The moor frog, scientifically known as Rana arvalis, is an amphibian found across Europe and Asia. This semi-aquatic species displays unique characteristics and behaviors, adapting to diverse wetland and terrestrial environments.
Identifying the Moor Frog
The moor frog is a slender amphibian, displaying a reddish-brown coloration, though shades can vary to include yellow, grey, or light-olive. It measures between 5.5 to 7.0 centimeters in length. A distinguishing feature is its solid belly, often white or yellow, with small dark spots sometimes visible on the throat.
It has a pointed snout and a large, dark spot behind its eye, near the ear. Subtle black stripes extend from its nostrils along the sides of its head. These markings, along with its size and body shape, help differentiate the moor frog from other similar frog species in its range.
Life Cycle and Environment
Moor frogs inhabit wet environments, including lowland swamp meadows, floodplains, marshes, and ponds that are free of fish. They prefer habitats with still or slow-moving water, ample vegetation, and a muddy or sandy substrate. While semi-aquatic, they spend significant time on land, particularly outside the breeding season, often migrating up to a kilometer to summer feeding grounds after reproduction.
Their diet consists of terrestrial invertebrates, including insects, their larvae, earthworms, snails, and spiders. The breeding season for moor frogs occurs in spring, from March to May, depending on the local climate. During this period, males develop a temporary blue coloration, which is believed to signal their fitness to mates. This blue hue, along with stronger forelimbs and nuptial pads, is most pronounced when the males are in the water for breeding.
Females lay their eggs in large clusters within shallow, vegetated water, with each female depositing up to 2000 eggs. These egg masses develop into tadpoles after several days, undergoing metamorphosis into young frogs over several weeks. Young frogs reach sexual maturity around their third year.
Conservation Efforts
The moor frog is classified as “Least Concern” by the International Union for Conservation of Nature (IUCN). Despite this designation, many European countries consider the conservation status of the moor frog to be unfavorable, with populations declining in certain areas. This decline is attributed to habitat destruction and pollution.
Threats include drying standing water bodies, changes to hydrological conditions, agricultural intensification, and urbanization, which lead to habitat loss. The species is also sensitive to water quality changes from pesticides, intensive fertilization, and waste disposal. Efforts to protect the moor frog involve safeguarding its habitats, monitoring populations, and mitigating human activities, with the species being protected under various European directives.