May is the time when Toads Sing

In the Bras d'or Lake Bio­sphere Re­serve

The Victoria Standard - - Environment - AN­NA­MARIE HATCHER

The Mi’kmaw word for May is Squoljuiku’s which trans­lates to ‘frog croak­ing time’, a noisy month in the Bras d’or Lake Bio­sphere due to the des­per­ate songs of am­phib­ians look­ing for mates. Al­though we are all fa­mil­iar with the short and fran­tic calls of the spring peeper, there are sev­eral types of frog and a toad which con­trib­ute to the spring am­phib­ian cho­rus. The spring sound­scape in the Bio­sphere is en­riched by the songs of spring peep­ers (Ji­jawej), wood frogs (Samqwani’j), north­ern leop­ard (grass) frogs (Samqwane’j), pick­erel frogs (Mko­qte’j) and the Amer­i­can Toad (Sqolj); each con­tribut­ing a unique song to the med­ley.

That sharp so­prano trill in the nights and early morn­ings of spring is con­trib­uted by male Amer­i­can toads, float­ing in their favourite pond and anx­iously try­ing to at­tract a fe­male. Sqolj is the last am­phib­ian to go into hi­ber­na­tion in the fall, and is full of des­per­ate sex­ual vigour in the spring. They have a haunt­ing call, with their long vi­brat­ing vo­cals fill­ing the night air in May and June. If a group of males hud­dle to­gether to pro­duce a cho­rus of trills, each des­per­ate male will choose a dif­fer­ent note for his call, pro­duc­ing a pleas­ant har­mony in the cold spring air.

The Amer­i­can toad adults are found in a wide va­ri­ety of ter­res­trial habi­tats rang­ing from mown grass to gar­dens and heav­ily forested ar­eas. Ideal adult habi­tats are damp ar­eas with dense veg­e­ta­tion and lots of in­sects. They in­habit ponds only dur­ing the breed­ing sea­son. Breed­ing oc­curs in many types of fresh­wa­ter such as warm, shal­low ponds, shal­low streams and river mar­gins and even large pud­dles and road­side ditches. There is ev­i­dence that they pre­fer wa­ter bod­ies with few or no fish and that in­di­vid­u­als re­turn to the same wa­ter bod­ies where they were born. Dur­ing this spe­cial time of year, the toads’ breed­ing an­tics may re­sem­ble a clumsy orgy. When a singing male en­coun­ters a re­cep­tive fe­male, he latches onto her back and they float, en­twined, while his sperm fer­til­izes her ex­pelled stream of gelati­nous eggs head­ing to the bot­tom. It some­times gets a bit con­fus­ing for the poor guys and sev­eral males may try to at­tach to the same fe­male at the same time, form­ing what is com­monly called a ‘toad knot’. Keep in mind that the fe­males are much larger than the males, but it must be a bit of a nui­sance as she tries to main­tain a clear path for breath­ing while con­cen­trat­ing on ex­pelling streams of eggs! The process of the male(s) latch­ing onto the fe­male for fer­til­iza­tion is called ‘am­plexus’.

The counter-shaded eggs (black on top and white on the bot­tom) are about 1.0 to 2.0 mm in di­am­e­ter and the strings may con­tain sev­eral thou­sand. The lar­vae that hatch from eggs a few days or weeks later are called "tad­poles" and they stay in that stage for up to two months. The tad­poles are easy to iden­tify. They are small when com­pared to tad­poles of other species, very dark and have skinny lit­tle tails com­pared to their round bod­ies. They grow to over a cen­time­ter in length be­fore trans­form­ing. Newly-meta­mor­phosed toadlets are usu­ally around 1.0 cm long when they first emerge in Septem­ber. They are mini-toads with an at­ti­tude and coloura­tion sim­i­lar to that of full grown adults.

The lit­tle toadlets move out of their wa­tery nurs­ery and dis­perse into the nearby fields and forests. The adults live in many habi­tats in the Bras d’or Lake Bio­sphere with lots of mois­ture and plenty of in­sects to eat (yes, that in­cludes mos­qui­toes and black flies). Some nat­u­ral­ists be­lieve that a sin­gle Sqolj can con­sume up to 10,000 in­sects a year! The mini toads grow rapidly in the first year. By their sec­ond birth­day, they are near full-size and the males are ready to mate. The fe­males are a bit slower to ma­ture and will be ready by their third birth­day. They can live up to 10 years, over­win­ter­ing in bur­rows that they dig ex­tend­ing be­low the soil frost line.

The Amer­i­can Toad may not be the most charis­matic res­i­dent of the Bras d’or Lake Bio­sphere, but it does play a valu­able role. It has the abil­ity to trans­form thou­sands of mos­qui­toes, black­flies and slugs into rich or­ganic toad fae­ces fer­til­izer. Think about the hum­ble toad when you plan lawn care this spring. That chemical ni­tro­gen-rich lawn fer­til­izer which makes your grass a ver­dant green is toxic to th­ese lit­tle gar­den helpers. Let’s aim for a less green, more di­verse lawn and en­cour­age Sqolj to take up res­i­dence and help you with your ‘pest’ prob­lems!

The Amer­i­can Toad pop­u­la­tion ap­pears to be in good shape ac­cord­ing to the In­ter­na­tional Union for the Con­ser­va­tion of Na­ture. How­ever, we would like to keep a closer watch on this species. Am­phib­ians are in­di­ca­tors of en­vi­ron­men­tal change. If you would like to help keep track of the health of our Bio­sphere pop­u­la­tions, please be­come a Frog­watch vol­un­teer. Reg­is­ter at: https://www.na­ture­watch.ca/ frog­watch/.

Dr. An­na­marie Hatcher is a con­sult­ing ecol­o­gist and a board mem­ber of the Bras d’or Lake Bio­sphere Re­serve As­so­ci­a­tion. For more in­for­ma­tion about the Bras d’or Lake Bio­sphere Re­serve As­so­ci­a­tion, please visit http://blbra.ca/ or check out our Face­book page.

Photo by Ryan Hod­nett.

An Eastern Amer­i­can Toad.

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