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.

Marbled salamanders, another species of “mole salamander” (like spotted, Jefferson, and tiger) receive the superlative for the earliest breeders as females actually lay their eggs in the fall when vernal pools are dry. The eggs hatch during autumnal rainstorms and the larvae overwinter beneath the ice while the adults head underground to brumate. But the most interesting behavior undoubtedly belongs to the Eastern tiger salamander. These large amphibians navigate the frigid fresh water throughout the winter months, sometimes laying egg masses as early as December. They are listed as an endangered species in New Jersey and are restricted to just a few locations in the southern portion of the state. As my amphibian work largely keeps me in north Jersey, tiger salamanders have long occupied a position on my herp bucket list. Until last month, that is, when my colleague Larissa invited me to join her, a team of USFWS & ENSP biologists, and a few extraordinary volunteers on a quest for tiger salamanders.

Mole salamanders, true to their name, spend a significant portion of their lives underground. This, coupled with the fact that we can’t rely on calls to reveal their locations, make these amphibians a bit tricky to survey. Even during the breeding season, daytime visits to the pools are generally unlikely to yield adult sightings. Therefore, the best way to determine presence and persistence of salamander populations is by conducting annual egg mass counts during the species respective breeding periods. This was our mission on February 6^th.

The study area that we visited was a complex of 9 distinct pools that have long been known to support tiger salamanders. The pools have been monitored using egg mass surveys for many years. Historically, a few were so deep that boats were required to effectively perform counts. On the day of our survey, only three had any water at all, and the deepest pockets only reached our knees. According to the experienced members of our team, this dearth of water in the smaller pools has become more common in recent years.

We began the day in the largest pool, where veteran volunteer John immediately spotted an adult tiger salamander that quickly sped beneath refugia along the bottom. The group fanned out along the pool’s edge. Each person was responsible for scanning 5-10 feet on either side of them. We walked slowly through the water to ensure that we did not inadvertantly step on adults that may have been nestled within the sediment near our feet. As we made our way forward, we searched for egg masses, which look like gelatinous blobs filled with tiny black dots, counted them, and recorded whether they were attached to vegetation vs. free floating on the bottom and if they were freshly deposited. Determining the approximate age of the egg masses can be difficult for beginners but John and Wayne, another volunteer with >20 years of tiger salamander experience, were very generous with sharing their knowledge. Egg masses expand in size as they absorb water from their surroundings, thus the more tightly packed the gel appears the newer it is.  Overall, we located > 500 egg masses during the course of the day, as well as 4 adults, 2 marbed salamander larvae, and 9 red bellied turtles. The latter two are voracious predators of newly hatched tiger salamanders.

While numbers returned during this year’s survey effort were pretty consistent with last year’s, the low water levels within the main pools and lack of water in historic pools underscores a major concern that we have for the stability of vernal pool obligate species in the face of global climate change. South Jersey has, thur far, received no snow this winter. As snowmelt is a primary source for pool formation, we must wonder whether its absence, compounded by inconsistent weather patterns, could render these important breeding grounds obsolete in the near future. Annual data collected to document trends and changes in these unique communities will become paramount as we look to engineered solutions to remedy this problem.

If you would like to be part of the solution, please consider the following:

1. Never remove wildlife, including tiger salamanders, from the wild. It is illegal and they are happiest where they are.
2. If you are a fan of off roading, whether on an atv, dirt bike, Jeep, etc., please stick to designated trails! While driving through puddles may seem fun, you never know who you might crush by doing so.
3. If you come across rare wildlife while enjoying nature, report it to NJDEP. We cannot protect wildlife if we do not have documentation that it is there.
4. Spread your knowledge to friends, family, and other community members. Most people will choose to do the right thing if they are aware that they have a choice to make.

I’d like to extend my gratitude to Wayne, John, Matt (expert volunteers), Heidi and Robin (USFWS), Bill Pitts (ENSP), and, of course, Larissa (CWF) for inviting me out for this experience. As a young biologist and relative newcomer to the field of herpetology, it was inspiring to learn from folks that have put in the time to develop invaluable passion and wisdom for these amazing creatures. Looking forward to next year’s effort!

Tags: amphibian, Amphibian migration, Conserve Wildlife Foundation of New Jersey, Eastern Tiger Salamanders, egg masses, Mole salamanders, new jersey wildlife, salamander migration, salamanders, South Jersey, vernal pools

This entry was posted on Wednesday, March 8th, 2023 at 2:23 pm and is filed under Amphibians. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.