The Status of Reptiles and Amphibians in the Filey recording area
Common Lizard Zootoca vivipara
The Common Lizard remains something of an enigma within the FBOG area. Historical records up until the 1970’s appear to have been frequent from along the cliffs north and south of Carr Naze, but subsequently this species has been recorded only sporadically, with long periods involving no records. This would suggest either a small loose colony exists along the undercliff or that individuals from a larger viable colony are recorded dispersing through the FBOG area. Common Lizards generally occupy loose colonies distributed along topographical features, and at low densities can be surprisingly difficult to observe. Certainly pockets of optimum habitat exists along the undercliff, particularly along the southern scrub filled gullies and gaps of Filey Bay.
Common Lizards occupy topographically viable areas, with moderately dense vegetation of variable heights, typically with a shorter structure being dominant. The importance of raised promontories for undisturbed basking are also typical of such habitat, perhaps explaining why populations do not occur on the southern side of Carr Naze, which supports almost optimum albeit restricted habitat.
Slow Worm Anguis fragilis
Historical records (1904) suggest that this species was once present within the FBOG recording area, directly to the south of Filey Town. However the subsequent lack of records strongly suggests that this species became locally extinct some time ago. Slow Worms are recorded in similar under cliff habitat at Scalby Mills (Scarborough), with most other wider populations linked to the North Yorks Moors making any re-colonisation from these situations almost impossible, for what as a species is poorly dispersive. Due to the species’ secretive and largely subterranean nature the presence of a small colony along areas of infrequently visited undercliff, while unlikely, cannot completely be ruled out.
Common Frog Rana temporaria
Perhaps the most familiar amphibian across Britain, the Common Frog has a widespread distribution throughout the FBOG recording area. This is essentially a pioneer species, often choosing small ephemeral ponds, pools and puddles. This makes the Carr Naze and Top Scrub pond complex ideal, with breeding in most years (as with e.g. the Reighton pond complex and East Lea), although one would expect larval predation by newts to be high at these sites. Breeding also occurs at Filey Dams, where large spawn counts can occur during some seasons.
Aside from aquatic habitats, the distribution in the FBOG area is diverse and reflective of suitable terrestrial habitats, including plantations, rough grassland, scrub, coastal undercliff, urban areas (with green space and shrubberies), grazed pasture and hedgerows. Well drained arable habitats are typically avoided, with the exception of nocturnal migrations, due to the requirements of high soil/vegetative moisture levels during the terrestrial phase. This may influence dispersion into and out of the FBOG area in certain locations, as with other amphibians. This is also true of excessively urban situations like Filey Town centre, with inadequate refugia or dispersion routes across road and building networks. It is likely however that the many garden ponds (e.g. on the periphery of Filey town and in neighbouring villages) provide ample suburban habitat for this species.
Common Toad Bufo bufo
The only other widely occurring anuran within the wider area, the Common Toad has a similar distribution within the FBOG recording area as the Common Frog. Common Toads are more indicative of mature permanent open waterbodies and are better equipped at undertaking long migrations through less humid habitats. This is evident on Carr Naze, where adults emerge from daytime refuges in dry subsidence/shrinkage cracks to feed in the grassland during the evening.
Toads are our least aquatic amphibian and may only spend several nights a year in ponds (during the breeding period). This non-reliance on aquatic habitat results in a more widespread distribution than Common Frog in the FBOG area; most areas of scrub, rank grassland and closed canopy tree cover are occupied, although the toad is less able to exist in areas of grazed pasture, improved grassland or gardens and urban situations.
Breeding occurs in most waterbodies from locations occupied by fish and wildfowl (e.g. Primrose Valley pond and Filey Dams) to phemeral fish-free shallow pools (e.g. Top Scrub and Carr Naze ponds). Toad larvae are far less prone to fish or newt predation compared to frogs and thus large aggregations can be seen occupying the upper open water column within these ponds. The jet black tadpoles with their short blunt tails are marginally toxic, and distasteful to most predators. Due largely to the lack of small ephemeral pools favoured by frogs, and the toad’s capacity to breed in all local permanent waterbodies, one would suspect Common Toad numbers to outweigh those of frogs and for recruitment to be higher in the FBOG area (unlike most other parts of the British Isles).
Smooth Newt Lissotriton vulgaris
Another widespread amphibian within the FBOG area, the Smooth Newt can be found breeding in most local waterbodies, with a likely avoidance of the larger eutrophic pools frequented by fish and wildfowl, such as Primrose Valley Pond. This ubiquitous species is found in most shallow, fish free pools with a diversity of submerged and emergent aquatic plants. Typically a species of circumneutral, hard waterbodies, the underlying geology of our area provides optimum breeding potential. Certainly breeding populations occur in the Carr Naze/Top Scrub ponds, Reighton Ponds, Hunmanby Gap area and at Filey Dams/East Lea. At the latter site marginal areas of the larger waterbodies are frequented.
As with Common Frogs, the larvae are benthic, dwelling in the basal debris and are far less prone to fish predation when compared to Great Crested Newts. Their choice of terrestrial habitat, as with most amphibians, comprises damp rank grassland, closed canopy tree cover, scrub and often suburban gardens. Smooth newts are less frequently found in open short grassland, although a number evidently overwinter in the gaps, cracks and fissures on Carr Naze and elsewhere along the coastal undercliff. Occasionally individuals are observed during their spring migration along the cliff top paths.
Large numbers may hole up in disused rodent burrows during the winter close to breeding habitats, and breeding populations are probably most numerous in smaller ponds with an absence of Great Crested Newts. A good example of this is the wader scrape at the Tip, as well as the ornamental pond in Crescent Gardens, both of which are yet to support significant populations of the larger congeners and appear to have had good recruitment in recent seasons.
Palmate Newt Lissotriton helveticus
Palmate Newts are the restricted amphibian within the recording area regarding both abundance and distribution. This species is more typically associated with sodium and potassium rich upland soft waterbodies such as the acidic pools on the North York Moors, and populations within the FBOG area may be as a result of introductions. Two known meta-populations exist within the FBOG recording area, one in the Carr Naze/Top Scrub pond complex and the other in the Reighton Ponds complex. Despite the water chemistry being atypical for this species, they are more than capable of surviving in such areas. Smooth Newts tend to have a slightly higher rate of recruitment in such areas, but the two co-exist at both sites.
The only other notable difference in habitat niche is the increased ability of the Palmate Newt to operate at lower temperatures, and subsequently has better breeding success in more shaded ponds. It is possible that releases have occurred in other areas, or that dispersal has occurred from these sites; further survey efforts will shed more light on their status. As with the other two newt species, the bulk of egg laying occurs between March and June, and these months offer the best chance of seeing this species before it enters its secretive terrestrial phase.
Great Crested Newt Triturus cristatus
Another good indicator of mature, fish-free ponds, an extensive meta-population of the Great Crested Newt occupies our recording area, which is a continuation of the larger East Coast population complex. Great Crested Newts are frequently recorded within the Carr Naze/Top Scrub pools, which appear to support a moderately-sized but well spread meta-population. Much larger populations occur at Filey Dams/East Lea, The Bay Complex, Hunmanby Gap and Reighton Gap/ponds. Great Crested Newts are similar to Smooth Newts in that they prefer fish-free waterbodies with hard, circumneutral water, rich in calcium and/or magnesium.
Unlike Smooth Newts, larger, deeper waterbodies with an abundance of sub-merged vegetation are generally more associated with better recruitment and greater populations in this species, reflected in the Filey area. Great Crested Newts are the most aquatic of the three species, with suitable terrestrial habitat is usually occupied within 500 metres of breeding sites (as with the other two newt species). They have a particular affinity for tree cover, scrub, rank grassland and hedgerows where they are provided with refugia such as log piles, disused rodent burrows, rubble and a varied understory of herbs and grasses. Thus, areas such as the Top Scrub are particularly valuable for non-aquatic phase individuals.