Podiceps cristatus cristatus
Breeding Great Crested Grebes inhabit fresh waters throughout the non Arctic Palearctic and are variously resident, migratory and dispersive.
In Pembrokeshire the Great Crested Grebe was considered to be a not very common winter visitor by Mathew (1894), a rather scarce winter visitor by Lockley et al (1949) and a sparse winter visitor by Donovan and Rees (1994).
Throughout this period there was an increase in the UK breeding population, following the cessation of persecution post 1860. This increase has continued in the long-term, e.g. a 28% growth nationally between 1995 and 2005 as measured by the BBS.
Few fresh water sites in Pembrokeshire are suitable for Great Crested Grebes. One was seen at Bicton Reservoir in November 1980 and ones and twos occurred sporadically at Bosherston between 1984 and 1997.
One was at Heathfield Gravel Pit on 27th May 1999, with two there on 4th July 2001 and breeding was attempted in 2005 but was unsuccessful.
From one to five were seen at Llys y fran Reservoir in most years between 1985 and 1995, then in 1996 a pair bred but the nest was predated at the egg stage. Birds were present in the following years but breeding was not proven again until 2004. A pair present with three juveniles in July 2002 was suggestive but at that date could have come from elsewhere.
A single bird was seen at Rosebush Reservoir on 20th September1992, where a pair built a nest in 1995 but did not breed. A pair hatched a chick in 1997, were seen sitting on a nest in 1999 and 2002 and bred in 2004, 2005 and 2006.
A bird of the year was picked up unharmed in Haroldston Hall farmyard on 27th July 1966, it was released onto the farm’s irrigation reservoir where it spent several days before leaving.
The number visiting Pembrokeshire also increased, from 13 in 1936, through 19 in 1963 and 28 in 1985, to the subsequent annual totals recorded, as follows: