From Frogs, Logs, Dogs, Slogs, Bogs, Hogs, and Pollywogs - It's the Methow Conservancy Blog!
Occasional posts - from the quirky to the momentous - on the life and times of the Methow Conservancy.
(What you won't find in E-News)

Monday, March 19, 2018

Herpetology Course - Class #4 Rattlesnakes

Our 4-part 2018 "Conservation Course" started February 12th. Below are notes taken by Kristen Kirkby. See notes and videos from the previous classes here:
Class #1 - Herpetology Overview
Class #2 - Methow Reptiles

Class #3 - Methow Amphibians

Learn more about the Herp Course here

Class #4 -Rattlesnakes & the Methow's Northern Pacific Rattlesnake with John Rohrer, March 12, 2018


Watch and listen to the 1.75 hour lecture portion of the class on this video




Cool Terms ~ Ecdysis: Process of skin shedding
~ Ectothermic: only get heat from environment, don’t generate their own
          Thigmothermic: heat from contact with a warmer object
          Heliothermic: heat from the sun
~ Solenoglyphs: snakes with hinged front fangs
~ Viviparous: give birth to live young
~ Oviparous: young hatched from eggs


Class: Reptilia – Snakes, lizards, turtles
     Order: Squamata – Snakes and Lizards
          Suborder: Serpentes – Snakes
               Family: Viperidae – Pit vipers
                    Genera: Crotalus and Sistrurus – Rattlesnakes

There are 32 species of rattlesnakes in the world - of those 16 are in US (and territories). There are also 32 subspecies among the species.

In WA: only the Northern Pacific Rattlesnake (Crotalus oreganus oreganus), which is a subspecies of the Western Rattlesnake (Crotalus oreganus).

Federally listed (Endangered Species Act) rattlers:
~ New Mexican Ridge-Nosed (threatened) (AZ, NM)
~ Aruba Island Rattlesnake (threatened) (Aruba)
~ Eastern Massasauga (threatened) (Midwest US)

State Listed (species of concern):
~ Timber Rattlesnake (East of the Mississippi)
~ Eastern Diamondback (Southeast US)

The Rattle:The rattle is thought to have evolved as a warning to large animals, like deer and elk, so that the snakes wouldn't get stepped on. They still use the rattle as a warning today. A muscle at the end of the tail vibrates at 50x/second, shaking the "buttons" (made of keratin similar to our fingernails). The buttons are loosely connected so they shake against each other and make noise. A new segment or button is revealed each time the snake sheds it's skin. Shedding depends on growth (multiple times/year in warm, productive areas versus only 1x/year further north like in the Methow).

Food Acquisition:
~ Pit vipers have paired heat sensing organs and can detect tiny temperature differences (0.002 degrees F) at close range
~ Short-sighted, see varying shades of heat
~ Use venom to subdue prey; venom glands behind eyes give triangular shaped head
~ Venom is a mix of hemotoxin (destroys blood cells) and neurotoxin (affects nerves)
~ Sit and wait to ambush predators, then reach out, strike, and inject venom, then sit back and wait for the venom to take affect (less opportunity for injury from fighting prey). Then they use their tongue to smell/track prey down, and eat it whole.
~ Primarily eat rodents (baby rattlers eat lizards)

There are approx. 9000 venom bites/year in US (all venomous snakes not just rattlers); most happen in the Southeast, and most people are trying to catch or kill the snake. Of these, there are only about 5 fatalities per year, and this is typically because these victims choose not to get treatment or delayed it too long. 25-50% of rattlesnake strikes are dry (no venom). Treatment is antivenin

Snake Fungal Disease (Ophidiomyces ophidiicola) was identified in 2006 in Timber Rattlers in New Hampshire, found mostly in the East, and Midwest; it has not yet found in West. The disease may be linked to a warming climate, 5-15 degrees C is too cold for fungus growth, but folks have seen outbreaks in warmer dens.

North Pacific Rattlesnake (Crotalus oreganus oreganus)

Lives in British Columbia, WA, OR, ID, and CA. There are no protections in any state, so anyone can kill them anytime.

Live primarily east of the Cascades; in the Methow they live valley bottom (core habitat), and somewhat up in the hills (peripheral habitat)

Tan to green coloring, with blotches on dorsal surface; broad triangular head; typically 30-40” long and up to 60” (largest found in the Methow was 47”, 1093 grams).

They are ectothermic, so they only get heat from their environment; they can't generate their own heat like we can. But this also means they use and need a lot less energy (food). They use 1/5 to 1/10 of the energy requirement of a similar sized "endotherm" (a creature like a mammal or bird that). Consequently, they have a much broader range of suitable body temperatures, however they do need to maintain a temp above freezing (and 85-90 degrees is the optimal body temperature, physiologically).

So, they are challenged in northern latitudes: There's a short growing season; they need winter refuge (underground den), and they have a seasonal migration.

They den from roughly mid-September to mid-April, and dozens to hundreds of snakes are in a communal den. Individuals generally use the same den their whole lives. Den sites are 6-8 feet underground (under frost line). They need air flow and shelter from precipitation, so they require unique conditions. Most local dens are on talus slopes with rock outcroppings (~35 dens are known in the Methow).

Historical documents outline people killing 350-400 rattlesnakes from a den in Pateros (1930), even 1000 at one site. In 1952, someone documented killing 259 in one day at a site on Leecher Mountain.

Methow Research
John and others wanted to find dens, so they started radio-tagging rattlers with a transmitter to detect their location, and sometimes with an internal sensor to log body temperature.

They found that rattlers are active with temperatures of 60 degrees and sun. Individuals start coming out of their dens in April, but only a subset (15-20%) will come out of the den each day to sun nearby, and all leave their dens by mid-May.

Females always return to the same den, but males forage until mid-July, and then search out the track of a female to follow her back to her den and to mate.

Females give birth to 4-10 babies for the first time at 6-9 years old, and then every 1-3 years (need recovery time). Methow Valley females reproduce after 8 sheds. They give birth in late-August to early-Sept, and while it was once thought that the young were immediately on their own, research now shows that mom stays with the baby snakes for a week to 10 days, then she goes back to her communal den (if she's not already there), and the young snakes follow the mom’s smell to the den and imprint on it.

A rookery is a group of pregnant females that hang out and stay warm together.

N.P. Rattlers live up to 20 years (Timber Rattlers found to live up to 45 years)

Males have longer tales (length from vent), usually 3.5 cm+
Females have body constriction at vent, tail less than 3.5 cm
Other study findings:
~ Nuisance snakes that were relocated to new dens had the same recapture rate as snakes native to a den~ Dens affected by fires (e.g. Carlton Complex) showed no difference in growth rate than unaffected dens the following year, but rattlesnakes in fire areas were smaller (meaning larger snakes may have died), and showed some burn scars
~ Some difference in crypticism and color between females and males from Methow and Columbia, but not statistically significant findings.

Respect and appreciate your snake neighbors!

Monday, March 12, 2018

Herpetology Course - Class #3 Methow Amphibians


Our 2018 "Conservation Course" started February 12th with an introductory class by Professor Dan Beck. Below are notes taken by Kristen Kirkby. See notes and videos from the previous classes here:

Class #1 - Herpetology Overview
Class #2 - Methow Reptiles

Learn more about the Herp Course here

Class #3 -Methow Amphibians with Julie Grialou & Amphibian Disease and Toxicology with Jenn Zajac, March 5, 2018



Watch and listen to the 2 hour lecture portion of the class on this video


Terms
Amphibios = double life. Amphibians lead a double life with aquatic larvae (juveniles) and terrestrial adults (but there are exceptions to this rule). This characteristics allows amphibians to exploit different habitats over their life history.

Heterochrony means that an animals life history and development timing can be fairly "plastic." They change over time and can change as a response to things in the environment.

Neotenic is a term used for larvae amphibians who have become sexually mature - they never look like "adults."

Amphibs can absorb water and oxygen through their skin, allowing them to burrow into soils in relatively arid environments and find sufficient water. With the skin as a respiratory organ, some don’t even have lungs (e.g. lungless salamanders)

Anuran (Frogs and Toads)
5892 species in 38 families
Characteristics: No tail, diverse reproduction strategies, metamorphosis from larvae to adults, fused caudal vertebrae aid in jumping, stabilizing the pelvis, also have adaptations to capture prey (e.g. saliva)
Frog saliva is viscous like honey, super sticky, but it liquifies when it hits prey so that it covers them, then becomes more viscous to capture them and bring back into the mouth, then liquifies again for swallowing.
Amplexus is the mating position of frogs and toads. In water, the male clasps the female from the back and holds on while the female releases eggs. The male then releases sperm and the eggs are fertilized external (in the water).
Frogs make rounded egg masses, toads make long stringy ones

The Pacific Northwest has 5 families of frog/toads. They are:

Ascaphidae – Tailed frogs
Ancient family; endemic to NW; highly aquatic; “tails” are reproductive organ.  Tadpoles are like one big sucker mouth, which they use to cling to substrates in fast-moving water in headwater streams where they eat algae off the rocks.
In our NW region:

~ Pacific tailed frog (Ascaphus truei) (here in the Methow)
~ Rocky mountain tailed frog

Pelobatidae / Scaphiopodidae – Spadefoots

Great Basin Spadefoot
Ancient family, not technically a true frog or toad. Adapted to arid environments, have a hard keratinized digging "spade" on a toe on the back feet; live mostly underground with explosive breeding when rain arrives in the spring. This if followed by a rapid development, with larvae metamorphosing in a few weeks. They mass together, creating more thermal mass and allowing for faster development.  Fairly small, squat, not big jumpers.
In NW:

~ Couch’s spadefoot (Scaphiopus couchi)
Great Basin spadefoot (Spea intermontana) (here in the Methow, in the shrub steppe, from Winthrop south, also in open ponderosa pine with seasonal ponds)

Bufonidae – True toads
Large, complicated family with a variety of development strategies.
In NW: 

~ Woodhouse toad (Bufo woodhousii) in south eastern WA
Western toad (Bufo boreas) in the Methow. Stripe down back, black spots on belly. Digging tool on back foot for burrowing, or they use rodent burrows. They are early breeders up high in the mountains.

Hylidae – Tree frogs / chorus frogs
Tree Frog Eggs

One of the largest families, very widespread, distinct wider adhesive toe tip.
In NW & in the Methow:

Pacific chorus frog (Hyla (or psudacris) regilla) use a wide variety of habitat, just need water source, wide toes at end, black stripe from tip of nose to shoulder, dark triangle on head (can change tone of color). They attach eggs to vegetation in lakes/ponds; they are relatively small in size (enlarge with age).

Ranidae – True frogs
Huge family (1377 species), worldwide, arid to temperate to tropical. Huge size range.
In NW:

Columbia Spotted Frog
~ Northern Leopard Frog (Lithobates pipiens) WA state listed, proposal to list on ESA was rejected because it’s abundant in other parts of its range and isn’t genetically distinct in WA
Columbia Spotted Frog (Rana lutieventris) In Methow. Red underside on legs; dorso-lateral folds; breed in shallow warmer water; lay big egg clusters communally; eggs often get algae on them, and get frothy-looking.


Salamander (Urodela)
585 species, 10 families (5 in WA/OR)

The Ambystomatidae family is known as the "Mole Salamanders."
Individuals can either metamorphose (change from eggs to larvae to adults), or be obligate "paedomorphic" (retain larval traits) individuals. They typically migrate to breeding habitat in large numbers. Terrestrial adults have robust bodies and limbs, and short, blunt heads.

In the Methow: 
Tiger Salamander

~ Tiger Salamander (Ambystoma tigrinum). Found in the shrub steppe and ponderosa forest. Eggs laid singly on vegetation in the water; larvae have long gills
Long-toed salamander (Ambystoma macrodactylum) Yellow stripe down back, eggs in parallel clusters.
In WA:
~ Northwestern Salamander (Ambystoma gracile). West of Cascade crest. Softball-sized egg masses. Mostly underground when on land; need moisture. Rib-like grooves on head; have perisoid glands (poison).

The Dicamptodon family are the "Giant Salamanders." They are endemic to PNW and there are 4 species OR/WA.

The Salamandridae family are called "True Salamanders"
They are mostly in Europe and Asia, except newts, which we have here in the PNW.
~ The Rough Skinned Newt (Taricha granulosa) Dry to the touch when terrestrial, but become slimy and develop dorsal fins in water where they go to breed; they are toxic and it's a good idea to not touch them!



Rough-Skinned Newt
The Plethidontidae family are the "Lungless Salamanders"
Terrestrial; are in wet areas but not in water. They are the most diverse. Nasolabial grooves (skin folds) help with chemoreception. There are 4 genera in Western Washington.

The Rhyacotritonidae family are the "Torrent Salamanders" (aka the Cascade salamanders. Rhyaco = stream, triton = greek sea god. They are endemic to the PNW; typically up high in watersheds. They are small and semi-aquatic.

Amphibian disease and toxicology with Jennifer Zajac

1/3 of all amphibian species are threatened (43% are in decline); 168 species have already gone extinct. There are multiple causes: habitat loss, pollution, invasive species, disease, etc.

Diseases:
Chytrid fungus (Bd)
Caused by a pathogen Batrachochytrium dendrobatids, which uses keratin in skin of amphibians and the mouth-parts of larvae, leading to low electrolytes in the animal and eventually cardiac arrest. The motile zoospore stage swims and is viable in water for 7 weeks without a host. Symptoms include lethargy, sloughing of skin, abnormal resting poses, loss of righting reflex, seizures and death.

Worldwide, it is thought to have originated in Japan, where it has little impact. There are different impacts in different areas on different species, but has led to serious decline in some areas, such as Central America.

Frogs and salamanders are both carriers, but frogs are more susceptible. Testing is done with a swab of the skin, legs, and feet to pull spores, which can be counted to tell severity of infection.

Chytrid has been found in Washington, but not much sampling has been done in the state.

Batrachochytrium salamandridrorant (Bsal)
Only affects salamanders; causes skin lesions; can be cured by holding critters at 25°C for 10 days.
Originated in eastern Asia on fire-bellied newts in the pet trade in 2013; currently only in Asia and Europe. Legal action is ongoing to try and keep it from the U.S.

Rana virus (RV)
Affects not only frogs, but fish and turtles, too. There is now global distribution as a group of different viruses. Leads to swelling of legs and body, hemorrhaging redness, white plaque in mouth (turtles), lethargy, and erratic swimming. It is lethal mostly at the larval stage, and 90% die off in 1-5 days. Man-made stressors such as pollution increase susceptibility.

Frog deformities (e.g. multiple hind legs)
Debated causes include: UV contamination, agrochemicals, parasites, trematodes, combination of those, but now it is believed to be from trematodes (internal parasites such as flatworms). More fertilizer leads to more snails leads to more birds leads to more trematodes leads to more deformities.

Toxicology: Susceptibility of animals to chemicals
Pesticide drift: chemicals from farmland drift, even to remote, seemingly pristine areas
The term "LC50" is the "lethal concentration" for 50% of study population.

Jen’s research looked at the interactive effects of chytrid, triclosan (ag chemical), and predatory effects. Triclosan is an antimicrobial used in MANY products, and found in 50% of US streams. She looked at Woodhouse toad tadpoles and the synergistic effects of these stressors.


Tuesday, March 6, 2018

Herpetology Course - Class #2 Methow Reptiles

Our 2018 "Conservation Course" started February 12th with an introductory class by Professor Dan Beck.  Below are notes taken by Kristen Kirkby.  See notes and videos from the previous classes here:
Class #1
Learn more about the Herp Course here

Class #2 -Methow Reptiles with Scott Fitkin, Feb 26, 2018

Watch and listen to the 2 hour lecture portion of the class on this video

The Class of Reptilia includes turtles, snakes, lizards, and crocodilians.  They are characterized by ecotothermy, dry scaly skin, lungs, internal fertilization (not dependent on water), and shelled, amniotic eggs.

Within a 100-mile radius of the Methow there are:
                1 species of turtle, 6 lizards, 10 snakes, but within the Methow we typically only see 1 turtle, 4 lizards and 6 snakes.

Turtles (Order Testudines)
Have a shell, can withdraw their head and appendages inside shell, are long-lived, and lay eggs on land. 
There are 257 species around the world, 2 native species in Washington, 1 of which is in the Methow.
Turtle vocab:
          Carapace: upper shell
          Plastron: bottom shell
          Emydid: semi-aquatic

In the Methow:
We have the Painted turtle (Chrysemys picta)
Distinguished by red patterning on plastron
Live in still, slow, shallow water with muddy bottom, need basking sites where they congregate
Omnivorous (mostly plants)
Reproduce at 5-6 years old; hatchlings over-winter in the nest and can withstand freezing (heart stops beating and use glucose in cells to prevent freeze damage)
Turtles absorb oxygen through their skin(!) when buried in mud or under the ice of a pond
Where to find them in the Methow!: Twisp-to-Carlton ponds, Davis, Paterson, Barnsley, Pearrygin lakes

Lizards (Order Squamata)
Have claws on digits, external ear openings, most can lose/regrow tail, and shed skin in large pieces.
There are 3300 species in the world, 7 species in WA, and 4 known in the Methow.
Lizard vocab:
          Oviparous: young hatch from eggs
          Viviparous: young born alive
          Autotomy: casting off of part of the body

In the Methow: 
We have the Northern Alligator lizard, the Pygmy Short-horned lizard, the Western Fence lizard, and the Western Skink.

Northern alligator lizard (family anguidae, Elegaria coerulea)
Long-bodied, snake-like, 3-5” from snout to vent (S2V), olive-brown with black/white checkering
Live in forested areas with rocky openings, up to 4600’, can live moister and cooler than other lizards
Insectivorous; viviparous (1-8 young), home bodies that stay within about 10m
Where to find them in the Methow!: War Creek bridge, Cougar lake, W Fork Methow, Buck Lake, Chewuch River

Short-horned lizard (family iguanidae, Phrynosoma douglasii)
Small, flat, round, cryptic (blend into surroundings)
Live in open shrub steppe to 3500’; Okanogan County is their northern limit (extirpated in BC),
Live on top of knobs with open shrub steppe, bitterroot
Insectivorous (specialize in ants), semi-fossorial (lots of time underground), need loose soil
Viviparous (2-7, newborns are just 1” long)
Where to find them in the Methow!: Patterson, Lewis Butte, Big Buck wildlife area, Studhorse (report to Scott if found!)

Western fence lizard (family iguanidae, Sceloporus occidentalis)
Gray/black/brown, blotches of color which can change with surroundings; rough, keeled dorsal scales, males have blue undersides, S2V 3.5”
Insectivorous
Oviparous (up to 10 eggs), 60 day incubation
Reduce the prevalence of lyme disease by destroying the spirochetes in ticks that feed on them. 
Areas with W. Fence lizards had 5% of ticks carrying lyme, areas without had 50%
Where to find them in the Methow!: Pine Forest, above Aspen Lake, near rattlesnake dens

Western skink (family scincidae, Eumeces skiltonianus)
Long body, short legs, smooth shiny scales, S2V to 3”, brown/tan with striped pattern, blue tail
Very fast, will often lose tails
 Live in dry forest with rim rock to 3200’, often found under rock/bark
Construct burrows and lay 2-10 eggs, only lizard in NW that guards eggs
Where to find them in the Methow!: Pipestone, near rattlesnake dens

Snakes (Order Squamata)
No limbs, no moveable eyelids, no external ear openings, swallow prey items whole, and smell with protrusible tongue.  There are 2700 species in the world, 12 species in WA, and 6 known in Methow
Snake vocab:
          Ecdysis: shedding of the skin
          Thigmothermic: get heat from direct contact with a warmer object
          Solenoglyphs: snakes with hinged front fangs (rattlers)
          Opisthoglyphs: rear-fanged snakes (night snakes)


In the Methow: 
We have the Gopher snake, Western Racer, Wandering Garter snake, Common garter snake, Rubber Boa, and the Northern Pacific rattlesnake.

Gopher snake (family Colubridae, Pituophis catenifer)
Longest snake in the Valley at 4-5’; dark brown blotches on tan
Lives in shrub steppe and open pine to 3500’
Constrictor, eats small mammals, birds, lizards
Strongly thigmothermic
Lay eggs (4-20) in rodent burrows
Rattlesnake mimic (does not eat rattlers), great climbers
Initially aggressive, but calm quickly
Poop on you 25% of the time when you pick them up
Where to find them in the Methow!: Upper Bear Creek, Gunn Ranch Rd)
               
Western racer (Family Colubridae, Coluber constrictor)
Long, thin, narrow pointed tail, dull-green/gray dorsal, yellow/cream ventral, large dark eye, often has head up
Live in low elevation, open shrub steppe, on the edge of pine forest
Prey on lizards, small mammals, insects, frogs, eggs
Non-constrictor (grab and swallow)
Oviparous (3-7)
Visual, diurnal hunters; squat in rattlesnake dens
Poop on you 100% of the time, sometimes bite
Where to find them in the Methow!: Gunn Ranch, areas with lizards

Wandering garter snake / Western terrestrial (Family Colubridae, Thamnophis elegans)
Long, slender to 43”, many color morphs, light jagged dorsal stripe
Moist habitats below 5000’, terrestrial and semi-aquatic
Grab and swallow eater with diverse diet
Viviparous (4-19)
Opisthoglyphs with toxic (not to you!) saliva
Migrate long distances from hibernacula (den)
Poop on you 100% of the time, may bite
Where to find them in the Methow!: everywhere

Common garter snake/ Valley garter snake (Family Colubridae, Thamnophis sirtalis)
Long, slender to 52”, vibrant dorsal and lateral striping, often red spotting
Most widespread, everywhere there’s water available, more aquatic than wandering garter
Varied diet, lots of fish and amphibians
Cold tolerant, hunt in the water
Mate at spring emergence, viviparous (3-18)
Have resistance to toxic amphibians (like rough-skinned newt)
Poo on you 100%, might bite
Communal denning, world’s largest snake concentration in Manitoba with 1000s of snakes
Where to find them in the Methow!: everywhere there’s water, Methow and Chewuch rivers,

Rubber boa (Family Boeidae, Charina bottae)
Small to 30”, thicker body, small eye, small head and blunt tail look similar, tiny smooth scales, brown/olive dorsal, creamy yellow ventral, very slow moving (look like large worms!)
 Live in riparian, to dryer forest to 4000’
Semi-fossorial, mostly nocturnal
Specialize on shrews, small mice, kill with constrition
Viviparous (1-8)
Cold tolerant, active into fall
Have a vestigial pelvic girdle,
Poo 50%, never bite, slow and easy to handle, and they are sooo very cute
Where to find them in the Methow!: Mixed shade/sun with ground litter, Upper Chewuch, Twisp River, Winthrop trail

Northern Pacific rattlesnake (Family Viperidae, Crotalus oreganus)
Large, heavy-bodied to 48”, brown to greenish with dark blotches, banded tail, wide head, rattle
Live in shrub steppe and dry forest to 5000’, limited by good denning habitat
Only venomous snake around, most evolutionarily advanced, hinged fangs
Subdue prey with venom, eat lots of mammals
Viviparous (1-25)
Can “see” in dark with infrared detection
Live in communal hibernacula
Don’t handle!
Where to find them in the Methow!: south-facing rocky areas, Pipestone, Rendezvous, Finley Canyon, Golden Doe

Unverified Methow residents:
Night snake (Hypsiglena torquata)
Dark blotches on light background, dark head, <18”, vertical pupil
Live in arid, rock areas under rocks
Nocturnal, oviparous, opisthoglyphs

Sage brush lizard (Sceloporus graciosus)
Look like fence lizard, but no blue under males, smooth rear thigh, S2V 2.5”
Arid, sandy areas, likely in the lower Methow
Oviparous

Snake handling! Do it but do it carefully! (but not to rattlers!)
                Move slowly
                Support weight of snake with two hands
                Move hands with scales, not against
                Don’t grab behind head

Developing reptile issues:
                Snake fungal disease: is out east and has been moving west
                Pond turtle shell fungus
                Invasives (like bull frogs)

Rubber Boa up-close - Look at its eyes!