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Toad time

A digital visit to the toad pond

April is the month when amphibians in Rogaland start moving about. They awaken from dormancy (brumation) due to a steadily increasing temperature and head for the nearest pond to breed. Some staff at the Natural History Department at Museum Stavanger (MUST) donned diving suits, snorkels and swimming fins and dove into some local ponds to see how the toads were spending the Easter holiday.

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The male toads behave frantically as long as they don’t have a female to latch on to. It’s difficult to say whether the male approaching me (the photographer) is trying to chase me away, or if he sees me as a potential partner.

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This female toad has come down to the pond with her partner, who rides on her back ‘in amplexus’. They start hunting for a suitable place to spawn, that is, to lay and fertilise the eggs.

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Hunting for a place to spawn. The male toad is smaller and always rides piggyback on the female. She does all the swimming.

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Up to the surface to breathe.

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Ready to dive.

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Sceptical, yes! Best to stay in deeper water until that big blue thing with the camera leaves.

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Many toad ponds also contain leeches. Compared with the toads, these are large, and they are fatal when they suck all the blood out of a toad. In some places, leeches can be a big threat to the survival of local amphibian communities.

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A leech has latched onto the neck of a toad and sucked its blood. The toad is dead. The leech now has enough nourishment to reproduce its species, thus maintaining the pond’s biological diversity.

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The toads have spawned, meaning the females have laid their eggs and the males have fertilised them. The little black clumps to the left of the toads and also just behind them are frogs’ eggs, while the long strings are toads’ eggs. Frogs often spawn a few weeks before the toads.

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Toads don’t need all that much water to spawn. This picture is from a pond at Oanes. Toads manage to live alongside fish better than do frogs; toads are therefore more often found in lakes. Toad tadpoles taste vile in contrast to frog tadpoles, so the fish avoid them.

Det kan bli ganske lange slimbånd med egge når paddene først setter i gang.

The egg strings can become quite long once the toads finally start spawning.

Ofte er flere par samlet på samme stedet for å legge eggene sine.

Oftentimes several pairs of toads spawn in the same place.

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Sometimes the male toads are so eager to breed that they end up causing the female’s death. Here you see many males fighting over the same female. They all want to mount her, but she is already dead and hidden inside the ‘mating ball’. She probably drowned because, with so many suitors, she was unable to reach the surface to breathe.

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The party’s over and the toads have once again crawled out of the pond and returned to the woods. This female toad hasn’t managed it, but most survive mating season and will return to the pond next spring. The common toad (Bufo bufo) can live up to 40 years and is the amphibian in Norway with the longest life span.

It can be quite gruelling for a female to deal with all the male toads who want to mate with her. Oftentimes she is attacked by many males at the same time. In the video link you can see a female toad being attacked by a group of eager males.