A photograph of the only known instance of interspecies combat in male glassfrogs, photographed in Southern Ecuador. A red spotted glassfrog (Nymphargus grandisonae) grasps an Emerald glass frog (Espadarana prosoblepon) in a headlock. The males of certain species of glassfrog engage in this territorial wrestling behavior yet its typically limited to males of their own species.

A male marine iguana (Amblyrhynchus cristatus) on a lava beach in the Galapagos Islands National Park, Ecuador.

Breeding California newts (Taricha torosa) drift amidst aquatic vegetation in a muddy cow pond in the East Bay region of California. The male (above) will hold onto the female (below) rubbing his chin on her and wafting his tail - if she is charmed he will deposit a spermatophore on the pond bottom which she will pick up to fertilize her eggs.

A pair of male marine iguanas (Amblyrhynchus cristatus) bashing their heads together in a territorial dispute in the Galapagos. Neither was willing to back down and both were bruised and bloodied.

After eating a highly toxic newt a California red sided garter snake (Thamnophis sirtalis infernalis) is somewhat sluggish and takes a few min to push the newt down further as well as clear debris that is stuck in its mouth.

A juvenile smooth fronted caiman (Paleosuchus trigonatus) near a small jungle stream in Amazonian Peru.

This is a California newt (Taricha torosa) egg - I couldn't say exactly how old, but safe to say pretty fresh. It will rapidly develop into a small gilled larvae which will eventually hatch out and spend its early life in the water - in this case a cattle pond in the East Bay. This egg is past the initial cleavage stage where the single celled egg starts dividing into multiple cells. The compartments visible on the surface are individual cells and this is just prior to gastrulation where the blastopore forms (what will eventually become the gut/anus) and tissue layers begin to arrange themselves. Photographed in situ out in the water where the eggs were laid.

Potamites strangulatus, a semi aquatic lizard species that can be found in small flowing rivers in jungle settings.

A orange bellied water snake (Nerodia erythrogaster) coiled on a tire in its polluted wetland home. Honorable mention in the Human Impact category of California Academies BigPicture Contest.

Yellow pitcher plants (Sarracenia flava) growing in a North Carolina bog. These plants attract insects to their 'pitchers' where glands secrete sap with narcotic properties. Drugged insects fall into the plant and drown in the water at the bottom of the pitcher, the plant is able to supplement its nutrition this way.

A male bobcat (Lynx rufus) relaxing in the tall grass after hunting and eating a large gopher. Found across much of North America (nearly the entire United states, southern Canada, and 2/3rds of Mexico), these mesocarnivores are very adaptable and can be found in a variety of habitats from dense forests, marshes, deserts and just about everything in-between as long as suitable prey is available.

The White faced nunbird (Hapaloptila castanea) a rare inhabitant of the South American cloudforest. It is elusive and more often heard than seen.

A male glass frog (Hyalinobatrachium pellucidum) guards his eggs on a leaf in the Ecuadorian rainforest.

Melyroidea magnifica, a rarely seen species of cockroach from the Amazon. It lives in social groups inside trees and bamboo and periodically emerges to forage. Its diurnal activity and bright coloration suggest toxicity, mimicry or both.

A glassfrog (Hyalinobatrachium pellucidum) guards his eggs. Parental care is found in about 10% of frogs, and few are as devoted as species in this genus. The male remains with the eggs until they hatch guarding them from predators and parasites as well as keeping them hydrated. Although he won't leave the eggs, he continues to call in hopes of attracting another female frog.

The Amazon wood lizard (Enyalioides laticeps) relies on its excellent camouflage to stay hidden in the verdant rainforest. Active during the day, they may sit motionless keeping an eye on their surroundings until they spot a tasty bug.

California newts (Taricha torosa) aggregate in the muddy nutrient rich waters of a cattle pond. The newts breed and lay eggs in the shallows while other newts sneak in and attempt to devour freshly laid eggs.

A fishing spider has seized a pair of peters dwarf frogs (Engystomops petersi) that were in amplexus and getting ready to deposit eggs. The spider has the female yet the male remains holding on to her.

The Amazon Basin emerald tree boa (Corallus batesii) lives in rainforest canopy in the Amazon rainforest. It is rarely encountered as it seldom ventures to ground level.

Mountain Frog

A marbled four eyed frog (Pleurodema marmoratum), one of the two highest dwelling frog species in the world. It lives up to 5400 m asl in the Andes of Southern Peru.

The warty toad (Rhinella spinulosa) is the amphibian with the widest elevational range in the world, found from sea level to about 5200 m asl. At the high points of its range, there are no people and little light pollution or atmosphere to obscure the stars. The Inca people named a constellation Hanp'atu after this toad.

The marbled water frog (Telmatobius marmoratus), is one of the two highest elevation frogs in the world, both of which occur in the Cordillera Vilcanota. These frogs spend their entire lives in pristine freshwater habitats. A threatened species declining from harvesting by humans, destruction of their habitat, introduction of invasive trout, and the chytrid disease.

A sandhill crane takes a refreshing dip in a lake in Southern Wisconsin.

Southern Alligator lizard (Elgaria multicarinata) basking on a rocky hillside as the sun sets.

Poecilochirus species mites on a Scaphinotus species ground beetle. This genus of mite is well known for riding on beetles - particularly carrion beetles (which this is not). While the exact relationship between this type of beetle and mite is not known in the published literature, their relationship with carrion beetles is well documented. The beetles deliver the mites to a food source which the mites then disembark on. There they feed on fly larvae and eggs which compete with the beetle's larvae for food.