Frogs, Pacific Northwest
Frogs are amphibians, which comes from the Greek word amphibios which means living a double life.
Most are born in water as tadpoles and gradually change into adults although some, known as direct developers, are born fully developed. This allows them to be born and live far away from water, such as on mountaintops.
They mainly feed on insects and small animals like earthworms, minnows, and spiders. They don’t need to drink the way we do, they simply absorb water through their permeable skin!
The Pacific Northwest’s tiniest frogs are smaller than a penny, but did you know that the worlds largest frog can grow to be longer than 30 cm and weigh more than 3 kilos!
There are more than 4,700 species of frogs around the world. There are about 90 species of frogs in North America. Unfortunately, around 120 amphibian species, including types of frogs, toads, and salamanders, have disappeared from the planet since the early 80s. As they are indicators of the health of an area, this should be considered a serious problem.
They can be found on every continent in the world except Antarctica. However, the highest concentrations are found in warmer tropical climes.
On the coast, you can find bronze, bull, northern red-legged, chorus and the western toad. Frogs are known as an indicator species and can tell us how healthy an ecosystem is. The majority of amphibians complete the first part of their life cycle in the water and then move onto land as adults.
The Bronze Frog, (a subspecies of the northern green frog) is becoming quite common in the Pacific Northwest, but on Vancouver Island, it is invasive and should be considered a serious threat to our indigenous frog species that live on there.
This frog is a small to medium size frog that can reach up to 10 cm in length. The frog gets its name from the coloration of its skin, they are a bronzy color.
They have a white spotted belly and a dark green color to its upper head and back areas. The males will often have a yellowish throat area.
Being true frogs, they have completely smooth skin and quite large ear discs located on the side of their heads, these ear discs are much larger than other frogs. Their eyes are gold.
Like most other types of frogs, the bronze frog feeds on a diet of worms and bugs that are small enough to swallow.
They will also eat other smaller frogs and tadpoles, but they have plenty of predators that eat them as well, this includes many types of birds and small mammals such as raccoon’s, mink and ermine, I am not sure how predation is on Vancouver Island, but the fact that l am seeing more of these all the time, l would have to guess that there are few predators here that actively feed on the bronze frog.
My wife and I were walking home just after dark early one spring and came across about 100 little frogs ringed around a mud puddle, all calling at the same time. It was fascinating to watch them.
The Pacific chorus frog is a very common sight on the coastal areas of the Pacific Northwest. They are small frogs, up to 6 cm long and are a pale grey or tan to bronze or bright emerald green in color.
These frogs have a dark stripe that runs from the nostrils through the eye down as far as the shoulder. They are often marked with dark patches or stripes on the back, and a light cream colored belly.
They have long legs and their toes have sticky round pads that they use to grip and climb, the toes have little webbing between them, giving them the appearance of being long.
As in most frog species, the females are slightly larger than males. Outside the breeding season, these frogs may be found in forests, open meadows or urban areas, they are not very particular about where they live.
During the breeding season, the Pacific chorus frog makes its way to the water where there is a lot of plant cover. Often these streams or ponds are temporary, drying up by August. By using these wet areas for breeding, these frogs can avoid predatory fish and other amphibians, like the bullfrogs, which require a permanent water source for habitat.
The little frogs breed early in the spring. The males make their way to the breeding ponds first and call in unison to attract the females. The choruses can be incredibly loud considering the size of the frog.
After mating, the females lay small clusters of eggs that they attach to bits of vegetation in calm, shallow water. The egg clusters are irregular in shape and may contain up to 70 eggs. The eggs develop rapidly and hatch in two or three weeks. The tadpoles become frogs at approximately two months. The young frogs may be only one cm long. The young frogs mature quickly and are ready to breed by one year of age.
Adult toads have thick stocky bodies and short legs. Their knobby skin looks dry and lumpy and can range in color from pale green to red. They have pale colored bellies mottled with black and a pale green colored stripe down their backs.
Western toad eggs look like black pearls strung on a chain when you see them in the water. Tadpoles are black or very dark grey with a dark, rounded fin that runs the length of their tail. Tadpoles morph into toadlets that may be as small as 6 mm but otherwise are completely identical to the adult toads.
Adult western toads head to communal breeding wetlands in the early spring. The males search these areas for available females. Males mount females from behind and fertilize the eggs as the female deposits them in the water. After hatching into tadpoles, they quickly morph into toadlets.
We used to go down to the old spit road and watch the annual migration of these toads, thousands of them would cross the road at the same time, since then, this road has been removed and the land has been reclaimed by nature.
Dense groups of toadlets are often found clustered in large piles when the weather turns cool. They forage all summer long. As the weather turns cold in fall, these toads hibernate until spring.
These toads are poisonous. They have an enlarged gland behind each eye that secretes a white poison that can cause the mouth and throat to swell along with nausea, irregular heartbeat, and sometimes even death. These small toads can pose a big danger to pets like cats and dogs. People should always wash their hands after handling any toad.