When Disaster Has Struck….

It may turn out a boon for scientists

There are always some who benefit from wars, epidemics and other events that are generally seen as deleterious, in fact, disastrous. Take the historic eruption of Mt. Vesuvius in the year 79. It buried the city of Pompeii and its inhabitants under metres of ashes and in this way preserved the “activities” and details of the living conditions at the time of the disaster, which keep archaeologists busy to this day. Or think of the pharaoh Akhenaten’s home near modern day Amama, whose roof collapsed in 1353 BCE and trapped and preserved on its mud brick floor under dry conditions insects, which gave scientists a glimpse into the vermin people in those days shared their house with. Eva Panagiotakopulu et al. in 2010 identified grain weevils, flour beetles, mealworms, pupae of house and flesh flies from that site. Famous are also the disastrous falls of some animals into mud that subsequently froze and then preserved these creatures for thousands of years under conditions so excellent that even inner organs could be examined of specimens that were recovered and thawed.  

A disaster of a different kind (and of tremendous value to the palaeo-entomologist and evolutionary scientist) befell insects, spiders and other small creatures when a sticky drop of resin from a tree landed on them, trapped them and preserved them in what is now known as “amber”.  Some of the organisms known from such amber may have wandered into the stick secretion and trying to free themselves got more and more covered and ultimately embedded in it. Because of the specimens caught in this way, we know what groups of insects, spiders and other small creatures roamed the forests millions of years ago and how these species differed morphologically from those that now populate our forests. The reason for the excellent preservation is that the viscous resin not just entombs the trapped specimens, but that it prevents fungal rot and decay and ultimately, when hardened, conserves cellular and often even sub-cellular details remarkably well. Of the greatest interest, because of their rarity, are small vertebrates in amber. Numerous lizards, a young snake, tiny birds of the extinct Enantiornithes, baby dinosaurs, a small frog, all this and more, for instance, is available from 100 million year old Burmese amber. Amber washed up on Baltic Sea beaches is less old than Burmese amber (only ca. 40 million years) and unable to shed light on the assemblage of small vertebrates and invertebrates that shared the world 100 million years ago with the dinosaurs.

However, one of the most horrific disasters to befall Earth’s inhabitants are earthquakes and they must have accompanied the evolution of plants and animals “since the beginning”. This is why scientists of different disciplines have long been interested to find out, if there is something to be learnt from an animal’s behaviour prior to an earthquake. Anecdotal reports in support of such behaviours abound and date back to antiquity. But how reliable and verifiable are such reports and how long before an earthquake strikes do animals actually sense the event: minutes, hours, days?

There are apparently (long before the so-called P-wave that most animals would feel seconds before the strong and often highly destructive S-wave arrives) precursors that could occur days before the earthquake and such signals could involve tilting, groundwater changes and associated magnetic and electrical variations. There is experimental evidence that some animals are extremely sensitive to even the smallest tremors and vibrations (I’ve seen that in fish, spiders, etc.), but don’t such tremors occur very frequently without heralding an earthquake? That is, of course, very true and people would not have paid attention or remembered an animal’s unusual behaviour, unless there was indeed an earthquake and in “hindsight” one would associate an animal’ erratic behaviour with it. I was puzzled one day strolling along a lane on Hachijojima’s south coast, to see hundreds of dead earthworms, even though there hadn’t been any rain for days. I then thought that maybe the worms had been sensing slight earth tremors and were therefore leaving the soil. I waited for the next few days for an earthquake to happen (not at all a rare event on the volcanic island of Hachijojima), but it didn’t. Well, at least I could not feel it. 

© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2021.
Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original conten

Aberrant sexual behaviour (in animals)

I have to make it clear right from the start that this blog refers to animals and their sexual behaviour. With regard to humans any discussion on sexual behaviour is emotive, controversial and can become highly personal. Therefore, I steer clear of that and only wish to mention that Y.N. Harari in his wonderful book “Sapiens” expresses the opinion that what happens in Nature and we can observe has to be “natural”. However, the whole issue becomes murky, when we consider terms like “normal” (being the norm, practiced by the majority), aberrant (deviant or anomalous), or strange and atypical.

In 1911 a certain Dr G.M Levick, a member of Robert Falcon Scott’s “Terra Nova” Expedition to Antarctica, being stationed at Cape Adare amongst a huge Adelie Penguin rookery, recorded something about the penguins’ sexual behaviour which he found so shocking that he felt compelled to write down his observation in Greek. What he saw were, as he described it “deprived sexual acts of hooligan males”, who were mating with dead female penguins. (Actually, he assumed they were females, but sexing penguins is almost impossible  -I know that for certain having visited Antarctica and observed penguins on many occasions-  and the males Dr Levick had seen to have attempted to mate with dead females might have mated with dead males as well. Perhaps that never entered his mind as it simply might have been too shocking for Dr Levick to think of that possibility too; but in ducks it has indeed been described by Kees Moeliker, which earned him an Ig-Nobel prize in 2003.) In any case, his observations on the deviant sexual behaviour of penguins were finally published in English in 2012, a hundred years late.

In 2015 the Chinese PhD-student Wang Jishen and I observed a male cicada trying to mate with another (but dead) male, which is certainly not normal for an amorous cicada male. And when you scan the internet for unusual mating partners you will come across an elephant that (obviously by mistake or out of frustration) has been photographed mounting a rhinoceros. You may even find a scientific report about fur seals copulating with king penguins, a very unusual combination of sex partners. That small cage birds sometimes appear to make mock copulations with the owner’s hand or finger and that captive ostriches court a human has been reported. Dogs have been seen to copulate with a hole in the ground and that a male dog may clasp a person’s leg and start making copulatory movements has also been documented  – something I have experienced myself. As a youngster collecting tadpoles and other pond life, I had also experienced how male toads grabbed the tip of my shoe and were seemingly mistaking it for the rotund body of a female. So, what leads to these erroneous and biologically useless “aberrant behaviours”, given that they will certainly not result in any offspring?’

Arousal has to have been there and recognition of a chance to engage in sexual activity must have involved some sense organs, in most cases the eyes; but odour perhaps as well. In any case, specific hormones must have been involved as they prepare an animal for the mating season. Furthermore, a signal, a trigger or clue must have come from the mounted individual and according to Desmond Morris the large hemispherical breasts of human females, resembling round buttocks, would explain the most common mating position of humans. (Oh dear, I did not intend to mention humans  -anyway, Morris’ is only one suggestion and other behavioural scientists have expressed different opinions). Some observers believe that sexual frustration is involved in erroneous matings, for example when a more appropriate sex partner cannot be found. However, in case of young animals, e.g. calves mounting each other and even the fur seal copulating with a penguin, the behaviour could be seen as a practice run for the “real thing”, a kind of sexual play copying adults. Another reason suggested by some, could have been aggression that turned into something else. What’s involved is not easy to decide and when horses and donkeys mate or lions and tigers do “it”, what do we call that then? Acts of tragic attraction!

© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2021.
Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original content.

Statues and Buildings Built to Last?

No way: some whittle and nibble and make the structure brittle  –  but who does?

Statues and monuments: will they last forever if not pulled down? Pigeons love most (but not all of them as Yukio Hirose of Kanazawa University has shown in a study that earned him an ig-Nobel prize in 2003) irrespective of which ruler or famous person they were meant to honour. But the corrosive content of the bird’s droppings on the famous person’s head or shoulders damages the statue (and with that also the person’s grandeur). Bird droppings provide nutrients to organisms like algae, bacteria, fungi and lichens, all of which occurring on metallic statues but being far more abundant and damaging on stone buildings and brickwork. Actually, a former botanist colleague of mine operated a small company, offering services to remove unsightly and potentially damaging algae and lichens from stone walls, buildings and roofs tops.

The first colonizers of stony materials, be they bricks or concrete, are usually some green algae or, given a sufficiently moist surface, cyanobacteria and even liverworts. The water in the cracks and crevices of the brickwork, at least initially, is of a very high pH making it a strongly alkaline environment. However, the colonizing lower plants and seepages of weak acids will ever so slowly lead to the release of some minerals and to minute holes, grooves, or cracks in the mortar. An increasingly uneven surface then serves plants and their spores (in case of ferns) or seeds (in flowering species) in two ways: spores and seeds cannot easily be washed or blown away and roots to anchor the young plants can find a grip without much trouble. Holes and cracks, moreover, can store rainwater, dew, pollen, dust and nutrients.

Once some food for animals is available, the next wave of colonizers will arrive. At first they will be tiny and consist mainly of some wingless springtails and some mites, possibly some spiders that hide in the crevices and build flat sheet webs that cling to the building’s wall. Depending on whether one deals with a north, south, west or east-facing side of the building, the colonization histories will, of course, differ. Birds are not likely to colonize the brickwork of a building, especially when one deals with straight and vertical walls, but if the wall’s surface is sufficiently rough, small birds may visit and briefly cling to the brickwork for three reasons: they may peck at the mortar to replenish their calcium intake or they may want to ingest some tiny stony fragments to store in their stomachs to help them with opening seeds they have swallowed or they find small insects in the cracks and amongst the plant growth on the wall. Their droppings and occasional feather downs left behind further enrich this environment nutritionally, so that ultimately bigger and stronger plants can get a foothold on the building and whittle away more of it. At the same time their droppings are corrosive, attack the mortar and cause further little chinks.

How about metal, concrete or brick constructions in the water? They have become more and more popular for underwater constructions because of the notorious damage caused by shipworms of the family Teredinidae to wooden structures. Therefore, are the former any safer from being attacked by organisms? Apparently not, for there are reports that the paddock Martesia striata bored through the outer solid lead sheath and subadjacent asphalt-impregnated insulation of an electric underwater cable off the coast of Florida. Holes of 6 mm in diameter and 2 mm in depth were reported. Attacks of cement mortar and concrete in the water are well documented and involve a variety of rock-boring molluscs, for example the bivalves Pholadidea penita, Platyodon cancellatus, Lithophaga plumula, and Botula falcata. We have to conclude: even seemingly unpierceable structures are not impervious to biological attack.

© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2021.
Unauthorized use and/or duplication of this material without express and written permission from this site’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to V.B Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com with appropriate and specific direction to the original content.