Horned lizards, often called "horny toads," are a fascinating group of lizards found throughout North America. Despite their nickname, they are reptiles, not amphibians. Their unique appearance and defense mechanisms have made them familiar to many, particularly in the southwestern United States. This article delves into the dietary habits of horned lizards, exploring their primary food sources, foraging behavior, and the challenges they face in a changing environment.
Horned Lizard Identification and Habitat
The Hernandez’s short-horned lizard, also known as the horned frog, horny toad, horned toad, and greater short-horned lizard, is a wide, flat lizard, neither toad nor frog. It is flat-bodied and squat with scales around the top of its head. These lizards have snub noses, short legs, fringes near pointed scales on the trunk, smooth bellies, and short tails. They are gray, yellowish, orange-brown, or reddish-brown with dark spots on the back. These horned lizards can be found in semiarid plains, shortgrass prairies, pinyon-juniper forests, and montane regions between 2,000 and 10,000 feet in elevation. They are widely distributed in North America. They can be found as far north as southern Saskatchewan and Alberta and south into the Texas Panhandle and central Mexico.
The Myrmecophagous Diet: A Love for Ants
Horned lizards are primarily myrmecophagous, meaning that their diet mainly consists of ants. The Texas horned lizard and the regal horned lizard, in particular, have diets that are up to 90% ants, especially harvester ants. These ants live in large colonies and forage in the desert for seeds. Adult lizards may consume between 20 to 100 ants per day.
Harvester ants, also known as red ants, are large and possess a potent sting. However, horned lizards have developed adaptations to handle these stinging insects. They use their tongues to grab the ants on the back, which curls the stinger away from the lizard. Furthermore, they have a thick mucus in their mouths that provides additional protection against stings.
Supplementing the Diet: Other Invertebrates
While ants form the cornerstone of their diet, horned lizards are not exclusively ant-eaters. They will also consume a variety of other invertebrates to supplement their diet. These include:
Read also: Diet of Horned Lizards
- Beetles
- Grasshoppers
- Spiders
- Young snakes
- Snails
- Sowbugs
- Bees
- Other insects
The Greater Short-horned Lizard, in particular, has a more varied diet compared to other horned lizard species, consuming a wider range of ground-dwelling insects.
Foraging Behavior: Sit-and-Wait Predators
Horned lizards are considered "sit-and-wait" predators. They typically remain still, blending in with their environment, waiting for prey to come within striking distance. They are capable of short bursts of speed when necessary. They usually search for prey in open areas, moving quietly searching or waiting for an unsuspecting ant or other food item to come into view. When a prey animal passes by, the lizard quickly snaps it up with a flick of its tongue and swallows it whole. Horned lizards usually capture their prey with their sticky tongues rather than grabbing it with their mouth.
Predators and Defense Mechanisms
Horned lizards' foraging behavior puts them at risk of predation. They are preyed upon by a variety of animals, including hawks, roadrunners, snakes, lizards, coyotes, ground squirrels, mice, cats, and dogs. To avoid becoming prey, horned lizards have developed several defense mechanisms:
- Camouflage: Their color patterns closely match the soil they live on, allowing them to blend in with their surroundings. They can also flatten their bodies against the ground to eliminate their shadows.
- Immobility: When threatened, horned lizards will often remain still, relying on their camouflage to avoid detection. If forced to move, they will run a short distance and stop abruptly, making it difficult for predators to track them.
- Inflation: Horned lizards can inflate their bodies, making them appear larger and more difficult to swallow. When inflated, their protruding horns make an unappetizing meal.
- Blood Squirting: Perhaps their most unusual defense is the ability to squirt a stream of blood from the corner of their eyes. This stream can be directed at a predator's eyes and mouth, serving as a deterrent. This defense is typically a last resort and particularly effective against large predators like coyotes and bobcats. When threatened or being aggressive, their color becomes more intense. They will roll onto their backs and play dead to escape becoming prey. They can also accurately squirt blood up to three feet from their eyes at attacking predators.
- Playing dead: They will roll onto their backs and play dead to escape becoming prey.
Conservation Status and Threats
Several species of horned lizards are facing population declines. The Texas Horned Lizard, for example, has disappeared from East and Central Texas and is decreasing in North Texas. Similar declines have been observed in Oklahoma and New Mexico. Other species, such as the Pacific Coast Horned Lizard and the Flat-tailed Horned Lizard, are also in trouble.
The primary cause for these declines is habitat loss due to agricultural and urban development. Other contributing factors include:
Read also: Diet of the Colorado River Toad
- Over-harvesting: Collection for the pet trade and curio trade has impacted some populations.
- Invasive species: The introduction of exotic ant species, such as Argentine ants, has displaced native ant populations, which horned lizards cannot survive on.
- Predation: The introduction of domestic dogs and cats to areas where horned lizards were once abundant has led to increased predation pressure.
Many species are state-listed as protected, making it illegal to take, possess, transport, or sell them without a special permit.
Caring for Horned Lizards in Captivity
While it is illegal to keep many horned lizard species, it is also difficult to care for them in captivity. Most captured horned lizards eventually die from improper care. If you have a horned lizard, it is essential to provide them with the appropriate diet and environment.
- Ants: Horned lizards require a diet primarily consisting of ants, particularly harvester ants. These can be purchased in bulk from specialized suppliers. Note: Not all horned lizards eat harvester ants. If your lizard comes from a high elevation area like Colorado, Wyoming, Utah mountains, or if it is young it may not eat harvester ants. Please read Care Instructions below for more information.
- Ant Storage: Ants can be stored in the refrigerator for up to two weeks.
- Feeding: Adult horned lizards typically eat 20 to 60 ants per day, while juveniles need less. Supplement your lizard’s diet with crickets as well as Small Dubai Roaches and other insects.
- Habitat: If you are not keeping the ants in the fridge you will need to feed and water them regularly. Harvester ants will eat almost anything but their favorite foods are fresh vegetables and fruits. Feed them small pieces of celery, apple, lettuce, carrot, etc… Feed them small pieces about every other day.
- Water: If you aren’t keeping the ants in the fridge they will need water every day. Using a spray bottle, spray a mist of water onto the ants and sand once a day to keep the sand a little moist and give the ants some water.Wherever it is cold enough in the wild Horned Lizards hibernate during winter by tunneling underground. You may want to hibernate your lizard(s) during winter. They will need several inches of sand to tunnel into. You will need to research how to best help your pet(s) hibernate.
Read also: Diet of Toads