Studying Amphibians in the Field: Using Approximate Measures

Red Eft, the immature form of the Spotted Newt. (c) Kim M. Bennett, 2013.

 

Frogs and Toads and Salamanders... Oh, My!

Here in Connecticut, we have just come out of the April showers that were not.

Oh, we had wonderful, almost summery temperatures, and the buds began to break. But, without any measurable rain in April, almost everything remained frozen in time, waiting. The spring peepers we wrote about in the last blog post grew a bit subdued in their calls, not having anywhere to lay their eggs. The peas and lettuces that we early gardeners planted begged for water to carry them through what is normally our rainy and wet time of year.

But we have rain this week! And, with that rain, spring is bursting forth rapidly! The amphibian friends that have grown rather hidden over the past few weeks are coming out in droves now.

Our frogs and toads broke onto the scene early this year, with a few brave spring peepers coming out during a warm snap in February, and our woodland frog and toad species making their debut last month (we haven't gone down to the pond to check out the more aquatic friends, yet... Stay tuned.) This month marked the first month we have seen salamanders.

Our Amphibian Survey: May 2013

Here is a photo gallery showing our survey of amphibians, to date:

Our amphibian survey, May 2013. (c) Kim Bennett, 2013.

We created this survey form so we can observe the changes in the seasonal distribution of the amphibians in our area, over time, as well as to chronicle the seasonal patterns in each specific species over the course of a year. We like having all of the information on one sheet, which is posted on the refrigerator.

Even the adult children take part (the photo of the red eft, above, is courtesy of #2 Son, the Animal Whisperer, who dashed over to our house early [I mean EARLY] one morning after finding the little fellow in his driveway as he left for work).

To get an idea of the relative number of frogs, toads and salamanders in our area, we decided to color code our entries so we could know, at a glance. Besides, at least two of us in the house (probably more) have a fascination with those 16-color Flair packs they sell in Staples.

Did I ever tell you I have a thing for office supplies? I think it goes along with being a teacher.

While there are three main groups of amphibians here on our chart, they actually are divided into the following groups, taxonomically [click on the name to see a photograph of a representative species - or the link, if we've already written about it]:

• Mole salamanders (here is our post on the Spotted Salamander that the Plantsman rescued from the road one night after work)
• Lungless salamanders
• Mudpuppies
• Newts (see the image at the top of this post, courtesy of the Animal Whisperer)
• Toads (here is our last post, showing a photo of a Fowler's Toad that was strolling across the driveway)
• Treefrogs (there's a great video showing Spring Peepers on our frog survey post)
• Spadefoot Toads
• True Frogs (here's a little Wood Frog that somehow ended up in our living room) 

Since tree frogs are arboreal, often the only way that you can observe them is to learn their call. When we identify a frog (or a bird, for our bird list -- especially our owls) by call, we mark the entry with a (c).

The Animal Whisperer found a Gray Tree Frog once and brought it to show us. We considered that a treat, since you are not likely to actually see them, most of the time. They were a lot bigger than I expected them to be -- not tiny like Spring Peepers.



It's always good to have a site that you can go to, to listen to calls of animals. Connecticut Amphibians has excellent photos, descriptions, and audio files to help folks in our state learn more about the amphibians here.  They also have a great discussion of the importance of vernal pools to our local amphibian species, something that is an important part of any amphibian study, no matter where you live. -- [Here is an image of a vernal pool in the nature preserve near our home] -- The Yale Peabody Museum of Natural History has a lot of great information, as well, but no audio files.

Measuring Amphibians

In our home, as well as in my classroom, we learn to handle wildlife gently, if at all, observe creatures for a short time and in a respectful way, then turn them loose. So we have to learn to observe them very carefully when we have them, so we can compare later. Having a digital camera is a wonderful asset to both homeschool and classroom, when it comes to reflecting on and studying things that we can't really hang onto for a long time.

If you are going to use digital images as a way to observe animals, try to make sure that you snap them with something in the frame that shows scale. See the images, below, for ideas:

This photo from  "Frog-Hunting in Connecticut" shows a Fowler's Toad in the parking lot. I waited until it hopped closer to the parking space number (most of us can visualize how big those numbers are -- about a foot tall) so you could get an idea of how very large the toad actually was -- about 6 inches long, although adult Fowler's Toads can be up to a humongous 9.5 inches long! Wow!

I considered getting a ruler to place alongside the toad, but my dog was so excited about the toad that I was afraid 1) the toad would be startled and hop away or 2) the dog would try to eat it.

Here's a great way to get a pretty accurate measurement of your amphibian, if it's one that slows down enough for you to gently pick it up.

The fingertip joint of an adult's first finger is about an inch long. Actually, this joint, even in a child from about the age of 8, on, is about an inch long. I used to teach my third graders to use their first finger joint as an approximate measure, if they didn't have a ruler. In this photo, you can use this measure to estimate that this little eft (which is probably on the large side, for efts) is about 3 1/2 inches long, from nose to tail tip. Red efts range from 1 1/2 to 3 1/2 inches long.

Here's that photo of the Spotted Salamander from "A Night-time Surprise: Spotted Salamanders", showing another visual cue you can use to estimate the size of one of your amphibian friends.

My son was carrying the salamander from one side of the road to the other, in the front of his tee-shirt. In the photo, you can see the hem of his shirt. If you are wearing a tee-shirt now, check out the hem at the bottom. If it's a regular shirt, the folded over and stitched part will be about an inch wide. Accounting for the semi-curled up nature of the little fellow, we can estimate its size to be about 8-9 inches long, from nose to tail-tip, so it's probably an older member of its species, which range from 5 inches to 10 inches long, depending on their age. They can live up to 10 years, if they don't get run over during breeding season.

Data Sheets and Notebooking Pages, for Your Amphibian Studies

In the last post, I shared a link to "Animal and Plant Surveys: 10 Reasons to Get Outside and Survey," which explained the science behind surveys as a learning task. I also included links to blank survey sheets, such as the one I showed, above, which you can use to keep track of your animal species.

An amphibian study is a great opportunity to compare animal species, too. For one way to study comparison using an interactive bulletin board, see "Comparing Nests: The 'Same and Different' Center."

There are many sources of Venn diagrams (all kinds of varieties). At  {.docstoc}, you have many to choose from, all downloadable, free of charge.

We download a lot of our general nature study pages from The Notebooking Treasury - we have been members since we began homeschooling in 2010. From now through May 31st, 2013, they are having their NotebookingPages.com 7th Birthday Sale-a-Bration Event, with discounted merchandise, chances to win prizes, and specially priced memberships (for new members) and membership extensions (for current members).

Become a Notebooking Pages LIFETIME Member (as we are) during their NotebookingPages.com 7th Birthday Sale-a-Bration Event, and you get all this:

• Save $25 on your membership
• Receive access to 150+ current notebooking products
• Receive ALL future notebooking products
• Receive up to two years FREE access to their notebooking (& copywork) web-app, The Notebooking Publisher™
• Receive a $100 e-gift Bonus Bundle from various homeschool publishers
• Earn a chance to win some great prizes … an iPad mini, $100 Amazon.com gift card, LIFETIME access to The Notebooking Publisher™, and a LIFETIME membership to MomsToolBelt.com.

How could you resist?

Try Our Amphibian Study Pages - FREE!

During the next four weeks, you can enter to win a copy of My Amphibian Survey, a 36-page e-Book full of notebooking pages, centers ideas and curriculum extensions on amphibians. Two lucky contestants will get copies of this e-Book. Also, in honor of springtime, we are raffling off one copy of Nests, Nests, Nests! - our fall e-Book on nests of all kinds of animals (including amphibians) for one lucky contestant. Just enter using the Rafflecopter Form, below.


a Rafflecopter giveaway

 

Frog-Hunting in Connecticut: Our 10 Frog Species

Jumping Jehoshaphat! It's Frog Season!

After what seemed like an incredibly long winter here, we finally have the most spectacular spring weather ever! Patio tables are being dusted off and set up, little cell packs of potting soil are showing up on people's front steps after work. Kids have ditched long pants for shorts, and knees are going to school skinned.

This month's Outdoor Hour Challenges have been studies of reptiles and amphibians, and I almost thought we wouldn't be able to participate! While it's still a little cool for our reptile friends to show up, there are signs of amphibians all around.

Sing a Froggy Song...

WAY back in February, we had a brief warm period -- warm enough to leave the sliding door cracked so the cats could run in and out at night. On one of those nights, when we were walking our dog before bed, we heard a familiar, but very lonely, spring voice...

Spring peeper (Pseudacris crucifer) [Credit: Potomac Overlook Park, 2012 via Creative Commons]

I guess one little fellow thought he'd brave the elements and get a jump on the cutest spring peeper girls.

Now that we have temperatures in the 40's and near 50 most nights, we hear the wonderful chorus every night.

Other fun facts about spring peepers:

• My Caribbean friends say that our spring peeper is very much like the little coqui that folks from Puerto Rico love so much. 
• The call of the spring peepers is affected by air temperature. The warmer the air, the more "peeps" per minute. The Audobon society has a great article all about the song of the spring peeper.

Frogs, Toads and Other Nighttime Friends

If you limit your nature study to daytime, you are missing lots of cool stuff! In fact, some of our best nature study happens by accident, when we are walking the dog before bedtime. Not long ago, as I waited for Lucky to find just the right spot in the woods along the driveway, I heard a deep snort. Not really wanting to find out if it was a young black bear (they demolish bird feeders in our town on occasion), or a buck that got surprised by the dog, we quickly found a more well-lit place to hang out. But what a story we had to tell when we got back in the house!

So, on one of these evening sojourns last week,  we spotted the biggest toad I have ever seen, not hopping, but lumbering, first left front and right rear leg, then right front and left rear leg, across the driveway. The dog thought this was the most exciting thing next to a cat running by -- but I didn't let him catch the toad, because toads secrete something from their skin that makes potential predators vomit.

Fowler'sToad, Bufo fowleri. [Photo credit: Kim M. Bennett, 2013]

We have so many toads where we live, that you have to take a flashlight when you walk down the drive at night, or you might step on one. During the day, they burrow under the woodchips in my flower bed. I have more than once been surprised while working in the flowers, when the ground erupts suddenly and hops away!





[One of my kids' favorite books when they were very young...]

Froggy Went A-Courtin'...

My youngest son discovered a pond deep in the woods. Since the weather is going to be rainy tomorrow, then nice on Friday, we expect there to be a lot of frog activity over the next few days. So we're gathering our frog egg collecting materials to be ready.

We have a huge crop of skunk cabbage in the woods, which tells us that these are low spots that often collect water. If you have a low spot that is wet every spring, it may be a vernal pool. My eldest son, the naturalist, says that you can tell a vernal pool from a generic wet spot, because the leaves are gray and washed out, and look dusty during dry times of the year.

Vernal pools are important for amphibians, since all of them (that live in Connecticut) depend on water for their larval stage. Larger vernal pools are also frequented by migrating birds in the spring. These pools don't have to be very big, but, in our town, they are important enough that builders are not allowed to build over them.

When you walk in the woods, look for skunk cabbage, and ground that seems spongy and soft. After rains, check here for amphibian eggs.

Vernal pools are important habitats for amphibians. [Photo credit: Kim M. Bennett, 2012]

Our Frog Survey

There are ten frog and toad species native to Connecticut. Next to each, I have marked them to indicate their status (per the Department of Energy and Environmental Protection):

E = endangered

T = threatened

SC = special concern 

D = declining

S = secure

U = uncertain

I = introduced

1. Eastern Spadefoot (E)
2. Northern Leopard Frog (SC)
3. Gray Treefrog (D)
4. Wood Frog (D)
5. Eastern American Toad (S)
6. Fowler's Toad (S)
7. Northern Spring Peeper (S)
8. Bullfrog (S)
9. Green Frog (S)
10. Pickerel Frog (S)

It makes me sad to see some of our froggy friends on the decline or endangered. Amphibians are so very sensitive to environmental changes and toxins.

Wood frogs occasionally hitch a ride into the house, on the sliding door. [Photo credit: (c) Kim M. Bennett, 2012]

We adapted our animal survey to use for our amphibian work this month. So far we have three critters on the list:

• Northern Spring Peeper (Pseudacris crucifer) (Feb/Mar/Apr)
• Eastern American Toad (Bufo americanus americanus) (Apr)
• Wood Frog (Rana sylvatica) (Apr)

 
We'll keep track of each month that we see each species, to get an idea of their patterns in our area, adding to the list as they wake up for the spring.

If you'd like a copy of the survey sheet, click the link, below. Check out the "FREEBIES" tab for other pages we have made available for free.

See also "Animal and Plant Surveys: 10 Reasons to Get Outside and Survey" (Simple Science Strategies) for more on the use of surveys in nature study.


This post was linked to the following great carnivals and link-ups: