Ospreys
Whereas most of the information contain within this wiki is related to the railway, a bit also covers the geological commerce of the area (i.e., Slate quarrying). A volunteer has written on the subject of the local bird life.
Osprey, or Gwalch y Pysgod ( = Fish Hawk), Pandion Haliaetus, is a large bird weighing 2 - 4lb (1-2kg) with a body length of just under two feet (580mm) and a wing span up to 5ft 8in (1700mm), mainly brown on the back and off-white, flecked with brown, underneath. They were hunted to extinction in the C19 but recolonised Scotland in the last century and they have been re-introduced at some lakes in England.
In 2004 a pair built a nest in a pine tree on the Traeth Mawr near Pont Croesor. The Royal Society for the Protection of Birds has extensive security arrangements and a viewing hide, next to our projected railway halt, with telescopes for visitors.
The hawks migrate to West Africa each September and return in late March; they may live for twenty years or more, being constant in their mate and in their nesting site. In 2005, a strange female landed at the nest and was pointedly ignored by the male; she moved on and the regular female arrived a couple of weeks later to a great display of affection. For so large a bird, the cheeping call, like a small game bird, is curious.
The nest is large, about the size of a double bed. In 2004, the nest fell and the chicks were killed, so the RSPB fixed the tree and the nest that winter. In 2005 two chicks were raised, one egg was addled; in 2006 two out of three chicks were raised, unfortunately one seems to have choked on its food and died suddenly. The three eggs are about the size of a hen's egg; they are laid in late April or May and hatch after five weeks' incubation in late May or June. The chicks fledge, 'take their first flight', some seven weeks later, in July or August. Their rate of growth is prodigious.
The mother is the larger bird, and she mainly stays in the nest housekeeping, dissecting fish to feed the chicks, teaching them tidy habits ("stick your bottom out of the nest"), cleaning and dropping rubbish overboard while father goes fishing. However they change places while mother goes to stretch her wings and have a wash.
Father dives from a height into the river to catch fish, a spectacular sight. Normally he takes grey mullet, which are large, slow-moving and surface-feeding, but he will take anything that offers; I have seen him take perch. Three fish a day will keep mother and two chicks happy. He can lift fish up to 3lb (1.5kg) but usually settles for less; he then carries them held fore and aft like a torpedo, to reduce wind resistance on the way back to the nest, which may be some miles. He has been seen over Llyn Cwellyn in one direction and in the Traeth Bach near Portmeirion in the other. In 2005, he came fishing regularly outside Boston Lodge Works, where the tea interval was adjusted to watch him.
Of the varied wildlife of North Wales, the osprey is possibly the most exotic, yet in times past they were common. There are one or two other ospreys around, sometimes on their migration to and from Scotland; they have been seen diving for fish by the Cobs, both at Porthmadog and Conwy, so they obviously do not mind trains. We are arranging to build the Rheilffordd Eryri past their nest while they are away in the winter, the main civil engineering works are being done in the winter of 2006-7 and the track should be laid in the winter of 2007-8.