Conserve Wildlife Blog

Posts Tagged ‘vernal pools’

Animal, Vegetable, (Mineral doesn’t apply)…

Tuesday, March 21st, 2023

This post is the second in our “super salamander (and frog)” series in which we’re exploring some of the unique adaptations exhibited by local amphibians that would seem more appropriate within the confines of a comic book than out and about in our Garden State landscape. Today’s focal species is the spotted salamander (Ambystoma maculatum), our benevolent Poison Ivy. Full disclosure, this topic has nothing to do with plant, though salamanders themselves are not sensitive to the compounds that make humans itchy and have been known to use “leaves of three” as sources of shelter.

For those of you who may be unfamiliar with the DC Comic Universe, Poison Ivy is a villain who often opposes Batman (and occasionally Superman) during her crusade to protect plants and rid the world of environmental destruction. Though her goals may seem in line with ours here at CWF, her methodology differs dramatically and she is often defined as an eco-terrorist. A former botanist, Poison Ivy, AKA Pamela Isley, was poisoned by her professor. Though she survived the experience, the toxins drove her insane and transformed her into a human-plant hybrid. And that is where our connection lies…

If you’ve ever seen an egg mass deposited by a spotted salamander, you may have noticed that the casing often appears green. This is caused by an association with a very particular kind of green algae called Oophilia amblystomatis. The connection between salamanders and algae has been recognized for > 130 years. For most of that time, it was thought that the algae just occurred within the egg. This is a sensible mutualism- it is auspicious to both species involved. Spotted salamander eggs develop in vernal pools. These temporary wetlands may have relatively low concentrations of dissolved oxygen, so the introduction of algae, which can create oxygen through photosynthesis, into eggs can certainly benefit growing larvae. Under experimental conditions where salamander eggs containing algae were cut off from sunlight, growth and development was delayed and resulting individuals were smaller than those exposed to natural circumstances. On the other side, larvae produce CO2 and nitrogenous wastes, which can be used to the advantage of the algae. Studies have shown that Oophilia are most successful in water that has been exposed to spotted salamander eggs, even if they are not within the eggs themselves. Case closed, right?

Developing spotted salamander larva with Oophilia algae. (C) R. Hangarter

Wrong. In 2011, a team of researchers at Dalhousie University in Halifax, Nova Scotia, discovered that the relationship between these two organisms is, literally, skin deep… The algae don’t just infiltrate the salamander’s egg masses. They are also found within the salamander’s tissue cells. This type of connection is called an endosymbiosis- one cell living inside another cell. Coral reefs and their associated algae are the poster children for this phenomenon, but it is not uncommon among invertebrates. Vertebrates, however, tend to have much more active immune systems that are programed to recognize a cell growing within another cell as a health threat. We can be grateful for that, as dangerous pathogens (e.g., malaria), can spread this way. In the case of salamanders and algae, the above-mentioned team discovered that the amphibians were actively suppressing their immune systems to allow for the success of the algae, which indicates that they must continue to benefit from this association. The algae show signs of stress when encapsulated within the body of salamanders; sunlight becomes harder to access, so rather than creating energy through photosynthesis, they switch to the process of fermentation.

The endosymbiotic mutualism between spotted salamanders and green algae is totally unique among vertebrates. No other amphibians, reptiles, mammals, birds, or bony fish are known to support a similar relationship. Research on the mechanisms and the meanings of this “partnership” are ongoing, but scientists are hopeful that the discovery could yield novel techniques for medical advancement.

While spotted salamanders are certainly not hybridizing with their algal associates, in a way, they walk the animal-plant boundary as they incorporate both types of cells within one compact package, therefore making them the amphibious analogs of DC’s Poison Ivy.

Spotted salamander crossed during the 2022 migration.

Our final installment will shift the focus to frogs and, in particular, one that doesn’t mind the late winter chill…

New Jersey’s Amphibious Amazons

Thursday, March 16th, 2023

by Christine Healy, Wildlife Biologist

I felt confident, after the mild conditions that we experienced in January and much of February, that March would skip the “lion” phase of the well-known adage and come in and out like a lamb. I was clearly incorrect…

In anticipation of the amphibian migration, I thought it would be fun to write about some of the most unique adaptations displayed by three early-breeding vernal pool obligates that we target during our Crossing program. These species require access to temporary wetlands in order to complete their life cycles and are thus at greater risk of motor vehicle collisions than other amphibians that don’t rely on these resources. As I started drafting this, I kept thinking about parallels between the behaviors that I chose for each species and superheroes/villains whose background and abilities relate. And so, I’m kicking off this series with our very own Wonder Woman, the Jefferson Salamander.

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Crossed One Off the Bucket List

Wednesday, March 8th, 2023

by Christine Healy, Wildlife Biologist

Every January, once the confetti has settled from the new year’s celebration, I start thinking a lot about amphibians and preparing for their springtime migration. That behavior, however, is not collectively adopted by all of our local frogs and salamanders. Different species have found different ways to adapt to the challenges of a complex lifecycle that relies on environmental factors to inform physiological changes. Wood frogs, as well as spotted and Jefferson salamanders, have conformed to an early spring breeding strategy. Once the ground thaws and snow melt has raised the water level in vernal pools, they are on the move. Since amphibians in temperate climates hibernate (or more correctly, brumate – the “cold-blooded” equivalent), you might think that their appearance in February and March means that they lead the pack. While this seems a reasonable assumption, it’s actually incorrect.

A close up of an adult Eastern tiger salamander
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What’s Happening at Waterloo?

Tuesday, April 11th, 2017

By Allegra Mitchell, CWF Biologist

 

Waterloo Village in Byram Township, Sussex County is more than a tourist attraction and local gem, it is also home to the largest cross-road amphibian migration in New Jersey. Each spring, frogs, toads, and salamanders stir from their hibernation to make their way to their breeding sites. Some of these sites, like the one at Waterloo, are vernal pools – small, temporary bodies of water that appear in early spring as snow melts and rain and groundwater gathers, and disappear throughout the summer as they evaporate. The ephemeral nature of these pools can’t support fish, which would prey on amphibian eggs and larvae. Vernal pools therefore provide some protection for amphibian offspring, with many species such as wood frogs and spotted and Jefferson salamanders – both of which are listed as New Jersey species of Special Concern – relying exclusively on these vernal pools for breeding.

 

 

The greatest challenge for amphibians breeding at Waterloo Historic Village is crossing Waterloo Road. Living in the most densely population state takes a toll on many species of wildlife in the form of habitat loss, degradation, and fragmentation. Each year, many amphibians become victim to vehicular collision as they move from their hibernation sites across Waterloo Road to the vernal pool in which they reproduce. Amphibians may be disproportionately affected by vehicle-caused road mortalities compared to other wildlife because of their tendency to migrate en masse to breeding sites. These annual road mortalities can have devastating effects on amphibian population sizes, especially for the local at-risk salamander populations. In fact, as little as about 10% annual risk of road mortality in spotted salamanders can lead to the local extinction of an entire population.

 

Wood Frog eggs. Photo courtesy of MacKenzie Hall.

To address this problem, the Conserve Wildlife Foundation of New Jersey (CWF) and the New Jersey Endangered and Nongame Species Program (ENSP) organized amphibian rescue efforts. Since 2002, dedicated volunteers have assisted frogs, toads, and salamanders across Waterloo Road during the busiest migration nights. This aid has proven effective in reducing amphibian road mortalities, but it is not a permanent solution to the problem. Efforts are underway to construct under-road tunnels to help guide amphibians safely across Waterloo Road. These tunnels will provide safe passage for these critters throughout the breeding season, including on their migration back into the woods where they will hibernate. Since this return migration is more sporadic and less weather-dependent than migration to the vernal pool, it is much harder to protect amphibians as they make their way back to the forest.

 

 

This year, CWF scientists have begun the initial phases of research to understand current amphibian population sizes and the impact of vehicle traffic on these animals at Waterloo. Scientists and volunteers have been out 7 days a week since amphibian migrations began in late February to tally daily roadkill on Waterloo Road. This study will be used to evaluate changes to frog, toad, and salamander populations as the under-road amphibian tunnels are installed. CWF scientists have also conducted egg mass counts in the vernal pool at Waterloo Village to estimate the current population sizes of the different amphibian species in the area. Having this knowledge will allow CWF to improve on future projects to minimize road-related human-wildlife conflicts.

 

Spotted Salamander egg mass. Photo courtesy of MacKenzie Hall.

Along with improving conditions for amphibians in this location, CWF’s work at Waterloo Village will serve as an example of New Jersey statewide initiatives to reconnect wildlife habitat as a part of the Connecting Habitat Across New Jersey (CHANJ) program. The goal of CHANJ is to make our state landscapes more permeable to wildlife movement so that all of New Jersey’s residents – human and wildlife – will have the space they need to thrive.

 

In an effort to bring people and wildlife together in a positive way at Waterloo Village, CWF scientists are leading educational walks for the public and local schools. Through hands-on interaction, local residents can learn about and appreciate the remarkable wildlife right in their own back yards and what they can do to support conservation efforts.

 

All New Jerseyans can help wildlife this season by planting native plants for their gardens, building bat boxes where bats can roost, and, of course, by keeping an eye out on the roads, especially on warm, rainy nights when amphibians might be migrating.


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Allegra Mitchell is a biologist for Conserve Wildlife Foundation of New Jersey.

 

Tiger Salamander Season

Wednesday, December 28th, 2016

Volunteers Survey For This Rare and Elusive NJ Salamander.

by: Larissa Smith, CWF Wildlife Biologist

Adult Tiger Salamander @ M. Tribulski

On a cold December evening I met up with ENSP biologists and dedicated Tiger Salamander project volunteers to survey for Eastern Tiger Salamanders. The group had been out surveying all day in Atlantic County without spotting any tiger salamanders and were cold but still raring to go. The pool we surveyed has been a successful tiger salamander breeding pool, within a complex of enhanced vernal pools. We weren’t disappointed as we quickly found adult salamanders in the pool and egg masses.

Another great find was a neotenic (gilled adult).  This was a larvae, most likely, from last season that didn’t metamorphose and still had external gills. It had not yet left the pool, whereas most larvae metamorphose and leave the pools in June to July of their hatching year.

Neotenic adult @ M. Tribulski

Surveying for TS@ M. Tribulski

We surveyed a second pool in the complex, but found no sign of adults or egg masses. We found fish in the pool, which is an indicator that there won’t be salamanders since the fish eat the eggs and larvae.

New Tiger Salamander breeding pools have been found by the TS volunteers, in Cape May and Cumberland Counties. It is encouraging to know that these salamanders continue to live and breed in New Jersey and that gives me hope for the future of all NJ wildlife.


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