Bumble Bees Near the North Pole

Is that a fact?

It depends, of course, what you mean by “near”: England seems quite near for birds that fly from France across the Channel (la Manche) to reach the English coast, but for insects it sure is a long, long way. The distance from the southernmost edge of Greenland to its northernmost coastline is over 2,600 km, which is (when I heard that bumble bees live in North Greenland) ‘only’ about 800 km away from the North Pole, corresponding to the distance between San Francisco – San Diego or Le Havre in the north and Marseille in the south of France). I was pretty amazed. How can these insects survive there?

It was at the South Korean Ecology Conference that I saw a poster that a scientist by the name of Dr Won Young Lee had put up to report on his research in Greenland as well as in Antarctica. I was curious to meet that person, as there simply aren’t many researchers who have been active in both Arctic and Antarctic environments. When I explained to him where in Greenland I had been and that I had also visited Antarctica nine times, he told me about his research and then happened to mention how surprised he was when in North Greenland at a latitude of nearly 83° N, he had seen bumble bees. I had come across two species of bumble bee (Bombus polaris and B. hyperboreus) in southern Greenland, but had not been aware of the fact that these cold-hardy insects would be distributed to the furthest north of the island. It hadn’t been an interest of my Polar research till then (despite an electrophysiological study of mine in 1981 of the functional properties of the eye of the North Finnish species B.hortorum). 

But now I wanted to know more and requested to join the next expedition to North Greenland (which, however, did not happen as it ‘fell victim’ to the Corona pandemic) to catch some of these bees. Luckily, though, Dr Lee had preserved a Bombus polaris queen bee from North Greenland and with the help of my Iranian colleague Dr Saeed M. Namin (a skillful molecular entomologist) and the support of our Department’s Head (Prof Chuleui Jung), we embarked on a study to investigate the phylogenetic relationships between all known “High Arctic” bumble bee species and to speculate how B. polaris  got to North Greenland and how global warming could possibly affect its distribution and survival there.

We concluded that the female specimen we analysed was most closely related to Canadian populations of B. polaris. Geographic proximity, occurrence of B. polaris on Ellesmere Island 500 km to the west and wind direction were thought likely factors that aided B. polaris to establish itself in North Greenland. A moderately high level of genetic diversity of B. polaris in Greenland was determined reflecting the successful adaptation of the species. However, bumble bees need food and shelter and only the queen overwinters. But where and how in North Greenland’s permafrost-hard soil is there sufficient shelter? And how about pollen and nectar for food? In the broader context of entomological life in the high Arctic, our results on B. polaris allow us to conclude that the survival of pollinating species in the high Arctic under the changing climate scenario depends not only on the weather but also on an individual’s opportunity to continue to locate suitable food sources, which in North Greenland are provided by flowers of the abundant Pedicularis spp., Salix arctica and Ericaceae of the region. Other plants with a northern distribution like Stylophorum sp. and crowberries can be considered pollen and nectar providers, respectively, and are likely to be also visited by B. polaris. Will climate change affect them?

According to one of the foremost Arctic bumble bee researchers (Dr Grigory Potapov), some High Arctic species used to occur much more widely in the past. Will it help us predict the fate of B.polaris? More research may be needed and I’d love to be part of it.
My next destination? I hope it’s North Greenland!

© 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.

Taking a Stroll in the Park (a Mossy Park that is) …

But you’ve got to be tiny

I remember that when I got back to Scott Base from a stroll up Observation Hill and showed our botanist Keith Thompson the photo of a cluster of moss plants he exclaimed: “Wow, you found a forest in Antarctica!” And now I wish to get a little deeper into the topic of a moss being called a forest.

Mosses are Bryophytes, usually rather small plants with thin leaves of just a single cell layer and no proper root system. Even the tallest moss, Dawsonia from New Zealand, with a spore-bearing stalk up to 50 cm tall, lacks like all of the other smaller Bryophyte  species, the typical vascular system and flowers of the higher plants. These tough little plants, with an ancestry that goes back 400 million years or more, were planet Earth’s terrestrial pioneers. With the exception of some freshwater species like Fontinalis antipyretica (there are no mosses in the sea) and those of swamps and bogs like Sphagnum, whose dead layers form the peat, Bryophytes are known to grow on almost anything that at least occasionally becomes soaked in water:  stones, tree trunks, bottles, roofs, monuments, and even other living plants and animals. The weevil Symbiopholus of Papua Niugini may support the growth of moss on its back and sloths, too, can have mosses in their fur. What is sometimes referred to as “moss caterpillars”, however, are not caterpillars with moss on their backs, but the larvae of nymphalid butterflies that possess moss-resembling protuberances on their bodies.

As a student in the Botany course many, many years ago, the plants I loved most were the true mosses (not including liverworts). The stage in their life cycle that has leaves and we recognize as a moss, has sexual organs and represents the gametophytes. Yes, mosses possess so-called antheridia  (which produce bi-flagellated sperm) and archegonia (which produce the egg cells). The reproductive organs, depending on the species, may be on the same or two different plants. The plants and thus their sperm and egg cells are haploid. To produce a fertilized egg, a sperm needs to reach archegonia where it can find an egg cell. For that ‘journey’ the sperm needs to swim and must wait until there is sufficient moisture. Once an egg cell has been fertilized, a new structure (attached to and growing out of the moss’ leafy gametophyte) develops and becomes noticeable as the thin and sometimes several cm tall, unbranched sporophyte. This structure possesses diploid cells and develops at its tip a spore-containing capsule. The spore-producing cells undergo meiosis, so that the spores are all haploid, some with male and some with female traits. When the spore capsule opens to release the spores, the wind carries them to various places or in the rare cases of species that grow on carrion or dung little flies may carry away spores. Should the spores land in a suitable spot, they grow into a thin threadlike protonema, which resembles a green alga, before changing into the more familiar moss with its little stems and green leaves. Being able to soak up water (but also surviving months without it), these moth gametophytes form a habitat for a multitude of invertebrates. 

Most famous of the latter are the cute tardigrades, champion survivors, just like the ever present rotifers and some tiny roundworms. Using a magnifying glass and even with the naked eye one would almost certainly encounter springtails, various mites, tiny eyeless arthropods known as Protura and Diplura, and probably very small flies, minute beetles, book lice (Psocoptera) and thrips. If one is really lucky, one may come across some pseudo-scorpion, a top predator in this micro-world. Easily recognizable as relatives of centipedes, but much smaller and thinner, are the multilegged and pale Symphyla and Pauropoda. Yellow Geophilus centipedes, ants and tiny micryphantid spiders would be the giants in this ‘forest’ and visible with the naked eye, but to spot the many ciliates and bacteria that are present, you’d need a microscope. Organisms like larval craneflies, caterpillars of micropterygiid mini-moths, and stigmaeid mites, feed on the mosses’ green parts and some nematodes are even known to induce the formation of tiny moss plant galls. Unfortunately, such a variety of different organisms would not have been present in my Antarctic “moss forest”, but take a clump of green moss sometime and go exploring:  take a walk on the wild side (of the mini world).     

© Dr V.B. Meyer-Rochow and http://www.bioforthebiobuff.wordpress.com, 2022. 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.

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