17.10.2024 - Indoor Meeting : Waterbird Monitoring in the Wensum Valley and Beyond

Speaker: Neil Calbrade
Reporter: Cath Robinson
Neil has been working for the BTO for many years and is the Waterbirds Surveys Officer. These surveys cover : WeBS and also the Goose and Swan Monitoring Programme: GSMP. The BTO does love its acronyms....

So, WeBS monitors non breeding waterbirds in the UK working jointly with the RSPB and JNCC. (see what I mean). Records go back for wildfowl to 1947, with waders added in 1969 and WeBS starting formerly in 1993.
Over 30,000 volunteers (mostly) are involved in counts in the UK with 160 local organisers: the Norfolk organiser is Mark Clay. Numbers are in the order of 3.5 million birds.
The UK has internationally important populations of waterbirds: vast numbers of duck, geese and waders. Many of these birds breed in the high Arctic and come to the UK because of its relatively mild winters and good food supply. The UK accounts for 28% of European estuarine resource so lots of mud for feeding. It is also on important migration routes, so a good stopover for feeding up. The Wash tops the principal sites in the UK with a 5 year mean count of 423,000. (The North Norfolk coast comes in at 7th in the league with Breydon Water 9th).
There are a variety of counts: the Core Counts are monthly and currently there are 3,300 sites.
These are supplemented by Low Tide Counts for estuarine sites in the winter (these target those intertidal feeding species) and Special Species Focus Counts.
The Core Counts assess the size of populations and assess changes to these populations. Core Count estuaries are counted at high tide. Apparently with experience you can get quite good at estimating vast numbers.
GSMP: The BTO relatively recently took over responsibility for these counts as WWT stopped being involved. These assess the breeding success of native geese and migrant swans in the non-breeding season.
The Icelandic Breeding Goose Census done in November covers Pinkfoot and Icelandic Greylags. About 75% of Icelandic breeding Greylags overwinter in the Orkneys along with the resident Greylags. To try to assess the Icelandic population then an extra count is done in August before their arrival and then again in November when the main Census is carried out.
So the resident population can be subtracted from the November total.
Some counts use age assessments to assess reproductive success: looking at % of young birds in non-breeding flocks and the average brood size. Birds like Brent Goose and White-fronted Goose where 1st winter birds have different plumages make this more feasible.
So as a result of all these counts (and volunteer hours!) the BTO has huge amounts of data which is generally available online [www.bto.org/webs-reporting]. There is a help section with tutorials.....but highlights are also published in an annual report and there is a Waterbird newsletter.
Neil spoke of the use of the data to feed into international waterbird population estimates; to define statutory borders for SPA and SSSIs, to provide data prior to developments and to counter some prospective developments. They are very aware that the data would be used for any prospective Wash barrier.
It also illustrates the phenomenon of Species Shift: Short-stopping. With climate changes some birds are stopping short of their traditional wintering grounds. Counts of White fronted Geese are down while they are higher in the Netherlands. Counts of Dunlin and White fronts are down on the west coast and higher on the east.
The data also shows population trends over time: Pinkfoot overall doing very well but with a recent dip which we wondered might be due to the different agricultural practices for sugar beet. Little Egret and Great White Egret numbers are soaring while Mallard and Pochard not doing so well. The online data set I suspect might give many fruitful hours of study.
Vacant WeBS sites are shown on the website. and Neil reassured us that many are small inland waters which would not need vast experience. Do get in touch if you are interested.
Thanks to Neil for his interesting and informative presentation.