Lizards are some of the most numerous and diverse animals found in rainforests around the world. With over 10,000 known species, lizards have adapted to fill a variety of ecological niches in these complex ecosystems.
But what do these scaly creatures eat to survive in the hot, humid rainforest environment?
If you’re short on time, here’s a quick answer to your question: Most lizards found in rainforests are insectivores who prey on ants, termites, beetles, and other small invertebrates. Some larger lizard species may also eat small vertebrates like frogs, birds, eggs, and smaller lizards.
In this comprehensive guide, we will cover the diverse dietary habits of rainforest lizards in detail, looking at the different food sources utilized by various lizard families and species.
Insects and Other Invertebrates
Lizards thrive on the bounty of insects and other small invertebrates found in abundance within the warm, humid rainforest. These creatures make up the bulk of many lizard species’ diets. With over 30 million insect species on Earth, rainforests harbor an incredibly diverse buffet for lizards to feast on.
Ants
Ants are a particular favorite, with some specializing in raiding ant and termite nests. Their small size, lack of wings, and colonial nesting behavior makes them an easy meal. Certain lizards like the Tokay Gecko have even developed special adaptations like sticky toe pads to more effectively hunt and consume ants.
Termites
Termites pose a similar draw, offering lizards rich nutrition within their softer bodies. As social insects, termite mounds also provide concentrations of prey for opportunistic lizards to take advantage of. The Armored Ground Gecko is one species known for breaching termite mounds in search of food.
Beetles
With over 400,000 classified species globally, beetles represent a hugely abundant food source for rainforest lizards. Their hardened outer wings require more effort to crack open, but the nutrient payoff is worthwhile. Small beetles can usually be swallowed whole after crushing.
Larger beetles may need to be torn into pieces first using the lizard’s teeth.
Spiders and Other Arthropods
Any small invertebrates are fair game for hungry rainforest lizards. This includes spiders, caterpillars, grubs, worms, snails, slugs, millipedes, centipedes, and more. Lizard species like the Tokay Gecko even consume small frogs and rodents when given the chance.
Generally though, the vast majority of a rainforest lizard’s diet originates from the rich diversity of insects and other arthropods available.
Small Vertebrates
Frogs and Toads
Rainforest lizards love to feast on the abundant frogs and toads that dwell in the warm, humid environment (see references below for sources). Small tree frogs and colorful poison dart frogs make for tasty meals and provide essential proteins and nutrients.
Larger amphibians like giant marine toads and paradox frogs are also on the menu. A 2008 study found that frogs and toads make up over 15% of the green iguana’s diet in the Costa Rican rainforest.
Small Mammals
In addition to amphibians, small mammals like bats, shrews, rodents, and opossums offer sustenance for hungry rainforest lizards. Species like the tegu actively hunt for these furry critters, using their keen sense of smell to track them down.
Smaller lizards may eat juvenile mammals or even pick at carcasses they discover. A surprising 2019 report revealed that the Common Iguana’s diet consists of up to 30% mammals in parts of Panama.
Birds and Eggs
Tree-dwelling lizards find easy pickings when it comes to birds and their eggs in the diverse rainforest canopy. Swift chameleons and anoles often pluck eggs right out of nests or grab hatchlings when parent birds are away. Larger varieties like the Jesus Christ lizard may consume entire adult birds.
In fact, a 2010 National Zoo study showed that ground-nesting bird species had declined in areas with high iguana populations, likely due to excessive egg predation.
Other Lizards
As competition for food increases among the over 2,500 species of rainforest lizards, some turn to hunting smaller lizard species to survive. Large predatory lizards like the giant monitor have even been known to attack reptiles as big as juvenile crocodiles!
But most stick to small skinks, geckos, anoles, and young iguanas. A fascinating 2011 analysis of komodo dragon stomach contents found that a staggering 28% consisted of other monitor lizards.
Fruit and Nectar
Lizards in the rainforest have a wide variety of fruit and nectar sources to choose from. The abundant plant life in rainforests provides a veritable fruit buffet for opportunistic lizard species.
Fruits
Many rainforest trees, vines, shrubs, and epiphytes produce juicy, sweet fruits that lizards relish. Some examples include:
- Figs – The fruit of various Ficus species trees are an important food source. Many lizards gobble up ripe figs that fall to the rainforest floor.
- Berries – Shrubs like raspberries and blackberries provide soft, pulpy fruits that lizards readily consume.
- Bananas – Wild banana and plantain fruits contain plenty of starch and sugar to fuel arboreal lizards.
- Guavas – These small, tasty fruits are devoured by a variety of ground-dwelling and climbing lizard species.
During fruiting seasons, some clever lizards like anoles even stake out fruiting trees and aggressively compete for the ripened fruits against birds, monkeys, and insects.
Nectar
In addition to fruits, many rainforest dwellers subsist on floral nectars. Species like chameleons, anoles, and skinks lap up the sweet secretions from flowers of:
- Bromeliads – Colorful tank bromeliads and other epiphytic species produce appealing flowers that lure in nectar-seeking lizards.
- Orchids – These diverse rainforest epiphytes frequently support small arboreal lizards.
- Passion vines – Lush flowers of climbing vines like passionfruit provide gourmet nectars.
The sugars in nectar help fuel lizards’ high-energy lifestyle. And by feeding, the lizards also serve as inadvertent pollinators when bits of pollen stick to their snouts and skin.
So whether it’s a juice-dripping fig or the flowing nectar of an orchid, rainforest lizards have no shortage of sweet, energizing plant products to indulge in!
Carrion
Lizards are opportunistic feeders and will eat whatever food sources are available to them. In the rainforest ecosystem, carrion or dead and decaying animals provide an important food source for many species. Here are some key points about lizards and carrion in the rainforest:
- Carrion is abundant in rainforests due to the high diversity of animals and fast rate of decomposition in the warm, humid conditions.
- Various lizard species will scavenge on carrion as part of their diet when it is available, including monitor lizards, tegus, and some geckos.
- Large bodied lizards like monitor lizards are well adapted to eating carrion and can detect dead animals from far away using their keen sense of smell.
- Smaller lizards may also feed on insects and larvae that are attracted to and feeding on decaying carcasses.
Eating carrion provides lizards with a good source of protein to fuel growth and reproduction. It also requires less energy expenditure than hunting live prey. However, carrion feeding does come with risks like exposure to parasites and bacteria.
Some noteworthy examples of carrion feeding lizards in rainforest habitats include:
- Komodo dragons – These largest lizard species are known to consume large carcasses of pigs, deer, buffalo and even dead or injured horses.
- Perentie monitor – An Australian monitor lizard that feeds extensively on kangaroo carcasses.
- Green iguanas – Mostly herbivorous but opportunistically scavenge on dead animals.
Conclusion
Lizards occupy a wide variety of niches across rainforest ecosystems. While most species are primarily insectivores, some have adapted to also consume small vertebrates, fruit, nectar, and even carrion.
Understanding the dietary diversity of lizards provides insight into how these reptiles have evolved to thrive in the complex web of life found in tropical rainforests around the globe.
