Is your garden bumblebee-friendly?

It is likely to come as a surprise to most non-entomologists that there are around 250 species of bumblebee, and that the UK has 24 native bumblebee species including the rare Shrill Carder Bombus sylvarum  and Great Yellow Bombus distinguendus, both of which are under threat of national extinction (two other species have gone extinct in the UK in the last 70 years).

Aside from providing us with honey and wax, bees and many other insect perform an essential ecosystem function estimated to be worth $14.2 billion in 2005 within the EU25 countries – the pollination of our crops and other plants. In addition, some wild plant species can only be pollinated by bumblebees. Changing land use, however (such as the cessation of crop-rotation, destruction of hedgerows, and increased use of pesticides), has put many pollinators under threat, and bumblebees are no exception.

Although each nest contains 50-400 bumblebees, the effective population (which only counts those members that can breed and so contribute directly to the next generation) is only around 1.5 per nest, because the queen bumblebee is the only members of the nest who can produce offspring (and she is fertilised by a single male who has just one set of chromosomes, termed haploid). Bumblebees eat pollen and nectar and where their preferred plants are at low density their nests can be sparsely distributed, resulting in low effective population densities in many preserved area, that are not self-sustainable in the long-term.

Conservationists, therefore, have realised we cannot rely solely upon nature reserves to keep bumblebee species extant (surviving). For once, each one of us who owns a garden or allotment can make a direct and significant contribution to conservation by planting bee-friendly plant species, such as heather, foxglove and lavender – and as bees are umbrella species, simultaneously you will be conserving less pretty, but no less deserving, other bugs.

Find out more about what you can do personally to keep our bumblebee species alive at The Bumblebee Conservation Trust – you can even contribute to science by reporting which bumblebee species visit your garden.

References

Goulson D et al. 2011. Translating research into action; bumblebee conservation as a case study. Journal of Applied Ecology 48: 3-8

Further Information

– The Bumblebee Conservation Trust 
– BugLife
– Hymettus Ltd
– Bees, Wasps and Ants Recording Society
– Xerces Society
– Bumblebee.org
– Bees and Chicks
– Bumblebee videoclips – BBC

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Research News: Pandas prefer old forests

The giant panda (Ailuropoda melanoleuca) is one of conservation’s icons, but these bears are secretive and their ecological needs are not well understood. Scientists have long known that panda populations are strongly associated with bamboo (no surprise, as bamboo is the only food that giant pandas eat); however, new analysis of a large dataset of giant panda habitat-use has shown that they also prefer old-growth forest. In fact, after bamboo, old forest is their second strongest habitat association, and this preference is substantially stronger than their link with other factors previously deemed important for pandas, such as slope, canopy cover, and altitude.

Knowledge of an animal’s habitat requirements is vital to ensure that preserved areas, such as nature reserves, contain sufficient correct habitat to allow a sustainable population to survive. This research demonstrates that secondary forest (forest that has been felled and then allowed to grow back) is not equal to pristine forest when viewed by a panda, and that primary forest is essential to the continued conservation of the giant panda.

Reference

Zhang Z et al. 2011. Old-growth forest is what giant pandas really need. Biology Letters 10.1098/rsbl.2010.1081

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Research News: one-fifth of world’s vertebrates are threatened with extinction

The IUCN (International Union for Conservation of Nature) compiles a ‘Red List’ where each species is described and their status classified – from Critically Endangered (50%+ probability of extinction within 10 years or 3 generations (whichever is longer)) through Endangered (20% probability of extinction within 20yrs or 5 generations) and Vulnerable (probability of extinction of 10% within 100yrs) to Near Threatened and Least Concern (Fig 1).  A paper by Hoffmann et al (2010) published in Science today has analysed this data on 25,780 species of the world’s vertebrates (all mammals, birds, amphibians, and cartilaginous fish (sharks and rays), and most reptiles and bony fish) and found that one-fifth of Earth’s vertebrates are Threatened and that this figure is increasing yearly.

Figure 1. Red List categories (from IUCN website)

This is sad, but not wholly unexpected news – after all, although extinctions have always happened in our planet’s history, the current levels are 100-1000 times above pre-human rates (Pimm et al 1995) and it’s well known that a vast number of species are in trouble. Fortunately it’s not all bad news as Hoffman’s study also demonstrates that conservation does work and, although current levels of conservation are not enough to overcome the significant threats to animals, there have been successes with species being downgraded in recent time due to the efforts to conserve them. Hoffmann mentions that the Humpback Whale Megaptera novaeangliae has moved from Vulnerable to Least Concern since the commercial whaling ban in 1955, and Butchart et al (2006) calculated that between 1994 and 2004 at least 16 bird species were saved from extinction by the conservation programmes implemented for them; so a turn-around of the extinction trend is possible with concerted effort, political will, and public support.

With Hoffmann concluding that, on average, 52 species move one category closer to extinction each year, the time for us all to take action is now.

References and Further Info

Butchart SHM et al 2006. How many bird extinctions have we prevented? Oryx 40: 266-278

Hoffmann M et al 2010. The impact of conservation on the status of the World’s vertebrates. Science – published online 26 Oct 2010 (doi 10.1126/science.1194442)

IUCN Red Data category specifications

Pimm SL et al 1995. The future of biodiversity. Science 269: 347-350

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