As a kid, I had a delightful encounter with hundreds of tiny toads as they left a pond. Transformed from aquatic tadpoles to air-breathing, miniature adults, they scrambled ashore in a choreographed exit, before intrepidly hopping away in all directions to seek their future on land. I wanted to hop along with them!
Although they are mostly active at night, regular toad encounters have been part of my life. Building a house started with digging a foundation into a side hill and spreading gravel over what would be the basement and barn floors. That attracted enthusiastic toads that were quick to hop, adopt, and shuffle into the gravelly dampness.
More recently, the gravel soils of a property we bought in New Brunswick came with an abundance of toads. We enjoy watching them backing themselves down into shady, cool gravel on hot weather days. Special tubercles — two rounded points of bone — on their hind feet enable them to shovel soil aside. In this manner they can progressively submerge and often bury themselves entirely.
Eastern American toads, Anaxyrus americanus, come out of their subterranean hibernation places in May and June. When they arrive at a pond on calm evenings, calling begins. It begins with a single, slightly lower introductory note, then a monotone trill that lasts up to 30 seconds. “Come hither,” in toad-speak.
Each male in a breeding chorus selects a different note. Hopeful for love, many young male toads continue to serenade late into the summer. When calling, their throat puffs out like an inflated balloon. American toads also communicate using body postures, touch, and chemical cues.
Introduced to Newfoundland 63 years ago, this toad species extends as far west as eastern Manitoba, and north to Ungava Bay. In the south, they range over much of the eastern U.S. as far west as Kansas.
While frogs have soft, moist, smooth skins, more rotund toads dress in drier skins with warts. Mostly cloaked in varied shades of brown, some sport olive, reddish, yellowish grey, or black colouring. A light line extending down the middle of the back is often visible. Female body lengths (5.7 to 10.5 centimetres) can be larger than males (4.9 to 7.6 centimetres).
There’s a myth that toads spread warts. That’s not the case: a virus, not toads, causes warts. But a pair of large, elongated parotid glands on the toad’s shoulders secrete a bad-tasting, white, sticky poison called bufotoxin. It can irritate a predator’s mouth when it attempts to devour a toad. This poison is only harmful when swallowed or if it gets in the eyes, but it can make many animals very sick. After handling an upset toad, wash your hands.
Frogs lay eggs in round blobs, whereas American toads lay in two strings. Female toads seek vernal pools where fish that eat eggs are absent. The small, round eggs are lighter on the bottom and darker on the top to blend in with the background when viewed from above or below. Acid rain and acidic snow, which accumulates over winter then melts in the spring, can threaten developing embryos. The eggs hatch in two to 14 days, depending on the water temperature.
Young toad tadpoles have skinny tails relative to their body size. These black tadpoles avoid predators by hiding in shallow water, often in thick vegetation or under dead leaves that litter the bottom of the pool. They also swim close together in schools during the day. Toxic chemicals in their skin discourage some potential predators. Most fish quickly learn to avoid eating American toad tadpoles.
Eating Chlorogonium algae helps the tadpoles develop more quickly. After 50 to 65 days, they become adults, having completely absorbed their tails. When their transformation is complete, the “toadlets” may remain in the water for a short time. Entire groups of tadpoles may reach the toadlet stage all at once and a mass migration to higher ground takes place, which is what I witnessed as a child that had delighted me so.
They hop, heading for shaded forested areas bordering the marshes, ponds, and pools from where they were born. Although they tend to stay in one area if the habitat is good, toads have been recorded travelling up to a kilometer. Developers forcefully oust many when they drain wetland breeding ponds.
Toadlets eat small bugs and other invertebrates (small spineless creatures) as they roam the forest. Adults consume a variety of insects and other invertebrates, including crickets, centipedes, moths, snails, ants, spiders, beetles, slugs, and earthworms. While most toad species wait for prey to come along and then pounce on it, American toads can shoot out their sticky tongues. They also use their front legs to hold and eat larger food, grasping the food and pushing it into their mouths. One American toad can eat up to 1,000 insects every day, making the species a friend of the farmer and gardener. Most toads die within a year or two, but a few live to be 10 years old in the wild, and captive toads have lived about 30 years.
Growing young American toads shed their external skin every couple of weeks or so. Adults lose their skin about four times yearly. When it happens, the old skin usually splits along the back, slips off like a jacket and collects under the tongue. It’s rare to find a shed skin because toads commonly eat their skins immediately — natural recycling!
Diving beetles, hawks, herons, raccoons, crows, and ducks will eat toads, but their main predators are snakes. Garter snakes are immune to the poisonous glands of American toads. Faced with a perceived predator, many toads will urinate on themselves to become a less attractive meal. Or perhaps they’re just scared? If you pick one up, be forewarned! They’ll also inflate their bodies with air to make themselves more difficult for a snake to swallow. Toads have evolved many defences.
American toads are adaptable to a variety of habitats if there’s unpolluted, semi-permanent water for them to use in the breeding season. This adaptability has allowed them to successfully colonize suburban and agricultural areas. Toads don’t drink water but let it soak in, absorbing moisture through their skin. This is a good reason to not using chemicals on your lawn and garden.
Toads like loose garden soils. When you discover one in the garden, consider placing an overturned clay flower pot (with an access hole chipped open on one side) into a shaded spot in the garden. For those who read The Wind in the Willows by Kenneth Grahame as a child, the pot will be a scaled-down version of Toad Hall: a home for your slug-eating friend.