Southern Dune Frog, Arenophryne rotunda

Detailed introduction

The Southern Sandhill Frog ( Arenophryne rotunda) is a small, round-bodied, native Australian frog native to the sand dunes, specifically adapted to sand dune environments. Belonging to the genus Arenophryne in the family Arenophryneidae, it is a typical "burrowing frog," living year-round in deep sand near the sea and considered one of the representative amphibians adapted to arid sandy environments.

Classification and nomenclature

• Chinese reference name: Southern Sand Dune Frog (general translation);

• English name: Southern Sandhill Frog;

• Scientific name: Arenophryne rotunda (Sandhill Frog, often considered the "southern" sandhill frog, relative to the northern population);

• Family: Myobatrachidae → Genus: Arenophryne

Appearance and Identification Features

The southern sand dune frog has a very unique appearance, looking like a small, round frog:

• Body shape: Adults are usually about 3-4 cm long, with short, round and stout bodies, giving them a "short and fat" appearance;

• Body shape: The body is almost round or short oval, the head is not clearly distinguishable from the body, and the snout is short and blunt;

• Back color: mostly sandy yellow, grayish brown or brown, often with small spots or cloud-like patterns, which are very similar to the surrounding sandy environment and have a very good camouflage effect;

• Abdomen: The abdomen is lighter in color, usually milky white or light gray;

• Skin texture: The skin on the back is slightly rough or has small particles, which helps it adhere to the sand.

• Limbs: The limbs are relatively short but very powerful, especially the hind limbs and hind feet, which are suitable for digging and "drilling backwards" in loose sand.

• Head and eyes: The head is flat and the eyes are not as prominent as those of the tree frog, making it more suitable for hiding in the sand;

• Overall impression: Round, short and stout, with a color close to that of sand, it is a "sand expert" that can be easily distinguished from ordinary frogs.

Distribution range and habitat

The southern dune frog is a species endemic to the coastal dune belt of western Australia .

• They mainly live in the coastal sand dunes and sandy shrublands of the southern part of western Australia.

• Its distribution range is relatively narrow, mostly limited to deep sandy areas near the sea and adjacent low-lying vegetation areas.

Typical habitat characteristics include:

• Moving or semi-fixed sand dunes near the coast; coastal sandy plains;

• The surface is composed of deep, loose fine sand, interspersed with a small amount of low shrubs and herbaceous vegetation;

• Rainfall is generally low, the environment is relatively dry, and there are large temperature differences on the ground.

Lifestyle

The southern dune frog is a nocturnal burrowing frog highly adapted to sandy terrain.

• They spend most of their time underground in the sand, digging "backwards" into the loose sand to avoid the high temperatures and moisture evaporation during the day;

• When the temperature is slightly lower and the air humidity is higher at night, they crawl out of the sand to move around and forage.

• When faced with danger, they will quickly use their hind legs to "dive backward" into the sand, leaving only slight sand marks before disappearing from the surface.

vocal characteristics

The calls of dune frogs are typically low-pitched and slightly nasal, used for courtship and territorial assertion at night.

• On damp nights, especially after rain, male frogs emit a series of short, deep calls from the shallow sand or among vegetation.

• The call is described as a repetitive, slightly trilled "cluck" or "quack" sound that can travel a considerable distance on quiet dune nights.

• Because of their open habitat and low background noise, calls are an important clue for monitoring their population.

feeding habits

Southern dune frogs feed on small invertebrates common in sandy environments:

• Ants, small beetles, spiders, small crickets, and other insects that move on or under the sand;

• Some small insect larvae and other arthropods;

• They typically emerge from their caves at night, moving slowly among the sand and vegetation to ambush or actively hunt passing prey.

Reproduction and Development

Similar to many frogs in arid regions, the reproduction of the southern dune frog is closely related to rainfall and soil moisture:

• During rainy seasons or after heavy rains, male frogs call out to attract mates in the shallow sand or near the roots of shrubs.

• Female frogs lay their eggs in damp, secluded burrows in the sand, rather than in open water.

• The eggs and embryos develop in the moist environment of the sand, and many studies suggest that they have characteristics close to "direct development," with the larvae completing most of their development in the sand.

• After hatching, the tadpoles can move independently in the dune environment, reducing the stage where they must rely on surface water.

Protecting the status quo and threats

In the current global assessment, species related to the southern sand dune frog are generally considered to be at a relatively low global threat level (e.g., Least Concern or near Least Concern) . Nevertheless, due to their narrow distribution range and unique habitat, they still require continued attention.

The main potential threats include:

• Disturbance and damage to the dune system caused by coastal development, road construction, and tourism activities;

• The activities of off-road vehicles and motorcycles on sparsely populated sand dunes compact the sand and destroy micro-habitats;

• Introduced vegetation alters dune structure and water retention;

• Climate change is causing changes in rainfall patterns, affecting the stability of soil moisture in sandy areas.

Designating coastal protected areas, limiting human disturbance in sensitive dune areas, controlling invasive species, and monitoring amphibian populations in arid regions can help protect the southern dune frog and its unique sandy ecosystem in the long term.