Articles

Guest Post: Green Tree Frog’s Body Chemistry is Affected by Nearby Calls

Today, we have a guest post from my friend – Chris. He wrote this for an assignment at school and thought my readers would like to read it.

IMG_0887

When male green tree frogs are looking for mates, they call with advertisement calls, telling the world “I’m here, this is my territory, come get me.” These advertisement calls are mostly the types of calls that you hear whenever you go out in the woods, especially in the spring. They’re the calls most frequently used by frogs, and the ones that are the most predictable, allowing us to use them to recognize frog species the same way we do with bird calls. However, these calls have a side effect; They don’t just attract female frogs, they also bring in other males that want the females and territory that the calling frog might have.

Bringing other male frogs leads to aggressive interactions between male frogs frequently. These don’t look quite like the types of fights that we may be used to though, as they tend to result in the frogs showing off with aggressive calls to each other until one backs down. These calls do a good job acting as a proxy for a fight without the risk of injury and other costs of actually fighting, as the larger, more fit frog usually wins.

A study from Christopher J. Leary from the University of Mississippi looked at how both these aggressive calls and advertisement calls affected both frogs emitting them and frogs hearing them. It had previously been established that advertisement calls from males generated more sex hormone production in females around, as well as in the calling male, but this study addressed also how it affected listening males, and how the aggressive calls impacted both males involved. He found that winners of these fights between male frogs showed slightly higher levels of corticosterone, a stress hormone, immediately after the fight, but the losing male showed much higher levels of the corticosterone. This may change these losing frogs strategies to reproduction in the future. Changes to the frog’s body chemistry begins to explain a phenomenon called satellite males, where some frogs stop trying to compete for mates and territory, and instead try to be sneakier and intercept females for quick mating opportunities. This change was hard to understand in the context of evolution, as giving up mating opportunities or competing for mating opportunities seemed like it would never be beneficial from an evolutionary perspective, but if it is caused by lost conflicts, this may help us understand why frogs would make this change of strategy.

His results on the impacts of advertisement calls on listening males were less clear though. He found slight drops in androgen, the main sex hormone, levels among males listening to other male’s advertisement calls, which was backwards of the expected result. Previous research had suggested that frogs would produce more sex hormones when hearing other males advertising, which makes logical sense, as this would lead to them seeking out conflict with the other males looking to steal their mates and territory. Leary’s result is suggested as an adaptation by these frogs to try to prevent rival males from hearing their song and attempting to come fight for their territory and mate, but this result seems unclear, given its disagreement with some previous research.

Other studies will surely be done in the future to try to verify this surprising result, and to investigate the complicated dynamics of frog interactions when looking for mates. But the major result of the impact of the aggressive calls on other frogs helps us better understand how frogs find and compete for their mates, and may help explain satellite males.

Reference: C.J. Leary. 2014. Close-range vocal signals elicit a stress response in male green treefrogs: resolution of an androgen-based conflict. Animal Behavior, 96 (2014), pp. 39-48

Advertisements
Articles

World Frog Day

Today, March 20th, is World Frog Day! If its not obvious, I really like frogs and so do you if you are reading my blog! Frogs are currently facing serious threats to their survival currently. From information from the IUCN Red List site, I have made a graph of the conservation status of all the frogs. This graph excludes the categories extinct in the wild and data deficient.

WINWORD_2018-03-20_00-02-22

Over a quarter of these frog species are listed as Endangered or Critically Endangered. This is not good and we need to stop these trends. Now let’s see what happens to the graph when we add in species that are listed as data deficient (ones that the IUCN doesn’t have enough info to categorize them).

WINWORD_2018-03-20_00-14-24

Around a quarter of frog species we don’t even know their conservation status. We don’t know if we need to help protect them. We need to find out these answers.

For this World Frog Day, why not give to some frog charities such as The Amphibian Foundation, The Honduras Amphibian Rescue and Conservation Center, or Save the Frogs!?

Articles

Venomous Frogs

1280px-Perereca-de-capacete_-_Aparasphenodon_brunoi.jpg
Bruno’s Casque-Headed Frog by Renato Augusto Martins

We all have heard of poisonous frogs such as the Golden Poison Frog or the Cane Toad but do you know that there are venomous frogs?

What is the difference between poisonous and venomous? To be venomous, the animal needs to inject the toxin into the blood stream of it’s victim. Snakes inject their toxins with their fangs, scorpions with their tails, and stingrays on their barbs. A poisonous animal doesn’t inject any toxins, they just produce them. Lazy poisonous animals.

There are only two known venomous frogs in the world and both happen to come from Brazil. These species are the Bruno’s Casque-Headed Frog (Aparasphenodon brunoi) and the Greening’s Frog (Corythomantis greeningi).

You are probably wondering, how do these frogs inject their prey? Fangs? Super cool claws? Well sorry to disappoint but they literally use headbutts to inject their venom. They have spines on their head that connect to a gland that produces the venom. How weird.

How deadly is the venom of these frogs?  It was calculated that a single gram of the toxic secretion from a Bruno’s Casque-headed Frog can kill around 80 people. It’s venom is 25 times more toxic than pit vipers from the genus Bothrops. The Greenig’s Frog is not as toxic but still like twice as toxic as the pit vipers. F

p02yyf57.jpg
Greenig’s Frog by Carlos Jared
Articles

Frog Reproduction

It’s almost Valentine’s Day and I know all of you are wondering, how do frogs have sex? Today is your lucky day because I’ll be explaining it. There are many different ways that frogs and toads reproduce and if I try to cover them all, this post might become its own book.

Frogs and toads generally start breeding in early spring or late winter if the weather is nice. They also start breeding at the change from dry season to wet season. The breeding season ends in summer, giving the offspring the longest time to develop before winter or dry season comes.

Bufo_bufo_couple_during_migration(2005).jpg
By Janekpfeifer at de.wikipedia – Uploaded by Janek, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=251993

The most well known way that frogs reproduce is in the water through external fertilization. Male frogs can be found in bodies of water calling for female mates during the night. Some frogs breed in vernal ponds / ephemeral pools (temporary ponds created by melting of snow and spring rain) because these ponds lack fish that can prey on their offspring. Other frogs look for more permanent bodies of water because their tadpoles don’t undergo metamorphosis until after the next winter. For this sort of reproduction, females come into the territory of a male and the male jumps on her back. This mating position is called amplexus. Males will often try to mate with anything, including different species of frogs, toads, and fish. Male frogs don’t have penises, they have an opening called the cloaca where the sperm is released. Females have this opening too, where the eggs come out. The male grips the female from behind so that when he releases his sperm, there’s a better chance at fertilizing the eggs. Other males sometimes will come into the frog’s territory and also jump on the female while the other male is holding her. They sometimes even form giant piles of frogs or toads. Occasionally, it gets so rough, the female is killed. Usually though, the female releases her eggs and the male fertilizes them and she goes on her merry way.

While some frogs mate in the water like that, many others mate on the ground, and some even mate in the trees. During reproduction in the trees, the couple makes a foam nest out of the eggs and other secretions to keep the eggs dry. For the species that reproduce on land, the eggs might never need water because when they hatch, the offspring is immediately a froglet and not a tadpole.

Ascaphus_truei_web
By Mokele – Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=11586685

Not all frogs use external fertilization, some use internal fertilization. There are different ways that frogs and toads use internal fertilization. Some frogs such as the Tailed Frogs from Ascaphidae, perform internal fertilization then lay fertilized eggs later. The Tailed Frog’s tail is used in fertilization.

The Nimba Toad (Nimbaphrynoides occidentalis) is the only known viviparous frog / toad. The frog is pregnant for 9 months and the babies feed off the mom’s secretion.

The genus Nectophrynoides and the Golden Coquí (Eleutherodactylus jasperi) are the only known ovoviviparous frogs and toads, where they have eggs inside them that hatch and then they give birth to little froglets.

Limnonectes_larvaepartus_adult_female
Photo By Mirza D. Kusrini, Jodi J. L. Rowley, Luna R. Khairunnisa, Glenn M. Shea, Ronald Altig – Kusrini MD, Rowley JJL, Khairunnisa LR, Shea GM, Altig R (2015) The Reproductive Biology and Larvae of the First Tadpole-Bearing Frog, Limnonectes larvaepartus. PLoS ONE 10(1): e116154. doi:10.1371/journal.pone.0116154, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=37784743

Ok just kidding about them being the only ovoviviparous frogs because there is another one but it’s kind of different. The Fanged Frog (Limnonectes larvaepartus) is also ovoviviparous but instead of giving birth to froglets, it gives birth to tadpoles.

 

Articles

Do frogs fart?

cm3KICy (1)
Art by LifeisDANK

A few days ago, my friend and I were talking and he asked me if frogs fart? I thought about it and I have never heard my frogs fart before but I had no idea if I just missed their farts or not.

You don’t have to know the answers to everything to be a good scientist, you just got to know where to find the answers. Former Herper of the Week, Nick Caruso, actually made a database of animal species and if they fart. Here’s a link to it – https://docs.google.com/spreadsheets/d/19gMMn4Wmw3BNLWMojEy7kgrjnjVB2JlMSwd1s-nYyUc/edit#gid=0.

From there, we learn that frogs have weak sphincters so that if they fart, we probably can’t hear it. It also goes on to say that African Bullfrogs and Horned Frogs do fart and it smells bad.  Maybe I need to set up a recorder to see if Rayna farts.

If you want to learn more about animal farts, you can pre-order a book that Nick Caruso co-authored called Does It Fart?: The Definitive Field Guide to Animal Flatulence on Amazon today! It will be released on April 3rd this year. You can also get a copy for me because I’m poor.

JPEG_20180201_210105

Articles

Differences between Salamanders and Newts

 

Have you ever wondered what the difference between a salamander and a newt is? Well wonder no more. If you don’t know, salamanders refer to any species in the order Caudata. The order contains over 700 different species in 10 different families. To examine what a newt is, we have to look at just one of those 10 families – Salamandridae. Don’t be afraid by the name, there are newts in here. The family is split into three different subfamilies or groups. They are Pleurodelinae, Salamandrinae, and Salamandrininae. The subfamily Pleurodelinae contains all the newts! There are 16 different genera in the subfamily and includes the majority of the species in the family. Why isn’t it named Newtidae instead of Salamandridae?

So now you know the taxonomic differences between newts and salamanders but what are the observable differences? Adult newts live more of an aquatic or semi aquatic life style while salamanders generally live more of a terrestrial life style. There are some salamanders that live aquatic life styles such as the Axolotl but the majority of adult salamanders are terrestrial (land loving). Because of the fact that adult newts are more aquatic, newts have tails that are wider and more paddle like and they have more webbed feet. Not all newts have these tails and some do live more of a terrestrial lifestyle.

Articles

13 Largest Salamanders in the World

One toed amphiumadanhipes
by Dan Hipes

The One Toed Amphiuma (Amphiuma pholeter) can grow up to 13 inches. They are the smallest of the three different kinds of Amphiuma. They are found in Southeastern United States.

017

The Eastern Tiger (Ambystoma tigrinum) can grow up to 13 inches but usually between only 6 to 8.25 inches long. It is found in the eastern United States, southeastern Canada, and Mexico.

Ambystoma_mavortium_2006.jpg
photo by  Daiju Azuma

The record largest Western Tiger Salamander or Barred Salamander (Ambystoma mavortium) measured in at 13 inches but it was also a neotenic salamander. They usually are 6 to 8.5 inches long. They are found in the western United States.

Dicamptodon tenebrsosus - Pacific Giant Salamander
photo by John P. Clare

Coastal Giant Salamander (Dicamptodon tenebrosus) can grow up to 13 inches long but usually only up to 6 inches longs. They are found in the western part of the United States and Canada.

photo from the NPS

The Common Mudpuppy (Necturus maculosus) is the largest mudpuppy. The longest one recorded was 19 inches long. They are usually between 8 to 13 inches long. It is found in the Eastern United States and Southeastern Canada.

photo by Arne Hodalič

The Olm (Proteus anguinus) grows usually between 8 to 12 inches long but they can grow up to 16 inches. They are the largest salamander in Europe.

Siren_intermedia_2
photo by Stan Shebs

Lesser Siren (Siren intermedia) can grow up to 2.25 feet. It is found in Southeastern United States.

by Brian Gratwicke

The Hellbender or Snot Otter (Cryptobranchus alleganiensis) often grows between 11 and 22 inches long but the record length recorded is 29 inches (2.4 feet) long. It is found in the Southeastern United States.

Siren_lacertina
photo from the USGS

The Greater Siren (Siren lacertina) can grow up to 3.2 feet long but are usually recorded at lengths between 20 to 30 inches long. It is found in the Southeastern United States.

photo by opencage

Three Toed Amphiuma (Amphiuma tridactylum) can grow up to 3.4 feet long but usually only between 1.5 feet to 2.5 feet long. It is found in Southeastern United States.

photo by Brian Gratwick

Two Toed Amphiuma (Amphiuma means) can grow up to 3.8 feet long but are usually around 14.5 to 30 inches long. It is the largest of the Amphiumas. It is found in the Southeastern United States.

photo by V31S70

Japanese Giant Salamander (Andrias japonicus) measures in at 4.9 feet long, making in the second largest salamander in the world.

by  ZSL

Chinese Giant Salamander (Andrias davidianus) is the largest salamander in the world. It has been observed to grow to 5.9 feet but lately most of the salamanders found are smaller than that. The average length is usually around 3.9 feet long.

Articles

Froggin

IMG_1138 (2)

Hello reader! You may have stumbled upon this site somehow and you might be wondering, what is froggin? Froggin or Frogging is the act of catching frogs just like fishing is catching fish. Gone Froggin is about non-lethal, safe frog catching. We don’t want any frogs to die because keeping a healthy populations of frogs allows everyone to enjoy froggin for many years.

Articles

10 Smallest Frogs and Toads in the World

Here’s my list of the 10 smallest frogs and toads in the world. I determined the order by the frog’s max size. This is what my research found but if you find a smaller one, don’t hesitate to holla at me.

Paedophryne_kathismaphlox
Image By Fred Kraus – Kraus F (2010) New genus of diminutive microhylid frogs from Papua New Guinea. ZooKeys 48: 39–59. doi:10.3897/zookeys.48.446, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=10595008

At 10.9 mm, Paedophryne kathismaphlox is 10th smallest frog in the world.

chrome_2018-02-01_20-35-32.png

Stumpffia yannik measures in at 9.8 –10.6 mm, making it the 9th smallest frog

1280px-Sechellophryne_gardineri
Image by Evan Pickett

Gardiner’s frog (Sechellophryne gardineri) is only 10.1 mm long, make it the 8th smallest frog.

Eleutherodactylus_iberia10
Image by Pierre Fidenci

Monte Iberia eleuth (Eleutherodactylus iberia) maxes out at 10 mm. 7th smallest frog

2723823072_186143f4ea

Izecksohn’s toad (Brachycephalus didactylus) is only 9.8 mm long. It’s the 6th smallest frog

Paedophryne_verrucosa2

Image By Fred Kraus – At the lower size limit for tetrapods, two new species of the miniaturized frog genus Paedophryne (Anura, Microhylidae) doi:10.3897/zookeys.154.1963, CC BY 3.0, https://commons.wikimedia.org/w/index.php?curid=17670695

Paedophryne verrucosa is the 5th smallest frog, only being 9.3 mm max.

Paedophryne_dekot2

Paedophryne dekot is the 4rd smallest frog in the world. It measures in at a max of 9 mm.

chrome_2018-02-01_20-31-32.png

Stumpffia contumelia is the 3rd smallest frog, measuring between 8.0 –8.9 mm

1024px-Paratype_of_Paedophryne_swiftorum.png
Image By Rittmeyer EN, Allison A, Gründler MC, Thompson DK, Austin CC – (2012). “Ecological Guild Evolution and the Discovery of the World’s Smallest Vertebrate”. PLoS ONE 7: e29797. DOI:10.1371/journal.pone.0029797., CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=18014489

The second smallest frog in the world is the Paedophryne swiftorum measuring in at 8.6 mm.

Paratype_of_Paedophryne_amauensis_(LSUMZ_95004)
Image By Rittmeyer EN, Allison A, Gründler MC, Thompson DK, Austin CC – E. N. Rittmeyer et al. (2012). “Ecological Guild Evolution and the Discovery of the World’s Smallest Vertebrate”. PLoS ONE 7: e29797. DOI:10.1371/journal.pone.0029797. → Figure 2 → tiff, CC BY 2.5, https://commons.wikimedia.org/w/index.php?curid=18014488

The smallest frog in the world is Paedophryne amauensis. It is only 7.9 mm long.

Articles

NBA Teams but Frogs

IMG_1138 (2)

Chicago Bullfrogs

peeper

Philadelphia Spring Peepers

Spea_bombifrons
Plains Spadefoot by Stanley Trauth

San Antonio Spadefoots

TO ACCOMPANY FEATURE STORY AUSTRALIA-TOADS.

Cleveland Cane Toads

Miami Reed (frogs)

Boston Coastal Tailed Frog

Atlanta Hairy Frogs

hyalinobatrachium_fleischmanni01a
Fleischmann’s glass frog by Mauricio Rivera Correa

Golden State Glass Frogs

giant squaker

Los Angeles Squeckers

 

1280px-Litoria_nasuta
Rocket Frog by Wikiuser Froggydarb

Houston Rocket Frogs

Toronto Rain Frogs

244

Los Angeles Cricket (frogs)

ZSL_London_-_Vietnamese_mossy_frog_(01)
Vietnamese mossy frog by Katie Chan

Minnesota Mossy Frogs

Brooklyn Natterjack Toads

Purple Frog

New Orleans Purple Frogs

Phoenix Suriname Toads

Detroit Parsley Frogs

Portland Poison Dart Frogs

Dallas Mountain Chickens

IMG_0277

Washington Wood Frogs

Indiana Gopher Frogs

Atelopus_varius_1

New York Clown Frogs

0407_Mgouldii-Kellerberrin-

Oklahoma City Turtle Frog

1280px-Australia_green_tree_frog_(Litoria_caerulea)_crop.jpg
Whites Tree Frog by LiquidGhoul

Utah Whites Tree Frogs

Sacramento Coquis

Denver Colorado River Toads

1280px-Budgett's_Frog
Budgett’s Frog by Ltshears

Milwaukee Budgett’s Frogs

samuraiblue2_zps7d185bcd

Charlotte Horned Frogs

Orlando Mantellas