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Berlin Forest Grunewald and River Havel-Waterside

River Havel

The river Havel has its source in the Mecklenburg Lake Plateau and after 94 km flows in the area of the border between the federal states Brandenburg and Sachsen-Anhalt into the big river Elbe.

Havel runs besides the already mentioned states Brandenburg and Sachsen-Anhalt also through Berlin, the capital city of Germany. On its way, the river passes several bigger and smaller lakes, which serve as water reservoirs, even in hot summers, in which many german rivers and lakes from low water levels.

In its most parts, Havel is navigable, and weirs and locks regulate water levels and water supply.

Historically, Havel since at least 928 of our Western calculation played importent roles as natural border and water route. Through the middle ages up to times of the GDR wetlands as important ecosystems were stepwise drained. In more recent times the protection of unique nature refuges is proceeding. In 2004 for example, the Naturfreunde Deutschlands and the German Fishing Federation elected the Havel area as River Landscape of the year.

In 2005 the Federal Agency for Nature Conservation (BfN) and the Nature Biodiversity Conservation Union (NABU began the land restoration to create refuges for rare bird species , beaver, river lamprey, otters and other animals and plants.

The footage of my video was captured close to the bathing beach area „Lieper Bucht“. Visible are the Havel islands Lindwerder and Schwanenwerder as well as edges of the forest area „Düppeler Forst“.

River Havel and Forest Grunewald in Berlin, quadcopter footage. Copyrights Stefan F. Wirth, December 2018. Please like my video also on youtube, in case you like it.

Forest Grunewald

Adjacent to the Lieper-Bucht area, the huge urban forest Grunewald extends over 3000 hectare between the Berlin districts Charlottenburg and Zehlendorf.

It was elected as Forest Area of the Year by the Union of German Foresters in 2015. The Grunewald ecologically has a specific mosaic of ecosystems: heathlands, neglected grasslands, dunes, dandpits and marshlands. They all bear a remarkable biodiversity of rare animal and plant species.

Geomorphologically the Grunewald area was formed by galcio-fluvial processess during the Weichselian glaciation , which endet about 11600 years ago. Glacio-fluvial sands cobver the area in layers up to 20 meters and more.

The footage of my video also shows the so called Grunewald Tower. The memorial for the German Emperor  William I was planned in 1897 and finally built up by the architect Franz Schechten. The tower was finally inaugurated in 1899 and renovated between 2007 and 2011.

The footage was captured with a DJI Mavic pro quadcopter in mid December 2018.

 

Berlin, December 2018. Copyrights Stefan F. Wirth

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Male and female of Histiostoma sachsi and unsuccessful mating with a „stranger“

Mites of the Acariformes vary in very different forms and life-strategies. One taxon of very tiny and soft-skinned mites is named Astigmata. Within them the familiy Histiostomatidae is especially rich of species, most of them surely not yet described or discovered.

Modyfied mouthparts and a specific mode of dispersal

These mites feed on microorganisms using a complex mouthpart-apparatus with multifunctional abilities. They can be found in habitats, which dry out quickly. When it’s getting too dry, a specific instar of the mites takes a ride on insects or other bigger arthropods for dispersal to a new and fresh habitat ( strategy called Phoresy).

Histiostoma sachsi is one of numerous (often closely related) long haired (in females) species. It was originally in 1957 described from cattle-dung. I found it in compost.

Long upper-setation in females and tactile camouflage (mimesis)

Adult females are characterized by a long setation on their uppersides. They use them to hold parts of the old nymphal cuticle and soil particles on their backs. This seems to be due to a strategy named mimesis or camouflage. It’s a tactile camouflage as an optical sense in this kind of microhabitats plays almost no role.

Normal and unusual copulation position, trial of an interspecific copulation

Males mate their females via a dorsal copulation opening and thus need to ride on them. In H. sachsi, that copulation opening is located very close to the hind-edge of the body. That way it is even despite of the camouflage cover accessible. It seems even slightly being elevated out of the body surface in order to surmount adjacent soil particles. This is an adaptation of this particular species. It might share such morphological characters only with very closely related (not yet described) species In other members of genus Histiostoma, the copulation opening is usually more centered related to the hind body.

The copulation position requires that males insert their aedeagus („penis“) into the copulation opening. They additionally use their legs to grasp into the females body. That kind of leg arrangement and thus the whole copulation position can differ from species to species.

This is why copulations between members of different species already fail, because the right copulation setting does not fit, nor does the shape of the aedeagous. Nevertheless the phenomenon of unsuccessful trials for interspecific copulations can sometimes be observed in laboratory cultures. Such a trial is also visible in this video, where a male of Histiostoma feroniarum (also appears in my compost samples regularly) tries to mate a female of H. sachsi. It cannot even almost get in a proper copulation position and seems to hold on to the dorsal camouflage cover of the female. it could only remain in a transverse position related to the female body and thus not get access to the copulation opening, normal would be a longitudinal position with the sameame orientation of female and male.

Adult mites of the family Histiostomatidae (Astigmata) and a „false“ copulation. Copyrights Stefan F. Wirth, Berlin December 2018. Please like my video also at Youtube, in case you like it.

Chemical communication and chemo-sensitive leg setation

Mites of the Astigmata communicate and find their general orientation due to chemo-sensitive setae, mostly on legs I and II, which are named solenidia. They are even on the magnification level of my footage well visible on the male’s legs. Although a direct body contact is not necessary for a innerspecific communication by chemically interpreting scents produced from mite glands, the observed male in my video repeatedly was seeking for intense body-contacts and obviously „observed“ his conspecific while doing so with its first two legs. This might have intensified the perception of pheromones.

It showed this behavior also, when passing by the „false copulation-pair“ described above. It additionally seemed to invest power in its leg movements as if it would try to remove the „competitor“ on the female, in this case even belonging to another species.

Competitive fights between males

That mites of the Histiostomatidae can use their strongly sclerotized first legs to fight under each other for an access to a female is known to me from my older observations about the species Histiostoma palustre and Histiostoma feroniarum.

Origin of the compost samples

The compost samples were collected in SW-Germany (Saarland in October 2018). The footage was recorded in December 2018 in Berlin.

Berlin December 2018, copyrights Stefan F. Wirth

Habitat compost: Mite Histiostoma sachsi carries old cuticle and dirt as camouflage

My parents have a compost area in their backyards. I use it as reference habitat for two mite species of the family Histiostomatidae (Astigmata): Since I began my research in 2000, the compost regularly contained Histiostoma feroniarum with its typical male dimorphism. Since summer 2017 another species appears additionally regularly: Histiostoma sachsi. Both species do not appear under the same conditions. While H. feroniarum prefers fresher decaying material, H. sachsi on visibly older decomposed tissue. There mite be even more mites of the Histiostomatidae exist in this complex compost habitat, but under my laboratory conditions, only the two named species were so far successfully reared out of samles always again. Regarding the determination of H. sachsi on a species level, I was more careful in my comments to a former video (June 17), in which I named it Histiostoma cf. sachsi due to doubts about a correct identification. Meanwhile, also due to the morphology of the deutonymph, I determine „my“ compost mite as Histiostoma sachsi Scheucher, 1957. But it is still to emphasize that Scheucher described H. sachsi from cattle dung, not from compost. But generally, both habitats can sometimes share the same inhabitants.

Adult females carry their old cuticles and „dirt“ on their backs as tactile comouflage

Biologically conspicuous is darkish material, which especially adult females carry on their backs. Unlike males, females posses elongated setae on their backsides. These setae support the holding of material such as old cuticle and soil particles. In slide preparations, this cover usually appears amorphic and contains substrate from the mite’s environment. My video footage indicates that the basis of this cover is a retained old cuticle from the former nymphal instar . That this cannot easily be proven with the light microscope is due to the very soft and fine character of the cuticles in these mites. Remnants might become decomposed by microorganisms after a while.

Compost: the habitat of the mite Histiostoma sachsi Scheucher, 1957 (Acariformes, Astigmata, Histiostomatidae). Copyrights Stefan F. Wirth, please like my video also on youtube, in case you like it.

The phoretic dispersal instar, named deutonymph, in mites of the Astigmata controls its body position due to sticky leg endings and suckers on their undersides

Deutonymphs of H. sachsi represent one of my resent models to study mite-dispersal behavior. My research focus since a while concerns ultrastructure and function morphology of the deutonympal suckerplates and other structures to attach to insects for dispersal (this dispersal strategy is called phoresie). The anterior front-suckers on the suckerplate of the mite’s underside is extendable and very flexible, not only to find a suitable position on the insect carrier. When falling, the deutonymphs use it to lift their bodies up into a proper position again. Additionally they will try to get hold using „sticky“ lobe-shaped setae on the endings of legs I and II. Both is visible in my footage. The forelegs seem generally to make the first contact, when trying to get on a suitable carrier.

Deutonymphs of Histiostoma sachsi take a ride on other mites (Oribatida)

The suitable carrier of H. sachsi is unknown to me. Some astigmatid species have even a range of carrier-„hosts“. In my samples, deutonymphs at least attach to other mites, especially to mites of the Oribatida. This is in a very short scene visible in my video too.

Copyrights Stefan F. Wirth, Berlin December 2018

Lake Teufelssee in Berlin as part of a glacial meltwater lead

Lake Teufelssee in the Berlin urban forest Grunewald is known since ancient times, but is even much older. This is unlike the adjacent hilly landscape, which is named Teufelsberg („Devil’s Mountain““, referring to the nearby lake). It represents an area of mounds of rubble, built up with debris of the destroyed Berlin after the Second World War. Teufelssee („Devil’s Lake“) however is part of a glacial chains of lakes, a result of a supraglacial stream from the period of the Weichselian glaciation.

Air-view footage of lake Teufelssee in Berlin. Copyrights Stefan F. Wirth, please like my video also on youtube,in case you like it.

Geomorphology of Berlin, lake Teufelssee and glaciofluvial sands

Berlin itself represents geomorphologically a push morain from the Weichselian glacier times (until 11.600 years ago). This until today explains the uniform and scarce vegetation in and around Berlin, which is due to specifically sandy ground conditions. Sand layers with a thickness of at least 20 m date back to glaciofluvial sands, being a result of the advance of a glacial tongue.

Vegetation and climatic zone

The stock of trees in the Grunewald area is dominated by oaks and pines, being well adapted to this ground composition and the Berlin geomorphology. The climate of the Berlin area is characterized as part of the temperate climate zone in the transition between maritime and continental climate. Aspects of the continental climate are predominant, which is why snowy winters as typical for the Southern parts of Germany are rare.

Instead winters are often very cold and with low precipitation unlike the hot summers, where most rainfall occurs. The winter 2018 to 2019 is following an unusually warm summer with long periods of heat and without rainfall. As a result, water bodies Germany-wide carried less water than usually. But in which intensity lake Teufelssee was or is still concerned is unknown to me. Differences to former years are not obviously visible.

Berlin recreation areas and the ancient origin of the term „devil“

Teufelssee and Teufelsberg represent local recreation areas and offer enthusiasts and families with children a popular playground in summer, and in case the lake is frozen, also in winter.

The appearance of the German word for „devil“ in Teufelssee and Teufelsberg is assumed to refer to an ancient place of worship in this area.

Copyrights Stefan F. Wirth, Berlin December 2018

Tod den Naturwissenschaften – Es lebe „Inter“? Warum das individuelle Geschlechtsempfinden zwar staatlichen Schutz verdient, jedoch nicht zum biologischen Fakt erhoben werden darf

Im letzten Jahr bereits beschließt das Bundesverfassungsgericht, dass es in Deutschland als Diskriminierung anzusehen sei, wenn von Bürgern verlangt werde, sich in offiziellen Dokumenten entweder dem männlichen oder weiblichen Geschlecht zuzuordnen. Konsequenter Weise entschied der Bundestag nun, dass etwa im Zusammenhang mit Wahlunterlagen neben der Einordnung in männlich oder weiblich als dritte Möglichkeit „divers“ eingeräumt werden solle.

Geburten ohne eindeutige Geschlechterzugehörigkeit

Klingt absurd, ist aber nicht aus der Luft gegriffen, denn in der Tat ist es biologischer Fakt, dass statistisch bei etwa einer von tausend Geburten beide Geschlechtsmerkmale gleichzeitig ausgebildet sind. Aufgrund dieser äußerlich klar nachweisbaren Merkmalszusammensetzung ist der betroffene Mensch weder ein Mann noch eine Frau. Das bereits seit der Antike gut bekannte Phänomen wird umgangssprachlich daher auch etwa als „Zwitter“ oder „Hermaphrodit“ bezeichnet. Aus naturwissenschaftlicher Sicht sind jedoch beide Begriffe unzutreffend. Hermaphroditismus ist in der Pflanzen- und Tierwelt nämlich ein durchaus häufig auftretendes Phänomen. Per Definitionem wird aber vorausgesetzt, dass betroffene Individuen reproduktionsfähig sind. Dies ist bei Menschen, die mit beiderlei Geschlechtsanlagen auf die Welt kommen, hingegen nicht der Fall.

Ein echter Hermaphrodit: der Regenwurm. Copyrights Stefan F. Wirth

Es war bislang übliches Procedere, dass Menschen mit beiden Geschlechtsanlagen im selben Körper noch im Kleinkindalter einer sogenannten geschlechtsangleichenden Operation unterzogen wurden. Dabei wird das in Folge äußerlich auszumachende Geschlecht häufig nach rein pragmatischen Überlegungen ausgewählt, nämlich gemäß der leichteren medizinischen Praktikabilität in Bezug auf den Prozess des operativen Eingriffs. Damit geschieht den Betroffenen möglicherweise Unrecht. Dass überhaupt die Entscheidung getroffen wird, Menschen ohne eindeutige Geschlechtsanlagen auf eine männliche oder weibliche Erscheinung umzuformen, wird mit psychologischen Argumenten begründet. So könne sich ein betroffenes Kind leichter in eine Welt einleben, die durch zwei klar unterscheidbare Geschlechter dominiert werde. Obwohl mir dieser Ansatz sehr plausibel erscheint, liegt eindeutig eine Diskriminierung derjenigen vor, deren Eltern sich entweder gegen die frühzeitige geschlechtsangleichende Operation entschieden haben oder die nach Erreichen der gesetzlichen Mündigkeit die Entscheidung treffen, diese wieder rückgängig machen zu lassen.

Der Entschluss des Deutschen Bundestages ist daher richtig, wird allerdings einem Phänomen gerecht, das nur selten auftritt.

Einfluss sozialer und psychischer Faktoren auf die Geschlechterbestimmung?

Erwartungsgemäß wird die Thematik jedoch politisch instrumentalisiert. Etwa vom Lesben- und Schwulenverband LSVD, dessen Vorstand, Henny Engels, zu dem Schluss kommt „, dass sich das Geschlecht nicht allein nach körperlichen Merkmalen bestimmen lässt, sondern von sozialen und psychischen Faktoren mitbestimmt wird“. Dies ist faktisch falsch und mit den Kenntnissen der modernen Naturwissenschaften nicht in Übereinstimmung zu bringen. Zwar ist es Fakt, dass es vergleichsweise häufig vorkommt, dass Menschen an sich selbst subjektiv ein anderes als ihr biologisches Geschlecht wahrnehmen, dies hat jedoch keinen Einfluss auf das faktische biologische Geschlecht. Eine biologische Frau etwa, die sich jedoch männlich oder „inter“ fühlt, bleibt faktisch zumindest dann ganz eindeutig Frau, wenn sie weiterhin empfängnis- und gebärfähig ist. Führt diese Person beispielsweise eine geschlechtsangleichende Operation zum Mann durch, handelt es sich de facto um eine Frau, die infolge eines medizinischen Eingriffs juristisch zu einem Mann geworden ist. Das Geschlecht kann aus biologischer Sicht nicht gewechselt werden. Es handelt sich lediglich um eine körperliche Angleichung, die der psychischen Wahrnehmung der betroffenen Person gerechter wird. Dass es diese Möglichkeiten gibt, ist richtig. Dass Betroffene durch Gleichstellungs- und Antidiskriminierungsgesetze geschützt werden müssen, erst recht.

menschengemischt

Verschwimmen die Geschlechtergrenzen? Copyrights Stefan F. Wirth

Auch ist zu strikter Biologismus zu kritisieren, zum Beispiel dann, wenn es um die Frage geht, ob es sich bei einem Menschen, der mit der körperlichen Ausstattung einer Frau geboren wurde und sich auch weiblich fühlt, jedoch aus welchen Gründen auch immer unfruchtbar ist, um eine biologisch „vollwertige“ Frau handelt. Wäre der Ansatz aus wissenschaftlicher Sicht eventuell zwar vertretbar, würde er der Lebensrealität moderner Gesellschaften allerdings nicht einmal im Ansatz gerecht werden. Allzu schnell gelangte man zu Denkweisen, die nur als unmenschlich bezeichnet werden können  und beispielsweise integraler Bestandteil des menschenverachtenden Systems des Nationalsozialismus gewesen sind.

Es ist daher allgemein grundsätzlich richtig, nicht nur im Alltag, sondern auch per Gesetz der individuellen Selbstwahrnehmung und Selbstbestimmung ein Stück weit Rechnung zu tragen. Es ist dabei allerdings äußerste Vorsicht geboten. Grenzen müssen eingehalten werden. Ließe sich die Zugehörigkeit zu einem Geschlecht künftig durch ein Individuum willkürlich festlegen, käme das dem Niedergang der Naturwissenschaften und somit dem inzwischen Jahrhunderte alten Geist der Aufklärung gleich.

Zukunft der Naturwissenschaften

Was sollte denn dann der Biologie-Lehrer seinen Schülern, was der Biologie-Professor seinen Studenten vermitteln? Dass die Geschlechterdeterminierung im Tierreich allgemein Folge naturwissenschaftlicher Gesetzmäßigkeiten sei, es sich beim Menschen jedoch um eine Glaubensangelegenheit handele? So weit dürfen wir nicht kommen! Daher ist es aus meiner Sicht bereits ein falscher Weg, dass die geplanten Reformen der großen Koalition vorsehen, dass in bestimmten Ausnahmefällen kein ärztliches Attest, sondern eine eidesstattliche Versicherung des Betroffenen ausreichen solle.

Das naturwissenschaftliche Verständnis der AfD

Das Thema erhitzt die Gemüter. Und so fühlen sich nicht nur eher linke Verbände zu kritischen Äußerungen genötigt. Auch das rechte Lager wittert umgehend ein Podium, um politisch konservatives Gedankengut zu verteidigen. So äußert die stellvertretende Fraktionsvorsitzende der AfD: „Die Geschlechtszugehörigkeit ist seit Bestehen der Menschheit ein objektives Faktum – so wie Alter und Körpergröße auch.“ Ein objektives Faktum ist vielmehr, wie sachlich unzutreffend diese Äußerung ist. Die Stellungnahme der Frau von Storch verwundert allerdings auch nicht weiter, hat sie doch bereits an anderen Stellen ihr fragwürdiges naturwissenschaftliches Verständnis vorgeführt, etwa, als sie in einem Interview forderte, es müsse erst einmal bewiesen werden, dass der Mensch Einfluss auf die zunehmende Klimaerwärmung ausübe.

Copyrights Stefan F. Wirth, Berlin Dezember 2018

 

 

What happens with our trees in Winter? A forest area of the naturerefuge Teufelsberg Berlin in air-view

The Berlin forest Grunewald in winter, shown from the area of the urban nature refuge Teufelsberg. The colors, brownish and grey with a little bit of green, dominate the winter landscape. This has biological reasons: Trees of a forest drop their leaves during the autumn-period. This happens in order to reduce water loss due to evaporation. Before they fall, leaves change their colors, sometimes into powerful red or yellow forms.

Why do trees drop their leaves?

Chemically, the plant modifies chlorophyll into colorless components. Proteins (result of photosynthesis) out of these chlorophylls are resorbed by the plant (tree) in order to save nutrients for the cold season. Carotinoids then retain inside the leaves and appear in red or yellow shades. In winter, most trees are completely leafless and remind to skeletons, waiting for the next warm period.

Leafless trees in winter at nature refuge area Teufelsberg in Berlin, copyrights Stefan F. Wirth. Please like my videos also on youtube, in case you like them.

The Teufelsberg area in Berlin, a nature and sports refuge

The Teufelsberg represents the second biggest mountain inside Berlin/Germany. It consists of rubble from the Second World War and extends about 80 m out of the plain around. It is named after a lake, which is located very nearby: the Teufelssee. The Teufelsberg is part of the „Grunewald“, an urban forest in the west of Berlin. Since 1950 the area was filled up with rubble from the city of Berlin, which was almost completely bombed down during the second World War.

Until 1972 about a third of all rubble from bombed buildings in Berlin were transported to the top of this mountain. After 1970 finally, the Teufelsberg was formed into a nature and free time area. Skiing and mountainbiking for example were enabled.

Kites, US-listening-station and drone footage

Today, also during the summer, people use the winds on the top of the mountain to fly kites. Since the late 1950s during the Cold War a listening station was built close to the Teufelsberg, which still exists as a ruin. The footage was captured with a drone (Dji Mavic Pro).

 

Copyrights Stefan F. Wirth, Berlin December 2018.

Western lowland gorilla: locomotion, eating and facial expressions

We humans are nothing else than a species of great Apes and thus belong to the clade of the primates. Gorillas and chimpanzees represent our closest recent relatives.

Relationship to Homo sapiens

In earlier times, it was even stated that the two chimpanzee species and the two gorilla species altogether were the sister-clade of the Homo sapiens. This is not the standard of knowledge any more. Due to molecular evidence and other characters, it could be reconstructed that chimpanzees alone represent the sistergroup of modern humans. Gorillas are sister-taxon of the clade consisting of cimpanzees and Homo sapiens.

Knuckle-walking

The consequence of this systematic scenario is interesting, as the conspicuous mode of locomotion that can be found in gorillas and chimpanzees, the so called knucklewalking, might have also existed in very „primitive“ and extinct human species.

Two gorilla species

Another newer finding is that the four subspecies of gorillas (western lowland gorilla, Cross River gorilla, eastern lowland gorilla and mountain gorilla) represent two species, the western gorilla (Gorilla gorilla) and the eastern gorilla (Gorilla beringei). Visible in my film footage are specimens of the western gorilla, more exactly western lowland gorillas (Gorilla gorilla gorilla) from the Zoologischer Garten Berlin.

Preferred habitats

Gorillas live preferably on the ground, but are also good tree climbers. An exception is the mountain gorilla, which seems to avoid tree climbing. Gorillas even do not avoid water, but only access  water bodies, in which they can stand.

Social structure

The social structure of gorilla groups can be simplyfied as consisting of one dominant male (silverback), his females and subadult specimens. In case several adult males remain in a group, only the dominant silverback is reproductive. The normal case is that adult males leave their groups, remain for a while alone and try to find access to a new group. Interestingly, in gorillas also females leave their groups after adolescence . As a result, females of a group are usually not closer related with each other.

Diet

Gorillas represent the biggest great apes, but usually are vegetarians, preferring fruits, seeds and leaves as food. To gain enough nutrients, they need to invest a major time of their daily activities with eating. It is still unknown, which role carnivorous food plays for these apes. Some were observed during „termite fishing“. It might be that insects and smaller vertebrate might enrich their diet. In order to grasp smaller food particles, gorillas possess a quite well developed hand motor-skills, as visible in my footage.

Western lowland gorilla filmed in Berlin Zoologischer Garten, copyrights Stefan F. Wirth, Please like my videos also on youtube, in case you like them.

Facial expressions

As all gorillas, also the western lowland gorilla is characterized by very well developed facial expression abilities. it’s a character, which they share with chimpanzees and humans due to a common evolutionary event in the early ancestor line of the great apes. A differentiated facial expression, comparable with the one of humans, requires a suitable innervation, skull muscle origins and specific numbers and shapes of facial muscles.

Culture and the use of selfmade tools

It was earlier thought that cultural abilities and the use of selfmade tools would be unique for humans. The modern primatology could proof that this is not true. Both characters evolved obviously in the ancestor line of the great apes. Especially chimpanzees and gorillas are known for using tools, for example in order to perform termite-fishing. The transfer of a specific knowledge or abilities via teaching to the offspring is named culture. Also gorillas are able to do so.

Berlin, July/November 2018, Copyrights Stefan F. Wirth

Round-leaved sundew: How a fly can die

The round-leaved sundew Drosera rotundifolia is a carnivorous plant. It digests mostly small arthropods in order to gain additional nitrogen on floor coverings with a lack of sufficiant mineral nutriment.

Sundew and its digestive secretions

Along the edges of the rounded leaves, tentacles are arranged, which produce sticky secretions, consisting of enzymes and formic acid. Attracted by a fragrant smell, small animals approach this deadly plant.

Please like my videos also on youtube, in case you like them. Copyrights Stefan F. Wirth

The secretions trap them finally to the leave. After some hours the tentacles move towards the leaf-inside due to growth „movements“, where digestive glands are located. Later even the whole leaf rolls that way that more glands get into a contact with the prey. The whole digestive procedure then needs several days. My video only shows the effect of sticky tentakles to a fly, which finally is unable to flee.

Fly on a sundew leaf, independent evolution of carnivorous plants

The fly specimen might have represented a too large prey, which is why it at first resisted against the slimy and sticky secretions. However later, its body is thus covered with threads of adhesive that it remains fixed to the sundew leaf. Carnivorous plants evolved several times independently within the Angiosperma. That means that pitcher plants, as for example Sarracenia or Nepenthes, systematically do not represent close relatives of the sundew or even between each other. Under comparable ecological conditions, selective pressures caused options for plants to enrich their nutrients by the ability to digest smaller animals using specific organs, usually being homologous to leaves. The way carnivorous traps develop, differs in the various groups of carnivorous plants.

Micro-habitats for mites or nematodes

Decaying remnants of partly digested arthropods can especially in Sarracenia or Nepenthes become micro-habitats, in which mites or nematodes might find suitable living conditions. Some of them can even be resistant against digestive enzymes of these plants. Whether microorganisms ,such as mites, also can occur on sundew, is unknown to me. Common inhabitants of pitchers of Sarracenia or Nepenthes are represented by mites of the Astigmata, e.g. of the family Histiostomatidae.

Distribution of the round-leaved sundew

The round-leaved sundew is native to the whole northern hemisphere in bogs and wetlands.

Copyrights for film and text: Stefan F. Wirth, October 2017/ November 2018

Microscopic wrack inhabitants: Mites (Ameronothridae), Protozoans, nematodes and Dipterans

Decomposing detritus (mostly dead algae debris) of marine organic material, laying onshore more or less close to the water line, containing seaweed or cadavers of aqatic animals, is named wrack. Wrack can appear under different kinds of ecological circumstances. In case, it would be in permanent contact with sea water, it might be mostly decomposed by marine organisms. But due to different reasons, wrack can land apart from a permanent sea water contact or even no sea water contact at all any more.

Here mostly terrestrial organisms with a tolerance for salty conditions would inhabit and decompose this piece of detritus. Sandhoppers (Cristacea) are known to switch between wracks of different conditions. They can for example carry mites or nematodes from one wrack habitat to another. Dead organic material generally always needs to be decomposed by living organisms, otherwise the whole ecological system would be harmed.

A specific kind of micro habitats

A small habitat, which would dry out after a while and thus exists only for a limited time, is called ephemere biochorion. Organisms being adapted to live there, must have adaptations, to leave their habitat by time to avoid desiccation. One option is a life strategy, which is named phoresy. Weaker organisms, unable to desperse themselves efficiently use other animals, such as winged insects, to take a ride on them to new habitats with suitable conditions for a development. Generally phoretic organisms can for example be represented by different groups of mites (e.g. Uropodida, Gamasina, Tarsenomidae, Scutacaridae, some Oribatida, Astigmata) and nematodes (Rhabditida).

Mites and nematodes

In case of wrack, decomposing close to the waterline, but without or only occasional water contact, Pellioditis marina (Nematoda, Rhabditida) is for example known as phoretic inhabitant along German coasts. Worldwide, crypitical sibling species of P. marina were meanwhile discovered. Depending on the exact situation of the wrack, also aquatic nematodes could appear there for a while. I couldn’t determine the nematode in my footage unfortunately at all, because I did not prepare slides of them enable a larger microscopic magnification. Phoretic mites can be associated with sand-hoppers (Amphipoda, Crustacea) and thus appear in wrack. Mites of the Histiostomatidae (Astigmata) were for example discovered in such a context by some researchers.

Mites of the Ameronothridae (Oribatida), sand-hoppers and dipterans

I so far never found them randomly, but also didn’t explicitely seek for histiostomatid species until now. My sample did not contain any Astigmata or I at least didn’t find them. Common inhabitants of decomposing wrack are oribatid mites of the Ameronothridae. This taxon with a worldwide distribution is charaterized by specific adaptations to deal as terrestrial organisms with (partly extreme) salty marine conditions. They are mostly algae feeders. Some species are known to appear in wrack. The sample, which I collected in context of the so called „Geo Tag der Natur 2018“ (Geo (journal) day of nature) in Norddeich Mole (East Frisian coast of Germany) contained many specimens (ca. 40, sample size of about 20×20 cm) of the Ameronothridae-species Ameronothrus sp.. My footage shows only one living specimen, as all had died until I began my filming activities.

Inhabitants of decomposing algae tissue along a beach at German North Sea, all copyrights Stefan F. Wirth

But I preserved several dead specimens for scientifc purposes. Ameronothridae might, according to literature, use phoresy via birds, but also might disperse themselves over smaller distances, due to their well developed cuticle, protecting against desiccation, and their rather fast locomotion abilities. Larvae of different species of flies (Diptera) developed inside my sample and hatched under my laboratory conditions after about two weeks. They intensively contributed to a fast decomposition of that organic marine tissue. Sand-hoppers were by the way not found at all.

Bacteria and protozoans

Bacteria are most important decomposers. But the function of protozoans (here e.g. Ciliata) in regard to the process of wrack degradation, which could still be isolated alive after about two weeks of decomposition,  is unknown to me. My sample was found almost on top of a dike, meters away from the highest tide in that area and consisted mostly of the seaweed Fucus vesiculosus.It also contained sea gull feathers.

Berlin/ Norddeich Mole June/August/November 2018 Copyrights Stefan F. Wirth

Hamadryas Baboon Behaviors

They belong to the same phylogenetic clade of Primates than Homo sapiens. Hamadryas baboons (Papio hamadryas) miss our ability for a complex facial expression (unlike chimpanzees for example, our sister-group), but we can nevertheless read about their moods, when we look into their faces. When we watch boboons, then many of their behaviors and interactions look familiar to us.

The phylogenetic tree of the Primates (Apes), to which we humans belong, clearly prooves that we derived from old world monkeys due to evolution. Hamadryas baboons live in East Africa and there are well adapted in surviving in a dry environment. They are omnivorous feeders and prefer plants and seeds, but can also hunt smaller mammals or reptiles. This species of baboos is characterized by a specific sexual dimorphism, which represents an apomorphy for P. hamadryas.

Hamadryas baboons and aspects of their social behaviors. Copyrights: Stefan F. Wirth

Males have almost the double size of females, and their fur is silver-white and covered by a conspicuous mantle. The social system is rather complex. But it begins with a very simple society structure, which is called the „one-male unit“, which can be named synonymically a „harem“. Such a unit consists of one dominant male, several females and their infants. Several one-male units can cooperate with each other.

That way a more complicated social hierarchy within the populations is formed. I had primatology courses in Berlin, when I was a student and always had a special fascination for these baboons. That’s why I decided to record this footage in the Berlin Zoologischer Garten.

May 2016/ November 2018. Copyrights Stefan F. Wirth.