CERRILLOS HILLS HISTORIC PARK

The bull snake is a good snake, harmless to humans and l ivestock and an excellent means of controlling rodent populations, and also useful for the control of rattlesnake populations.

Bull snakes are large -- up to 6 feet in length -- somewhat thick and slow-moving snakes, with a head that looks small for the body. Because of their lack of speed, and the fact that the sun makes asphalt attractively warm, bull snakes are frequently found as road-kill. If they survive your Firestones they may live 22 years or longer.

There are many regional variations for the coloration of this snake, but in New Mexico the bull snake is commonly brown-black and tan-yellow. It has dorsal (top side) splotches that resemble side-to-side bands, two rows of lateral (left and right sides) dark spots, and 8 to 15 rings on its tail.

Mating is sometime between March and May; in June around 10 eggs are laid in a burrow, and the young hatch between August and September.

Bull snakes eat small rodents and are in turn eaten by raptors.

Bull snakes are surprisingly agile. They climb and burrow readily.

The mountain garter snake is slender and commonly 2 to 4 feet in length, brown to dark gray with striking lengthwise stripes of yellow or orange. Garter snakes are extremely widespread and extremely variable in appearance, even within a region.

Juveniles show a distinctive gray and light tan checkerboard, with light-hued stripes down the sides of the body.

Garters mate between March and June and the clutch of 6 to 25 young are born between August and September.

The primary food of garter snakes is small rodents.

Garters may excrete a somewhat foul musk when handled.

Patch-Nosed snakes are slender, fast, diurnal (daytime active) snakes, usually 20 to 45 inches long. They are most easily identified by the feature that gives them their name; a large rostral plate (the nose- point of their head is a single curved body scale).

The mountain patch-nosed snake is dark, often black, but with yellow stripes lengthwise on its back, and sometimes also on its sides.

Patch-nosed snakes prefer to dine on lizard above all else, but are also known to eat small snakes, snake eggs, and small rodents.

A poisonous pit viper, solitary, most active hot summer nights, spring and fall days; hibernates during the winter in disused prairie dog burrow or in a rocky crevice. In order to survive the winter the rattlesnake's hibernation den must be below the frost line. C. viridis has been found at altitudes as high as 9,000 feet, and although cold-blooded (at the mercy of local ground/air temperature) it is as likely to be found on a north-facing slope as a sunny south-facing one.

The well-known "coiled, tail rattle abuzz, head up and fangs bared" stance is the snake's way of saying "Leave me alone". This is very good advice, even from a snake in the grass.

Mating season is spring, and 5 to 30 young are born between August and October.

The rattlesnake normally waits for prey, then lunges, injecting venom by two fangs, and then waits for the poison to take effect. The snake may follow its prey until it falls. C. viridis eats mice, rats, prairie dogs, gophers, ground squirrels, and occasionally birds, eggs, lizards, frogs and toads.

C. viridis is the prey of the golden eagle and the racer, or coluber constrictor, but humans have had the greatest impact on now greatly- reduced rattlesnake populations in New Mexico.

One of the best and most humane approved methods of controlling rattlesnake populations is replacement: The introduction of numbers of nonvenomous bullsnakes.

Night snakes are 12 to 20 inches in length, and (surprise!) nocturnal. They are active on warm nights from May through October.

Their color extends from light brown-gray to yellowish to beige, and they have a dorsal (top side, or back) row of dark brown spots and smaller spots in a row on their sides. The best identifiers for a night snake are the three largish, elongated dark blotches at its neck (top and each side), and bulging eyes. The ventral (bottom side, or belly) is pale and without markings.

Night snakes lay their eggs in a burrow and have 2 to 7 young in a clutch.

One of the big advantages of being nocturnal is that the favorite prey of the night snake, the lizard, is inactive -- a stationary target. The night snake's saliva is toxic for lizards. Night snakes also eat lizard eggs, salamanders, frogs, small mammals, and bird eggs

The largest of the western rattlesnakes, the Western Diamondback in the Cerrillos Hills is very near the upper limit of its range. It is more common at lower altitudes. The diamondback has a short tail often ringed in black and white, a plump body with white-bordered black diamond-shapes in line along its back, and a wide triangular head. It is deaf, but makes very effective use of the infra-red (heat) -sensing pit (as in 'pit viper') behind each eye to locate warm-blooded prey.

C. atrox uses its rattle for protective warning, moving it at 40 to 60 Hz (cycles per second). Each molt (shedding of its skin) produces one more rattle, so if it hasn't lost rattles through trauma the age of a rattlesnake can be approximated from a distance. Dealing with this creature at a distance is not a bad idea. Diamondback venom, injected hypodermically through fangs in its upper jaw, may be fatal to humans. The venom is a complex mixture of toxins, but primarily hemorrhagins known as zinc metalloproteinases, which cause hemorrhage (bleeding), extensive tissue damage, and edema (fluid swelling). The snake grows 2 to 4 replacement fangs per year as fangs are sometimes left behind in the prey.

Diamondbacks are mostly nocturnal (nighttime) hunters of small mammals, birds, and sometimes other reptiles, amphibians, fish, and invertebrates (insects etc.), which they swallow whole. Rattlesnakes, along with most other snakes, are important for the control of rodent populations. In the chill of early spring and late fall they may be seen warming in the daytime sun.

The snake is a fertile species and in spite of people's widespread fear of the creature and regular killings, it is not an endangered species. Their natural enemies include raptors, road runners, and wild turkeys. The diamondback is now rare in Arkansas and Colorado, but dry, rocky, shrub and bush-covered plains and hillsides from Texas to southern California and deep into central Mexico are its home.

Diamondbacks mate in the spring, and the process may go on for hours, including periods of rest. Gestation is 167 days, and from July to August 10 to 24 12-inch long young are born live. Technically, this is called ovoviparous; the young break through thin egg membranes inside the mother and then emerge live. Young diamondbacks are immediately on their own and experience a high mortality during their first year.

The mature 3-year old diamondback is commonly 4 to 5 feet long and weighs up to 15 pounds, but it can grow to a length of 7 feet. In captivity diamondbacks have survived 25 years. The immature rattler pictured here - probably less than one year old, as indicated by only one rattle - was rescued from the bottom of an abandoned mine shaft.

The snake is known to be very defensive, excitable, and aggressive. Males may engage in a ritualized confrontation that involves twisting together and holding the head at odd angles.

In winter diamondbacks often form hibernaculae or hibernation dens in mammal tunnels or other deep holes where they remain, inactive, awaiting the return of warm weather.

In Spanish the rattlesnake is la vibora de cascabel.

The collard lizard is a diurnal (daytime active), long-tailed (4-inch body plus 10-inch tail), large-headed lizard. But its most distinguishing characteristic has to be its collar, a set of three thin rings -- black- white- black -- around its neck.

Collard lizards are green to tan overall, but peppered dorsally (on back) with white spots. The male collard has more vivid colors, especially a yellow-orange throat, but during the breeding season the female becomes colorful as well.

Collard lizards mate between April and June, and the eggs are laid in July.

They eat insects, spiders, snakes, lizards, and occasionally plant matter.

Interesting traits of the collard lizard include sometimes running on its hind legs, and waving its tail before pouncing on prey (much like a cat).

Horned lizards ("horny toads") are fascinating critters. They are important in Native American lore, being one of the creatures represented on Mimbres pottery. One term used for horned lizards in Mexico is torito de la Virgen, "the little bull of the Virgin Mary".

The roundtail horned lizard is a solid pale color; white, tan or pink. It has four large occipital (back of head) horns that are all of equal length, and it has no abdominal fringe scales (little spikes along its sides).

Commonly 86% of the roundtail's diet is comprised of ants, which contain a lot of indigestible chitin, and the horned lizard with its enormous belly is well designed to digest them.

It is oviparous, laying about 10 eggs in a clutch. (Horned lizards adapted to colder climates tend to be viviparous (live birth), an apparent adaption to the hatchling's need for warmth. See Short Horned Lizard.)

For protection horned lizards try to become invisible; they don't run, they mimic a rock. Unlike some horned lizards, the roundtail when handled does not squirt blood from its eyes.

Horned lizards ("horny toads") are fascinating critters. They almost never survive in captivity (though they can sometimes live on their fat reserve for months), and are consequently very poor candidates for pets.

The small short horned lizard has reduced occipital (back of head) spines -- short horns -- and an open notch in its head between them. It has one row of abdominal fringe scales.

The short horned is found at higher elevations, and as an adaption to the colder environment is viviparous (has live births). Compare this to the Roundtail Horned Lizard, with which it shares the Cerrillos Hills.

The diet of horned lizards is almost entirely ants. The tanklike shape of horned lizards is the result of the large stomach -- in the case of the short horned, a full 13% of its body weight -- needed to process the necessary quantity of ants. Much of an ant, the hard chitin exoskeleton, is not digestible.

Horned lizards are eaten by shrikes, roadrunners, hawks, snakes, foxes and coyotes.

For protection horned lizards try to become invisible; they don't run, they mimic a rock. Unlike some horned lizards, the short horned when handled does not squirt blood from its eyes.

The whiptail has a 3- to 4-inch long body plus another 8 or 9 inches of tail, and a long triangular head. It may live 6 years or longer.

It is light tan to yellowish with dark brown to black blotches arranged in rows between lighter narrower stripes. The dorsal (back) scales are small and granular and the ventral (belly) scales are larger and rectangular.

Whiptails are diurnal (daytime active) in spring and fall, and crepuscular (dawn and dusk active) in summer. They like sandy soil and rabbitbrush.

To survive, whiptails require at least 150 frost-free days a year, and the Cerrillos Hills lie near the upper limit of their range.

They breed in May or June, and the eggs hatch with 2 to 7 young in August. But whiptails are also on occasion parthenogenic (able to reproduce without mating).

Though they are regarded as harmless you should take care when handling an adult whiptail. They are surprisingly strong and have very sharp claws.

A non-native introduced to the western US in the early 1900s, the warm weather, predatory, North American bullfrog is the largest true frog in North America. Mature bullfrogs are 6 to 8 inches long and weigh over a pound, and their normal lifespan is 7 to 9 years.

Bullfrogs are colored some shade of brown or olive, with prominent sacral humps (the bent back is obvious), the feet on their hind legs are fully webbed, and the pupils of their eyes are horizontal.

The tympanum (the round eardrum-like thing next to the eye) of a male bullfrog is much larger than the eye, and on the female it is the same size as the eye or smaller. During breeding season (spring-summer) males have a yellow throat and females a white throat.

Adult males stake out territory next to water and try to attract females with their call. The males are vigorous defenders of their turf.

The female bullfrog lays around 20,000 eggs in protected water, and then the male fertilizes them. If another male can get close he may fertilize them as well. The tadpoles, the larval stage of the bullfrog, need 3 years to mature, and for this reason bullfrogs require permanent water to survive. At 5 years the bullfrog is sexually mature.

The bullfrog hibernates by burying itself in mud or wet soil.

The bullfrog is a sit-and-wait hunter, eating snakes, worms, insects, frogs and tadpoles. They are opportunistic cannibals. There are reports of bullfrogs eating bats.

Bullfrogs are useful for the control of insect pest populations, but they also tend to outcompete and diminish the populations of the native frogs.

This toad, native to New Mexico, is a desert resident that likes rocky and open lands near water. The canyon toad is nocturnal (nighttime active) except during breeding season (May through August in NM), when it may be seen at any hour.

It is a small toad with a flattened head and body profile, 1½ to 3 inches long, gray-brown to pale olive, and it may have red bumpy spots (tubercles) on its back.

The identifier for canyon toad is the paratoid gland, the blister-like bump rearward of the eye. If it's a canyon toad it will have two paratoid glands and they will be the same size as the eyes.

Breeding happens when it rains, sometime between May and August. The male calls from the puddle's edge to attract the female. The female canyon toad is the only North American toad that lays eggs singly, though she may also deposit them in small clusters or strings.

Canyon toads eat mostly insects. They dig their own burrows in soft soil. And they have little or no skin gland secretions so they are easily handled.

The taxonomy (classification and name) of this toad is in flux. Some authorities give Scaphiopus hammondi as the Western Spadefoot and Spea multiplicata as the New Mexico Spadefoot. It is further confused because they hybridize (interbreed) with the Plains Spadefoot and possibly others.

Whatever it is, it likes sandy, gravely soils where it breeds during the summer rains, and it is not a true toad. The spadefoot is short (less than 2½ inches long), stout, with a blunt snout, somewhat smooth skin, vertical pupils of the eye, with small teeth in the upper jaw. The dorsum (top side) is dusky olive-brown-gray with darker blotches. The ventrum (belly) is white. It has no paratoid glands like the canyon toad, but it has "spades" on its rear legs!

The spade is a horny, dark, sharp-edged tubercle (bump) on the inner surface of the hind foot, and the toad uses it to dig, backwards, into the soft soil. The spadefoot is mostly nocturnal (March through September) and is most common to areas where it can readily dig.

In July and August in New Mexico the female spadefoot deposits clusters of sometimes hundreds of olive-pigmented eggs onto objects in water. As the water may be a temporary rain puddle the development of spadefoot eggs is rapid. The total time from egg to tadpole can be as little as 2 weeks.

Spadefoots (how's that for a plural?) eat insects such as ants, beetles, grasshoppers, and crickets.

When handled the spadefoot secretes an odor like popcorn or roast peanuts that can cause sneezing.