All the eggs are shed in one batch, this event usually occurring early
in the morning.Job done, they recuperate, sometimes in deep water,
then they move ashore till next year.
The eggs start to swell on contact with the water, and they float on
the surface. As breeding spots are traditional many frogs will usually
have gathered there, so more and more egg deposits become larger and
larger, and frequently the water is covered with frog spawn.
Tadpoles hatch after two or three weeks, and swirl and feed and try
to avoid capture.
External gills are absorbed at about four weeks. The hind legs appear
at about seven weeks, and by week twelve the tail is absorbed. The front
legs emerge. The lungs are used.
In spite of best endeavours, most of the eggs, tadpoles, young frogs
are eaten by fish, insects, animals, birds, and few remain to leave the
water for a ground existence at June or July. Three thousand eggs may
produce a few frogs who mature.
What precipitated me to write about frogs was seeing thousands of
eggs in a few damp patches last week. I suspect the frogs miscalculated,
thought they had found a fine breeding place, and bred. But a small
drought would dry out these patches, and I do not think that the
creatures would survive.
It seems to be much wasted effort to me, but I can hope I am wrong.
Coming Events
Saturday 9, daily to Saturday 23 - Family trail around the
grounds of Castle Espie to celebrate Saint Patrick's Day and the corning
of spring.
Saturday 16, Sunday 17 March - National Science Week,
recycling paper is the theme, 2pm, details from Castle Espie, 91874146.
Friday 22-Sunday 24 March - RSPB/Birdwatch Ireland, joint
conference. An exciting agenda has been arranged for this conference to
be held at the Great Southern Hotel in Rosslare.
Sunday 24 March - Ranger Ramble at Colin Glen Forest Park. at
2pm, details 9061 4115
Monday 25 March - Lisburn RSPB will have Anthony McGeehan tell
you how to Know Your Birds better, 7.30, Friends Meeting House, phone
9260 1864
Thursday 28 March - Birdwatch Morning, 10.30, Castle Espie,
see flocks of birds, call 91874146
Saturday 30 March - Lisburn RSPB field trip to Rea's Wood and
Sixmilewater, talk to 9260 1864
Friday 29-Saturday 30 March - Sounds messy, but try to get
involved in the biggest ever Easter Eggsculpture, at Castle Espie, from
noon, call 91874146
Sunday 31 March -More eggs, this time at Oxford Island, and it
involves a self-guided trail around the Nature Reserve, and the mystery
of the mixed-up eggs, at 12.00, call 38322205