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Copris_lunaris

Nesting by the Horned Dung Beetle (Copris lunaris): 1 – Initial stage, male (left) and female (right) working the ‘dung cake’; 2 – Female alone, making brood-balls of the ‘cake’ for laying eggs. Illustration by V.A. Timokhanov (Almaty, Kazakhstan).

Waste disposal is a growing problem for any industrialized nation. The UK alone generates about 100 million tonnes of waste each year, the majority of which is still being disposed of through landfill. The present story is about dung beetles or scarabs (family Scarabaeidae) that are involved in processing and decomposing dung.

On average, about 40% of the food intake of mammals is either excreted as urine or passed out of the body as faeces. This waste is decomposed and returned to the soil by insects that use dung as food for themselves and for their larvae, thereby preventing it from building up. How this is accomplished is best known for cattle dung.

A cow’s fresh dung pat is colonized by a succession of dung-breeding insects, numbering several dozen species and often exceeding 1000 individual insects. A total of 275 species has been reported to occur in cattle dung in Britain. The majority of them are dung beetles that feed directly on dung. There are three main ecological groups of dung beetles. First, small-sized beetles (Aphodius species) usually feed in the main dung mass. Others, like the horned dung beetle, dig burrows beneath the pat and pack pieces of dung into them for feeding their larvae (see figure above). The third group includes beetles that make spherical dung balls, roll them away and bury them intact in shallow burrows. The Sacred Scarab is the most famous of the rollers. As well as dung beetles, the pat is colonized by dung-feeding fly maggots, predatory beetles which feed on eggs and larvae of other insects, small parasitic wasps, fungus-eating insects and mites, etc. At the advanced stage of degradation, soil invertebrates, including earthworms, begin to move into the dung pat. The natural rate of dung degradation depends on temperature, humidity, habitat and season of deposition. In Britain, the complete natural disappearance of a dung pat is achieved in two to three months.

Sacred_Scarab_Stockholm

Sculpture of the Sacred Scarab in the Natural History Museum in Stokholm, Sweden. © Dmitri Logunov, Manchester Museum.

It is known that each cow produces an average of 12 dung pats per day, or over 9000 kg of solid waste per year. It is estimated that each year approximately 200 million tonnes of waste are produced by livestock in England and Wales, and about 900 million tonnes in the USA. About third of this is recycled by dung beetles. In the USA alone, the annual economic value of this service is at least $380 million.

Unfortunately, the activity of dung beetles is severely disrupted by current agricultural practices, such as the treatment of livestock with persistent anti-helminth drugs given to kill parasitic worms or helminths. Residues of these drugs can persist in the dung and are lethal to the beetles. As a result, the dung pats of animals treated with anti-helminthes remain biologically undegraded for months, fouling available grazing area. If left unprocessed, livestock wastes may present a health risk to humans, because they can contain some pathogenic microorganisms.

By recycling the nutrients locked up in dead organic materials such as dung, insects make these nutrients available to new life. As recyclers, they do an indispensable job for our planet. Without organisms breaking down dead organic materials and recycling nutrients in the wild, as well as in gardens and on farms, the planet would soon be piled deep with the waste products of its inhabitants, and potential spread of diseases would be unavoidable. Whether we like it or not, our own existence directly depends on insects and their ecological services. As M. Telfer (2004) put it: “Not everyone welcomes having ‘creepy-crawlies’ around but we should be grateful for what they do.”

In the following video, our special guest, Ms Roisin Stanbrook from the Manchester Metropolitan University, is taking about the ecological role of dung beetles in Kenya.

The presented story is based on: Logunov D.V. 2010. Nature’s recycling squad. Biological Sciences Review, 22(3): 22-25.

Further reading:

Berenbaum, M.R. (1995). Bugs in the system. Insects and their impact on human affairs. Helix Books.

Waldbauer, G. (2003). What good are bugs? Cambridge-London: Harvard University Press.

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Do butterflies migrate and if they do how long distances are they able to cover? How many British Lepidoptera species do migrate to the country? Why do butterflies and moths migrate? These and other questions related to migratory species of Lepidoptera (butterflies and moths) were discussed with an expert, Prof Laurence Cook of the University of Manchester (Manchester, UK).

The interview is presented here in two parts.

Watch interview, part one:

Watch interview, part two:

You can find useful information about two British migrant species (Painted lady and Humming-bird Hawk-moth) and the initiative ‘Migrant Watch’ online on the Butterfly Conservation site, here.

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The Brown Trout (Salmo trutta) is a European species of salmonid fish, which consists of two distinct forms. One of them is purely freshwater, referred to Salmo trutta morpha fario; another is known as the Sea Trout (S. trutta morpha trutta) that migrates to the oceans for much of its life and returns to fresh water only for spawning. Here you can find some facts about the Brown Trout.

However, this fish species is also able to adapt to living in caves. In the UK, several populations of cave-dwelling Brown Trout have been found. Graham Proudlove, an Honorary Curatorial Associate at the Manchester Museum, presents a story of this unusual “cave” fish (see below).

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In recent years, an increasing concern has been caused by the decline of butterflies in Britain. Almost half of the 59 resident species have reduced their ranges over the last 150 years, and five species have become extinct: Black-veined White (Aporia crataegi; c. 1925); Large Copper (Lycaena dispar, c. 1851); Mazarine Blue (Cyaniris semiargus, c. 1903); Large Blue (Maculinea arion, c. 1979); and Large Tortoiseshell (Nymphalis polychloros, 1980s?). Many of the remaining butterfly species continue to decline nationally or even have become extinct locally on many sites. One of such species is the Silver-studded Blue (Plebejus argus), which is scarce elsewhere in the UK with a high extinction rate (evaluated as 25%): i.e., the species no longer occurs in about a quarter of the localities from where it was recorded in the 1970s. In the UK, this species declined most severely from 1950 to 1980, but with relatively few extinctions occurring between 1980 and 1985 (data by Warren, 1993, for Central Southern Britain).

The main reason for extinction/declining of this and other butterfly species in the UK is a combination of habitat loss and fragmentation/isolation, and changes in habitat management (especially, in Forestry Commission and Public Authority sites). Butterflies are known to be highly sensitive to environmental changes and therefore they often decline whilst their larval food-plants are still widespread and abundant. However, any changes in butterfly populations are to be seen as early indicators of habitat changes that in the future will affect many other wildlife groups.

The Silver-studded Blue is more usually associated with heathland habitats, and a number of regional nature reserves have been specifically established to protect it. One of such sites is the Prees Heath Common Reserve (Shropshire), the last sanctuary for the Silver-studded Blue (Plebejus argus) in the Midlands.

Stephen Lewis, Officer at the Prees Heath Reserve, visited the Manchester Museum on 19/12/2014 in order to study historical records of the Silver-studded Blue from the Midlands on the basis of museum specimens.  He also gave us a short interview about the conservation of the Silver-studded Blue in Shropshire (see below).

A more complete story of the Silver-studded Blue butterfly at the Prees Heath Common Reserve presented by Stephen Lewis can be seen in the following short video.

If you are interested in British Butterfly Conservation (the British Butterfly Conservation Society) and their currently formulated strategy for British butterflies please visit the society’s site.

Further reading:

Warren, M.S. 1993. A review of butterfly conservation in Central Southern Britain: I. Protection, evaluation and extinction on prime sites. – Biological Conservation, 64, 25-35; pdf-file online.

Warren M.S., Barnett L.K., Gibbons D.W. & Avery M.I. 1997. Assessing national conservation priorities: an improved red list of British butterflies. – Biological Conservation, 82: 317-328; pdf-file online.

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It is known that during the latest Pleistocene glaciations (2.59-0.01 Million years ago) the territory of Britain, as well as of Ireland and many other territories of the northern hemisphere, were covered by glacier and were uninhabitable for terrestrial fauna. During glaciations animals and birds either migrated southward or died out. Palaeontological and genetic evidence indicates that the majority of the contemporary fauna of Britain arrived from continental Europe dispersing across a land bridge that existed between Britain and mainland Europe during the short period after ice retreat and before it was submerged by rising sea level (ca. 0.45 Mya).

However, surprisingly, there are few British species that were able to survive the latest Ice Ages, for instance, the endemic Groundwater Shrimp (Niphargus glenniei; see on the photos below) currently known from cave ecosystems of Devon and Cornwall only. Another endemic species of the groundwater shrimps, restricted to Ireland, is Niphargus irlandicus. None of these species is known outside southern England and Ireland correspondingly.

Niphargus glenniei, the Groundwater shrimp that is adapted to live in subterranean environments. Shrimps are blind, lack pigmentation and have elongated appendages. Photo credit: Chris Proctor.

Niphargus glenniei, the Groundwater shrimp that is adapted to live in subterranean environments. Shrimps are blind, lack pigmentation and have elongated appendages. Photo credit: Chris Proctor.

As argued by McNerney et al. (2014), the most recent common ancestor of both species and all other Niphargus species (over 300 species distributed in cave ecosystems across Europe) was isolated approximately 87 Million years ago, i.e. during the late Cretaceous period (100–66 Mya). More importantly, that the two endemics (glenniei and irlandicus) should have been where they are now for at least 19.5 Mya and thus they have survived the entire Pleitocene period and many glaciations in the groundwater. This makes both groundwater shrimps the oldest known species of the British fauna.

This story is based on the paper by McNerney et al. (2014), The ancient Britons: groundwater fauna survived extreme climate change over tens of millions of years across NW Europe. Molecular Ecology, 23: 1153-1166; doi: 10.1111/mec.12664

 

 

 

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While travelling from the Town of Stykkishólmur to the Town of Grundarfjördur (road No.54, along the northern coast of Snaefellsnes Peninsula), about half-way, we came across a road sign depicting a shark (see on photo). The information desk below this sign said that there the place Bjarnarhöfn is named after Björn Ketilsson from Norway who settled in here around 900AD and also that there is one of the oldest churches in Iceland built up in 1856-59. Being puzzled we immediately turned to the place and were not disappointed.

The road sing and the building of the Shark Museum at Bjarnarhöfn, Iceland

The road sign and the building of the Shark Museum at Bjarnarhöfn, Iceland

What we found there was one of the most eclectic Museums I’ve even seen, the Shark Museum. The Museum contains all sorts of objects related to every-day life of a small fishing farm in Iceland: anything one can image from the kitchen tools or a gramophone of the early 20th century to taxidermy of Icelandic variety of chickens and models of Viking or more recent fishing boats. However, the main story was about shark fishing and the production of shark meat. The guests of the Museum are met by the friendly curator and owner, known as the famous ‘Shark Man’ Hildibrandur of Bjarnarhöfn. Details of the shark fishing industry (mostly on the large local Greenland shark – Somniosus microcephalus) in Iceland were shown on a big screen, and all the kinds of relevant fishing equipment, from the shark-fishing boat to harpoons and fishing nets, were exhibited on the walls and display cases. Shark-liver oil was once an important export commodity for Iceland. The shark meat was cured with a particular fermentation process to make the notorious Icelandic delicacy known as hákarl (see also here).

The boat and equipment needed for fishing the Greenland shark; the Shark Museum at Bjarnarhöfn, Iceland.

The boat and equipment needed for fishing the Greenland shark; the Shark Museum at Bjarnarhöfn, Iceland.

A variety of museum objects reflecting an every-day life of a shark-fishing village in Iceland, plus something else; the Shark Museum at Bjarnarhöfn, Iceland.

A variety of museum objects reflecting an every-day life of a shark-fishing village in Iceland, plus something else; the Shark Museum at Bjarnarhöfn, Iceland.

We were able to visit the drying house where shark and fish meat is hung to dry for four to five months before use. Shark meat (hákarl) and dried fish (harðfiskur), as well as nice pieces of traditional Iceland knitting, could be purchased from the Museum. We also found out, the owner offers individual/personal guided tours of the Museum. Unfortunately, as he does not speak English, a personal tour was not an option for us.

Drying of shark and fish meet; the Shark Museum at Bjarnarhöfn, Iceland.

Drying of shark and fish meat; the Shark Museum at Bjarnarhöfn, Iceland.

One of the oldest wooden churches of Iceland built up in 1856-59; Bjarnarhöfn, Iceland.

One of the oldest wooden churches of Iceland built up in 1856-59; Bjarnarhöfn, Iceland.

We were more than impressed by the Shark Museum (and the old wooden church, see on photo below), as what we saw was a true authentic story of the life of an individual shark-fishing village told by those who have been involved in their family business for generations. I am sure that the content of this Museum sooner or later will become an essential part of a National Museum of Icelandic Culture and Lore, should such museum be ever organized in Iceland.

Dmitri Logunov (the Curator of Arthropods at the Manchester Museum) and the owner of the Shark Museum,  Hildibrandur of Bjarnarhöfn.

Dmitri Logunov (the Curator of Arthropods at the Manchester Museum) and the owner of the Shark Museum, Hildibrandur of Bjarnarhöfn.

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On the second day of our field trip to Iceland, we visited the interesting site lying in the southern municipality of Reykjavik, called Garðabær, which literally means ‘Garden Town’. We walked around the beautiful Lake Urridavatn surrounded by boggy meadows full of sedge, dwarf bushes (like blue berry) and cotton grass (see on the photo).

Boggy meadow with cotton grass (left) and the blue berry bush (right) near Lake Urridavatn in Iceland

Boggy meadow with cotton grass (left) and the blue berry bush (right) near Lake Urridavatn in Iceland

On the meadow side of the path to the lake we found a plastic cup thrown by someone a few days ago. Incidentally, the cup, which was partly filled with rain water, became a deadly trap to insects and spiders. Having inspected the content of the cup I found two specimens of crab spiders (Xysticus sp.; male and female), one specimen of the ground beetle (family Carabidae) and one harvestman (family Phalangiidae). So, the cup ‘worked’ exactly in the way as true pitfall traps (see also here) that are used by scientists for ecological surveys. A poor thinking or maybe carelessness of someone who threw this plastic cup away instead of dropping it into a waste bin resulted in some casualties of minibeasts. Throwing a plastic cup (or any unwanted plastic item) away is hardly seen as a great deal or an action causing any threat to wild life. However, my short and simple story seems to say otherwise. In simple words, it reminds us that recycling waste is essential to both natural environment and humans, minimizing an unnecessary risk of damage to the environment and helping out our planet be a better place to live in. More about recycling can be seen here and here.

The plastic cup that became a deadly trap to a number of minibeasts near Lake Urridavatn in Iceland. See also a short video below.

The plastic cup that became a deadly trap to a number of minibeasts near Lake Urridavatn in Iceland. See also a short video below.

 

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