Nature Notes

A series of articles by Roy Pickering. They all have as a starting point an observation in the Quay but then expand as the thoughts develop. Nearly all of the articles were first published in the hardcopy, Exmouth News

Cache in hand or Waste not, want not!
by Roy Pickering

Last week, a friend of mine told me of a hyperactive nuthatch that was busily raiding his bird feeder and secreting a huge haul of nuts in crevices of a nearby tree. When we had proper winters, such forethought must have been very important because animals that live in temperate zones or worse, have to solve the problems that winter brings, like plummeting temperatures, frozen water supply and a shortage of food. Some, like the reindeer and many small birds, prepare for bad winters by building up fat reserves but, in general, “fatties” tend to be less mobile and more vulnerable to predators than “thinnies” so there is a balance to be struck. Habitual “fatties” such as hedgehogs and dormice avoid the worst of it by gorging, yawning and waddling away to a quiet corner where they can sleep off their excesses and spend the long winter in a state of torpor. With luck, their fat will see them through and they will wake up again in the Spring. A more genteel way of combating barren times is to put food on one side when it is plentiful and, as it happens, many animals cache food as a matter of course.

Nature’s bounty! A red squirrel’s cache of cones and nuts overflows the hiding place

However, whilst nuts and grain might last forever, most other foods are perishable and require to be preserved. Web spiders are by nature pretty ruthless; they preserve their live catch by carefully wrapping it in a silk cocoon within which the hapless victim remains in perfect condition until required. Butcher birds or shrikes take a leaf out of Vlad the Impaler’s book but with perhaps less sophistication - there is no greasing of the spine on which the living prey is transfixed! The object, of course, is to keep the larder from running off. There are many other ways of preventing escape but a couple of examples illustrate the point; moles incapacitate earthworms by simply biting off their anterior segments whilst certain shrews achieve the same end by use of toxic saliva which paralyses. Both create large caches for later consumption. Deep freezing is another way of keeping things in good condition: certain owls of the tundra use this method and solve the defrost problem by “incubating” each corpse as required, sitting on it as if an egg!





A shrike impales a mouse on a spine

Now it is all very well caching food but there are two problems that immediately arise; firstly, you have to remember where it is and, secondly, the chances are that someone else will find first. This situation can lead to some remarkable outcomes. For instance, a young jay stores food but his cache is pilfered by other individuals. After this salutory lesson, the young jay uses his first counter strategy – he hides the food out of sight. Sadly he ignores the fact he is being observed. Now at this point, experienced jays that have been thieves themselves employ a more subtle approach which involves nonchalantly scratching around until the potential pilferers hop out of sight whereupon the smart one quickly moves the caches that have been observed to new hiding places. This works pretty well but the ultimate cunning plan is when the really smart jay feigns innocent naivety, keeps track of all potential observers, pretends to cache food but is actually hiding it somewhere else! When all is said and done, such shenanigans are wasteful of effort and many species, such as the red squirrel, simply settle for reciprocal pilfering which is the logical alternative - you can have some of mine but I shall take some of yours! A form of sharing which develops into communal or social behaviour in some species, like the beavers. As far as we know, bartering and money only occur in the human species. Fat cats come to mind but that is another story!

September 2009

                                    Ants and atoms

I trod by accident on an ant’s nest today; it housed a colony of the common black ant Formica niger. Most of the nest was underground but there were remnants of the carefully-constructed and neatly-maintained little runways over the surrounding surface. There was the usual resultant panic-stricken, frantically-scurrying melee; I said sorry and went on my way. When I returned a couple of hours later, the runways had been carefully restored and it was business as usual. These tiny insects had heaved “boulders” and moved them according to some plan which must have involved the transfer of information in some manner which I couldn’t fathom. How on earth did they do it? What goes on down there in their tiny world?

In an even tinier world, quantum mechanics has been invented to describe how things behave amongst the atoms. What happens at that level involves rules that defy the commonsense we derive from our everyday experience up here. However, Roger Penrose, no less, believes that quantum mechanics is necessary to understand our consciousness; he visualises the brain as a hypercomputer capable of subjective consciousness. He suggests the brain has access to non-computational processes imbedded in spacetime fundamentals; we are talking about a quantum computer in which quantum coherence is related to consciousness. Most of the higher animals have some form of brain together with a level of consciousness. Our commonsense is governed by the limitations of our senses and what our particular type of brain makes of the data it receives from these various senses. Through a quirk of nature, our larynx allows us to speak and our communication is primarily through language but are there other forms of mind to mind communication of which we are unaware or only vaguely aware or that we had and have largely lost? In the quantum world, the entanglement of a pair of spatially-separated quantum systems can be used as an instant information channel over any distance between them. However, the opponents of such ideas applied to living organisms say that the brain is a macro system and quantum systems in the brain decohere quickly and cannot possibly control brain function. Maybe, as quantum computing currently in its infancy develops we shall understand more about the workings of the brain.

Most biologists take it for granted that living things are no more than complex machines working according to the known laws of the physical world. However, some such as Rupert Sheldrake, have gradually come to the view that this there is more to it than this and when so little is really understood, there is room for at least the possibility that some aspects of life depend upon laws or factors as yet unrecognised. We know that the blueprint for the structure and habits of living creatures is handed on through the genetic code but any building has to emerge from a pile of bricks according to plan so how do the protein blocks spawned by DNA organise themselves into the living shapes they assume. Sheldrake has a shot at this by proposing that there are fields within and around each living organism or morphic unit which organise its characteristic structure and pattern of behaviour; he goes on to speculate that such fields could be applied to special qualities of living organisms, such as instinct, learning and memory, which are difficult to explain in purely mechanistic terms. Such fields are neither a type of matter nor energy and, like quantum matter fields, are only detectable by their effects on material things. Sheldrake postulates that morphic fields can propagate across time and space and do not fade over distance and that there is a feedback mechanism between these fields and the corresponding living organisms, which he calls morphic resonance. Sheldrake regards morphic fields as a universal database that living forms tap into – a sort of collective memory of nature. If it is true, then this “hypothesis of formative causation” would be profoundly important.

The theory would, for instance, offer an explanation as to why patterns of behaviour spread more quickly than might be anticipated – remember a few years ago how suddenly every blue tit seemed to attack silver-topped milk bottles! And how is it that the habit of trampling the soil to bring up earthworms is widespread – blackbirds do it, thrushes do it and so do gulls. It is claimed that once a rat has learned a new trick in one place, other rats elsewhere seem to learn it more easily. Colonies of insects would be organised by social fields embracing all the individuals within them and the repairs I witnessed would be controlled by this collective intelligence. Termites conduct similar repairs to their mounds, working from both sides of the breach and meeting precisely in the middle even though they are blind. A collective memory passing backwards and forwards in time and laterally in space would account for how first year birds manage to accomplish complex migration de novo. Sometimes animals seem to be too perfectly adapted for natural selection alone to be responsible – Sheldrake’s theory allows a certain purposefulness which is anathema to mechanistic biologists. Finally, and by no means least, telepathic pets would not be remarkable, they would simply be a case of morphic resonance with another mind in which our mind is pretty passive!

There are hints of Jung’s “collective unconscious” and of Bhuddism in all of this and Sheldrake admits his morphic fields could be replaced by occult terms such as “akasa” and “subtle bodies”. Well now, are we talking  scientific fact or fascinating Science Fiction?!

June 2009

                                Parasites and scroungers!

The very large bumble bee that droned over our garden fence this time and plonked onto the terrace wasn’t the friendly one you have been introduced to before. No, this one was definitely sinister, a cuckoo bee, a vestal bumblebee with smoky wings and no pollen sacs, not geared for hard work - so good old honest Bombus terrestris beware! Your nest and your brood are at risk. Any moment now, the aliens could take over like it was Midwich. It is the time for cuckoos. Last week, the tors around the Golden Dagger mine to the south of Warren House Inn echoed the lek calls of lonely males and more than once, a newly-formed pair flew past urgently. This is meadow pipit country and the cuckoos have gathered to take their pick and before long, gigantic, demanding chicks will gape and gape again whilst their exhausted foster parents forage far and wide desperately seeking to satisfy gargantuan appetites.

Shrouded in a mantle of respectability by being awarded the epithet kleptoparasitism, what we are really talking about is stealing! There is inter-specific stealing and there is intra-specific stealing which is robbing your own kind which somehow seems even worse. What is stolen is most often but not always caught prey or gathered and stored food, with the additional benefit that the victim is able to find food in places the thief cannot reach. Kleptoparasitism is a common theme in nature, repeated over and over again. Thus we have cuckoo wasps and bees. There are cuckoo spiders that inhabit the webs of larger spiders and various blue butterflies that overwinter in the nests of ants, like the common blue that is rife on Dawlish Warren just now or the very rare large blue found in just one or two locations in central Devon, whose caterpillars spend 10 months underground as carnivores devouring the larvae of the ants that have adopted them. Because they are so well organised, hard working and predictable, ants make good victims and various animals lie in wait on defined ant forage routes, ready to pounce and mug the passing column as it moves in their mini-world. A common sight on the estuary is a cluster of oystercatchers, crows and herring gulls; the oystercatchers are adept at opening mussel shells, the crows are adept at robbing the oystercatchers and the gulls bully the crows. But the herring gull itself is victim to the greater black-backed gull which delays its own breeding season so that it can rob the nests of the herring gull to feed its own young. Gulls sometimes harass terns causing them to regurgitate food but the real gangsters here are the skuas whose relentless pursuit of terns is their main business. And so it goes on - shallow-diving birds parasitise deeper-diving birds; dominant house sparrows sit back and wait for subordinates to do the foraging; razorbills rob their neighbours. It’s a way of life and some species are career crooks - the thieving magpie is so committed it has even been seen snatching the kill of a peregrine. Kleptoparasitism means that host species have to work a jolly sight harder in order to pay their taxes. What a sobering thought it is that the Promised Land that flows with milk and honey is a concept based on inter-specific kleptoparasitism. Even more sobering - you and I have to work that extra bit harder to support the myriads of thieves, vagabonds, bankers and all other forms of intra-specific kleptoparasite ever present in our society. The choice is to tolerate them or build more prisons. Now which politician gets your vote and spends your money?! 
       

March, 2009

A very large bumble bee droned purposefully over our terrace in the crisp Spring sunlight, disappearing into the nearby low undergrowth. Minutes later, preceded by heavy take-off noise, the jumbo re-appeared, circling to get her bearings before setting off on a foraging mission. It won’t be long before her first brood of workers emerges from the nest somewhere down there amongst the shrubbery, to help raise more workers and eventually the queens and drones that will carry on the line.

Eusociality is a natural phenomenon which, apart from some shrimps and a couple of mole rat species, is only found in certain groups of insects, viz. bees, wasps, ants, aphids and termites. In eusocial species, only a few individuals reproduce and the majority are biologically sterile, existing to carry out specialised tasks and to care for the reproducing members of the colony. The behaviour and often the morphology of such worker castes can be distinctive. It cannot be much fun, for instance, being a replete in the nest of a Myrmecocystus ant, hanging by your jaws to the ceiling of a special chamber, belly hugely distended through being stuffed non-stop with surplus food and water – a living larder to be raided when times are hard. Or being a pothole filler for the marauding columns of the army ant Eciton – nothing like being trampled on for several hours to help speed up the column and then to have to go back and spread your legs to form part of the bivouac protecting the egg laying queen. The prize, however, must surely go to soldier termites of the genus Reticulitermes whose heads are bung-shaped and exactly the right size for closing off the entrance holes to the mound! What a job! Such altruism extends even to the ultimate sacrifice in defence of the colony.

In its most developed form, eusociality involves huge colonies, literally millions of individuals, and yet somehow the structure and organisation works; the different types of worker match the requirements, communal projects are undertaken and methods of communication are efficient. There is evidence, too, that problem solving occurs – red ants carrying pine needles up a steep slope fall over backwards but the remedy is obvious, you turn round and drag the needles up the hill. It is almost as though the society is evolving like an intelligent organism but the process is far from being understood. Is there a form of collective consciousness? All one can say is that there has been plenty of time for whatever it is to have happened – ants have been around for 150 million years and termites even longer. Both shared the planet with the dinosaurs. Insect societies must also have solved the problems of stress and social tension. Not so with other species. John Calhoun’s famous experiments (1962) with rats and mice in which he allowed them to breed freely in confined areas became quite influential for a time in studying the human condition. He found that what was initially was a sort of rodent Utopia rapidly degenerated into Hell – as the population densities increased to over-crowding, so fighting broke out. Robbery, rape and murder became the norm. The rodents eventually were so stressed out that they stopped breeding and, even when shifted into a normal colony, had become permanent social misfits. Calhoun did point out that it wasn’t just density that was to blame but also the degree of social interaction but people wanted to make what seemed to be the obvious link to our own urban problems. Although there is some evidence that insect societies can react to stresses like hunger and workers can fall out, by and large they are, apart from slave making practices, truly Marxist; one for all and all for one. In the packs, pods, schools and shoals of other animals there have to be “rules” to subjugate or bypass individual needs so that order is maintained. Self-awareness challenges such mechanisms and, in our society, individual needs are formulated as rights within the social framework. Trade unionism will not allow the exploitation of the workers and human rights legislation shifts the balance even further. Somewhere in here must fit the Ten Commandments!

A remarkably stress-free and unconcerned Bombus terrestris flew back over the fence and buzzed its way amiably into the Mimosa bush.

January, 2009

Outside the pub, a feral pigeon strutted his unseasonal stuff to a disinterested female. Inside the pub, a youth with cockscomb and tattoos sought to ingratiate himself with an equally disinterested female who, nonetheless, accepted his offer of half of bitter and a packet of crisps. Neither the pigeon nor the youth was thinking deep thoughts about mixing genetic material in order to improve the chances of survival of the species but Nature was pondering that problem for them. Animal courtship and display routines are commonplace and such routines are obviously concerned with the selection of mates but, quixotically, often seem to result in choices that turn out to be completely irrational! A more fitting explanation is simply that the overwhelming instinct for self-preservation has to be turned off by some form of distraction and something else more frantically compelling has to be turned on, however briefly, to allow mating to take place at all. Bearing in mind that animals are at their most vulnerable when their attention is diverted, it isn’t surprising a jack rabbit doesn’t dilly-dally when there are buzzards about!

Whilst the rabbit is a pretty docile sort of creature, our brown hares, come next March, will be boxing each other madly. Fighting is one way of sorting out who gets the girl. In some species like the peacock and the black grouse, during the season, the males gather at the same spot every morning to form a lek for the purposes of competitive display plus a bit of fighting and the females wander down to the arena to take in a bit of the action as well. An exploded lek is when the males don’t gather but try to attract attention by shouting their heads off – certain bats honk loudly, bitterns boom, turtle doves call wistfully and the cuckoo always announces his arrival. The subterfuge varies but the message is the same – here I am, come and get me!

Muscle-bound alpha males undoubtedly have sex appeal in certain quarters but physical combat is a wasteful pursuit and the males of many species resort to posturing and threatening gestures which have become ritualised into signals.  Ritualisation is imbedded in most display routines but, in some cases like the birds of paradise, the display becomes almost an end in itself. The chaps gather every morning at the arena for a hard day’s graft dressed to the nines and showing some pretty nifty footwork to boot – the ballerina dance alone of Carola’s parotia has 27 elements, whilst another of the parotias is known to have 49 elements at 7 levels in its dance routine. The females sit in a row on a nearby branch like so many Strictly Come Dancing judges! The winner is a gorgeous, talented, promiscuous, absolutely useless git with no urge whatsoever to support wife and family! Nature surely got this one wrong but it was ever thus!

Intelligent females are quick to sense an advantage if males are that desperate. Female chimps have learned to offer sexual favours in return for a banana. The girl in the pub smiled and the youth, reading the signal, promptly went to the bar and returned with a large glass of wine and another bag of crisps.

September, 2008

April, 2008

                 SAND MARTINS AND SWIFTS ARE THE EARLY BIRDS 

                                             by Roy Pickering                                                             

The Sand Martins are back. They have slipped along the estuary and are hawking over the marshy areas. The first of the hirundines to return for the summer, they will soon be followed by that perfect flying machine, the Swift.


                        

                                              Caption: Common Swift in flight

This is a bird that fascinates; a bird that does literally everything on the wing, only descending to earth to lay its eggs and to rear its young. When it wants to sleep, the creature climbs to 10,000 feet, closes down most of its brain and switches to auto-pilot. The perfect flying machine.


                  

                   Caption: Swift on nest - when eventually the young literally fall out
                                   of the nest, it will be at least a year before they touch the
                                   ground again


Despite man’s fantastic inventiveness, it seems that nature has always been there and done it before us. The early 20th century biplanes were based on birds in flight and energy conservation has always been an “in thing” in the world of nature. Even the humble sparrow doesn’t fly flat out when it takes off, but uses the undulating flight idea popular with most small birds. Flap like hell for a bit, then coast for a while and flap like hell again! The use of natural forces to provide the energy for flight is an evolutionary challenge which has been solved in many different ways. For instance, our Common Buzzard is pretty good at soaring and, like glider pilots, depends on locating thermals, rapidly rising columns of air caused by the warming of the ground below. Some birds such as the Vultures have become so specialised at soaring that they can stay aloft for hours on end without a single wing beat. Their breast muscles have become so weak that take-off is a problem. Not surprisingly, they tend to inhabit desert regions where the up currents are particularly strong. Another avenue which nature has explored and exploited is the differential wind speeds over large expanses of water. If you are lucky, you will see Shearwaters working the waves off Exmouth, but the southern oceans provide the best conditions for the Petrels, Shearwaters and Albatrosses. Because of the frictional effects, there is a gradient of wind speeds close to the water which the Petrels and Shearwaters are able to use. Thus, they use this energy to effortlessly skim through the wave troughs, taking their food from the surface. Our own Gulls hang on the wind, but the Albatrosses have exploited wind energy as an art form.
 
January, 2008                        

The Assassins

by Roy Pickering

A male Peregrine Falcon swept across Mudbank Lane foreshore, putting up the mixed flock of waders, gulls and ducks. It banked hard at the end of its run and returned fast across the same area and came back for a third time, flicking its wings to change its line several times. As it veered over the road away from the shore, it took a panicking Redshank in mid-air and headed away with the victim in its talons. Its mastery of flight was breathtaking.

A week or so later, a female Sparrowhawk  performed a similar manoeuvre over the stubble fields towards the end of Gore Lane. Large numbers of pied Wagtails, chaffinches and larks spend their winter days gleaning in these fields. The hawk appeared, the gatherers went up and the predator selected its prey.  It  made its  assault but missed and continued on to a perch in the hedgerow  where it sat  motionless  for some time. The small birds  circled  and then returned to their foraging, carrying on as though nothing had happened and  apparently unaware of the menacing shape half-hidden in the hedgerow.  What had happened to the one Lapland Bunting in the flock  that  had caused a traffic jam  in the lane? It was no longer in evidence.

In Madeira recently,  a Madeiran Sparrowhawk  (a sub-specific form endemic to the island) patrolled the promenade every day, gently cruising and occasionally perching on the lava cliff. Flying between the Date Palms and Oleander bushes, canaries and goldfinches and blackcap warblers socialised and sang their ditties oblivious to danger. Presumably, every day there is one less.  

                            Over-sexed and over here!

by Roy Pickering

                                          
That Ruddy Duck has arrived on the estuary! The male of the North American species (Oxyura jamaicensis) is a rather pushy fellow with such a passion for the dark-eyed Spanish White-Headed senoritas that the EU has had to take action before the latter species is wiped out by hybridisation. The Ruddy Duck is one of the stiff-tailed ducks, so named because its tail is more or less permanently erect as can be seen in the accompanying photograph.

 
                        



There aren’t any White-Headed ducks on the Exe so our chap is going to feel very frustrated in no time at all. However, it is only a short hop to Spain and that is why DEFRA has been told by EU to cull in order to help control the situation; our borders have been manned and we will fight them on the beaches!

When the good Nor’westers blow, it is the season for ducks. Apart from the stiff-tailed individual, we now have dabbling ducks, diving ducks and sea ducks around us in huge numbers. The dabblers are those such as Mallard, Wigeon, Teal, Pintails and Shoveler which can always be seen at Mudbank Lane. Diving ducks such Tufted, Goldeneye, Pochard and Merganser are arriving and can be seen off the Quay towards the Warren and Cockwood. The Red-Breasted Merganser, the Daffy Duck look-a-like, will be familar to most residents but the Goldeneye is not so frequently seen and the photograph below may be helpful. Look out for the unusual “hairstyle” and the vivid golden eye iris. Note that it is not always as “gorgeous” as this one!



       
 


There was also a rare sighting of a male Long-Tailed Duck near Cockwood which sometimes came into the channel near the Warren but it may have moved on by now.

Large flocks of sea ducks are visible but are usually well offshore. Orcombe Point allows distant viewing but good binoculars or a telescope are necessary. Usually, the flocks are either Common Scoters or Eiders.



                  THE 24,000 MILE TRAVELLER CALLS TO SEE US
 
                                              by Roy Pickering

Exmouth Quay is less favoured in winter by our feathered visitors than the Warren spur, which is recognised as a landfall in migratory terms. However, we do have a burgeoning resident population of well-fed house sparrows with a tendency to obesity! Otherwise, there is plenty to see by gazing out over the water with the fascinating Terns passing through at the moment. The familiar Sandwich Tern, with its raucous cry, stubby build and gannet-like dive, predominates, but others are around. Casual observers refer to the Comarctic Tern locally because they have difficulty in distinguishing between Common and Arctic Terns. Both are more elegant than the Sandwich, with their streamer swallow tails and red bills, but with practice the Common can be recognised by its longer head and bill. The Arctic Tern is the more interesting because of its annual 24,000 miles circum-polar migration between its Arctic and neo-Arctic breeding sites and the rich feeding grounds off the Antarctic ice shelf. The dark gull-like Skuas also move south at this time. They harass Terns and other seabirds, chasing them until the pursued bird disgorges food. Such activity among birds is not uncommon and a friend recently observed a Magpie robbing a Peregrine of its prey, although for Skuas it is a way of life. Ospreys are passing on their way to winter in Africa and two have loitered around Powderham and one has been seen fishing at this end of the estuary.