The Bucket Theory

Preserved specimen of California newt at the Museum of Vertebrate Zoology, University of California, Berkeley.
This is specimen MVZ:Herp:8101.
Photograph from the Museum's Collections Database at     

http://mvz.berkeley.edu   

Late at night I was pouring through field guides, scientific publications, and online catalogues of museum specimens, but they didn't give me answers as to how red-bellied newts arrived in the Stevens Creek watershed. The little creatures we found were so far out of their reported range, if I was going to get any sleep, I needed the help of experts. So I started calling around.

Wolf's Milk - A Bioblitz Preview

Wolf's milk - actually not a fungus or a Hostess pastry - a fact I learned while browsing iNaturalist   

The National Park Service is having a bioblitz at the Golden Gate National Recreation Area in the San Francisco Bay area on March 28 and 29, 2014. Sponsored by National Geographic, it's gonna be huge. They expect thousands of citizens to join over 300 scientists observing and documenting the plants and animals of Marin, San Francisco and San Mateo Counties at 12 locations of GOGA (the National Park Service's four-letter code for this park).

A bioblitz is an event where animal and plant species are identified in a specific location over a short period of time. The eyes and ears of students and citizens are led by scientists to cover as much area in the park as possible and to confirm identifications. The inventory is useful to understand the park's ecology but it is also a great way for everyone to experience the biological richness of our public lands and the techniques of scientific inventory.

An Honorable Herpetologist

slender salamander  

I was sad to learn of the recent passing of the great herpetologist Robert C. Stebbins.  Long before I met him, I was fascinated with his descriptive and beautifully illustrated field guides to western amphibians and reptiles.  Matthew Bettelheim has posted information about Dr. Stebbins here and is inviting people to share their memories of him. The commentary there will be worth visiting in the next few weeks as Dr. Stebbins encouraged so many people to discover the fascinating world of reptiles and amphibians.  My thanks to his family, colleagues and friends for sharing Dr. Stebbins and his legacy.

Tonight, I think I will share some photos of my favorite times with California herps to say my goodbye. So many scaly and slimy adventures of learning and delight.

Snow Moon

Full moon through California buckeye tree at the Dipper Ranch, February 25, 2013

Late February's full moon is the Snow Moon.  In central coastal California, we had snow for about 4 hours this winter.

I meant to photograph the full moon just as it was coming over Georgia's Ridge. I was inside getting ready by cleaning my best lens only to get distracted by amazing reflections of the cowboy light in the newly cleaned lens.

Moving in Straight Lines

Handsome thighs of a California red-legged frog

I took a workshop last week on the California red-legged frog.  The classroom portion covered biology and behavior, and the day and nighttime field portions covered habitat, life stages and pouncing on frogs under the careful guidance of the certified instructors.  By 10:00 pm of the nighttime training, we were all basically returned to our childhoods. The boys were counting up how many frogs they'd captured, and the girls were wondering why they were following boys around in the woods at night.  Once I took my gloves off, my frog capture rate went up to about 80%, but I preferred the spotlighting duty of being the first to detect the alien-eye-rays bouncing from the willow thicket back to our strategically aimed flashlights.

February Scrambled Ramble

Find a caption for each of the photos below by sorting out the smashed-together words at the end.  All photos are plants and animals currently strutting their stuff in February on the Dipper Ranch.  Click on a photo for a larger view.

Call of the Ponds

In the frenzy of breeding, some amphibians get confused.

The frogs, toads and newts are heading to the ponds and creeks for their annual breeding. With all the rain we've been getting, these are happy herps. Now is a good time to visit ponds and creeks to witness this seasonal event.

The skewed distribution of rain in California means that some ponds and creeks are wet only in the winter and spring months. If there is rain. As a result, many California amphibians only visit the wet areas for a short period during their hectic breeding season and that is the time you are most likely to see and hear them. Not only is the water a window into their reproductive rituals, but in their frenzy to complete their duties before the rain ends, they seem less sensitive to human curiosity.

A male aquatic-phase newt shows off his black nuptial toes.

The male amphibians usually splash down first and undergo some type of physical transformation to prepare for their upcoming adventures. Male California newts develop smooth skin, swollen limbs and streamlined tails for navigating to their sweethearts in water. They get rough, black tips on their toes, called nuptial pads, to grip the female during mating.

Small in size, the male treefrog pumps a bellow below his chin so that his call can be heard from long distances by female frogs (and people too).

From every pond, creek, ditch, cattle trough and puddle at the Dipper Ranch right now, comes the chorus of male treefrogs. Their two-note (kreek-ik) call, which advertises their fitness for breeding to the female treefrogs, is mostly heard on warm nights, but also on rainy or overcast days. At the height of the breeding season, the treefrogs can't seem to resist calling even during a sunny day. The treefrog chorus will suddenly fall silent as you approach a pond's edge, but soon one frog will start trilling, and not to be outcompeted, the others will quickly join in.

Treefrogs in amplexus. As the female (bottom) releases eggs, the male releases sperm for external fertilization.

Newts in amplexus. Sometimes extra males join in.

Fertilization of eggs is facilitated by amplexus, wherein the male embraces the female from above or behind. In the newts, amplexus occurs as the pair swims slowly and gracefully together around the pond. Surely, this is one of the most peaceful rites of springs to be witnessed at the edge of a pond.

A female newt grasps pond vegetation as an egg mass emerges between her rear legs. Another newt egg mass floats in the water below her belly.

Eggs of each of the amphibian species can be distinguished by their different shapes and sizes. See links below for photos and descriptions. It's worth returning to the ponds and creeks in the next few weeks to witness the hatching of tadpoles and larvae and their transformation into tiny land-hardy frogs and newts.

So gather the family and go visit a pond or stream. Walk right up to the edge of the pond or into shallow waters and squat down to watch the aquatic play. Some activities you might try during your pond-gazing visits:

• Can you name the different types of frogs, toads and newts?
• Do you hear different frog calls?
  
• Can you see the difference between the males and the females?
• Can you see different types of eggs?
• What are the amphibians eating in the pond?

For clues, see the links below for more information and photos.

• King of the Pond
• Raining for the Homeless
• Frog Calls
• Night Life at the Ponds
  
• Big Changes in Frogtown
• 256 Newts
• Egg of Newt
  
• Tadpoles Compared
• Frog Alert
• California Herps website
  

Peering at you peering at him.

Names of amphibians mentioned in this posting:

• Sierran treefrog, Pseudacris sierra - formerly called Pacific Treefrog, Pacific chorus frog, Hyla regilla or Pseudacris regilla.
• California toad - Bufo boreas halophilus
• California red-legged frog, Rana draytonii
• Coast range newt, Taricha torosa torosa

256 Newts

How many newts?

Last night, a night misting in anticipation of a storm, we undertook the first-of-the-year frog surveys. We visited all four Dipper Ranch ponds from 8 pm to midnight walking about 1.5 miles downhill and then the same route back again. The fog kept all surfaces wet without totally blocking the moonless night sky and the temperatures were in the low 40's. Good conditions for amphibians.

As we walked out of the house, we could hear a treefrog chorus in the distance. I had heard occasional treefrog calls for the last month, but this was the first night of the rainy season that we could hear multiple frogs sing together. When we passed through the gate around the farmyard, we heard several treefrogs echoing off the metal sides of the cattle trough in the nearby corral.

Sneaking out of the pond on a Saturday night.

The Woods Pond had shallow water, a small amount of water draining through the outfall, and we did not see or hear any treefrogs or see any newts. That changed once we climbed the berm around the nearby Newt Pond. The Newt Pond was a few inches deep and no water was inflowing through the rusty pipe from the uphill spring. We saw 12 coast range newts wandering around the grass at the edge of the pond. Many of them were swollen with slick skin and razor edges to their tails indicating they had already spent time in the water. One of the land-based newts was eating an earthworm, while 6 newts were swimming about the cloudy pond. One treefrog was sitting quietly on the grass about 15 feet from the edge of the pond.

After they have been in the water, the skin on the back of male coast range newts changes from a bumpy, dark surface to a smooth bright orange.

As we climbed the slope above the Newt Pond, passed its feeder spring and walked out into the upper meadow, we saw 27 newts rambling about. We started to get excited. The newts were wandering in many different directions, sometimes alone and sometimes following another's tail.

Newts can travel long distances to breeding ponds and streams, often tumbling down steep slopes and creeping under and crawling over barriers like this pipe.

Between the gate separating Pasture 3 from Pasture 1 and Mustangs Rock, there were 65 newts on and alongside the road. They didn't seem to mind our close inspection via headlamps and usually continued about their business. Still 1/2 mile from the nearest pond and perhaps a quarter mile from ephemeral drainages, we continued to see the earth crawl with 54 more newts as we ventured downhill to the Monotti Pond (formerly called the Plum Pond).

We were not the only creatures wandering in the misty night, as nearly 100 yellow dots shined back at our headlamps. Although I claimed they were aliens, my ranch-raised companion was not fooled. The cattle were curious to see humans walking about at night and did not clear the ranch road until we were within a dozen feet of them. Then they followed us at a distance down to the Monotti Pond as we passed 13 newts and the treefrog chorus swelled.

How the male Sierran treefrog makes such a loud sound to call in the female frogs.

The Monotti Pond had no outflow, but treefrogs were loudly calling from the cattail stand. The treefrog chorus would stop temporarily whenever we talked or we or the cattle moved, but soon one frog would call and then, not to be left behind in courting the females, others would join in, and the din would start all over again. Within a few minutes, the frogs became accustomed to our presence so that I could walk around the pond without stilling their bellows and I counted 4 newts on land near the pond and 20 newts swimming about the shallow water. We decided not to count the frogs as they were harder to see than to hear.

We usually see newts in ponds where we witness their aquatic breeding. On rainy nights, their amphibian nature allows them to leave the pond and hunt for terrestrial invertebrates.

With our ears ringing, we headed towards the Mallard Pond. Of the 47 newts we passed on the way, many were eating earthworms and one swallowed a pill bug before our very eyes. The Mallard Pond was eerily silent with 5 newts on the land and 3 in the water. The Mallard Pond is surrounded by forest, so perhaps it takes longer for the amphibians to seek it out than the Monotti Pond which is completely surround by grassy slopes.

With feet braced, this newt tugs a resistant earthworm out of its hole.

On the return trip, we saw plenty of newts but did not count them. We realized that the newts which were still with their heads tilted or pointed, were probably hunting since many of them were peering under leaves or down holes. Once a newt got one end of the worm between its jaws, it would intermittently lunge forward and gulp down another section of the struggling worm. Newts have small teeth, thus they were not severing the earthworms, just slowly swallowing them whole. This explains why some newts were dragging big bellies as they slipped back into the pond.

Midnight greeting party - the California toad

When we finally reached the farmyard, a large California toad greeted us in front of the barn. We did not see or hear any red-legged frogs all night. We will keep surveying the ponds and hope to catch the earliest arrival of these big frogs, and record the earliest dates of frog and newt mating and egg laying. 256 newts in a night (64 newts an hour) has altered my perception of the night life around here.

As the night falls, poisonous orange predators emerge from ponds or their dens
and hunt down the slimy & wicked.

See also:
Coast range newt, Taricha torosa torosa
Sierran treefrog, Pseudacris sierra (formerly called Pacific treefrog, Pacific chorus frog, Hyla regilla or Pseudacris regilla)
California toad, Bufo boreas halophilus

Big Changes in Frog Town

--- Sierran treefrog tadpole with tiny leg developing in the tail membrane. ---

The Pacific treefrog tadpoles spent the summer transforming into mini-frogs. Meanwhile, their name changed to Sierran treefrog.

--- Big tail, small legs at Plum Pond, May 20th. ---

A treefrog tadpole completes its aquatic life from egg through tadpole to small frog in about three months - longer, if water temperatures are cool. Depending on when the eggs where originally laid, treefrog tadpoles typically metamorphose in California from June to late August.

-- The Plum Pond on May 11th with visiting black cows. ---

As the summer flies by, the Plum Pond shrinks but still gets enough spring seepage that it does not completely dry up. Depending on their seasonal rotation, the cattle may drink from this and other ranch ponds as late as mid-July. Frogs are plentiful at the Plum Pond, although hard to find on hot days.

--- The Newt Pond was shallow and muddy on May 10th. ---

The Newt Pond dries up every year, sometimes filling and drying several times in the year. This year it dried up for good by June 7th which is 56 days later than last year. Earlier, in anticipation of its annual demise, I collected a few treefrog and toad tadpoles from the Newt Pond and have been raising them in a fish tank. Because of the cooler conditions in my kitchen, the tank tadpoles are developing more slowly than those in the Plum Pond.

--- On June 13th in the kitchen tank, most of the treefrog tadpoles (top three) had legs,
but the California toad tadpole (bottom) did not. ---

In late May, the Plum Pond had treefrog tadpoles at several stages of development swimming about the warm, shallow water eating mostly algae. The youngest tadpoles had small rear limbs pushing out of the base of their tails. Frogs with larger legs used them to navigate through tangled vegetation.

--- Treefrog tadpole with muscular rear legs at the Plum Pond, May 20th. ---

On some Plum Pond tadpoles, the pair of front legs had burst out of a fold of skin in front of the belly. At this point, the tadpole is about to come out of the water and there are numerous internal changes also occurring. Its tail gets less finlike and more stump-like as it is adsorbed into the body. Lungs develop. The tadpole stops eating for a short time while its sucking mouth converts to jaws and its digestive system is converting from one that processes vegetable matter to one that breaks down animal matter.

--- Suction mouth and big, shiny belly of a tadpole in the kitchen tank on June 13th;
it also has new rear legs and soon the front legs will push through the bulge in front of the belly. ---

--- All 4 legs but still packing a stumpy tail at the Plum Pond, May 20th. ---

--- In the kitchen tank on June 26:
left - newly metamorphosed treefroglet,
right - treefrog tadpole. ---

With all 4 limbs, the metamorph creeps out of the water, although it quickly leaps back in whenever disturbed. Over the next 5 or so days, the stumpy tail disappears completely. Initially, the froglet looks dark and skeletal, much smaller than the tadpole of a few days ago, probably due to its temporary fasting during metamorphosis.

--- New treefrog at the Plum Pond on July 13th and only 3/8" from nose to rump. ---

--- The first treefrog to metamorphose in the kitchen tank is a rich copper color. ---

The young frog will use the suction-like discs on its toepads to climb pond vegetation where it will sit in wait for passing prey, mostly small, flying insects. If successful at its new hunting strategy, it will fill out into the more typical frog shape.

--- Adhesive toe pads allow the treefrog to climb up many surfaces, even glass. ---

Some herpetologists have recommended reclassifying the Pacific treefrog because of differences in its body structure from the eastern treefrog, and also because of subtle differences between the populations throughout its California range, including something to do with those fancy toepads. For this blog site, I've committed to using the nomenclature and taxonomy for reptiles and amphibians as designated by the California Herps website because I think it's a good resource that stays current with the experts and particularly with field biologists working in California. While the tadpoles were transforming this summer, Gary Nafis converted to the new treefrog names on his website and I am too. See the California Herps website for more details on this name change and distribution maps.

See also:

Sierran treefrog, Pseudacris sierra - formerly called Pacific Treefrog, Pacific chorus frog, Hyla regilla or Pseudacris regilla.

California toad - Bufo boreas halophilus

Tadpoles Compared

--- California toad by Debbi Brusco ---

Here's a California toad guarding his hole from the foreclosure agents. You can tell he is a toad by the yellowish line down his back. And the warts. But how do you tell a toad tadpole? They're black commas.

Let's update the progress of the toad eggs. We originally mistook them as tangled shoestrings in the Newt Pond on March 18th. California toad eggs are black dots laid inside long, double-walled, clear jelly tubes. On March 22, we noticed the tubes had started to break apart even though the eggs were still roundish and the embryos were not developed. Toad tadpoles hatch out in 5 or 6 days by busting through the jelly tube.

<--- busted toad tubes by David Tharp ---


I am not sure why these tubes were already broken apart. My guesses are: the Newt Pond is high on a ridge, and sometimes the wind creates a fetch that agitates the shallow water and may have broken up the tubes prematurely. Curiously, we saw many tiny, white mite-like critters clustered on the jelly tubes and maybe they were breaking them up. Or maybe the hatching is spread apart by several days and some tadpoles busted out early, loosening their brethren eggs. Good thing the toads hatch out in just a few days, otherwise, I would probably come up with more theories.

<--- 'mites' on toad tubes by David Tharp ---


In any event, the hatching seemed successfully, as by April 5th, thousands of toad tadpoles were massing along the edges of the pond. The toad tadpoles start out about 6 mm long and are dark black, so black you can't make out their features.

Compare this to the Pacific treefrog tadpoles that hatch in 6 days, quickly grow to 1 cm, develop enormous tummies and are camouflaged with dark olive backs marked by black dots and a coppery underside.




<--- treefrog tadpole on left, toad tadpole on right ---

I am not sure why the toad tadpoles are so dark and obvious and the treefrog tadpoles have cryptic coloring. I carefully watched adult newts nosing about the pond vegetation in a hunting pattern and they did not snap at the black commas as they wiggled by. Adult toads have toxic, foul-tasting substances (Pickwell) in their "warts" (why dogs usually spit out toads), but I don't know if the tadpoles are so equipped. Pickwell notes that predacious water insects capture and suck the fluids from frog and toad tadpoles.

Meanwhile, the newt eggs have been developing into twitching knife-like larvae and carving out of their individual eggs and then the outer casing. A number of newt egg clusters were washed up on shore on the windy day I last visited the Newt Pond. As I tossed them back into the pond, I noticed several newtlets pop out of the floating cluster and swim away. I cheerfully shouted, "I birthed them!" and the coyote hunting rodents in the nearby meadow looked my way.

<--- newt larvae about to bust out ---


Toad and frog tadpoles are herbivores and spend their days scraping up algae and decaying matter from rocks and the pond bottom with sucking mouths and tiny teeth. Newts are carnivorous all their life, so their larvae are devouring small pond critters. I rarely see newtlets in the ponds; as carnivores, maybe they lurk in the shadows.

The toad tadpoles will metamorphize in about 8 weeks from egg laying or mid-May. Will the water in the Newt Pond last that long? It rained today, so maybe. They hop out of the pond as tiny toads 6 mm from snout to tail end, and sometimes they still have a bit of tadpole tail they carry around for awhile. The treefrog tadpoles take about 12 weeks to metamophize, so that would be mid-June. Hmm, not sure if the Newt Pond is going to last that long, but treefrog eggs in the deeper Plum and Mallard Ponds will certainly have enough water to get to hopping stage.

I rarely see tadpoles of the California red-legged frog. They are larger (up to 7.5 cm long), dark brown or yellowish above, shiny pink below with white spots in a line along each side (Stebbins). From above, their eyes are closer to the centerline of the head and not along the outer edges like the treefrog. Both the red-legged frog tadpoles and the newtlets can spend over a year before they metamorphize, so they need longer-lasting ponds.

Thanks to my pond companions who provided some of these great photos and co-speculate on the mysteries of shoestrings and busted jellies. We are going to have a toad party in May if the Newt Pond lasts that long.

<---can you find the hidden treefrog tadpole?---

See also:
California toad, Bufo boreas halophilus
Pacific treefrog, Pseudacris regilla
Coast range newt, Taricha torosa torosa
California red-legged frog, Rana draytonii

Gayle Pickwell, Amphibians & Reptiles of the Pacific States, Dover Publications, 1972.
Robert C. Stebbins, Western Reptiles and Amphibians, 2003.

King of the Pond

Who would you say is the King of the Pond?


The California red-legged frog because it is big and so are its eggs?
<-- photo by K. Greene --



The coast range newt, after all, it is full of deadly neurotoxins?




Or, the Pacific treefrog because there are so many of them, they're so darn loud and they wear a superhero mask?

I suspect the kingship has something to do with eating habits.

At the Dipper Ponds this year, I first spotted a few clusters of red-legged frog eggs in early February. The eggs were approximately 1/2 inch in diameter and tightly wedged together like grapes in fist-sized or larger clusters. On Sunday, I saw a few dark tadpoles already zipping around the Plum Pond. I think they were red-legged frog tadpoles, so they are developing the fastest at this stage. One point to the red-legged frogs for grabbing the early window, and another point for their large-sized eggs stuck together in big clusters.

By mid-February, I had found only one treefrog egg mass and the female newts were still swimming about with swollen abdomens. February closed with days of rain and amphibians still in amplexus.




Now, in early March, the newts and treefrogs are adding their eggs to the ponds' production.













Last Sunday, the Newt Pond had dozens of loose globs of clear jelly attached to pond vegetation, 3/8ths to 1/2 inch in diameter and sometimes covered with debris or algae.












On closer inspection, I could make out several clear circles of eggs within the cluster, each containing either a dark dot or a small, knife-like larvae with a white belly. Because of the small size of the individual eggs, and the loose jelly nature of the irregularly-shaped cluster, I knew these were treefrog eggs. One point to the treefrogs for the large numbers of eggs, another point for their strategic placement at many locations throughout the pond, and a third point for the incidental camouflage.

In an old trough in the sun by the Monotti Barn, rainwater had collected. Treefrogs had suctioned their way up the tall sides and laid eggs on stems floating in the 3" deep water. Some of these eggs had recently hatched (perhaps because the shallow water is warmer), and the brand new tadpoles rested on their sides on the bottom of the trough like bicolor grains of rice. Another point to the treefrogs for finding innovative places to breed, some even inaccessible to other amphibians.

At the Plum Pond, the shallow water was suddenly festooned with piles of semi-transparent ping-pong balls as if the newts had communal egg-laying events. In contrast to the small, delicate treefrog egg masses, the newt egg masses have a firm, rubbery exterior enclosing several dozen eggs. One point to the newts for their sturdy piles of eggs.




As I was stepping over the Mallard Pond's outlet, I spotted 9 female newts resting together on their sides in a quiet pool. I immediately noticed that these newts were unusually still. Although newts are generally intrepid and not too concerned by my presence (neurotoxin bravado), they usually swim away from the pond edge when I move about. I squatted down for a closer look and noticed that each female was in the process of laying a large egg mass. In the group of nine, I could see egg masses at all stages of emergence and they were surrounded by many previously laid eggs.

The process was happening very slowly, almost unbearably so for me, and the female newts seemed to be in a trance unaware of their surroundings. One female was even gripping the shoulders of another. I tried not to project my own child-birthing experience on these bright orange amphibians, but the process looked rather difficult. Even after witnessing the event nine-fold at once, I am still baffled that these 3/4- to 1-inch diameter firm masses come out of the narrow newt bodies. One point to the newts for laying such enormous egg masses and another point for undertaking the struggle communally.











After watching the quiet females deliver the next newt generation, I began to wonder what the male newts were up to. Approximately 30 feet away, I found a group of male newts swimming tight circles around a cluster of red-legged frog eggs. Every now and then, a newt would thrust its head into the cluster, thrash its tail and tug loose and swallow a single large frog egg.

In late February, I saw single newts thrashing about in a similar way in the Plum Pond. At that time, I realized they were tearing apart jelly and gobbling up treefrog eggs.

After those amazing sightings, I think I will crown the hungry newts as King of the Pond. At least for now. Interestingly, newt egg masses are large and firm perhaps to prevent other species or their own from gobbling them up. I have also read that for some species newt eggs are even more toxic than the adults.

Actually, red-legged frogs, treefrogs and newts return to these ponds year after year, so somewhere within their life cycle, the frogs must have strategies to survive the gobbling nature of the newt. Still, with their female communal birthing pools and sushi-eating males, the newts certainly take the prize for interesting behavior.

California red-legged frog, Rana draytonii
Coast range newt, Taricha torosa torosa
Pacific treefrog, Pseudacris regilla