Helford’s herons and enigmatic egret

Two of the Helford’s most noticeable birds are the two resident members of the Heron family the Grey Heron (Ardea cinerea) and the Little Egret (Egretta garzetta). Almost the size of a Golden Eagle, the Grey Heron is the most widespread large predatory bird in the UK, equally at home in the remote highlands and islands, rivers and marshes in the English lowlands or in many urban parks. The Little Egret on the other hand, is currently progressing a steady march northwards from the English Channel coast which commenced in the late 1980s.

By the time you read this, I will be undertaking my annual count of the nests of these birds on the Helford for the British Trust for Ornithology (BTO). Started in 1928, the BTO’s Heronries Census is the longest-running single species survey in the world. Quite obviously a mass of data has been gathered over the years that enables the population to be monitored very accurately indeed. The UK population is currently estimated at around 14,200 pairs. This represents a 30% increase since 1978. Helford contributes about 0.1% towards this total! Since the mid 1980s, all the herons on the Helford have congregated to form a single heronry in the mature oak woodland on the western side of Polwheveral Creek. Since that time numbers of pairs have usually been in double figures. Recent counts include (number of pairs in brackets): 2006 (14), 2005 (13), 2004 (12), 2003 (10) – generally very stable numbers. Prior to the mid 1980s there appear to have been smaller heronries scattered across the Helford Estuary – for example at Carne in Gillan Creek.

However, studying some of the statistics surrounding the Little Egret, it almost beggars belief that the species is doing so well. You may well know that the trade in egret feathers in the Victorian and Edwardian fashion industry led directly to the formation of the Society for the Protection of Birds in 1889 (it became ‘Royal’ 15 years later), but are you aware of some of the astonishing figures behind the headline? In the first quarter of 1885, 750,000 egret skins were sold on the London market; in 1887 a single London dealer handled 2 million skins; in 1914 India, 1 ounce of feathers was trading at 10-28 times the equivalent weight of silver. We might think that ‘factory farming’ is a relatively modern phenomenon – it isn’t. To meet the insatiable demand, egret farms developed with pens holding up to 60 pairs. When the eggs hatched, they were removed and hand-reared, causing the birds to lay again. Sometimes pairs had 4 or 5 broods a season. As if this wasn’t bad enough for them, they were themselves plucked four times a year.

Considering that this only took place a century ago, one can only marvel at nature’s rejuvenating powers. From the 1950s the Little Egret colonised westwards across much of Europe arriving in Brittany in 1960. 20 years later they had reached the UK and following a long period of raised hopes by ornithologists, breeding was first confirmed at Brownsea Island in Poole Harbour in 1996. Helford followed a close second the year after. Nature herself can be fickle however. While numbers of pairs nesting at Helford jumped from 5-6 pairs in 2004/5 to 11-12 in 2006, during a visit to Brownsea last year the warden told me that they are now seeing no young fledged due to predation by ravens. Would anyone condone action to protect a new ‘invasive’ species against a long-standing native? The question is rhetorical.

Each year I am surprised how difficult it is to accurately count the nesting pairs. Despite their large size and the fact that they nest early before leaves are out, the nests can be well hidden in the dense ivy that clumps in the canopies of the oaks. It seems to get denser each year. The egrets sit slightly later than the herons. By Flora Day the oaks are bursting and it is a real challenge to pick out the motionless snowy-white birds through the foliage. By that time the heron chicks are well-grown and often standing up in the nests awaiting their next meal.

If anyone fancies experiencing a dawn watch at Polwheveral, the dawn chorus walk at 0630 on Sunday 22nd April will get us quite close. I can’t promise a repeat of last year, though, when on a cold but sunny April morning I had fantastic views of only my second Cornish Osprey fishing below the heronry and then perching alongside it. But you never know……
It will be interesting to see if the number of Egrets overtakes the Herons this year, and to observe if their interactions change as the balance of the two species alters in their breeding colony.

Martin Rule, with thanks to BTO and Birds Britannic

Extract from HVMCA newsletter No.34 Spring 2007

© Helford Voluntary Marine Conservation Area