the potential niche using ecological niche modelling, while emphasizing conservation strategies and immediate actions. The distribution of P. varaldii can be divided into four disjunct areas, at least two of which consist of small populations. The largest threats to P. varaldii include the transformation of habitat and breeding ponds into agricultural and industrial areas, the pollution of breeding ponds due to extensive livestock pasturing and the possible expansion of Procambarus sp. into the Mamora cork oak forest. Additional threats constitute a reduction of gene flow and loss of genetic variability as a result of habitat fragmentation. The ecological niche models (ENMs) of P. varaldii revealed fundamental environmental conditions along parts of the northeast Moroccan Atlantic and Mediterranean coastline. The species mainly inhabits well vegetated areas upon Quaternary soils at low altitudes. Proposed conservation actions include the development of a biannual monitoring program, identification and designation of protected areas within the distribution and development of a management plan for Mamora forest. K Key words: Anura; conservation; habitat suitability; Maxent; Morocco; NDVI.Revisión de la distribución, idoneidad del hábitat y conservación del amenazado endemismo sapo de espuelas marroquí (Pelobates varaldii). Desde su descubrimiento, el sapo de espuelas marroquí (Pelobates varaldii) ha recibido poca atención por parte de la comunidad científica. Como consecuencia de multitud de amenazas, P. varaldii está actualmente catalogado como En Peligro de Extinción en la lista roja de la UICN, siendo su distribución muy fragmentada y no completamente conocida. El presente estudio analiza su distribución, amenazas y nicho potencial utilizando el modelado de nicho ecológico al tiempo que se enfatiza en posibles estrategias de conservación y acciones inmediatas. La distribución de P. varaldii puede dividirse en cuatro áreas disyuntas, al menos dos de las cuales corresponden a poblaciones de pequeño tamaño. Las mayores amenazas para P. varaldii incluyen la transformación de su hábitat y medios de reproducción en áreas agrícolas e industriales, la contaminación de sus charcas de reproducción como consecuencia de la ganadería extensiva y la posible expansión de Procambarus sp. hacia el alcornocal de Mamora. La reducción del flujo genético y pér-dida de variabilidad genética como consecuencia de la fragmentación del hábitat constituyen amenazas adi-

Amphibians of Morocco, including Western Sahara: a status report

“…Tadpoles remaining in permanent bodies of water are disappearing because of introduced predatory fish (Gambusia holbrooki; see also SALVADOR, 1996 andSTUART et al, 2008) and sudden draining during the larval period. Additional discovery (November 2008, DE POUS et al, 2012 08122°N, 6.06908°W) signals an additional threat to this and other species. Invasive crayfish present an increasingly serious threat to aquatic organisms, including amphibian larvae, wherever they become established (COOPER & ARMSTRONG, 2007).…”

“…Current major threats to survival derive from loss and degradation of habitat due to conversion of suitable land to pasture for, and water pollution by, livestock. Survival is contingent upon sandy soil, and industrial farming is expanding into coastal areas (DE POUS et al, 2012). Populations are often restricted to temporal ponds where hydroperiods may not be sufficient for completion of larval development (developmental period is unstudied, but is dependent upon water depth, temperature, and availability of food; four to six months is likely).…”

“…Mosquito fish (G. holbrooki), for example, are known to be detrimental to amphibian breeding success (SEGEV et al, 2009) and recent introductions of mosquito fish into numerous montane springs may compromise populations of A. maurus and other species (DONAIRE-BARROSO & BOGAERTS, 2003b;BEUKEMA et al, 2013). Discovery of New World crayfish Procambarus cf lophotus (DE POUS et al, 2012) suggests impending threats to aquatic amphibians in this area as well. "Once established, no methods exist by which a non-indigenous crayfish can be exterminated without unacceptable harm to native crayfishes and other organisms" (LODGE et al, 2000).…”

“…Little is known about microhabitat use by most Moroccan amphibians (but see EL HAMOUMI et al, 2007;DE POUS et al, 2012;BEUKEMA et al, 2013) and any analysis must be performed within the framework of major habitats. Landscape ecology can highlight relationships among species and landscapes, follow shifts in relationships through time, and monitor the influence of anthropogenic changes in the landscape (NAUGLE et al, 2005).…”

“…2a), an endemic, is locally distributed within the northwestern coastal plain among cork oak and other forested habitat and in areas of uncultivated sandy soil next to temporary ponds; DE POUS et al (2012) provided 134 georeferenced localities. Spawning sites are ephemeral ponds and dayas (Fig.…”