I came across Volucella zonaria today beside the Neath Canal near the square pond. It is a very large and striking hoverfly, close in size to that of a bumblebee. It is a Hornet mimic.
This species became established in the Britain in the 1940s and seems to be spreading out from the South-east. In much the same way as Bombus hypnorum , but not quite as dramatically!
This link from the NBN shows its distribution in the UK, however it is a little better recorded in Glamorgan than this map suggests. With a number of records from Cardiff, Ogmore (vicinity) and Maesteg. http://data.nbn.org.uk/gridMap/gridMap.jsp?allDs=1&srchSpKey=NBNSYS0000007098"
On the saltmarsh near here a flock of 22 juv shelduck flying through and also 3 Egyptian Geese was unusual.