Grey Heron (Ardea cinerea) have increased in numbers in the last 30 years Time to eat 1: fish are the standard, usually from 10-16cm in length Time to eat 2: amphibians are also fair game for Grey Herons
Bittern (Botaurus stellaris) in flight at the Wetland Centre in London In typical pose Bitterns swim as well as walk when searching for their main food, fish

With their size, colouring, leisurely flight and almost stone-solid appearance as well as regular raiding visits to garden ponds Grey Herons (Ardea cinerea, wingspan 185cm) are among our most familiar wetland birds. They eat fish but plenty more besides, including amphibians, reptiles and ducklings, with up to 500gms a day needed. Their nesting requirements can place them at something of a disadvantage, since they normally use trees with the nest roughly 25 metres above the ground. The eggs are laid fairly early in the spring, and strong winds can pose a major problem.

The RSPB reserve at Northward Hill in Kent, which has been under unjustifed threats for years with proposals for housing development and new airports in the Thames Estuary including at Cliffe, has the highest concentration of Grey Herons in Britain. Quite why successive governments believe an increase in air traffic, with more airports and runways constructed, is either desirable or necessary is beyond the understanding of anyone with even two brain cells to rub together. The plans to build new runways at Stansted Airport announced early in 2007, then at London Heathrow and/or London Gatwick covered by the Airports Commission which reported in 2015, are typical of the muddled, anti-environment thinking that lies behind this approach.Environmentally friendly flying

The same can be said for the intention to lengthen the runway at Lydd Airport in Kent and build a new terminal to allow two million passengers a year. This plan was disgracefully given approval by the local authroty in March 2010 and by the Secretaries of State for Transport and Communities and Local Government in 2013 despite opposition to the scheme from their own planning officers plus such well-informed bodies as Natural England. Lydd is adjacent to the magnificent Dungeness National Nature Reserve and RSPB reserve, so it would be difficult to come up with a more irresponsible place to suggest and approve of airport expansion.

To place this in wider context, the public advantages of such developments and an additional runway at Heathrow or Gatwick are nil; the disadvantages are gigantic. The fact that more people than ever wish to fly abroad on holiday has no bearing whatever on what is necessary for society or the economy. Indeed, UK residents going abroad to spend their money is a hit to the economy here.

This may be disputed by owners of airports, all of whom appear to believe that if there is economic growth, citizens must have the right to fly wherever they want, whenever they want. As non sequiturs go, that is a truly presidential effort, but what do you expect when the idea is coming not from objective observers but from organisations which primarily are interested in making money?

Given the amount of fossil fuel expended and pollution emitted by the average jet passenger plane - a Boeing 747 burns 15,500 litres of fuel an hour, as well as throwing out bulk nitrogen on take-off - any runway construction or increase in flights will be a scandalous example of unsustainable development. In the same way that importing fruit and veg from the southern hemisphere during theEnvironmentally unfriendly flying winter is an absurd waste of 'air miles'.

Defenders of increasing the level of transportation by air claim, accurately enough, that planes account for around three per cent of global carbon emissions. What is not pointed out is first, that this is the fastest growing source of emissions, and second that, according to the Intergovernmental Panel on Climate Change (IPCC), this form of transport will account for 15 per cent of all carbon emissions by 2050.

If anything, the public should be discouraged from flying, not encouraged, and to this end, reassessing and/or selectively disregarding the Chicago Convention of 1944, leading to the novelty of taxing aviation fuel, with the proceeds ring-fenced for use in protecting the environment, would be a step in the right direction as regards environmental responsibility.

The Convention baldly states: "fuel, lubricating oils, spare parts, regular equipment and aircraft stores on board an aircraft of a contracting state (...) shall be exempt from customs duty, inspection fees or similar national duties or charges".

There are also Air Service Agreements (ASAs) between states governing the treatment of fuel loaded on to an aircraft. These usually contain a clause to the effect that fuel in transit or supplied in the territory of a contracting party is exempt from taxation.

There is, of course, no reason why such Agreements should not be renegotiated, and for what it's worth the EU has been discussing the institution of an aviation fuel tax off and on since 1997. Indeed, a few years ago the EuropeanCormorants watching Grey Herons arguing Parliament voted by 430 to 74 in favour of such an impost, though predictably nothing has happened given the vested interests working against such a sea change. Whatever validity the Chicago Convention had when promulgated, circumstances have changed dramatically since then, and apart from anything else, where is the justice in taxing to the hilt petrol and diesel for road vehicles, while not taxing aviation fuel?

If people prefer to fly to or from Schiphol or Charles de Gaulle Airports, good luck to them. The supposed economic loss to Britain is not proven, certainly not as regards tourism, and anyway, we surely should be looking at the future, beyond instant gratification and supposed short-term economic success which may well ultimately encourage long-term decline.

Whatever the score there, Grey Herons seem to have increased significantly in numbers in the last 30 years, with anything up to 10,000 nests annually.

By comparison, the Bittern (Botaurus stellaris, wingspan 130cm), a stockier member of the heron family requiring extensive reedbeds in which to live and breed, is rare indeed but offers a tremendously heartening story in conservation.

Drainage together with agricultural 'improvement', plus hunting and possibly colder climatic conditions in the 19th century - Bitterns are distinctly vulnerable to severe winter weather - resulted in the species becoming extinct for breeding in Britain in 1868. The same thing happened in Sweden. A modest recolonisation occurred in Norfolk from 1911, leading to the individual and remarkable courtship 'boom' being heard from a peak of over 50 males in the 1950s. A radical decline then set in and by 1997 only 11 Bitterns were heard booming.

Action was needed, and showing its usual ability to combine science with passion the Royal Society for the Protection of Birds led the way in a united front of conservation groups that had government and EU support funded by the EU-Life programme. Reedbed habitats were made more suitable for Bitterns and in 2004, six years ahead of schedule, the UK population reached the milestone of 50 booming males set in the UK Biodiversity Action Plan. (The boom can be heard 5km away, andLittle Egrets (Egretta garzetta) have successfully colonised Britain is the only real guide for calculating numbers.)

The next target is 100 booming males by 2020. Rising sea levels will not help the Bittern given that so many extensive reedbeds are close to the coast, including at the strongholds of Minsmere in Suffolk and Leighton Moss in Lancashire, but new beds further away, as at Lakenheath Fen, should help.

When breeding, Bitterns are exceptionally hard to see, but a number winter here, coming from Germany, Sweden and the Netherlands. The latter country, with at least 250 pairs, and France, with 300+ pairs, host the largest breeding colonies in western Europe. Ukraine has by far the greatest number in Europe at large with an estimated 20,000 pairs.

Close to London, Lea Valley in Hertfordshire and the Wetland Centre at Barnes have visitors each year and the pictured bird at the latter site offered exceptional views in 2006-7, with less of the habitual skulking behaviour associated with the species.

Now for some good news. Colonisation by the Little Egret (Egretta garzetta, wingspan 100cm) has been one of the best events in British birding over the last 20 years. The species started appearing in significant quantities in the late 1980s and first nested on Brownsea Island in Dorset in 1996.

Fish eaters, they are steadily extending their range. Poole Harbour and Chichester Harbour hold some of the largest numbers, and they are also common in East Anglia especially in winter, when the population is swelled by migrants. Breeding pairs are calculated to be around 150, with five times that number spending the winter here.

Images © Jeremy Early. All rights reserved.

In 2013 I published My Side of the Fence - the Natural History of a Surrey Garden. Details may be found, and orders placed, via this hyperlink My Side of the Fence. In November 2015 Surrey Wildlife Trust published the atlas Soldierflies, their allies and Conopidae of Surrey, jointly written by David Baldock and me. Details are on this web page: Atlas.