With the breeding season coming to an end, it is time to review the bird life successes and failures on the reserve this year. Well, bitterns, our top target species, did very well with six booming males. This was double last year’s figure and in July, it seemed that young were on the wing across the reserve. This exceeds all expectations and bodes well for expansion in future years, as gravel extraction continues and new habitats are created. All the work done by our sterling volunteers has been fantastic. This has included pre-dawn monitoring of “boomers” and planting reed plugs. This pays dividends when a young bittern flies out from the reeds and right over your head!
Following the mild winter we have also had a good increase in bearded tits with at least 24 pairs. This is up from nine last year. Their pinging calls echoed across the reeds accompanied by the chatter of both reed and sedge warblers throughout May and June.
Overhead, marsh harriers skydanced and had a reasonable year. A total of six pairs raised 14 young. Hobbys have been reported as being scarcer than usual this year, but at Ouse Fen they are often seen hunting dragonflies over the reedbeds on sunny days. Barn owls have had a great year. We had four boxes with three well grown chicks in each during July. Other boxes were occupied by stock doves and jackdaws.
Here is a picture of one of the young barn owls:
Image credit: Hannah Bernie
The black headed gull colony did very well at Barleycroft Lake with 274 pairs. There were also eight pairs of common terns, raising lots of young between them. At Berry Fen, duck numbers were high and there was plenty of variety with a pair of garganeys present through the period. Breeding wader numbers were also plentiful with 23 pairs of lapwings and 12 pairs of redshanks. Over at Needingworth Pits, turtle dove numbers picked up as some birds arrived quite late. There was a total of four calling birds on territory.
Migrants of note were three black winged stilts that were seen on and off from 16 May to 23 May. One of these was a ringed bird from a collection, and it remains with us until now. A great white egret was present at Berry Fen as the water levels dropped, along with 39 little egrets on 24 June. There is also a great white egret in the area currently.
Water levels have remained high through the summer so there has been a shortage of migrant waders due to a lack of mud. However; both green and common sandpipers have been seen regularly along with a few greenshanks, ruffs and common snipe.
It has been a good year for butterflies. The nettles and thistles have provided caterpillar food and nectar for hundreds of small tortoiseshells, peacocks and red admirals. There have also been occasional sightings of painted ladys and clouded yellows.
On the mammal front, we have seen Chinese water deer, water shrews and lots of water voles. This shows that the new wetlands are providing secure habitats on a large scale. There have also been occasional otter sightings too, which is an encouraging sign.
Autumn wildfowl numbers are building and into September thousands of ducks and geese will join us to spend the winter here. We have planned some works to improve and vary the margins of the reedbed. We are also planning to improve the viewpoint overlooking the reedbed at the southern end of the reserve. This should provide clearer and closer views of the special wildlife that calls Ouse Fen home.