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Quick answer
No spawn could be related to the weather or an abundance of
predators.
Further
information
Depending on the weather, it may still be too early for
amphibians to be returning to the pond. Frogs and toads breed in
the spring when they migrate towards water; this migration is
weather dependent (they prefer mild, wet evenings) and so is
determined by location - it tends to occur later in the north
and east of the country and earlier in the south. In the past
there have been reports of spawning amphibians in December!
In some cases, lack of breeding amphibians in your pond could be
the result of a population decline locally. This might be an
indicator of pond loss - ponds form 'stepping stones' for
amphibians across a landscape and if they disappear, so can local
populations of amphibians. Their terrestrial habitats are just
as important as amphibians spend a lot of time on land, foraging,
sheltering/hibernating and colonising new areas. If these
areas or 'corridors' have been blocked (by a new road or even a
fence) or destroyed (through development), the route to your
garden may have been lost.
Amphibian populations can fluctuate dramatically year on year,
so having years with low numbers of amphibians can be a natural
phenomenon and nothing to worry about. If no breeding adults
appear in your pond, there may be other juvenile amphibians in
the area that will turn up next year as breeding adults (frogs
take two or three years to reach breeding age). An outbreak of
disease in previous years or a particularly hard winter could
also impact on numbers returning. You may be tempted to
introduce some spawn from elsewhere to try and help your local
population but we advise against this. By moving spawn you can
accidentally introduce diseases and invasive pond plants.
If you have seen frogs but no spawn it's important to remember
that all amphibian life-stages form a natural part of the food
chain. Spawn is probably the lifecycle stage that is the safest
from the attack of predators, despite the numerous predators in
and out of the pond. Spawn will also sink below the surface in
deep water so it may not be visible. Occasionally spawn can sink
below the surface and die; it is particularly susceptible to
late frosts.
Spawn/tadpoles
were present but disappeared.
Nature's Calendar
- mapping the first appearance of frogspawn.
Protecting
spawn from frost.Native amphibians.
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