Rise of the Salamanders

After a dry, smoky spell, we finally got a good rain last night to clear the air. The soaking moisture also lifted some long-toed salamanders (Ambystoma macrodactylum) up to the surface to feed. After not seeing one all of spring and summer, I found four in the yard after midnight. These little guys have moist skin and spend most of their lives under the duff and deeper. But when the ground is wet, they often rise to the surface where it's more efficient to look for small spiders and insects to eat.

An adult long-toed salamander watches and waits for a midnight snack to walk by

Kissing Cousins

Northern Pacific Treefrog (Pseudacris regilla regilla)

I'm struck by how much the face of this Northern Pacific Treefrog (Pseudacris regilla regilla) looks like the face of a snake.

Chorus frog practices flashing "bunny ears"

The amphibians (frogs) branched off the family tree from a common ancestor with reptiles (snakes and lizards) about 320 million years ago. In fact, reptiles are more closely related to birds and mammals than to amphibians. This means that, in a family reunion group photo, the elder amphibian representative would be on one end, and the young reptile member would be on the other end. In the middle would be (in relative order) mammals, turtles and the dinosaur family (birds and crocodiles).

Does this thought give you pause when thinking about this summer's family reunion? You might want to be a little choosy when deciding which cousin you stand next to for the big photo op. Someone might try to flash "bunny ears" behind your mammalian head.

Links in the Food Chain

A Cyclops swims past a one-inch-long juvenile, long-toed salamander.

With its one red eye, the Cyclops (Cyclops spp.) is a tiny crustacean that's related to crabs and shrimp. Cyclops are omnivorous, eating smaller critters like diatoms and dinoflagellates. In turn, the Cyclops are eaten by all manner of invertebrate predators, like larval dragonflies.

Larger dragonfly larvae can catch and eat small salamanders, like this long-toed salamander (Ambystoma macrodactylum). But the tables can turn as the salamanders grow larger.

The aquatic, juvenile salamanders have an overlap period when they possess both shrinking gills and emerging limbs. The growing salamanders eventually develop lungs, absorb their external gills, and leave the pond for a life on land - where many will be relished by garter snakes.

Silent Summer, Noisy Spring

An adult Pacific Treefrog showing toe pads and a dark eye line ending at the shoulder

This frog portrait shows you all the clues needed to identify this native amphibian.

The Northern Pacific Treefrog (Pseudacris regilla regilla) is one of the Pacific Chorus Frogs, and it's Montana's only frog with a dark eye line and obvious toe pads. (Here the wet eye line is reflecting a blue sky.) The light-colored throat also tells us that this is a female, as males have a dark throat patch. The upper body can vary in color from brown to green, bronze to gray, and individual frogs can lighten or darken their color to better match their surroundings. This evening, I discovered this handsome greenish-gray specimen hiding in our grayish wood pile.

I'm betting that you've never seen a Pacific Treefrog - not because I'm a gambling man but because I've only seen three of them in all my years wandering the Montana woods. The adults are nocturnal, hiding in silence during the day, and they only come down to water in spring.

I'm also betting that you've heard them quite clearly, if you've ever spent a spring evening near a small pond or shallow lake in the Pacific northwest. Males arrive at the breeding ponds in late March - from one-quarter to several miles away - calling loudly to the females that arrive a week or two later. The females select a mate in the dark based on his calling behavior. The male repertoire includes calls to attract females, to attract other males, and to space males around a pond.

Pacific Treefrog distribution is patchy in northwestern Montana. Surveys by the Natural Heritage Program have found them widely distributed at lower elevations. In Glacier Park, they've only been reported in the area around West Glacier, and in nearby ponds along the Middle Fork.

Here at the end of the road, a chorus of hundreds on a windless spring night is a milepost that tells us that we've made it through another Montana winter, and the treefrogs' sudden exuberance always stops me in my tracks. The eggs that are laid in April will hatch in mid-May, and the tadpoles will transform into frogs from July to September, depending on the water temperature.

The new adult frogs will leave the water in fall and patiently wait for the return of spring - like a lot of us in these parts.

Long-toed Salamanders for Lunch

Adult long-toed salamander

"Hey you guys," the bearded one calls out, "look at this thing I dug up!" "What is it?" asks the young woman holding a shovel.  The unbearded guy pipes in, "Is it a lizard?" "It's a newt," the bearded one says with authority. "Put him back," the woman hefting the spud bar tells the boys. The unbearded one declares, "Let's eat him!" to mixed laughter and eewwws.

I know they're just kidding around, just a bunch of young Montana Conservation Corps kids, digging up a rotten set of wooden steps at a Forest Service campground, and having fun in the fall woods. I climb up the hill to join them. "That's a long-toed salamander," I explain. "They live underground most of the year. Only come up to feed at night, and to breed in spring. Just re-bury him over there, out of your way." But my help spoils their fun. They preferred the thought of eating a newt - that would have made for a good story to be recounted for years, long after adulthood kidnaps their carefree days.

Long-toed salamanders (Ambystoma macrodactylum) are the most common of Montana's three salamander species, but they only occur in the northwestern corner of our state. The first museum specimens were collected in 1891 during Northern Boundary Survey of the 49th parallel. The species ranges west to the Pacific, and up from Oregon to northern British Columbia. Their success in the northwest is probably due to their versatility. They occur from sea level to 9,100 feet elevation (in the Big Hole area of Beaverhead County), from wet coastal forests to cold mountain meadows.

They have four toes on their front feet and five toes on their hind feet. Macro dactylum translates to "long toe," referring to the extended forth toe on their hind feet, and giving them their common name. Just don't call them newts, and don't eat them.

Your Long-toed Neighbors

Presenting the handsome, long-toed salamander -- probably the most common amphibian in western Montana. What, you've never seen one? Well that's probably due to your unusual habitat use. You evolved to live above ground and be active during the daytime ("diurnal"), just the opposite of our four-inch long, subterranean and nocturnal neighbors. As a result, we don't notice each other very often.

As adults, long-toed salamanders spend most of their lives burrowed below ground. They live in moist niches like decaying logs, rock fissures and small animal borrows. On summer nights, they'll climb to the surface to eat worms, spiders, insects, and other tasty morsels. Here in Montana, they hibernate through the winter, apparently burrowing down deeper.

In early spring, they'll often migrate across snow to reach their breeding ponds, marshes and lakes. Determined salamanders will converge on the breeding sites from up to half a mile away, but an estimated 95% of adults live within 200 meters of their breeding pond. (Dispersals, on the other hand, can sometimes cover great distances. Genetic research from southwestern Montana has shown that salamanders are capable of moving between ponds that are seperated by mountain ridges.)

The first ones to reach the breeding ponds are adult males, who then court the females as they arrive a week or so later. The handsome male will rub his chin on hers -- in that seductive, salamander way -- encouraging her follow him and pick up a spermataphore that he then deposits in the shallows. How could she resist?
 
Fertilization is internal and she'll soon lay several hundred eggs in multiple masses, anchored to plant stems in water 2-3 feet deep. The adults return to land and, in 3-4 weeks, larval salamanders hatch out, spread out, and hide out in the aquatic plants and debris along the pond bottom.

This aquatic, larval stage may last from several months to several years, depending on water conditions and food availability. These youngsters are about two inches long and look like tadpoles with legs. They sport three pairs of feathery gills branching out from either side of their rather large head.

During metamorphosis, the larval gills are absorbed and the salamanders emerge from the water as air-breathing juveniles. They move uphill during rainy nights, away from the pond. These juveniles will reach sexual maturity 1-2 years after metamorphosis.

Montana's long-toed salamanders may live for 5 or 6 years, while lifespans of up to 10 years have been reported in warmer parts of their range. The species ranges from southern Alaska to northern California, between the Pacific coast and the Rocky Mountains. The spotty populations have managed to occupy a wide range of habitats, from semi-arid sagebrush deserts to sub-alpine meadows.

Salamanders must negotiate a wide range of obstacles, both natural and man-caused. For example, severe drought can cause 100% larval mortality if the breeding pond goes dry. The predators of larval salamanders include fish, dragonfly larvae and (non-native) bullfrogs. Adults are eaten by voles, garter snakes and Kingfishers.

Non-native fish introductions cause big problems for Montana's little salamanders. Over the years, more than 50 species of non-indigenous fish have been introduced to our state. Almost half of our 1,650 high elevation ponds and lakes -- waters that were historically fish-free -- now contain non-native salmonoids. These fish now dominate areas where larval salamanders used to be the top of the aquatic food chain. While introduced fish have extirpated native salamanders in some Montana lakes, salamanders have also recolonized a few lakes after non-native fish were removed.

Another potential problem for salamanders is maintaining a migration route between upland habitat and breeding areas. A good example of this occurred in Glacier's sister park, Waterton National Park.

A population of long-toed salamanders went unnoticed in Linnet Lake, until concrete curbs were added to the adjacent road in 1990. The following spring, hundreds of salamanders migrating downhill towards the lake couldn't climb the curbs, and they became trapped in the road. During one week in April 1992, community volunteers manually lifted more than 2,000 salamanders over the curbs during cool, rainy nights. So the considerate Canadians -- having evolved much further along in their wildlife ethos -- lowered the curbs and built four salamander crossing tunnels under the road. As a result, salamander mortality from cars fell from 44% to 0%.

Happily, that population of long-toed salamanders has gone back to being virtually unnoticed by their diurnal neighbors.

Behind the lens: We had some help noticing this salamander during migration, about 75 feet from the lake. When we first met him, he was halfway down the throat of a 12-inch long, writhing garter snake. On seeing us, the snake dropped the salamander and disappeared. The salamander didn't appear too injured, so we hid him under some woody debris near the water's edge, and wished him well.

Note that, unless it just fell out of a snake's mouth, you should avoid picking up or touching wild animals.