Spea hammondii (Baird, 1859)

Common Name and Taxonomy

Spea hammondii, commonly called the western spadefoot, is a relatively smooth-skinned species of American spadefoot toad.

Eye Characteristics

Its eyes are pale gold with vertical pupils.

Body Coloration

It has a green or grey back, often with orange-tipped skin tubercles, and a whitish abdomen.

Hind Foot Structure

Each hind foot bears a wedge-shaped black spade.

Adult Size

Adult toads measure 3.8 to 7.5 cm (1.5 to 3.0 in) in length.

Juvenile Appearance

Juveniles look similar to adults, but have more distinct spotting.

Population Distribution Overview

Populations of Spea hammondii are localized but widespread.

Geographical Range

It occurs across California's Central Valley, extends south to San Diego, and lives in some parts of the desert.

Habitat Preferences

This species prefers local grassland, scrub, and chaparral habitats, but can also be found in oak woodlands.

Activity Patterns

It is nocturnal, and active only during the wet season, summer storms, or on evenings when substrate moisture levels are elevated.

Handling and Skin Secretion Volume

It can be handled easily, and produces less skin secretion than similar toad species.

Secretion Properties

Its secretions smell like peanut butter and may cause sneezing.

Population Status

While Spea hammondii is experiencing some habitat loss, it remains common across its range, and population declines are very minor.

Regional Conservation Listing

Despite this, it is listed as near threatened in some California counties.

Lifespan

The average lifespan of Spea hammondii is about 12 years.

Sexual Maturity

Individuals reach sexual maturity in their third year.

Breeding Period

Breeding and egg-laying normally takes place from late winter to the end of March, and males can be heard calling during this period.

Seasonal Egg Count Variation

Sources conflict on the number of eggs females lay per season: one source notes females can lay up to 2,000 eggs per season, while another states females may lay more than 500 eggs in one season.

Egg Cluster Characteristics

Females lay multiple small, irregular clusters that hold between 10 and 42 eggs each.

Egg Laying and Fertilization

Egg clusters attach to underwater objects in temporary puddles or ditches, and males deposit sperm onto the eggs.

Egg Hatching Time

Tadpoles can emerge in as little as 15 hours.

Tadpole Development Pressure

After hatching, tadpoles must complete development into toads before their puddle habitat dries up.

Metamorphosis Duration

Development from egg to fully transformed toad takes 8 to 16 days, most commonly 12 to 13 days.

Metamorphosis Speed Distinction

This is the fastest metamorphosis recorded for any frog or toad.