Archive for the 'Amphibians' Category

A Blue View: A Free Spring Chorus, Courtesy of Frogs

A Blue View is a weekly perspective on the life aquatic, hosted by National Aquarium CEO John Racanelli.

From the smallest plants and animals invisible to the human eye to entire ecosystems, every living thing depends on and is intricately linked by water.

Tune in to 88.1 WYPR every Tuesday at 5:45 p.m. as John brings to the surface important issues and fascinating discoveries making waves in the world today.

April 2, 2014: The Sounds of Spring Peepers & Wood Frogs

A Blue View podcastClick here to listen to John discuss the
chorus of sounds produced by frogs to
attract mates during the breeding season!

Through the winter, woodlands and meadows are mostly quiet at night. But with the arrival of spring rains and warming temperatures, that silence is broken by loud choruses of wood frogs and spring peepers. These are the first frog species to come out of hibernation and begin the year’s amphibian breeding season.

Spring peepers are small, just one inch in length, but you wouldn’t know it from their sound. Each peeper can produce a call as loud as 90 decibels. Multiply that by the number of frogs in a wetland habitat, and you have a sound that can rival that of a rock concert.

Spring Peeper

Photo of spring peeper via Wiki Commons.

Why so noisy? That’s how the male spring peepers attract females from the surrounding woodlands. As the females come out of hibernation, they are carrying between 200 and 1,000 eggs, and the females are outnumbered by the males at about 9 to 1. Competition is intense, and females choose males based on the quality of his song.

Because of this competition, males wrestle for the best spots at the chorusing site. Interestingly, Dr. Don Forester and David Lykens of Towson University discovered that some spring peeper males were successful in breeding with females through a very deceptive strategy. Because calling requires a huge amount of energy, some spring peeper males, known as satellite males, don’t call at all.

Instead, these satellite males save energy by positioning themselves near the top singers. They then intercept females moving toward the calling males. Satellite males are smaller than calling males and would probably be at a disadvantage in trying to attract females with a less impressive voice.

Though the spring peeper is often considered the first frog to emerge from hibernation and therefore an early sign that winter is indeed over, the wood frog is usually ahead of the peeper. In fact, in mild winters, wood frogs have been observed arriving in woodland pools as early as February.

Wood Frog

Photo of a wood frog via Wiki Commons.

Wood frogs are often referred to as “explosive breeders” because they arrive in large numbers and have a short breeding season, usually only lasting the first few weeks of late winter or early spring. Wood frogs almost exclusively lay their eggs in vernal pools, which are small temporary bodies of water that form in depressions.

Because these pools dry over the summer, wood frogs must lay their eggs, the eggs must hatch, and tadpoles must fully develop and metamorphose before the pools dry. The wood frog’s strategy is to arrive first and maximize the time needed to make it the entire way through the process. Wood frog tadpoles often dine on the newly laid eggs of later arriving frog species.

Even as these frogs perpetuate their life cycle, they do face challenges. Their well-being is intricately linked to the survival of their woodland home and their vernal pools. Be considerate of these habitats in your neighborhood by preventing trash and other pollution from traveling through your waterways. Slow down while driving on warm spring nights, allowing amphibians to migrate safely across roadways. And when you pay these amazing creatures a visit in their natural habitat, observe but don’t disturb.

Want to buff up a bit more on your amphibian knowledge? Check out our latest infographic on all things frog

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Happy World Frog Day!

Can YOU freeze during winter hibernation, thaw, and continue on? Yeah, we didn’t think so… 

In celebration of World Frog Day, we’ve put together an infographic that highlights some of our favorite amphibian facts!

national aquarium frog infographic

Did you know? The word amphibian comes from the Greek word amphibios, which refers to the fact that the early life stages of many frogs are aquatic and that the adult stages are generally terrestrial.

There are approximately 6,000 known species of frog found worldwide (on every continent except Antarctica)! Frogs are especially prevalent in North and South America! Not all frogs are poisonous, but run-ins with those that do posses toxins can be fatal.

Join us in sharing your love for frogs on Facebook and Twitter

Three New Species Discovered in Australia’s “Lost World”

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The first-ever biological expedition of Australia’s “lost world” – the small patch of rain forest in Cape York – has resulted in the discovery of three new species!

Cape York is a large peninsula located on at the tip of Australia’s state of Queensland. This secluded piece of the continent is largely regarded as one of the largest, unspoiled wilderness areas on Earth.

cape melville australia

Cape Melville. Photo via National Geographic.

This past March, an expert team of scientists and filmmakers ventured to the small range of mountain plateaus on Cape Melville (located on the northeastern part of the peninsula). During their four-day expedition, the group discovered and identified three new species of animals: a leaf-tail gecko, a blotched-boulder frog and a shade skink.

These species are especially exciting and interesting for our community as they’re representative of the unique ways animals adapt to the harsh environment of Australia. For example, the blotched-boulder frog has evolved to minimize the need for water in its reproduction – an adaption to suit its dry rocky environment!

It’s thought that primitive versions of the leaf-tail gecko once flourished in the Australian rain forest. Now we know that they have survived over the years by using their flat, uniquely-shaped body to camouflage itself into the rocky terrain, avoiding predators and waiting patiently for prey!

leaf-tail gecko

Leaf-tail gecko perfectly camouflaged. Photo via National Geographic.

It’s exciting to see these discoveries make headlines because many outside of the continent are unaware that a lot of Australia, a country almost the size of the continental United States, has yet to be discovered. Unlike the South American rain forest, which has been well-traveled and documented by scientists for decades, Australia’s land is rough and oftentimes difficult to navigate. It’s climate range can also make extended trips a challenge.

To learn more about these recent discoveries, click here. I’ll be sure to share more information as the team continues their expedition!

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The Life Cycle of Poison Dart Frogs Explained

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National Aquarium has had a long, successful history of breeding poison dart frogs. Here in the Upland Tropical Rain Forest exhibit, we have 16 species of poison dart frogs. Over the last few decades, scientists have become very interested in the reproductive strategies of these species and how they care for their young.

blue poison dart froglet

Dart frogs are incredibly intriguing animals. In addition to possessing toxins and bright colorations/patterns, they also have a fairly complex life cycle!

For most species, females will choose a leaf lying on the rain forest floor to deposit a mass of eggs, which the male will then fertilize. Males are oftentimes in charge of guarding the eggs while they develop.

poison dart frogs developing

Here at the Aquarium, most of our tadpoles develop behind-the-scenes in their own simulated bromeliad cup.

Once the tadpoles have developed, one parent will carry each tadpole to their very own pool of water held in a plant, known as a phytotelma. In the wild, some dart frog species (including many of the species we have in our collection) choose the water-filled cups at the base of bromeliads to safely store young.

Many tadpoles are omnivorous and most species will feed on algae and/or other small animal life (including other tadpoles). During their time in the bromeliads, the tadpoles will progressively metamorphose into full-fledged froglets!

The transition takes approximately two months, and they typically reach adult size and maturity within a year.

The normal life span for these animals in zoos and aquariums is about 10-15 years. Here at the Aquarium, we’ve had frogs live to be at least 23 years old!

ken howell rain forest expert national aquarium

A Blue View: World Water Day

A Blue View is a weekly perspective on the life aquatic, hosted by National Aquarium CEO John Racanelli.

From the smallest plants and animals invisible to the human eye to entire ecosystems, every living thing depends on and is intricately linked by water.

Tune in to 88.1 WYPR every Tuesday at 5:45 p.m. as John brings to the surface important issues and fascinating discoveries making waves in the world today.

March 20, 2013: The Streams of Maryland

A Blue View podcastClick here to listen to John discuss the important role
freshwater plays in the survival of all living things!

Held annually on March 22, the United Nation’s World Water Day brings attention to the importance of freshwater and advocates for the sustainable management of freshwater resources. Globally, freshwater accessibility is critical for the survival of all living things, yet it is a significantly threatened resource. In Maryland, our own freshwater streams and rivers need our help as they run to the largest estuary in the United States, the Chesapeake Bay.

Even if you don’t live on the water, the health of the Chesapeake Bay watershed, which encompasses more than 64,000 square miles to six states and the District of Columbia, affects each of us every day. More than 100,000 streams, creeks, and rivers weave through the Chesapeake’s vast watershed. In fact, according to the Maryland Department of Natural Resources, we all live within 15 minutes of a stream, making freshwater health not just a Maryland issue, but a backyard issue as well!

Healthy streams are organically balanced, with enough oxygen to support life. Decaying plants and animal waste provide a balanced amount of nutrients, and the water is not too acid or too alkaline. In these healthy streams, runoff is kept to a minimum, and chemicals from farms, factories, and residential areas do not make their way into the stream. Countless species rely on healthy freshwater ecosystems to thrive. Fish, snakes, turtles, frogs, invertebrates…DNR states that Maryland is home to more than 100 species of fish, 20 species of salamander, and 10 species of turtle, just to name a few stream-dwellers.

diamondbackterrapin

The diamondback terrapin is just one of the many species of reptiles that rely on Maryland waterways!

In a recent assessment by the Environmental Protection Agency (EPA), just 45 percent of sampled streams in the Chesapeake Bay watershed were rated fair, good, or excellent. As outlined in the EPA’s Strategy for Protecting and Restoring the Chesapeake Bay Watershed, the goal is to improve the health of the watershed so that 70 percent of sampled streams measure fair or better by 2025.

To help increase our understanding of stream health, DNR coordinates a team of volunteers who collect important stream quality data across the state. This program, called Stream Waders, is the volunteer component of the Maryland Biological Stream Survey. The use of these volunteers allows more streams to be sampled, giving a big-picture view of Maryland’s waterways. Volunteers participate in a one-day training session, then spend a couple days in March or April collecting aquatic invertebrate samples from stream beds.

The study of aquatic invertebrates, such as mayflies, caddisflies, and dragonflies, is instrumental in the analysis of streams. Because invertebrates vary in their sensitivity to pollutants, a healthy stream has both sensitive and tolerant invertebrate species while an unhealthy one would have only pollution-tolerant species. Ultimately, the Stream Waders data is used in DNR reports and is available for review on their website.

In our daily lives, each of us can take steps to help keep our community streams healthy. Take a walk along a nearby stream and properly dispose of trash you find along its banks. Limit pesticide use in your yard so that it doesn’t make its way into freshwater supplies. Many local organizations host stream cleanups or wetland restoration events, so volunteer your time. Even just one day a year can make a real difference to a stream in your community.

Take action to keep our streams today by joining our Conservation team at one of our upcoming cleanups


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