Salamanders and Newts

As promised, our species comparison series returns to the world of herps. A few weeks ago we looked at turtles, tortoises, and terrapins, which are all reptiles. This week we’ll explore the differences between salamanders and newts, which are both amphibians.

Before going into the differences between salamanders and newts, let’s have a look at the differences between reptiles and amphibians. Both are cold blooded and can spend time on land or in water. Reptiles, however, spend more time on land generally. They breathe exclusively with lungs (some turtles are the exception, because nature hates following a hard rule). Amphibians spend more time in the water, generally, and can breathe air on the surface or below water, using their smooth, moist skin to exchange gases in many cases. Reptiles have dry, scaly skin that doesn’t breathe. Reptiles lay soft eggs on land, while amphibians prefer to lay their eggs in the water, usually in a gelatinous mass.

Rough-skinned newt

 Just as tortoises and terrapins are turtles but not all turtles are tortoises or terrapins, all newts are salamanders but not all salamanders are newts. Newts are a type of salamanders that prefer to spend most of their time living on land. Some lay eggs in the water, some on land. Some go through stages of development from larva to adult, some are just miniature versions of adults. Some salamanders have lungs, some have gills, some have both, and some have neither. There is much variety in the salamander’s order, so spotting the differences between salamanders and newts is difficult. A general rule is to look at the skin. Frog-like skin, which is smooth and wet, is a salamander. Toad-like skin, dry and warty, is a newt.

Northwestern salamander (USFWS)

A third critter thrown into the mix, also a member of the salamander order, is the siren. It looks and behaves like the salamander and newt, but instead of having four legs it only has two. Sirens have flat tails that they use for swimming, moving it from side to side like a fish does.

Greater siren (University of Georgia)

Are you confused by all this? Don’t worry about. I’m learning right along with you. Fortunately for you, all these technical terms and differences are merely to satisfy your curiosity; for me it’s a career choice. We’ll wrap up this series next week and leave the natural world for the labs and halls of scholarly debate. This week’s information comes from the SanDiego Zoo.

Splitting Hares

Continuing last week’s theme of animal comparisons, we will examine the tortoise’s fabled racing opponent, the hare and try to figure out how it’s different from a standard rabbit. Both are members of the mammalian order of lagomorphs, along with a cute little critter called the pika (which we won’t discuss today).

Desert cottontail, a rabbit species (NSP)

Jackrabbit, a hare species in spite of its name
(NPS)

Unlike the functional differences between turtles and tortoises, the differences between rabbits and hares are mainly cosmetic. In general, hares are larger and have longer ears. But there are more differences, being on Day One (before, actually).

Hares have a longer gestation period, by about two weeks. If rabbit and hare litters are born the same day, the hares will have fur and open eyes. They quickly become mobile. The rabbits will be hairless, blind, and cold. Unlike you, they can’t regulate their body temperatures. If you see a baby bunny just keep in mind, baby hares have hairs.

Baby hares are called leverets (USFWS)

Baby rabbits are called kits or kittens (Rabbit Smarties)

Hares live in above ground nests, while rabbits with the exception of the cottontail, are subterranean nesters. Hares are also faster and skittish, while rabbits are more relaxed and make better pets. Don’t try to catch a wild one to keep as a pet though.

So like last week, we found some similar looking critters, but there are differences. One thing these wascally wabbits have in common is that they both multiply like rabbits. Or hares.

This week’s information comes from NationalGeographic.

The Shell Game

Ever wonder what the difference is between a turtle and a tortoise? They’re both shelled reptiles so is it all just a name? Not exactly. All tortoises are turtles, but not all turtles are tortoises.

Desert tortoise (NPS)

A tortoise is a turtle that lives exclusively on land, while most (but not all, remember there’s always an exception) turtles spend most of their time in the water. Because of the lifestyle differences, turtles have webbed feet and tortoises don’t. And of course sea turtles, who only come on land to lay eggs, have flippers instead of legs. Tortoise shells are generally taller, while turtles have a flatter, more aquadynamic shell design.

Box turtle (NPS)

Loggerhead sea turtle (USFWS)

Now that you have that down, let’s introduce the terrapin. Terrapins are mix of the landlubbing tortoise and seafaring turtle. They spend half their time on land, half in the water. They have a more streamlined shell than a tortoise, yet it’s taller and rounder than a turtle’s. 

Diamondback terrapin (USFWS)

This week's compare and contrast is from the National Marine Life Center.