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.

Get Ready

Rain and snow greeted newly arrived cattle in December 2009

Cowboy V called today and he'll start trucking in cattle soon.  This weekend, rain or shine, we'll be closing gates.  I tend to leave the interior gates open after all the cattle are gone by midsummer, so the deer and I can frolic from one pasture to the next without pause.  Actually, the deer just stot over or flex under the wire fences, but they'll detour through an open gate if handy, and by staggering which gates are open, I guide the deer's sharp hooves along gentle slopes rather than carving up the steep ravines.

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

Dragoning

--- Pacific spiketail devouring a wasp or similar insect
as detected by the yellow & black parts dropping from its mouth. ---

Dragoning is to dragonfly watching as birding is to bird watching. Frogs were hard to find round here in September, but the Dipper ponds were buzzing with swimming and flying insects. So a-dragoning I did go.

The amphibious frogs, toads and newts spend their larval days in the water, and spend some or much of their adult life on land. Dragonflies and damselflies spend their larval days in ponds, gobbling up other pond critters, and then they metamorphize into swift predators of the air. Both the amphibians and aquatic insects return to water to breed.

--- Dragonfly wing position on left;
damselfly wing position (hard to see as they are held against the abdomen) on right. ---

Dragonflies and damselflies together as a group are the Odonata order of insects, commonly referred to as the odes. The basic way to tell the difference is that the dragonflies, which are usually larger and stronger fliers, hold their wings out flat from their body like airplane wings when they are resting. Damselflies, which are usually smaller and frequently rest on the ground or vegetation, hold their wings folded against their sides like a closed fan or above their body in an erect 'V' when they are resting.

--- Odes mating in the "wheel" position.
The male (above) is gripping the female behind her head with special appendages on the tip of his abdomen. With the tip of her curled abdomen, the female is picking up sperm from a special segment on the forward part of the male's abdomen. ---

I am curious whether the 3 summer ponds at the Dipper Ranch support different odes. Based on my rudimentary knowledge of ode biology, my guess is that the following conditions affect the type and number of odes at each pond throughout the summer: size of pond at time of survey and change since the beginning of summer; amount of open water surface; whether water is moving or still; absolute and relative amount of submergent, emergent, floating and pond edge vegetation; and amount and variation of insolation.

Factors which can be highly variable at the time of each survey and thus influence which dragonfly or damselfly species are seen at any one moment are: air temperature, wind speed, time of day and lateness in the summer season. I expect the number of ode species I see to increase as I gain experience with dragoning.

Here is my initial prediction on ode populations and results from my first dragoning adventures in the last hot days in September. Below, you will find a brief description of the general conditions of each pond, my predictions and then photos of odes seen at that pond with a summary of habitat preferences for each species as provided in Kathy Biggs' field guide. These are preliminary identifications as I am dragoning novice.

The Woods Pond is shallow (1-2" deep) throughout the summer and its surface is about 80% covered by emergent vegetation, mostly cattails and cyperus. In September, water was slowly trickling out of the earthen bank at its head, spreading through the small pond and draining downhill through its outlet, although there were periods of no outflow in midsummer. I would expect the Woods Pond to have fewer total numbers of odes, lower diversity, and to support species that like slow moving water. In addition to the species shown below, a large bluish darner was seen.

--- Pacific spiketail, Cordulegaster dorsalis deserticola, hillsides, small wooded streams. ---

--- Vivid dancer, Argia vividia, seeps, streams.
The triangular shapes on the abdominal segments along with the pinched stripe on the thorax help identify this species among the many blue dancers.
Dancers hold their wings above their abdomen which helps distinguish them from the bluets which hold them alongside their abdomen. ---

The Plum Pond is a small pond in bright sun. It starts the summer with 1/2 open water and 1/2 dense cattail stand. By September, the cattail thicket is surrounded by narrow band of water covered by azolla and smartweed. No above ground inflow is evident and there is currently no outflow. My guess is that the depth is up to one foot in late summer, and the combination of sun, plants and water results in lots of odes and lots of different species. In addition to the species shown below, I saw a species of forktail damselfly and the wheeling odes shown above at the Plum Pond, but I could not identify them.

--- Common green darner, Anax junius, fields & waterways.
I don't know what the black thread is beneath its abdomen. ---

--- One of the all-blue mosiac darners, Aeshna or Rhionaeschna species. ---

--- Common whitetail, Libellula lydia, marshes, streams. ---

The Mallard Pond is a medium-sized pond surrounded by tall trees. It looks several feet deep. It has a small island covered with several small trees and rose thickets. The pond and island edges are crowded with cattails, overhanging tree limbs, and the long dam face is bare earth. Even by the end of the summer, as much as 75% of the water surface is open with patches of floating vegetation. I suspect the pond is slowly fed in the summer by underground springs and there was no outflow in September. With these varied conditions, I expect the Mallard Pond to have more odes and a greater diversity of species, but the general closed margins might mean more damselflies and less dragonflies (the later being stronger fliers and perhaps preferring to have nearby grasslands for hunting).

--- Probably the blue-eyed darner, Rhionaeschna mulitcolor, ponds, lakes, slow streams. ---

--- Striped meadowhawk, Sympetrum pallipes, ponds and lakes.
The four velvety spots where the wings meet the body are distinct. ---

--- Western forktail, Ischnura perparva, weedy ponds. ---

--- Desert firetail, Telebasis salva, shallow water with algae scum.
Only all red California damselfly in Biggs' field guide---

After a preliminary set of late summer odes surveys, I found:

• The Woods Pond had 3 species of odes, with only one of those being a damselfly, matching my expectations of lower numbers and diversity.
  
• The Plum Pond had 5 species of odes, with two of those being a damselfly. I was surprised that the sun power didn't provide more odes, but it could have been the weather on the day I surveyed or my inexperience.
• The Mallard Pond had 4 species of odes of which 2 species were damselflies, a lower ode diversity and damselfly balance than I predicted.

These are very preliminary results, and I plan to go dragoning again next spring and summer.

--- Flying odes are hard to photograph.
One gets dizzy following them with binoculars or camera. ------

See also:

Kathy Biggs' California Dragonflies and Damselflies website with links to her excellent field guides

--- One of the blue darners.
They sometimes turned to face the camera when the focusing mechanism whirred ---

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

Toads Lay Eggs Too

After a challenging morning trying to explain the simpleness of grasslands, I introduced a like-minded associate to the Dipper Ranch ponds. While circumnavigating the Newt Pond, I was surprised to see a snarled black string in the water. I reached to pull it out when I realized it was actually the egg strands of the California toad. They look like long, clear jelly tubes filled with a double row of shiny black beads.

I occasionally see toads crossing the Dipper drive - in their shuffling toad fashion - on rainy nights. I have never seen their eggs before. One female California toad can lay over 10,000 eggs with the male helping to squeeze them out of her body and fertilizing them externally. It sounds like something out of the Willy Wonka factory.

Go outside and look around without an air of expertise. Nature may delight. One day, if I am especially humble, perhaps I will hear the chirping of the California toad, a sweet sound for this warty rambler.

See also:
California toad, Bufo boreas halophilus
Gayle Pickwell, Amphibians & Reptiles of the Pacific States, Dover Publications, 1972.

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