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Posts Tagged ‘environment’

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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Writing a poem seems to be a mystery for many people, and it is indeed an act of creativity by those who are able to observe the world within or around them and to perceive it in a new way. A poem can be about anything, from old love memories to a crawling bug; it is about capturing a feeling that you have experienced. However, it’s hard to know where you should start. Helen Clare, a freelance writer and poet from Manchester, presents a possible approach to how to write a poem on the basis of, say, a visit to the Manchester Museum. If you want to know how to write a poem, this story is for you.

Below you can listen to the poem narrated and presented by Helen Clare. The printed text of the poem can be found 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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A new photographic exhibition devoted to complex interrelations of humans and neotropical nature has been opened on the 3rd floor of the Manchester Museum. A brief Summary of the exhibition is given below:

The Ecuadorian Amazon is one of the most endangered regions of our planet. Many people want to protect the biodiversity that remains, but the reality on the ground is a complex dilemma. Economic necessity means that trees are valued for their timber more than for their crucial role in the ecosystem. Scientist and photographer Johan Oldekop, who was originally trained as a biologist at the University of Manchester (UK), studied the complex interaction between social and conservation issues in Ecuador during 2006-2011. As a scientist, Johan is interested in the socio-economic factors and land-use in indigenous Kichwa communities and their effect on the biodiversity of Ecuadorian Amazon. This exhibition presents his findings through his own stunning photographs combined with specimens from the Manchester Museum’s entomology and botany collections.

The exhibition will be opened until the beginning of June, 2013. Everyone is welcome!

Here are a few shots taken just after the opening of this exhibition.

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