The spring peeper (Pseudacris crucifer) is a small frog that produces a very loud sound that those who live on the East Coast of the United States are very familiar with. Peepers range in size from 0.5 inches to only an inch. Males call to attract females. They either sit on vegetation or in the water to call. They will defend a small territory in which they call. Those males who can peep more loudly and rapidly have an increased chance of attracting a female. Larger males also tend to breed more. Due to the energetic cost of this event, peepers are not sexually mature until they are 3 years old. Once they are mature they waste no time, and one of the 1st frog species to start reproducing after hibernation ends. Females also lay a whopping 600 to 1000 eggs per season making them an R selected species. They are in the family, Hylidae which contains a wide range of species but is generally considered to be treefrogs and their allies.
They are a terrestrial species and prefer to live in wooded areas near water bodies that they breed in. While they are good climbers (in fact they even have tiny suction cups at the end of each finger) they prefer to live hidden in the leaf litter or on the ground. They will lay their eggs in vernal pools, ponds or wetlands. The larvae then metaphorize 45 to 90 days later depending on water availability. The frogs have a preference for those waterbodies that have vegetation and those without fish which can be predators of their larvae. A study in Arkansas documented that the species uses caves in the event of a drought because of the high relative humidity.
Chytridiomycosis is a disease that is killing amphibians worldwide at alarming rates. To read more about amphibians see this blog post. The disease is caused by Batrachochytrium dendrobatidis or Bd for short. Bd is a fungus that is specific to amphibians. Currently, the disease is responsible for the greatest disease-caused loss of biodiversity in recorded history. Species have had massive drops in populations and seem to have disappeared overnight.Bd occurs inside the cells of the outer skin layer. It causes microscopic changes in the skin and enlarges this layer. This is deadly because amphibians absorb water and salts through the skin. In the family of lungless salamanders, and one lungless species of caecilian Bd causes them to suffocate. Bd travels into the mouthparts of tadpoles or other larval amphibians. When tadpoles change into adults the infection spreads to the skin. Spores, which are the reproductive part of the fungus, cause the skin to become enlarged. This reduces osmotic regulation and electrolyte blood levels drop which leads to cardiac arrest. Chytridiomycosis has almost a 100 percent mortality rate.
The class Amphibia contains amphibians which are some of my favorite animals. There are three major types which are frogs & toads (order Anura), salamanders (order Caudata), and caecilians (order Apoda). All these orders share certain characteristic including being endothermic, meaning they are unable to regulate their own body temperature. They have both lungs and gills, typically they have gills in the larvae stage but then develop lungs in the adult stage. Their eggs are anamniotic, meaning they are covered by a gelatinous mass that protects the eggs and prevents them from drying out. The warmer and moister an area the more likely it is that they will have more species of Amphibia.
The order Anura contains both frogs and toads, and over 3,400 species! They have longer hind legs than front legs which gives them the ability to hop. The tail is lost in the adult stage and adult males are typically the only ones that vocalize, and they do so to attract mates. Within the order, there are a few distinct families which include the tailed-frog (Ascaphidae), spadefoot toads (Pelobatidae), narrow-toed toads (Leptodactylidae), true toads (Bufonidae), and true frogs (Ranidae). These are only 5 families. I will post later but this is a good start. If you learned the basic characteristic of each family it will greatly improve the speed and accuracy with which you can identify species.
this family only has one species (Ascaphus truei) that lives in the Pacific Northwest
spadefoot toads (Pelobatidae)
mostly live underground and come out at night
have a horny digger on their hind feet and help them dig
breed in temporary pools, and therefore their eggs and larval can develop as quickly as 12 days
narrow-toed toads (Leptodactylidae)
most species are tropical and lay eggs on land
found in the Southern US to South America
there are over 800 species, so characteristics vary widely
true toads (Bufonidae)
over 350 species, 17 species in the US
skins very warty with parotid glands behind the eyes
shorter legs than frogs as they are designed for hopping, not leaping
usually burrow during the day, hunt insects at night
webbed feet, usually have distinct ridges down the back
aquatic larvae, aquatic and terrestrial adults
Going back to the salamanders, order Caudata, they are distinct by a long slender body, four limbs, and tail. There are 340 species worldwide. They almost call have smooth skin and glands that promote poison. Salamanders can be found in soil, leaf litter, or in water bodies. They have internal fertilization via spermatophores, which means that the male gives a packet of sperm to the female which she absorbs into her body to fertilize eggs. Breeding occurs in the early spring, often with the 1st warm rain. Salamanders start to migrate to the breeding location, in this process road present a huge barrier to them. Some states even have groups that go out during this time and act as crossing guards for the salamanders. If you are interested I found groups in New Hampshire and Vermont. Sexual dimorphism is common in salamanders meaning that the males and females have different physical characters. The 5 families I will talk about in this blog post are giant salamanders (Cryptobranchidae), mole salamanders (Ambystomatidae), Conger eels (Amphiumidae), lungless salamanders (Plethodontidae), and newts (Salamandridae).
giant salamanders (Cryptobranchidae)
largest living salamanders
the largest species is the giant salamander (Cryptobranchus alleganiensis) which can be almost 6 feet long and lives in Japan
one species, the Hellbender (Cryptobranchus alleganiensis), lives in the US but is near threatened
mole salamanders (Ambystomatidae)
characterized by their stout bodies
found in the US and Canada
there are 30 species of this burrowing salamander
named after the fact that they only emerge to breed
Conger eels (Amphiumidae)
only 3 species
named the overall body shape
found in the southern US
named for the number of toes they have; One-toed amphiuma (Amphiuma pholeter), Two-toed amphiuma (Amphiuma means), Three-toed amphiuma (Amphiuma tridactylum)
lungless salamanders (Plethodontidae)
breathe through the skin and the mouth
there are over 250 species, making it the most diverse family of salamanders
most are found in the Americas but a few are found in Europe
newts and salamanders (Salamandridae)
has the largest geographic distribution of any salamander family
most adults are smaller and rarely longer than 20 cm
Finally, the last order, Apoda, contains caecilians, which are the lesser known group of amphibians and for good reasons. Caecilians is latin for blind ones. They are basically salamanders without legs, although some do have very tiny legs. They live underground and very little is known about them. There are 160 species. THeir eyes may be covered with bone or skin. They hunt prey underground using their head as a sensor. My old biology professor called them nightmare material. vivipary is common among them, meaning that the young develop inside the mother and then they are born. They are found in the tropics in of South and Central America, Africa, and southern Asia. Their skin contains calcite scales which led scientists to originally think they were related to Stegocephalia which is a salamander/ lizard-like creature that lived 350 million years ago.
For the 1st species Sunday I am writing about the Spotted Salamander (Ambystoma maculatum).
In high school, I actually raised some from eggs. I learned a lot about them and salamanders in general during that process and they are very interesting animals! They are found all over the Eastern U.S. and are considered to have stable populations. Adults live in a forest and they lay their eggs in vernal pools or water bodies that lack fish. A vernal pool is an area that only has water during the spring, usually due to melting snow, and they serve as important habitat for amphibians. Adults are between 6 and 10 inches long but are rarely seen because they live in leaf litter, under logs, or in tunnels. They are also active at night.