It’s that incredible time of year when our local frogs are mating. The adult frog is about the size of your thumb, but they are singing with voices so big I can hear them a half-mile away at the neighbor’s pond. Hundreds of them.
Pacific Treefrogs live primarily in the western U.S. The species we see in Northern California is called Pseudacris sierrae or Sierran Treefrog. This lovely little creature has been classified and re-classified so many times, its name is confusing. For simplicity here, we’ll use its more common over-arching name: the Pacific Treefrog (they don’t live in trees).
They require water for mating, so around January or February, depending on how much the earth has warmed, the mature adults journey on their padded toes to ponds or ditches.
The males use their “advertisement calls” to announce their fitness to competing males and to attract females. The male’s throat sack balloons up when it makes this call.
Poor little treefrogs have a lot of predators.
Snakes, raccoons, herons, egrets, and other small mammals and reptiles eat them.
The frogs breed in shallow water sources that usually dry up after winter; taking their chances to reproduce by not being in a predictable, predatory drinking source.
Although their body color is variable (green, tan, brown, gray, reddish or cream), they’re usually just green or brown, like in these photos. Typically they are the color of their environment; but they do also have the ability to quickly change colors to avoid predation.
It is difficult to get any photo of this frog for many reasons: they are more active at night (dark); usually hidden in leaves or half submerged in water; and they stop ribbiting when they feel the vibration of your footsteps.
In addition, they’re super tiny.
Now it’s past mid-March and the males and females are no doubt beginning to pair up. The female will lay her eggs as the male fertilizes them externally.
She will lay an average of 400-750 eggs, in small clusters of 10-80 at a time.
The eggs are visible in daylight, but you have to almost have your face in the water to see them. Binoculars or a powerful camera lens help.
The eggs are gelatinous tiny balls in a cluster, usually clinging to a twig or plant stem. Here are some clinging to the orange weed as noted.
After mating season, the adults leave and the eggs hatch into tadpoles about two weeks later. Left on their own, the teensy tadpoles aggregate for thermoregulation and to avoid predation. They eat algae and bacteria. This stage lasts 2-2.5 months.
In this stage they undergo an incredible metamorphosis eventually growing four legs, and simultaneously losing their tails. The tail gets absorbed into the froglet body. Because there are hundreds of thousands of tadpoles in the neighbor’s pond, we see the tadpoles in various stages of metamorphosis.
Here you see a tadpole with both legs and its tail. The tail has not yet been absorbed. The sun shadows amplify its features.
This photo reflects two tadpole stages on one leaf.
Here is an older froglet swimming, still with its tail; it has more distinctive adult markings. There is also a younger tadpole, tail only, on the left.
Frogs, tadpoles, froglets — they are a yet another reminder of the miracles of life and all its stages.
Written by Jet Eliot.
Photos by Athena Alexander.