GB No. 1(16)/95
A shrill, resonant clatter disturbs the silence of the night. At first it comes from just one part of the pond, then from another, and eventually all the water vibrates with this sonorous sound. This is the mating call of the natterjack toad.
First I had made several unsuccessful expeditions to various places in Poznań where the natterjack toad (Bufo calamita) has been observed. Going into reservoirs at night and searching for tadpoles were not successful either. Eventually one of my friends from "Salamandra" told me that he had heard strange calls near Suchy Las, close to Poznań. I decided to check out a pond near the gate of the landfill in Suchy Las.
Some days later we arrived at this place. At the moment the car engine stopped, I was sure -- the voices we heard were the mating calls of the natterjack toad males. These voices were coming not from the pond, but from the landfill. There is another pond at the top of the huge rubbish heap covered with loam. The natterjack toads chose that pond to breed.
The natterjack toad differs from our other toads by a light stripe on its back. It is the rarest, smallest, and most resistant to dry and warm conditions. It usually lives in dry, sandy areas such as dunes, gravel pits, and farmlands. It is often observed near people's houses, just like the green toad (Bufo viridis). All Polish toads lead a nocturnal way of life. At night they search for food - insects, snails, etc. During the day they hide in holes in the ground, under stones or stems, etc.
The breeding time of the natterjack toads is spring -April and May, sometimes June. The breeding activity increases after strong rains and when the weather begins to grow warmer. When it gets cool, the natterjack toads stop breeding. This amphibian lays its eggs in small water reservoirs, flood waters, and even pools. Often the green toad breeds together with the natterjack toad, and sometimes one can observe crosses between the two species. Males are always first at the breeding pond, and they stay near the banks and attract females by their mating calls. When a female comes to the pond all the males try to intercept her. The male climbs onto the female's back and grasps it under his arms. This position is called amplexus. When the female lays eggs, the male spills its sperm over them and fertilizes the eggs.
The eggs of the natterjack toad as well as those of our other toads are layed in lines stretched between plants or sticks at the bottom of the pond. After a month or two the tadpoles hatch. At the time of metamorphosis they are the smallest in size of our amphibians.
The natterjack toad is not currently in danger of extinction in Poland, but it is our rarest toad. The conclusion is: protect it and the places where it breeds and lives. But how can we protect the landfill? I think it won't be necessary. We should take care of the tadpoles and protect them from drying out. We should not allow workers at the landfill to cover the pond with sand as well.
Albin Pawłowski
Polish Nature Protection Association "Salamander'
(Polskie Towarystwo Ochrony Przyrody "Salamandra")
Umultowska 100/42
60-614 Poznań