New Guinea harpy eagle

As its name might suggest, the New Guinea harpy eagle (Harpyopsis novaeguineae) is confined to the island of New Guinea, where it lives in forests up to 3,200 metres (10,500 feet) above sea level.

It measures up to 90 cm (35 in) in length. It has brown upperparts with dark barring across the tail. The breast is brown and the underparts white. When in flight, dark barring is plainly seen across the underside of the wings and tail.

The unfeathered legs and feet are yellow. The harpy eagle has a crest that can be raised at the back of the head. There is a ruff of feathers around the face. 

Female birds are larger than males but otherwise similar in appearance.

The New Guinea harpy eagle is a formidable hunter that takes a wide range of prey including wallabies and tree kangaroos. They will also take smaller domestic animals. The face ruff is used to help trace the source of sounds, and the bird also has excellent eyesight.

Harpy eagles not only swoop on their prey from above but also chase it on the ground for short distances by running and bounding on their long legs.

Breeding pairs return to the same nest site every year, building a large platform of sticks near the crown of a tree at around 20 metres (65 feet) above the ground. A single egg is laid.

© John Welford

Demoiselle crane

The demoiselle crane (Grus virgo) is found in a broad sweep of semi-arid and steppe land from eastern Europe into central Asia.

The demoiselle crane is a moderately large bird, standing up to 75 cms (30 ins) high and being up to 100 cms (40 ins) long. The wingspan extends to 180 cms (70 ins). The bird weighs up to 3 kgs (6.5 pounds).

It is an elegant and graceful bird in appearance, having a light-coloured body and crest, dark legs and neck, and prominent ornamental tufts growing from just behind the eye. 

The name “demoiselle” (French for “young woman”) was reputedly given to the bird by Marie Antoinette, the Austrian wife of King Louis XVI of France. This is evidence of the fact that many demoiselle cranes were – in past times – taken from their native environment to enhance the scene in the parks of western aristocrats and royalty. They were clearly able to breed successfully in their new homes.

In its original habitat the demoiselle crane feeds on grass seeds, grasshoppers, locusts and beetles, and sometimes on lizards.

The demoiselle crane carries out extravagant communal mating displays that strengthen the bonds between pairs. A group of birds will form a circle around a few individuals that leap and dance in turn, bowing and calling with their wings outstretched.

Unlike common cranes, which build huge reed nests, demoiselle cranes nest in shallow depressions in the ground, surrounded by stones. A clutch of two or three eggs are laid which take around 28 days to hatch. Fledging takes place at around 60 days with full independence at 10 months.

© John Welford

Swift

The swift (Apus apus) is remarkable for spending almost the whole of its life airborne, only “landing” to build a nest and raise a brood. During its lifetime of ten or more years a swift may fly well over a million miles.

Apperance

Swifts are often mistaken for swallows, although they are not closely related. The swift is 16-17 centimetres (6-7 inches) in length, which is shorter than the swallow, but the wing span is much greater (up to 44 centimetres for the swift as against the swallow’s maximum of 34 centimetres). However, the scythe-like shape of the swift’s wings is unmistakable. The tail-fork of the swift is also less pronounced than that of the swallow.

The swift’s plumage is sooty-brown above and below, on body, tail and wings, with a lighter patch on the throat. When seen from below the swift appears black against the sky.

The swift has evolved for life aloft, to the extent that its legs are so short that, should it land on the ground, it may find it impossible to take off again. The only purpose of its feet is to grip the edge of a vertical surface when nesting.

Behaviour and feeding

Swifts breed in the northern hemisphere and winter in southern Africa. A British-born swift may spend only about a third of its life in Great Britain, given that swifts arrive in late April or early May and leave again in August.

On fledging, a young swift immediately heads south, without its parents, and is likely to stay on the wing until it is ready to breed, three or more years later. It will eat, drink and even sleep while in flight.

Swifts feed continuously on a wide variety of flying insects and airborne spiders, and may consume as many as 10,000 in a day. They will cover large distances in their search for food, and have been known to fly for 100 miles to avoid bad weather.

Birds can fly to considerable heights, alternating rapid wingbeats with glides. Groups of swifts can sometimes be seen spiralling out of sight in the evening so that they can sleep as they glide back down.

Swifts can live up their name by flying at speeds of up to 70 miles an hour.  Their migration flights are rapid, with swifts only taking two or three weeks to fly from Europe to southern Africa.

Swifts are noted for the high-pitched screams they emit, especially when chasing each other round rooftops on fine evenings.

Breeding

When swifts eventually breed a nest will be built from material such as straw that is gathered on the wing and stuck to a vertical surface, such as the wall of a barn, with saliva. Once a nest is built, a pair of swifts, who bond for life, will use the same site year after year.

A clutch of two or three eggs is laid, with the young hatching at staggered intervals.

Breeding begins in May, when a period of colder weather may intervene. Should this happen, the normal incubation period of 19 days may be extended. The parent birds are also able to go into a state of torpor, hanging on the wall until the weather improves and the swifts’ food supply of flying insects becomes available again.

One problem for swifts is that modern buildings do not offer the same nesting opportunities that traditional ones do. Swifts are also disadvantaged when the owners of buildings block holes to prevent pigeons from nesting. Bird lovers can help swifts by providing nest boxes in suitable locations.

© John Welford

Greylag goose

The greylag goose (Anser anser) was once the only goose that bred in Great Britain, and the name could be a reference to it lagging behind when all the other species had migrated. It was from the greylag that the familiar white farmyard goose descended, and there is a hint of this in the cackles and in-flight honks that are produced by both types of goose.

The greylag is a large goose, at 30-35 inches (75-90 cms) in length. It is – unsurprisingly – brown/grey in colour, with the head and neck being paler than the body. The legs are pink and the heavy bill is pink or orange. The sexes are alike.

The natural breeding ground for greylag geese is wild Scotland, particularly the heather moors with their lochs and lochans. They will also inhabit sea lochs, which is unusual for geese.

Greylag geese pair up for life and they go through a re-enactment of their courtship dance should they be separated for any length of time and then get back together. This is a complicated ritual of calling and posturing.

Nests are built on the ground near water and are made from heather, grass or moss. The eggs hatch after about a month and the goslings take to the water within hours. They are ready to fly when about two months old. They stay in the family group until the following Spring.

© John Welford

Will increased atmospheric CO2 boost plant growth?

Here’s the deal – mankind is burning fossil fuels at such a rate that atmospheric carbon dioxide (CO2) is increasing to unprecedented levels (in historic times, that is). Plants need CO2 to photosynthesise, and therefore to grow and produce more of the same. So surely the more CO2 we humans produce, the better? Sorry – there are a few problems with this scenario!

Boosting growth

Yes – it is true that plant growth can be stimulated if more CO2 is available. It has been shown that extra growth of up to one third can be produced in a CO2 rich environment, and some plant growers have taken advantage of this fact in their production of crops grown under glass.

There is also an advantage to be gained when water is scarce. The pores in plant leaves allow CO2 to be absorbed but pores are also responsible for water loss through evaporation. If the pores do not need to open as much to admit CO2, because there is plenty to be had, then there are fewer occasions on which water can be lost.

Not all plants are the same

However, this vision of a greener world with more efficient food production is not as straightforward as some people might imagine.

For one thing, not all plants are the same. There are fundamental differences between the methods used by some plants species and others when it comes to fixing carbon in their tissues from the CO2 that they absorb. In particular, more than 7,000 plant species are what is known as “C4” plants, and these would not benefit from any increase in the level of CO2 available to them. These include several important food crops such as maize, millet, sorghum and sugar cane.

Plant growth in a warmer world

However, the main problem with the “CO2 boosts plant growth” theory is that atmospheric CO2 is also a greenhouse gas that is a major contributor to global warming. The uncomfortable fact is that you cannot have higher levels of CO2, to the benefit of non-C4 crops, without also having higher world temperatures.

The effects of higher temperatures on plant growth must also therefore be taken into account. Studies of tree growth in rainforests in Panama and Malaysia, for example, have shown that a one degree rise in temperature reduces growth by up to 50%.

Studies of past climate changes have shown that warming leads to more CO2 being released from land and sea than can be absorbed by plants. This suggests that any take-up of excess CO2 through increased photosynthesis will soon be counterbalanced.

A carbon sink?

One advantage of increased photosynthesis might be that CO2 produced by processes such as fossil fuel burning would be absorbed by the extra plants – both land-based and algae at sea. However, this would only work if the carbon captured by plants stayed in the ground or the sea and was never released. This is highly unlikely to happen, especially if the hope is that the greater prevalence of plants is in the form of food crops – what would be the point of growing extra food that was never eaten?

Effect on biodiversity

Although some plants could flourish in a warmer world, this is by no means true for all plants. If certain plants decline – due to problems over water supply, for example - this will have an impact on animal species. It has been estimated that 20-30% of all plant and animal species would be threatened with extinction by the end of this century if global temperatures continue to rise.

In terms of food crops, global warming would inevitably lead to patterns of growth being affected, with some plants becoming impossible to grow in some areas but available in others. This is because successful crop growing depends on many factors, including soil type, weather patterns and microclimates.

It will be the richer parts of the world that are better able to adapt to new conditions than poorer ones.

Biodiversity at sea will also suffer due to the acidification caused by increased CO2. Effects are already being noticed on coral reefs, which support a huge range of marine life. Phytoplankton are also at risk, and a decline in their number will have a major knock-on effect on the food chain.

The conclusion must therefore be that any short-term benefits to plant growth caused by increased atmospheric CO2 will soon be outweighed by the less welcome effects, particularly those resulting from higher overall temperatures.

© John Welford

How can whale populations be preserved?

The worldwide campaign against commercial whaling really took off in the 1970s, although the industry was already in decline by this time. However, despite many years of pressure by governments around the world, and by environmental protection organisations such as Greenpeace, whaling does still take place and there are other threats to a number of whale species. It is therefore too early to assume that the battle has been won.

Public opinion had much to do with turning the tide in favour of whales. The 1970s campaigns, which included direct action by people in small boats who disrupted whale hunts, were broadcast across the world and attracted considerable attention. This is turn put pressure on politicians who were forced to pass legislation to ban commercial whaling. In particular, the International Whaling Commission was pressured into passing a moratorium on whaling in 1982 which came into force a few years later.

However, this was not the end of the story, mainly because some of the countries that made most money from whaling either ignored the moratorium or found ways round it. The biggest loophole was the provision that allowed whales to be killed for the purpose of “scientific research”, and this term has been exploited, particularly by Japan, to justify the taking of large numbers of whales.

An important step was made in May 2014 when the International Court of Justice ruled that Japan’s claim to be undertaking whaling in the Southern Ocean for scientific reasons was bogus. Japan’s factory ship owners had no choice but to stop their operations, although they have threatened to resume whaling, presumably after they have come up with another justification that they hope will get round the rules.

Apart from Japan, the only other nations with substantial whaling operations are Iceland and Norway, but those operations are small in comparison with those of Japan.

Other Threats to Whales

Even if no nation undertook commercial whaling, whale populations would still be threatened by human activity and those threats apply to all whale species and not just those (such as fin and minke) that have been subject to whaling in recent years.

Global warming, leading to disruption of the marine food chain, is an obvious threat, as is the dumping of waste at sea. The massive amounts of plastic waste that have found their way into the Pacific Ocean are particularly worrying, as this is a growing long-term problem for which there does not appear to be a short-term solution.

Commercial fishing for other species also harms whales, many of which become entangled in nets that stretch for miles in open oceans.

What is the Answer?

Whale species will be preserved if they are given a fighting chance. The elimination of commercial whaling would help enormously, but this will only happen if the demand for whale products is removed. Whale meat is eaten in only a few countries, with Japan being the main culprit – many of the whales killed by Icelandic whalers are processed into meat that is exported to Japan. If Japanese people can be persuaded to change their dietary habits, the main incentive behind commercial whaling would be removed.

Because economic drivers are the most difficult to overcome, thought should be given to how the people who make a living from whaling can be given alternative ways to do so. Just as most “big game hunting” has given way to “big game watching” the same could be done for whales. There is money to be made in “whale tourism”.

Other moves that will help include reforms of fishing practices, similar to those being undertaken to protect sharks and turtles that are taken as the “bycatch” of the tuna fishing industry. It is also important to establish areas of ocean as “whale sanctuaries” in which the whole ecosystem is allowed to thrive without destructive human interference.

Above all, urgent steps must be taken to reduce worldwide carbon emissions and pollution of the oceans. Unless this is done, it will not just be whales that face the threat of extinction.

© John Welford

Six coastal canaries

With so much climate change scepticism around, it is useful to have indicators that anyone can observe and which will point directly to rises in overall temperature. The “canaries” concept is one that fits this particular bill.

Canaries as indicators of danger

In times gone by, coalminers used to take caged canaries down the mine with them, not for the company but as a safety device. It was known that canaries were highly susceptible to gas poisoning, so if your canary fell off its perch you knew that there was methane gas seeping into the mine and it was high time that you moved to somewhere safer. (The canaries often recovered when taken to a place with better air, although this was not always the case).

The United Kingdom’s National Trust has taken the “canary” concept a stage further by announcing a set of six “coastal canaries” that, should their populations show a sudden decline (or in one case a rise), will provide a warning that global warming has reached a dangerous level. These are species that are highly dependent on such things as sea temperatures and weather patterns for their survival and which will react most quickly when these factors change.

Six coastal canaries

The canaries chosen by the National Trust are:

1.       .Glanville fritillary butterfly. The range of this butterfly has got gradually smaller over the years, and it is now confined to the western chalk cliffs of the Isle of Wight. It will therefore be relatively easy to spot its complete disappearance, should that occur.

2.       Oysterplant. Grows on shingle beaches in northern England, Scotland and Northern Ireland. It will suffer if the sea becomes more saline or if higher sea levels mean that it has to spend more time submerged.

3.       Cliff tiger beetle. As cliffs crumble as a result of rising sea levels and increased storm activity, it becomes necessary to carry out more cliff stabilisation projects. This disturbs the cliff tiger beetle, which can only fly short distances and will find it difficult to find new hunting grounds.

4.       Puffin. Warmer seas are affecting populations of sand eels, which supply the puffin’s chief source of food. They breed in cliff-top rabbit burrows which can flood if there are too many heavy rainstorms.

5.       Little tern. This bird breeds on beaches just above the high-water mark. Too many exceptionally high tides and summer storms will have a significant effect on the little tern’s breeding pattern.

6.       Triggerfish. Aptly named for this purpose, the triggerfish is a warm water species that is beginning to be seen in greater numbers in British waters, notably off North Wales. There are other “trigger” species for the same reason, such as basking sharks, certain species of jellyfish, and zebra mussels, all of which are being seen more frequently.

As climate change continues to affect the coasts of the United Kingdom, many species will doubtless be affected. The above “canaries” are likely to be only the first of many.

© John Welford