The Great Spotted Cuckoo found this evening by Martin Bevan was still present until dusk apparently. Grid ref SN 961 095. Only parking for 5 cars near the reserve track so best to park in Penderyn then walk 1 mile NE towards Cwm Cadlan. Instructions as given on the South Wales Birding Facebook page are as follows:
At the LNR, take the path down into the valley, cross the bridge, take the path to the left and follow for about 500m to open area. Grid Ref SN 961 095.
A record shot can be seen on SWB FB page at https://www.facebook.com/groups/131921633659311/ [scroll down in Adrian Merediths post].
Glamorgan Bird Club 
The bird was apparently still present this morning. It came out of roost and was immediately attacked by a Common Cuckoo.! – per Phil Hill.
Great find MJB – bird showed well after an anxious wait this morning.