FROGS

OFNOVA SCOTIA

Eight kinds of frogs Live in Nova Scotia.

Northern Leopard Frog

Eastern American Toad

Northern Spring Peeper

Green Frog

Wood Frog

Pickerel Frog

Mink Frog

Bullfrog

Like their tailed cousins the salamanders,

frogs and toads are amphibians. Their skin is generally smooth and moist; some part of the life cycle takes place in water. The frog face features a wide mouth, 2 large exposed eardrums, protruding eyes with transparent lids and some sort of inflatable vocal sac. The vocal sac, usually located near the throat or along each side, amplifies male frogs' sounds into the loud mating calls we hear.

During spring and early summer, frogs gather in wet habitats to spawn. The males arrive first and begin calling to attract a mate. Each species has its own call, and most are easy to recognize

Spawning usually takes place shortly after, and the eggs hatch quickly into tailed tadpoles. Transformation into adult frogs may take 2 months to 2 years, depending on species and conditions.

Since most frogs are less secretive than salamanders, they are more vulnerable to predators. Large beetles, turtles, birds, snakes, fish and mammals eat frogs and their tadpoles. Also, cars kill many frogs as they cross roads on rainy nights.

The Eastern American Toad, Spring Peeper, Green Frog, Wood Frog, Leopard Frog and Pickerel Frog are all widespread in Nova Scotia. However, Mink Frogs are only known from scattered localities, and Bullfrogs have not been reported from Cape Breton Island.

The Eastern American Toad

Some people call these common creatures "hop toads", and they do indeed move about in short hops rather than long leaps. Most toads are brown, but their colour can range from grey-brown to red-brown. Breeding males have a black throat and are smaller than females. Toads emerge from hibernation and fill the night air with long, trilling calls in May and June. Strings of 6 to 12 thousand eggs are laid in warm shallows; the small dark polliwogs develop rapidly and transform into miniature toads by September. Toads are among the last amphibians to hibernate each fall, and may be seen into late November.

Toads have a dry, "warty" skin. The "warts" are glands that contain a white sticky substance intended to turn away predators biting the toad. Handling toads will not cause warts in people. Some people say toads have the most "character" of all the amphibians. They are the most commonly seen frog in towns because they frequent backyard gardens and front lawns, often staying in one area all summer. Their hind feet have special small knobs for shoving soil aside so they gradually sink and bury themselves. Toads eat a variety of invertebrates, especially ants, beetles, slugs, spiders and mites.

Northern Spring Peeper

Who can ignore a deafening chorus of Spring Peepers on a warm spring night? These thumbnail-sized tree frogs leave their woodland hibernation sites as early as March in southwestern Nova Scotia. Perched on grasses and sedges at the edge of ponds or roadside ditches, the males call mates with a shrill "peep peep peep". Their brown or gray colour, always with a dark stripe on the sides of the head and dark markings on the back provide excellent camouflage against the dead spring grasses. If the night is cold, Peepers retreat under leaves and stems. You'll likely hear hundreds before you ever see one.

Finger-sized

Getting set to peep

About 1000 eggs are laid singly on twigs and leaf litter at the pond bottom. Then adults head back to the woods for the summer, fall and winter. The males may continue to call from trees, clinging a metre or more off the ground with adhesive toe pads. Some call occasionally during the day throughout the summer and fall. The tadpoles develop rapidly and transform from July through September. This treefrog eats mostly soft-bodied invertebrates. Small spiders, moth larvae and water midges are a common food items. Because they are so easy to hear and identify, and may be very sensitive to changes in their aquatic habitats, Peepers have been the subject of widespread environmental monitoring programs like Nova Scotia's Frogwatch.

Green Frog

Green Frogs look something like small Bullfrogs, but their colour varies from yellow to green or bronze, sometimes with brown spots on the back. Some males, particularly individuals in shaded woodland ponds, are black on the back. A few metallic blue individuals have been found. Look for a ridge above the eye that extends part way down the back: this will distinguish Green Frogs from Bullfrogs - in Bullfrogs the ridge curves down right behind the eardrum.

Blue Green Frog

Green Frogs are common in lakes, ponds and streams. Practically any body of fresh water ispotential habitat, whether it is small or large, temporary or permanent, with or without plant life.

Breeding is in June and July. Males spread out among the shallows. The larger dominant males challenge other males that attempt to enter the best vegetated spawning sites. The male's call has been compared to the sound of a loose banjo string. You will hear it day and night, but especially during the first hours of daylight. After spawning, the female extrudes from 1,500 to about 5,000 eggs in a film-like mass among the surface vegetation. The tadpoles overwinter under the silt and dead plants on the bottom and transform the following summer, about one year after hatching. The adults stay in the pond and hibernate in early autumn. Green Frogs eat a great variety of small land and water creatures. Beetles, bugs, spiders, ants, moth larvae and snails are the big items.

Wood Frog

Wood Frogs are brown or tan-coloured. A dark brown mask on the sides of the head has earned them the nickname "robber frog", although the mask is not obvious in breeding males. Some females in red sandstone areas may become red coloured.

                                       E

gg masses

                                         

Wood Frog tadpole

Wood Frogs and Spring Peepers are the first amphibians to emerge in spring. The males, which usually far outnumber the females, congregate on the surface in vegetated areas of ponds. The call is a hoarse racket like a number of ducks quacking in a distant pond. Males are vocal all night long, if temperatures are above freezing. Breeding is over by May in most regions. Females lay fist-sized jelly masses of about 1000 eggs. The tadpoles develop rapidly and transform during July and August. Except for breeding, Wood Frogs live in damp deciduous or mixed woods. They begin feeding after the spawning season. They eat a variety of insects and other small invertebrates, especially spiders, beetles, bugs, moth larvae, slugs and snails.

Northern Leopard Frog

Northern Leopard Frogs, also called meadow or grass frogs, are bright grass-green with oval black spots. They spend a lot of time foraging in grassy places during the summer. You may see them in old fields, meadows, grassy-sedge woods roads and grassy roadside ditches. Juveniles are often seen resting on sphagnum moss at the edge of roadside ponds.

                                         

Egg Mass

                                         

Frog crossing road

Leopard Frogs emerge from underwater hibernation in spring. From mid-April to mid-May the males rest, with limbs spread out, on the surface in the shallows of ponds and vegetated coves of lakes. Their breeding call is a long rattling snore followed by several rapid grunts. Females lay about 3000 eggs in a loose oval mass in shallow water. Newly hatched tadpoles stay in a close group for some time. The tadpoles develop rapidly and change to frogs during July and August.

Leopard Frogs eat many insects and other invertebrates. Since they spend so much time in grassy places, they eat a lot of agricultural pest insects. Juveniles eat aquatic insects. Adults return to aquatic habitats during the autumn to hibernate.

Pickerel Frog

Pickerel Frogs are spotted, but with irregular rectangular brown spots in rows. This is the main way to tell them from Leopard Frogs, which have black oval spots. The basic colour is yellow-brown with orange on the groin and the underside of the back legs. Pickerel frogs are especially common along streams and lake shores near inlets and outlets. They also forage along grassy-sedge woods roads, roadsides, meadows and old fields. They are often found associated with Mink Frogs in vegetated water habitats and with Northern Leopard Frogs in land habitats.

                                         

Pickerel Frog features

                                         

Head

Pickerel frogs emerge from hibernation in spring and breed throughout May. The male's call is a short low-pitched snore which does not carry far. Females produce a globular mass of about 1000 eggs attached to plants about 10 cm below the surface. These egg masses are not seen very often. The tadpoles mature rapidly and transform into frogs during August and early September. Adults hibernate under the bottom debris and silt of their aquatic habitats. Pickerel Frogs eat ants, spiders, bugs, beetles, sawfly larvae, moth larva and a variety of other invertebrates.

                                         

Pickerel vs. Leopard

Mink Frog

Mink Frogs are generally green to brown, often spotted or mottled. Their preferred habitat is quiet waters with lots of plants like lily pads and pickerel weed. The height of the breeding season is in July. Males take their place at suitable spawning sites among the surface vegetation and begin calling a mate. The male calls day and night with a repeated "cut - cut-cut" sound. When a number of frogs are vocal it sounds like a couple of carpenters nailing shingles on a house somewhere in the distance. Females produce about 1,000 eggs each year. The tadpoles overwinter and transform the next July and August.

                                         

Uniacke Lake Frog

                                         

Mink Frog Habitat

Mink Frogs are very timid. Some careful sneaking is required to get close to one. Usually all you see is the water surface breaking in a number of places as they skid off vegetation and hide underneath. The best time to watch them is at night, because they tend to stay still while a flashlight beam is on them. Mink Frogs eat a variety of land and water creatures, particularly ants, beetles, bugs, moth larvae, spiders and flies. When picked up, they emit a smell like a mink (or rotting onions, if you can't quite recall the odour of mink).

Bullfrog

Bullfrogs are our largest frog. They are found in quiet coves of lakes with lots of vegetation, especially water lilies. Most are green or yellow-green, but rarely a blue Bullfrog (lacking yellow pigment) turns up.

“Blue Genes”

Bullfrogs are the last amphibians to emerge in spring. Their booming bass call is heard from mid-June to July, although last year's tadpoles may emerge a month or two earlier. Males move out from shore and settle among the water lilies to call females. She extrudes her eggs in a huge, film-like mass on the surface among the water lilies. Bullfrogs produce as many as 20,000 eggs each year. The tadpoles take two years to develop into young Bullfrogs; hind legs appear after the second winter. Tadpoles hibernate in the deep silt of the lake bottom.

Bullfrog tadpole

The Bullfrog season is short. By early September most are hibernating in muddy pond bottoms. The Bullfrog menu includes birds, other frogs, fish, even their own tadpoles, as well as the usual insects. When held by the hind legs, Bullfrogs may let out a startling scream or squeal.

How to hold a Bullfrog

There are 2,770 species of frogs known in the world.