The Natural History of Slapton Ley | Wildlife Surveys

Birds

Prior to 1998 there were few structured surveys on a long term basis at Slapton. 

In that year a long term survey of Mute Swan and Great Crested Grebe was begun, initially restricted to breeding success, but in 1999 it was extended to all the year round monitoring. In the year 2000 Coot were added to the list. These species were selected as representing conditions on the Ley with regard to euthropication which affects both the fish and macrophytes, these being the food sources for the selected species. Fluctuations in the populations of these food sources were thought to affect both the wintering populations and breeding success of the selected bird species and this has indeed proven to be the case. Water Rail has also been monitored annually since 1998. 

Young Great Crested Grebe (few days old)

The only passerine bird species for which a long term data set is available is Cetti's Warbler. The species was monitored for a national survey in 1996, the criterion used being the singing male in April and May. This showed the site to hold the third highest population in the UK. Since 1998 the population has been monitored using the same criterion and has been found to fluctuate on a cyclic basis, probably linked to breeding success and winter survival. 

In 2004 a survey of several passerine species was undertaken and duplicated in 2005. The species included Stonechat, Song Thrush, Cetti's Warbler, Sedge Warbler, Reed Warbler, Whitethroat, Blackcap, Willow Warbler and Reed Bunting. Other species including Cirl Bunting were commented on. 

In 2006 the survey work for passerine species concentrated on Slapton Wood with a consequent change in the species monitored.

To view the bird survey reports from the last decade at Slapton Ley, please click on the links below.

1998-2002     2004     2005