Field Report: 2018-04-22

A Tale of 2 Kings

A swing, a miss, and some beautiful kingsnakes


3
Days
2
Boat Rides
3/4
Target Species

As central Mexico’s lengthy “dry season” pulls into the home-stretch, the HERP.MX Field Team set off for Mexico’s northern latitudes for some early relief. Winter rains in the border states means spring activity, and the herpetofauna and history-rich corner of northern Baja California was calling.

June of 1961 found Cal State Long Beach entomologist, Dr. Elbert L. Sleeper collecting insects on the western slopes of the Baja Peninsula’s tallest mountain range – the Sierra San Pedro Mártir. The definition of contrast, the sierra’s occasionally snow-covered peaks tower some 3000m (10,000ft) above foggy coastal sage scrub to the west, and wind-swept desert dunes to the east. Dr. Sleeper was in the company of a 35 year old Andrew Meling – vaquero on the 10,000 acre cattle ranch bearing his family’s name – who was lucky enough to call the Sierra San Pedro Mártir his birthplace. Andrew had noted the presence of medium-size frogs at the end of a remote valley and an interested Dr. Sleeper, who’d collect herpetological specimens on occasion, made the strenuous hike to the mountain meadow.

On June 12th he managed to collect two of the critters in deep pot holes of a granite-lined stream. These frogs would eventually make their way back to Cal State Long Beach and into the hands of Dr. Richard B. Loomis, and then those of Dr. Robert Stebbins and Dr. Richard Zweifel who confirmed the frogs as a nearly 500km southern range extension for the Foothill Yellow-Legged Frog (Rana boylii).

And virtually as fast as they were found, they vanished. Dr. Sleepers original specimens were lost in shipping, and subsequent trips to find Rana boylii in the Sierra San Pedro Mártir have come up empty handed. While potential explanations ranging from extirpation to a specimen/locality mix-up have been documented in the scientific literature and muttered in private, we wanted to see for ourselves.

Baja Bound

A four-man HERP.MX Field Team converged on Tijuana before heading south to the access road into the Sierra San Pedro Mártir. Confident that earlier attempts for R. boylii at the known locality were sufficiently thorough, we placed our bets on a remote canyon at the end of ~30km hiking route traced with the help of Google Earth.

By the time we had pulled into camp it was too late to set off, but a San Diego Nightsnake (Hypsiglena ochrorhynca klauberi) made an appearance near the campsite.


The entrance to the Sirra San Pedro Màrtir National Park © Ivan Ahumada Carrillo / HERP.MX
The entrance to the Sierra San Pedro Mártir National Park
HERP.MX Camp
San Diego Nightsnake
(Hypsiglena ochrorhynca klauberi)

We awoke the next morning and started our hike through some of the most beautiful country that México has to offer — boulder strewn hillsides covered in manzanita, sprinkled with pines and punctuated by expansive dry meadows.

Habitat in the Sierra San Pedro Martír
Dry mountain meadows <br />© Chris Rodriguez / HERP.MX
A dry mountain meadow

Viper distractions, but habitat in sight

True to our pitviper hunting roots, a handful of Southern Pacific Rattlesnakes (Crotalus helleri) were spotted clustered around probable over-wintering sites. Snakes from the higher reaches of the San Pedro Martír are well-adapted to these cooler conditions with a pitch-black coloration and virtually no patterning.

A Southern Pacific Rattlesnake (<em>Crotalus helleri</em>) hangs a coil out of a rocky crevice <br />© Ivan Ahumada Carrillo / HERP.MX
A Southern Pacific Rattlesnake (Crotalus helleri) hangs a coil out of a rocky crevice
An adult Southern Pacific Rattlesnake (<em>Crotalus helleri</em>) rattles from a retreat <br />© Chris Rodriguez / HERP.MX
An adult Southern Pacific Rattlesnake (Crotalus helleri) rattles from a retreat
An adult Southern Pacific Rattlesnake (Crotalus helleri) basks in a rocky outcrop.
An adult Southern Pacific Rattlesnake (<i>Crotalus helleri</i>) basks in a rocky outcrop © Chris Rodriguez / HERP.MX
An adult Southern Pacific Rattlesnake (Crotalus helleri) basks in a rocky outcrop

Some water

Halfway into the hike we had arrived at the target arroyo which, to our surprise, was flush with life. One of our secondary target species, the endemic San Pedro Martír Garter Snake (Thamnophis elegans hueyi), made an appearance. Like with Rana boylii, these mountains represents the southwestern outpost for these wide-ranging garters, with the closest relative some 350km to the north in the San Bernadino Mountains of Southern California.

A rocky arroyo in the Sierra San Pedro Martír <br />© Chris Grünwald / HERP.MX
A rocky arroyo in the Sierra San Pedro Martír
A Pacific Treefrog (<em>Pseudacris regilla</em>) seeks refuge in the crack of a granite boulder<br />© Chris Grünwald / HERP.MX
A Pacific Treefrog (Pseudacris regilla) seeks refuge in the crack of a granite boulder
The endemic San Pedro Martír Garter Snake (<em>Thamnophis elegans hueyi</em>)<br />© Ivan Ahumada Carrillo / HERP.MX
The endemic San Pedro Martír Garter Snake (Thamnophis elegans hueyi)
A Southern Alligator Lizard (<em>Elgaria multicarinata</em>)<br />© Ivan Ahumada Carrillo / HERP.MX
A Southern Alligator Lizard
(Elgaria multicarinata)

A Western Skink (<em>Plestiodon skiltonianus</em>) <br />© Ivan Ahumada Carrillo / HERP.MX
A Western Skink
(Plestiodon skiltonianus)
Southern Sagebrush Lizard (<em>Sceloporus vandenburgianus</em>) <br />© Ivan Ahumada Carrillo / HERP.MX
Southern Sagebrush Lizard
(Sceloporus vandenburgianus)
San Pedro Martír Garter Snake (<em>Thamnophis elegans hueyi</em>) <br />© Ivan Ahumada Carrillo / HERP.MX
San Pedro Martír Garter Snake
(Thamnophis elegans hueyi)
Two-Striped Garter Snake (<em>Thamnophis hammondii</em>)<br />© Chris Rodriguez / HERP.MX
Two-Striped Garter Snake
(Thamnophis hammondii)

Southern Alligator lizards (Elgaria multicarinata), Gilbert's Skinks (Plestiodon gilberti), and Western Skinks (Plestiodon skiltonianus) scurried through leaf-litter while Southern Sagebrush Lizards (Sceloporus vandenburgianus) and Western Fence Lizards (Sceloporus occidentalis) darted across fallen logs and boulders. The waters' edge was active with Pacific Treefrogs (Pseudacris regilla), California Treefrogs (Pseudacris cadaverina), and California Toads (Bufo boreas halophilus) in the streamside vegetation and rocks with Two-Striped Garter Snakes (Thamnophis hammondii) in pursuit. Even a Garden Slender Slamander (Batrachoseps major) turned up, but despite careful searching through plunge pools and potholes — Rana boylii was no where to be seen.

Pacific Treefrog (<em>Psuedacris regilla</em>) <br />© Chris Rodriguez / HERP.MX
Pacific Treefrog
(Pseudacris regilla)
California Treefrog (<em>Pseudacris cadaverina</em>) <br />© Ivan Ahumada Carrillo / HERP.MX
California Treefrog
(Pseudacris cadaverina)
Anaxyrus boreas halophilus (<em>Anaxyrus boreas halophilus</em>) <br />© Ivan Ahumada Carrillo / HERP.MX
California Toad
(Anaxyrus boreas halophilus)
Garden Slender Salamander (<em>Batrachoseps major</em>)<br />© Ivan Ahumada Carrillo / HERP.MX
Garden Slender Salamander
(Batrachoseps major)

Some Colorful Consolation

Empty handed in our search for R. boylii and without a "Plan B Arroyo", we took aim at our third target, and one of the Sierra San Pedro Martír's most secretive gems: the Baja Mountain Kingsnake (Lampropeltis zonata agalma). Only five specimens from this mountain range have made their way into scientific collections since the species was descibed in 1923, however interest from the pet-trade has driven U.S. collectors to relentlessly pursue snakes at this locality for decades — largely unsuccessfully. With the exception of some isolated and incidental encounters, the majority of L. zonata agalma observations in "The Martír" have been made by Paul Lynum, and a handful of other collectors under his tutleage. Before leaving, Paul shared a tip that we hoped would prove useful: "find the Gilbert's Skinks, and you'll find the agalma."

Candy Cane on the Crawl

While Paul's methodical efforts had produced dozens of observations along the dry slopes of the sierra — in what could be considered marginal habitat — our search for Rana boylii had landed us in prime habitat for mountain kingsnakes.

After moving up from the arroyo bottom, it wasn't long before a Gilbert's Skink (Plestiodon gilberti) appeared under a rock, followed just minutes later by the brilliant pattern of an adult Lampropeltis zonata agalma crawling along the base of a boulder outcrop.

Micro-habitat for the Baja Mountain Kingsnake (Lampropeltis zonata agalma)
An adult Baja Mountain Kingsnake (Lampropeltis zonata agalma)
Baja Mountain Kingsnake (Lampropeltis zonata agalma)
Baja Mountain Kingsnake (<i>Lampropeltis zonata agalma</i>) © Brandon La Forest / HERP.MX
Baja Mountain Kingsnake (Lampropeltis zonata agalma)

Less than a half-hour later, a juvenile Baja Mountain kingsnake was flipped beneath a rock just up-the slope from the creek.

Content with our consolation finds, the team began the hike back up the arroyo and through the hills to camp — a return trip that wouldn't conclude until the early morning hours.

A short video clip of L. z. agalma and habitat
A juvenile Baja Mountain Kingsnake (Lampropeltis zonata agalma)
Juvenile Baja Mountain Kingsnake (Lampropeltis zonata agalma)
Juvenile Baja Mountain Kingsnake (<i>Lampropeltis zonata agalma</i>) © Brandon La Forest / HERP.MX
Juvenile Baja Mountain Kingsnake (Lampropeltis zonata agalma)

From The Mountains to the Sea

The trip westward out of the Sierra San Pedro Martír towards the coast produced a single Long-nosed Snake (Rhinocheilus lecontei) and much lighter Southern Pacific Rattlesnake (Crotlaus helleri). Looking to leverage their newfound Lampropeltis-luck, the team set sights on another king: the Todos Santos Island Kingsnake (Lampropeltis herrerae).

Southern Pacific Rattlesnake (<em>Crotalus helleri</em>) <br />© Ivan Ahumada Carrillo / HERP.MX
Southern Pacific Rattlesnake (Crotalus helleri)
Long-nosed Snake (<em>Rhinocheilus lecontei</em>)<br />© Chris Grunwald / HERP.MX
Long-nosed Snake (Rhinocheilus lecontei)

King's Isle

Lampropeltis herrerae was described in 1923 from specimens collected by Joseph Slevin earlier that same year on Isla Todos Santos Sur — one of two islands some 20km off the coast of Ensenada. The species was named in honor of Dr. Alfonso Luis Herrera, a researcher at the Instituto de Biología de la Universidad Nacional Autónoma de México and one of the founders of the Zoológico de Chapultepec.

Closely related to L. z. agalma from the Sierra San Pedro Martír, the species represents a relictual population whose existence is thought to be linked to the absence of competing species like Lampropeltis getula and Pituophis catenifer on its island home. Like the Baja Mountain Kingsnake, the Isla Todos Santos Kingsnake's commercial value has placed it under heavy pressure from poachers, and illegal collecting over the last few decades — still evidenced to this day by rusted traps and damaged rocks — has resulted in tightly controled access to the island.


HERP.MX's Chris Grünwald works to secure permission to visit the island © Ivan Ahumada Carrillo / HERP.MX
HERP.MX's Chris Grünwald works to secure permission to visit the island
Isla Todos Santos Sur in the distance © Chris Rodriguez / HERP.MX
Isla Todos Santos Sur in the distance
Arriving at the island

Almost as soon as we landed, we were met by two approaching boats with authorities from SEMARNAT and CONANP. After a quick review of our permits and assurances we would not be disturbing any nesting birds, we were off to try our luck in the hills.


Habitat on Isla Todos Santos Sur <br />© Brandon La Forest / HERP.MX
Isla Todos Santos Sur
Habitat on Isla Todos Santos Sur <br />© Chris Rodriguez / HERP.MX
Habitat on Isla Todos Santos Sur
Habitat with Isla Todos Santos Norte in the background <br />© Ivan Ahumada Carrillo / HERP.MX
Habitat with Isla Todos Santos Norte in the background

Black and White

Despite losing time and the prime-hunting window to travel and access issues, we got lucky. A large adult Isla Todos Santos Kingsnake (Lampropeltis herrerae) was spoted as it darted towards some shady rocks.


An Isla Todos Santos Kingsnake (<em>Lampropeltis herrerae</em>) © Chris Grünwald / HERP.MX
An Isla Todos Santos Kingsnake (Lampropeltis herrerae) seconds after it was spotted
The snake was spotted as it crawled towards the smaller rocks in the center of this photo
Isla Todos Santos Kingsnake
(Lampropeltis herrerae)
Isla Todos Santos Kingsnake in habitat
(Lampropeltis herrerae)
Isla Todos Santos Kingsnake (Lampropeltis herrerae)
Isla Todos Santos Kingsnake (<i>Lampropeltis herrerae</i>) © Ivan Ahumada Carrillo / HERP.MX
Isla Todos Santos Kingsnake (Lampropeltis herrerae)

And with that we were ready to call it a wrap. While we'd missed out on our primary target, Rana boylii, the secondary targets had made for a memorable and worthwhile outing.

We boarded the boat back to Ensenada, dined on some well-deserved seafood, then headed north to Tijuana where the team parted ways until the next field adventure.





© 2018 HERP.MX