Common Eastern Small Frog, Crinia signifera

Detailed introduction

The Common Eastern Froglet ( Crinia signifera ) is a small, terrestrial frog with a melodious call. Belonging to the family Myobatrachidae , it is widely distributed in southeastern Australia and is one of the most common frogs there, easily heard near water but not always easily spotted.

Classification and nomenclature

• Commonly used Chinese name: Common Eastern Small Frog (also translated as Common Eastern Frog, Common Eastern Small Frog, etc., there is currently no unified Chinese name)

• English name: Common Eastern Froglet

• Scientific name: Crinia signifera

• Family and genus: Myobatrachidae (Family of Australian frogs) → Crinia

Appearance and Identification Features

Although the common eastern small frog is small in size, it has a wide variety of patterns and very distinctive details:

• Size: Adults are typically 18–30 mm in length, making them very small frogs;

• Body shape: The body is slightly flat and the limbs are slender, making it suitable for moving around in muddy areas near water, grass, and fallen leaves.

• Back color: ranges from gray, brown, olive to near black, often with irregular spots, stripes or net-like patterns, with great individual variation;

• Back texture: The skin appears slightly rough, with visible small bumps;

• Abdomen: The ventral surface is mostly light-colored, such as white, grayish-white, or with fine spots; light spots may sometimes be seen on the throat.

• Other features: Partial webbing between the toes facilitates movement in shallow water and at the edges of wetlands; overall body color is relatively low-key, which is beneficial for camouflage among mud and fallen leaves.

Because of the extreme variation in the patterns on its back, the common eastern small frog is often called the "variable-looking small ground frog". When identifying it in the wild, it is usually judged by a combination of body size, call and habitat.

Distribution range and habitat

The common eastern small frog is a common species in southeastern Australia .

• It is distributed in New South Wales, Victoria, Tasmania, and parts of South Australia;

• Records exist from coastal areas to inland low mountains and hills.

It has a wide range of habitat adaptations:

• Natural environments: wetlands, streamsides, marshes, lake shores, meadows with small puddles, and forest clearings;

• Artificial environments: irrigation ditches in farmland, puddles along roadsides, small ponds in city parks and gardens, etc.;

• They can often be found and heard calling wherever there is shallow water or seasonal flooding nearby.

Habits and calls

The common eastern small frog is a typical nocturnal frog that prefers humid environments :

• During the day, they mostly hide in grass, rocks, piles of fallen leaves, and crevices along the riverbank;

• They are most active at dusk and night, especially after rainfall;

• Male frogs call at the edge of water, in shallow water or stagnant water. Their calls are short and repetitive, often described as fine "clicks," "ticks," or continuous "kik-kik-kik" sounds.

In suitable seasons and environments, many male frogs will call out at the same time, forming a dense "frog chorus". However, due to their small size and camouflage, many people can only "hear their voices but not see them".

feeding habits

The common eastern small frog mainly preys on various small invertebrates:

• Terrestrial insects such as ants, small beetles, and small flying insects;

• Small spiders, mites, springtails, and other terrestrial arthropods;

• They also occasionally feed on other tiny invertebrates and insect larvae.

They use their vision and sensitive receptors for vibrations to locate small prey nearby, then quickly extend their sticky tongues to capture them in their mouths.

Reproduction and Development

The reproduction of the common eastern small frog is closely related to rainfall and water conditions:

• The breeding season varies by region, but is generally more concentrated in the warmer and more humid seasons.

• Male frogs gather at the edges of ponds, still pools, ditches, and seasonal waterholes, calling out to attract female frogs.

• Female frogs lay their eggs in shallow water or near waterside vegetation, and the egg clusters are usually attached to aquatic plants or submerged objects.

• Tadpoles develop in water, are small in size, and are quite sensitive to water temperature and dissolved oxygen. It is especially crucial for them to complete their metamorphosis before the temporary water body dries up.

In some temporary waterlogged areas, large numbers of tadpoles can be seen moving together, a significant portion of which belong to this small eastern frog species.

Protecting the status quo and threats

The common eastern small frog is currently assessed as Least Concern (LC) on the International Union for Conservation of Nature (IUCN) Red List. This indicates that it has a wide distribution, a large population, and remains quite common in many areas.

However, local populations may still be affected by the following factors:

• Wetland landfill and water pollution reduce suitable breeding grounds;

• Urban sprawl and land development have led to the fragmentation of local habitats;

• Long-term uncertainties arising from diseases (such as chytriditis) and climate change.

The key to protecting this small native frog species lies in maintaining diverse shallow wetlands and clean water bodies, as well as preserving microhabitats such as riparian vegetation and leaf litter.