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Content Updated: 1st April 2015

SEASONAL UPDATE: April 2015

Spring lambs

Welcome to April and Happy Easter! The clocks have ‘sprung’ forward and the days are getting longer; summer is on the horizon! With bumblebees evident, photos of newborn lambs appearing on my Facebook newsfeed, and tadpoles in the pond, it feels like spring is well and truly under way, even if the weather in the last week hasn’t been particularly spring-like. After blue skies here in the south of England for much of the penultimate week of March, the British summertime weekend brought heavy rain and unusually strong winds both days, with most of last week being, at times, wet and always particularly windy. Currently, the weather models suggest that a ridge of high pressure will try and edge its way over the country next week, bringing more settled and mild conditions, although the end of April is currently looking wet, with above average temperatures for the time of year.

If you fancy getting out and about this month, perhaps to entertain the kids during the Easter holidays, the Sussex Wildlife Trust is hosting a series of events for kids, including getting up close and personal with creepy crawlies and some rockpool dipping – more details here. If you’re not in the Sussex area, most other Wildlife Trusts also have events organised and you can find more here. You may also want to consider the Natural History Museum’s free family Spring Wildlife event on 11th April (details here) or the Easter events on offer from Scottish Natural Heritage (details here). If organised events aren’t for you and you’re just planning a walk in the – fingers crossed! – spring sunshine, let’s take a look at the wildlife you might encounter this month.

Fox cubMammals: April is undoubtedly the month of the fox cub, this being the period in which most litters will emerge from the earth for the first time. (The first fox cubs of the year are now starting to come in to wildlife rescue centres now, too.) By the time the cubs appear above ground, they’re five or six weeks old and are very playful – brilliant to watch. Badgers are also becoming increasingly active now; the sow needs to remain well fed so she can provide milk for her growing cubs. Badger cubs will start appearing above ground towards the end of this month or early in May. Brown hares are also very active this month and it’s a good opportunity to see them chasing and boxing before the vegetation grows taller, obscuring their movements. April is also a good month for mole spotting as, having recently seen molehills emerge all over their lawn, my parents can testify! As the soil starts to warm up, earthworms move to the surface and the moles follow them. This increase in activity, and activity at shallower depth, means lots of molehills. If you see a molehill that looks larger than the others and shows evidence of movement, you could be looking at the ‘fortress’; it’s the focal point of the mole’s tunnel network that marks the location of the roughly football-sized nest in which the pups will be born. The mole’s breeding season starts in February and the first litters of pups will be born this month.

April is the month in which many of our red, fallow and sika deer will cast their antlers, and some of the larger bucks and stags have already started. The casting process is painless for the deer, who more often than not seem a bit surprised by the sudden loss of head weight! Antlers are usually cast within an hour or so of each other but some may drop a day or more apart, leaving the stag wandering around with only one antler attached. The newly-cast deer will be left with wounds on the top of its head where each antler used to be, but these heal over quickly and growth of the new antler will start immediately, covered in a hairy tissue called velvet. You may be fortunate enough to come across an antler while out walking and, in rare cases, even a pair together. Bear in mind, however, that the cast antler is bone, and offers a valuable source of minerals to the deer as it re-grows it new antlers. Consequently, deer will often eat their cast antlers and you’d be helping them out if you didn’t collect too many! Elsewhere, water voles are now quite active, and April marks the start of the water shrew breeding season, making a walk along your local river a worthwhile activity.

Birds: Bird-wise it is probably the cuckoo that epitomises April for me, and I have many fond memories of walking in the New Forest on my birthday listening to cuckoos calling. It’s not just cuckoos, though. Other summer migrants such as hobbies, swifts, swallows and martins start arriving back on our shores during this month; the latter two have already been recorded here in Hampshire this spring. More generally there is lots of bird song this month, with blackbirds and thrushes making themselves particularly evident. The seemingly endless trilling song of the skylark can be heard up high as these birds advertise their presence and mark out their territories. I have seen several chiffchaffs already this spring and friends of mine have reported Cetti’s warblers as well as woodlarks, tree pipits and meadow pipits. Some of our garden birds, long-tailed tits and robins in particular, are nesting now and many others are checking out potential nesting spots. Some ducks will now have their first broods and, more generally, April is a good month to visit your local lake or pond to watch for the highly ritualised courtship of great crested grebes. If you’re fortunate, you may also catch a glimpse of your local kingfisher, many of which will raise their first brood this month…but more on that later!

Frog tadpolesReptiles and amphibians: April is a great month for searching out reptiles and amphibians. There are still plenty of frogs around and several people I know have reported frogs still spawning. Meanwhile, spawn laid last month will, provided it survived the frosts, be hatching now; if in a warm spot the tadpoles may already be well developed. Newts are starting their courtship now and toads will be starting their spawning this month; this is a good time to join your local toad patrol and help pick these guys up off the roads as they travel back to their traditional breeding ponds. A trip out to look in the pond at night is quite likely to reward you with good view of your local frogs, toads and/or newts, if not something of an amphibian orgy.

Adders have been out of hibernation for a couple of weeks now and a few females have been spotted in the last week or so. Early spring is a good month to look for snakes and lizards because they have to spend quite a while basking, and this makes them more reluctant to leave basking spots; this can make for some nice views. Please be careful not to disturb any adders you find, because disruption can be detrimental to sperm production and affect their potential to reproduce later in the year.

Invertebrates: Most noticeably at this time of year the garden and countryside starts to come alive with the buzzing of bees. There is also an increasing number of butterflies to be found, with orange-tip and brimstones among the most noticeable at this time of year. The caterpillars of other butterfly species, including the small tortoiseshells and peacocks, can also be found this month – on stinging nettles in the case of these two. Named after its emergence around the 25th April, the spring breeze can be full of large black ‘dangly-legged’ St Marks flies, while the intriguing bloody-nosed beetle can also be found in the warmer parts of southern England in April. Bloody-nosed beetles get their name from their habit of producing a droplet of bitter-tasting red liquid that it uses to deter predators – the secretion actually comes from the mouth, but it looks like the beetle’s nose is bleeding.

Plants and fungi: There are plenty of daffodils around now and a few patches of snowdrops left, although most are past their best by now. If you’re fortunate enough to live near some chalk grassland you may find some striking purple pasque flowers, which are in bloom during April. The so-called ‘high-rise primrose’, otherwise known as cowslips, also bloom in open pasture and download during this month, and bluebells are starting to make their presence known in our woodlands. Common dog violet and the sweet-smelling magnolia flowers are also in bloom in April and the white globular fruiting bodies of the St. George’s mushroom are found in birch woodlands and old grassland.

Pick of the Month for April: the common kingfisher (Alcedo atthis)

Common kingfisherFor many of us, the only inkling that we’re seen a kingfisher is a flash of orange and blue heading off up the river or across a lake. I personally love seeing these little birds but, as the lack of personal photos accompanying this article suggests, I have yet to manage to get a decent photograph of one. Indeed, I am one of those who tend only to get fleeting glimpses of them as they go about their daily routines. After something of a winter hiatus, the world of the kingfisher started gathering pace back in February, when the birds started wooing potential mates.  With relationships typically established during March, and all this being a prelude to rearing their first brood, April is a good month for watching these enigmatic birds as they start to ramp-up their fishing activities.

(One important point to note, when observing kingfishers in the wild, is that they are a protected species. Kingfishers are fairly uncommon, easily disturbed birds, and they and their nests are afforded legal protection under Schedule 1 of the Wildlife and Countryside Act. The Act makes it an offence to take, injure or kill a kingfisher, or to take, damage or destroy its nest or eggs. It is also an offence, under the Act, to deliberately or recklessly disturb the birds around their nest sites during the breeding season.)

Beauty by name
Few people would deny that the kingfisher is among Britain’s most attractive bird species – you’d certainly struggle to find a more colourful contender. When the kingfisher was first formally described by Carl Linnaeus in 1758 he grouped it into the Gracula genus, together with the tropical starlings. Gracula derives from the old Latin graculus, translating roughly to ‘jackdaw’, and is it has been speculated that this was a reflection of their call. Now, much as I like jackdaws, I suspect most people would rank them below kingfishers in the ‘beauty stakes’. Fortunately, Linnaeus himself appreciated this little bird’s aesthetics too, and assigned it the species epithet atthis. In Greek mythology Atthis was one of three beautiful daughters of Cranaus, the second king of Athens. Atthis lived on the island of Lesbos about 600BC, and featured heavily in the work of the Greek poet Sappho. So, Linnaeus’ name for this bird essentially meant ‘beautiful jackdaw’.

Today, the common kingfisher retains the species epithet given to it by Linnaeus, but is now classified within the Alcedo genus (alcedo being the Latin word for ‘kingfisher’) and is thus scientifically known as Alcedo atthis. Taxonomically, all birds are grouped together into the class Aves and within this sits a group of usually colourful birds that we know as kingfishers, bee-eaters, rollers, todies, and motmots; this group is known as the Coraciiformes. How the Coraciiformes should be split, and the 90 or so species of kingfisher described worldwide arranged, is something of a contentious issue. Some authors follow the International Ornithological Congress’ convention and lump all the birds together into a single family (the Alcedinidae), while others recognise three distinct groupings: the familiar ‘river’ kingfishers, including ours (in the Alcedinidae family); the crested, pied and New World tropical birds, collectively known as ‘water’ kingfishers (Cerylidae family); and the short-tailed large-headed ‘tree’ kingfishers (Halcyonidae family) that include kookaburras. Genetic data published in 2006 suggest that the three family approach may be the best one, although the jury is still out. Regardless of how you group them, however, scientists generally agree that our common kingfisher (hereafter just “kingfisher”) is one of 11 species within the Alcedo genus.

Despite no longer being as common as its name might imply, the kingfisher is widely distributed; found throughout Europe and Asia, breeding in much of this range, and a winter visitor to North Africa. More specifically, kingfishers are found from Ireland in the west, through continental Europe and into parts of Asia, to Japan in the east and north into southern Sweden, Finland and adjacent parts of Russia. In the south, the kingfisher’s range extends into India, China, Thailand and Malaysia, even as far south as the Philippines and Papua New Guinea. There are, however, none to be found in the Americas, Australia or in sub-Saharan Africa. Within this vast range kingfishers generally inhabit clear, slow-running streams and rivers with plenty of bank-side vegetation. They may also be found on canals, on lakes (where they will sometimes nest, if there are suitable banks nearby) and sometimes even visit garden ponds to fish, more commonly in winter. Kingfishers tend to be resident in areas where the climate is mild year-round and they may be forced to migrate during particularly cold periods if their hunting grounds freeze over. Indeed, during the winter months kingfishers are often encountered in coastal areas, which has led to the belief that they migrate to the coast to overwinter. In their book Kingfisher, however, David Chandler and Ian Llewellyn suggest that most kingfishers probably don’t migrate, and that coastal birds are probably juveniles that haven’t established a winter feeding territory yet. That said, elsewhere, birds have been tracked moving across the Mediterranean into north Africa or crossing the mountains of Malaysia into southeast Asia for the winter; some birds may migrate 3,000 kilometres (almost 2,000 miles) or more between their breeding and wintering grounds and this migration appears to be conducted largely under the cover of night.

And stay out
Kingfisher divingIdeal habitat, according to Chandler and Llewellyn, would allow a kingfisher to set up a nest site next to water, although they have been observed nesting 250 metres (just under 275 yards) or further from their favoured hunting grounds. Once suitable habitat has been found, the kingfisher will establish an exclusive territory, from which it will expel others. Indeed, kingfishers are solitary for much of the year, coming together only to breed, at which point the male and female often merge their territories. Territorial disputes occur whenever one bird is caught trespassing on another’s territory and the response tends to be strongest towards same-sex individuals (i.e. males are generally tolerant of females but violently hostile to other males, and vice versa). When two same-sex birds meet both may display from nearby perches, calling and bobbing, after which fights may occur during which each bird will attempt to get hold of the other’s beak or wing. Many fights end up in the water, at which point each bird will attempt to drown the other. Charlie Hamilton James had some remarkable footage of two female kingfishers fighting in his Halcyon River Diaries series for the BBC, which ended in one of the females being snatched by a mink. (The footage of this fight can be seen on Charlie’s Vimeo stream here – skip to 01:37 for the start of the sequence) There is some dispute among kingfisher watchers as to which is the most aggressive sex: photographer and ornithologist David Boag wrote that males tended to be involved in more fights than females, while videographer and veteran kingfisher watcher Ian Llewellyn described how fights between females were “the most intense, sustained, aggressive and absolute”.

The size of a kingfisher’s territory will depend on a variety of factors, including the habitat quality, the abundance of suitable food and the population density. As such, there is considerable variation in home ranges reported in the literature. In Avon, one study found that there was a nest every 500m (one-third of a mile) or so along the river, while home ranges as small as 125m (100 yds) are known from Sweden, and some territories extending to several kilometres have also been documented. David Boag reported one male in Belgium that ranged over a 14 km (almost 9 mile) stretch of river. On his study site, the River Froome in Dorset, University of Navarra (Spain) biologist Antonic Vilches and colleagues found a density of 0.12 pairs per kilometre of river between May and July (the breeding season) – working backwards, this suggests that each pair held an approximately eight kilometre (5 mile) stretch of river as their territory. So, there probably isn’t any such thing as a ‘typical’ territory size for these birds, but about a kilometre (just over half a mile) of river is often given as a general figure. Territory acquisition by juveniles appears to be a process of finding a spot and sitting and waiting to be chased away; if nobody kicks them out, they start calling progressively louder until they establish the area as theirs after a few days.

Lightning hides the colour of night
So, we’ve already spoken of the kingfisher’s beauty, but what do these birds actually look like? How do you know the bird you’re staring at is a kingfisher? Well, kingfishers are roughly sparrow-sized birds, measuring some 17-20 centimetres (about 7 in.) in length, including about four cm (1.5 in.) of beak, with a wingspan of 24-26 cm (about 10 in.) and weighing in at 34-46 grams (1.2-1.6 oz.). Perhaps the biggest give away to the bird in question being a kingfisher is the colour. These little birds are what is perhaps best described as ‘electric blue’ on their back, tail, wings and most of the head, with a vibrant orange chest, stomach, feet and ‘cheeks’; the chin is white, as are patches of the nape. In both sexes, the upper mandible of the beak is blackish-blue colour – in males the lower mandible is the same colour, but in females it is a pale orange colour (below, left). Juvenile birds are similar to adults, but the blue is duller (almost greenish) and the orange is noticeably paler; the beak and legs are black. It should be noted, however, that all is not how it appears with the kingfisher’s colour.

It is in mythology where we find, in my opinion, the most entertaining account of how the kingfisher came to be so attractively coloured. In their 2010 book Kingfisher, David Chandler and Ian Llewellyn recount a French legend that tells how the kingfisher was a dull grey bird when on the ark. Apparently, when Noah got bored waiting for the dove he sent out to find land to return he sent the kingfisher to scout too. The kingfisher flew very high and was struck by lightning, colouring the back and wing feathers electric blue, after which it sought warmth from the sun; but it misjudged the distance and flew too close, singeing its underside and turning it orange. The kingfisher was, it seems, less successful than the dove and by the time it returned the floods had subsided and the ark was nowhere to be found – since then the kingfisher has been flying along rivers, searching and calling for Noah. Clearly the kingfisher didn’t obtain its striking colours from a lightning strike, but many early naturalists observed that these birds appeared to shimmer in sunlight and that the exact colour you saw varied according to the angle from which you viewed it.

Male and female kingfisherIf you handle a moulted kingfisher back feather you’ll notice that it’s actually relatively dull and grey until it’s held up to the light, at which point electric blue flashes through it as you move it in your hand. We have known that the kingfisher owes its colour to more than the standard pigmentation found in most other animals for several decades, but it is only comparatively recently that we have started to understand how the colours come to be. Ordinarily, objects appear colourful because they contain pigments that absorb light at some wavelengths and reflect it at others. The grass, for example, looks green because the blades contain chlorophyll, which absorbs most wavelengths of light, but not the medium-length wavelengths that we see as yellows and greens; it reflects these back into the environment making the grass appear green. In other cases, a particular wavelength of light may be scattered more than others, causing us to observe this colour: this, for example, is why the sky (sometimes!) appears blue, with short wavelength light being scattered by molecules in the air. In a fascinating paper to the Journal of Experimental Biology, published in 2011, University of Groningen biologist Doekele Stavenga and colleagues subjected the feathers of the kingfisher to examination under an electron microscope in a bid to try to establish the precise origin of the colouration.  Stravenga and his colleagues found that the barbs of the orange breast feathers contained small granules of pigment, while those of the back and tail feathers contained spongy ‘nanostructures’ that reflected light; those in the tail were a different size to those in the back, causing them to handle the light slightly differently and accounting for their different colours. The pigment in the breast feathers caused a diffuse scattering of low to mid-range light, giving a pretty consistent/uniform orange colour. The nanostructures reflected long-wave (blue) light more directionally, causing an iridescence (shimmering) in the feather. So, the kingfisher owes its colour both to pigment in the breast feathers and to the structure of its back, head, wing and tail feathers. (Photo: Male kingfisher on the left, with a female to his right. Notice the orange lower mandible of the female's beak.)

The royal family
Kingfishers are more akin to sand martins in their nesting behaviour than other birds; rather than building nests in trees or among ground vegetation, they opt to excavate a chamber in a river bank. The courtship process begins early in the season, with some males beginning the wooing process in February. At first, the male may behave aggressively towards any female present, but this soon subsides. Curiously, the courtship display – which consists of the male standing in a stretched upright position, with wings draped forward and head just above horizontal – is quite similar to the threat display, although it is often accompanied by soft whistling. During the course of the next few days the frequency of courtship displays will decline as the pair-bond becomes better established. The male will also chase his prospective mate, while calling continually, and will periodically present her with fish to show off his fishing skills and how suitable a provider he would be for her young.

Mating kingfishersDuring the courtship period the pair will excavate a nest hole in the bank in which to raise their young. Nests consist of a chamber roughly the size of an Easter egg (11x17 cm / 4x7 in.), within a sandy-soil river bank, which is connected to the outside by a gently upward-sloping tunnel that’s normally between about 60 and 100 cm (24-36 in.) long. Digging is carried out by both birds and starts with the male flying at the bank and pecking it, before returning to a perch and shaking the soil off his beak. This is repeated until a foothold is created and the female may be encouraged to join the excavation. The pair take their turns, digging into the bank and pushing the soil out behind them with their feet; one digs, the other rests and keeps watch, and then they swap. The excavation of the nest is normally complete, or pretty much complete, by the end of March, and this tends to be when mating occurs. Mating is often preceded by the male providing the female with a fish and, if in an agreeable mood, the female will push her tail out and the male will hover above her before landing on her back and mating. The mating lasts a few seconds and the two may remain next to each other on the perch for a while, or the male may fly off and return with another fish for his mate.

Curiously, I have not found any reference to the gestation period of kingfishers, but it seems that most will lay their first clutch around mid-April. Typically, the female will lay five to seven (maximum 10) glossy white eggs, each of which weighs just over four grams (about one-tenth of an ounce). One egg is laid each day until the clutch is complete and only then does the female start to incubate – the result is that all the chicks hatch out at roughly the same time, about 20 days later, although often one or two eggs fail to hatch because the parents cannot cover them. Both parents will incubate the eggs, taking it in turns, although there is some suggestion that the female is the one to incubate them overnight. The changeover is relatively straightforward: the other bird approaches the nest and calls before taking up a nearby perch and waiting for its partner to exit the nest. Once hatched, both parents will feed the chicks, which remain in the nest for a further 24 or 25 days. Once the parent has caught a fish for the chick it will manipulate it so that the fish is held in the beak with its head pointing forward, and the bird will fly back to the nest. Upon exiting the nest, having fed or incubated the chicks, the adult may dunk itself into the water to wash off any excrement it has picked up on its feathers. (The chicks reverse across the chamber and jettison their excrement into the tunnel.) As the chicks grow the previously un-lined nest becomes littered with a layer of regurgitated fish bones.

There are various estimates for the number of fish that a brood of kingfisher chicks will get through between hatching and fledging. David Boag estimated that, at its peak, a nest can easily consume 100 fish per day. Overall, it is suggested that the ‘average’ kingfisher brood may consume a thousand fish! In their study of New Forest kingfishers, former Southampton University biologists Jim Reynolds and MDC Hinge observed that the chicks were fed in the nest chamber for the first ten days, after which they were increasingly fed at the edge of the chamber, presumably with the ultimate view of tempting them out. Reynolds and Hinge also recorded a shift in the size of the prey brought back by the adults as the chicks grew; initially prey up to about 5 cm (2 in.) were brought in, while once the chicks had passed a week old fish up 10 cm (4 in.) were delivered. When the chicks leave the nest at about four weeks old, they will hang around on nearby perches and the parents may continue to bring them fish for another three or four days, after which they’re on their own and will likely be evicted from the territory.

Many kingfishers will raise two or three broods in a single breeding season and a single male may raise more, with other nearby females! It is fairly common for kingfishers to be faithful during a given breeding season, but it is not uncommon for them to change mates in successive seasons. There are also some records of a single male raising chicks with two (even three) females simultaneously in different nests. The incidence of polygamy from published studies, according to Chandler and Llewellyn, ranges from 6% to 35%.

Kingfisher with two fishEat like a king
As their name suggests, kingfishers are primarily piscivores (fish-eaters), although the remains of spiders, beetles, stoneflies, mayflies, shrimps and waterboatmen have been found in their pellets, and there is one record of a kingfisher taking suet from a bird table during the harsh winter of 1859/60. That said, attempts to get birds to eat non-fish prey (e.g. earthworms, newts, crayfish and dragonfly larvae) in captivity have generally met with failure. The variety of fish that they will take is broad, although they typically favour specimens between four and seven centimetres (1.3-3 in.), and includes: bullhead (Cottus gobio); minnow (Phoxinus phoxinus); three-spined stickleback (Gasterosteus aculeatus); chub (Squalius cephalus); loaches (Cobitis and Noemacheilus); grayling (Thymallus thymallus); dace (Leuciscus leuciscus); carp (Carassius); rudd (Scardinius erythropthalmus); roach (Rutilus rutilus); gudgeon (Gobio gobio); barbel (Barbus barbus); salmon (Salmo trutta); perch (Perca fluviatilis); pike (Esox lucius) and white bream (Blicca bjoerkna). In coastal areas, kingfishers have been observed feeding on goby, tompot blenny (Blennius gattorungine), Cornish sucker (Lepadogaster lepadogaster), sand smelt (Atherina hepsetus) and, occasionally, prawns (Palaemon serratus).

Despite the huge range of species potentially on a kingfisher’s menu, most birds appear locally selective, taking whatever species are most abundant in the area. On the River Test here in Hampshire, for example, Ron and Rosemary Eastman found that kingfishers ate mostly minnows, sticklebacks and bullheads, while a study on the River Lesse in Belgium reported that cyprinids and bullheads accounted for 90% of the remains in nest litter material, and researchers in Estonia recorded minnow, bleak and gudgeon dominating the diet of their study population. During their studies in the New Forest, Reynolds and Hinge looked at the biology of kingfishers in three watersheds and observed some interesting local variation. Overall, the biologists found that (based on analysis of 850 bones collected from seven nest sites in which 10 broods were raised during 1989) five species were taken: minnow (the most common); brown trout; bullhead; stone loach and stickleback. Looking at the figures the researchers present, it seems that minnow remains were found in 61% of nest material, while brown trout and bullhead accounted for 17% and 15% , respectively, and stickleback and stone loach were much less common (6% and less than 1%, respectively). When you look at the watersheds individually, however, it’s clear that one watershed caught all species (except stone loach) in roughly even proportions, while sticklebacks made up a significant proportion of the diet in another watershed. The authors suggested that the kingfishers are opportunists and the recoveries reflected the distribution of the fish species in these watersheds.

The fry of coarse fish – e.g. dace, roach, perch and, in particular salmon – can contribute significantly to (as much as 95% of) a kingfisher’s diet, and studies suggest salmon in particular may contribute anywhere from 2% to 55% of the diet. With this in mind Antonio Vilches and colleagues looked at the impact of kingfishers on salmon recruitment on the River Froome in Dorset. Vilches and his team studied the diet of a pair of kingfishers and found that, on average, 62 fish were brought back to the nest each day and that salmon parr accounted for about 2.5% of the total diet during the nesting period. Assuming two broods, the researchers calculated that the pair ate 86 salmon parr, which was roughly 0.8% of the estimated total number in the river. The conclusion of the study was that “the kingfisher has a negligible biological impact over this salmon population”. Despite such studies, some have been quick to point out that where kingfishers are numerous and/or when their impact is taken in conjunction with that of other predators (e.g. herons, grebes, cormorants, otters, etc.) the result can be a significant impact on salmon recruitment. The jury remains out.

Kingfisher pelletKingfishers tend to hunt from perches – typically a branch, post or root system – a metre or two (3-6 ft) above the water, from where it bobs its head to gauge the distance when food is detected before plunging steeply down to seize prey. The bird will normally return to the perch to either position the fish in its beak or consume it head first. If the prey lacks spines (e.g. minnows) then it can be swallowed immediately, while spined fish are held firmly in the beak and beaten against the perch. Studies by German ornithologist Ernst Kniprath, published in the mid-to-late 1960s, revealed that bigger fish are given a bigger battering than smaller ones and that the beating serves to unlock the spines, especially the lateral ones, from the fish’s body. While kingfishers have pretty efficient digestive systems, they cannot digest the fish’s skeleton and this is coughed up (right), covered in a smooth coating of bubbly mucus that presumably serves to protect the oesophagus, in a manner akin to how owls regurgitate pellets. Kingfishers need to consume between 60% and 100% of their body weight per day and will, on average, consume 18-20 minnow-sized fish to achieve this.

The catch success rate for kingfishers varies according to the individual’s experience, habitat, conditions and type of prey they’re going after and published success rates vary from about 25% (i.e. one in four attempts successful) to 80% (four in five attempts successful). In an attempt to understand some of the factors affecting catch success, Antonio Vilches and his team looked at captive birds. Vilches et al found that attacks in shallow water were more likely to bring success than those executed in deeper water, and that fish deeper than about 25cm (10 in.) were out of the kingfisher’s reach. Indeed, the birds actively avoided fishing in deeper water, suggesting they can assess the depth and weigh up their chances of success. The researchers also found that hungry birds were no better or worse at catching fish than well-fed ones and that bottom colour (white vs. natural gravel) had no impact on success rate; the birds took more fish from the white-bottomed tanks, which may reflect better visibility, but they were no more likely to catch a fish in this tank, which implies that more dives were made.  Experience did have an impact, with practice making for a more efficient fisher, and fish in shoals were at greater risk of predation than lone swimmers. Contrary to previous studies, Vilches and his team observed that bottom-swimming and mid-water fish were taken equally by their subjects.

Adverse weather, particularly flooding, can have an impact on kingfisher hunting success and one 1989 study reported that kingfishers starved to death during prolonged floods. In a study on kingfishers along the Blanice River, in the Czech Republic, Martin and Pavel Cech observed that flooding increased the river’s flow some fourteen-fold, from about two cubic metres per second (4 knots) to as much as 28 mps (54 knots), and that this reduced the visibility from about 50 cm to three cm (20 in. to 1 in.). This reduction in visibility caused the birds to switch from smaller bottom-dwelling fish (e.g. gudgeon and barbel) to larger top-water fish (e.g. chub and bleak). The kingfishers delivered fewer, larger fish to the nest and this resulted in no overall change in growth/development rate of the chicks. So, unsurprisingly, kingfishers seem able to adapt their behaviour to meet the prevailing conditions.

The flight of the kingfisher is fast – 40 to 50 kmph (25-28 mph) – direct and usually low over the water and is often accompanied by a short sharp whistle repeated two or three times. It is often said that the kingfisher has no song but, in his Collins Bird Guide, Lars Svensson writes: “Song, seldom heard, a series of call-like notes in jerky, irregular rhythm.” Svensson also describes the flight call as a sharp whistled ‘zii’, sometimes with an afternote making it ‘zii-ti’.

Kingfisher with preyTrials of life
The life of a kingfisher isn’t easy and they face many threats. Summer floods can destroy nests and severe winters can kill many individuals. At the same time, cats, rats and, in recent years, mink are predators that kingfishers must avoid; some also get hit by cars if they are required to cross roads. The most dangerous period for these birds is in the first few days after fledging, when they may become waterlogged and drown attempting their first dive(s). Many will die of cold and/or starvation within the first week or so of independence. Kingfishers are also still persecuted, illegally, by some anglers who see them as a threat to fish stocks and many were killed during Victorian times for a host of reasons, including to put in display cases, to use their feathers for hats, and even for use in predicting the weather! Some estimates suggest that only about 25% (one in four) kingfishers survive to their first breeding season in the following spring. As with most species, if they have what it takes to survive their first winter, their survival chances increase and a bird may expect to live for around seven years; reaching 15 is not unthinkable in the wild and the oldest wild bird on record made it to 21 years old.

Kingfishers experienced a ‘moderate decline’ in numbers between 1970 and 1990, which caused BirdLife International to list them as a “species of European Conservation Concern, category 3”. Populations have seen an improvement in fortunes more recently, but numbers have yet to return to the pre-1970 levels and BirdLife estimate there to be about 600,000 common kingfishers worldwide, with about 160,000 pairs in Europe. The RSPB puts the breeding population in the UK at between 3,800 and 4,600 pairs.

Whatever you’re up to this month, take care and I hope to see you back here in May. As always, I love hearing from readers; any queries or comments regarding the information on the site can be sent in using the addresses on the Contact page (Note: Some website questions are answered on the FAQ, while many animal-related questions are covered in the Q/A). Photos can be e-mailed to a dedicated e-mail address - please keep them coming and don't forget to check out my Photos Needed page. I'm also interested in hearing any reports of unusual behaviour in any of the animals featured on this site, or interactions between humans and wildlife. Thanks as always for your continued patience and support and a special thanks to David Pressland, Marc Stacey, Jeff Harrison and Simon Currie for donating their stunning photos to this month's update.

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WildlifeonlineOkay, for those of you that are new to the site, let's take it from the top!

What is Wildlife Online?
Essentially, WLOL is an educational website about British wildlife. The site contains profiles of various British animal species, with new articles in preparation all the time. The site also has articles looking at wildlife-related subjects, including hunting and animal emotions. This site is purely a hobby of mine; it does not generate any money or contain any advertising and, for the time being at least, I am happy for it to stay that way.

What does Wildlife Online aim to achieve?
The ultimate goal of the website is to be useful. My intention has always been to provide un-biased, accurate information that’s accessible to anyone with an Internet connection. Increasingly people are coming into contact with their local wildlife and whether such interactions are positive or negative, they generally inspire a desire to learn more about the species. Moreover, there are still a great many misconceptions surrounding our wildlife (fox behaviour springs immediately to mind) and these are brought up time and time again during discussions in the media. Each article aims to provide a reasonably comprehensive overview of the species in question by drawing on information from the media, books, TV programmes and the scientific literature. I feel that this combination of sources, along with my own observations and those of my friends/colleagues/readers provides a unique online resource of British wildlife information. My hope is that the information provided here will go some way to changing people's perceptions of the creatures with which they share their parks and gardens.

Why create a website when there are books and TV programmes about your subjects?
Books can be a fantastic resource and I can't imagine being without my library. Not all libraries are, however, equally well stocked, and not everyone has the funds to splash out on what are often very expensive wildlife books (especially those written by scientists). More importantly, much of the scientific research never makes it out of the journals into books and TV shows. Similarly, many of the early books -- which contain some of the pioneering work on the species -- are now long out of print and can be difficult or expensive to track down. Books have the 'luxury' of being able to devote their entire contents to a particular species, covering all aspects of its life history. Television, by contrast, is a much more limited and variable medium: the programme editor(s) has to create a show that is likely to hold the viewers' attention and appeal to a very wide audience. The result is that, although some reach this compromise very well, many documentaries focus heavily on the 'wow factor' (multitudinous slow motion shots of Great whites leaping out of the water in pursuit of seals, for example) and this often comes at the inevitable expense of the information about the animal. Finally, both books and TV programmes go out of date quite quickly; new research is being conducted all the time. Consequently, a website is an ideal and dynamic intermediate - it offers the opportunity to provide a decent amount of information about the subject that can be updated at the metaphorical drop-of-a-hat as any new research is published.

Why include so much information?
I honestly believe that if a job is worth doing, it's worth doing well. There are hundreds of websites with brief species profiles and if that's all WLOL offered there would be little point to it. I understand and appreciate that some people find being confronted with large volumes of text very daunting while others are of the 'too long; didn't read' mind-set and will thus be turned off by the amount of text facing them. I have tried to remedy this as far as possible via two avenues: there is a Speed Read section with a brief profile of each species featured in a main article; and each article has been 'virtually split', with the aid of hyperlinks, into sections that allow people to easily jump to the information they're looking for. Ultimately, I want to provide as much information as is feasible in order to provide the reader with the clearest appraisal of each species or topic; I hope that most readers approve of this approach.

Why haven't you included a complete bibliography?
My intention with WLOL is to provide the information in an accessible format, which means that anyone should be able to read an article and understand the information in it. Consequently, I didn't want to format it as a scientific paper because the current format allows for a much more informal approach and writing style which, I hope, will appeal to a wider audience. Most people should find enough information in the article (I typically provide the name or one or more of the authors and the journal and year) to track down the original scientific paper. When I take information from books, I always give the name of the author(s) and the full title of the book for easy reference. I am also happy to provide full details of any of the references upon request.

Are you really qualified to do this?
I'm certainly not an expert on any of the subjects presented on this site. The articles stem from my varied interests in natural history and biological sciences. In terms of qualifications, I trained as a scientist (studying natural sciences at degree and postgraduate level) and all I really do is interpret information, blend it with associated research and personal observation, and present it in what I hope is an accessible format. Unless specifically stated, I do not claim any of the information on this site to be my own research. I have built relationships with some of the many diligent researchers who have produced the data that I use, and I am happy either to recommend an expert or provide my own opinions on a subject.

As a final note, I want to make a quick reference to the quality of the material on the site. The great French philosopher and mathematician, Rene Descartes, once said: "If you would be a real seeker of truth, you first must be willing to doubt as far as possible all things." This is very sage advice, especially when it comes to believing what you read on the Internet. Most Internet sites (indeed, some books and TV shows too), including this one, have no form of peer-review (i.e. nobody with experience of the topic checks the site for accuracy); consequently pretty much anyone can have their own little corner of cyberspace and information can make it onto websites that is either misguided, or downright false! When creating material for this site I take every care to ensure that the information I present is accurate. Invariably errors will creep in; typos are almost inevitable (although each article goes through several levels of proof reading before it appears online) and research is always underway on the species featured here, so the data can go out of date almost overnight. Each page has regular (ish!) reviews, however, during which I update the information, adding details of new findings and taking out that which is now thought highly unlikely. You can see most of the books I have used in the preparation of this site on the Recommended Reading page and I have provided links to some of the most interesting sites I came across during my research – these can be found under the appropriate sub-heading on the Links page.

Anyway, I digress.... I hope you enjoy looking around the site and I hope equally that you get something worthwhile out of it. Any comments, suggestions or (constructive) criticisms are welcome via e-mail - appropriate addresses can be found on the Contact page.

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DISCLAIMER: All the photographs and artwork on this site are either my own work or have been donated by readers. All images remain property of their authors and, if you wish to reproduce any of the pictures, consent must be granted by the appropriate person - requests can be directed via myself or see FAQ. For more details on the content of this site, please see the full WLOL Disclaimer.

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