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May

21

2007
 
 

Scrambled organic eggs



Switch to organic farming could present bird species with additional hazards organic farms: eggcellent idea?What could be safer than life on an organic farm? If you’re a ground-nesting bird, such as the common but declining European lapwing Vanellus vanellus, the answer is plenty. Drawn by the lack of pesticides and herbicides, the lapwing’s chicks suffer the consequences of chemical-free farming. Steven Kragten and Geert De Snoo, environmental scientists at Leiden University, Netherlands, carried out a pairwise survey of lapwing nest success on organic and conventional farms. Writing in Ibis, they note that despite the greater density of nests on organic farms, nest success per 100 hectares – the bottom line as far as a bird’s survival goes – was roughly the same as on conventional farms. Shunning herbicides, organic farmers resort to mechanical methods of weed removal: the ensuing mêlée of whirring blades and crushing rollers means all to many nests meet a sticky end. Other ground-nesting species including skylark Alauda arvensis, yellow wagtail Motacilla flava and stone curlew Burhinus oedicnemus could also be vulnerable. The green life ain’t the simple life. Source: Kragten S & De Snoo GR (2007) Nest success of lapwings Vanellus vanellus on organic and conventional arable farms in the Netherlands. Ibis DOI: 10.1111/j,1474-919x.2007.00702.x Image © Kurt Hahn

Filed Under Economics and conservation, Habitat, Monitoring, Restoration, Socio-political issues | 1 Comment

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Apr

24

2007
 
 

Passage to freedom



Long distance bird migrants could be just the ticket for invading plants to hitch a ride Swallow, transport and fertilize!Barn swallows Hirundo rustica are helping spread the invasive rooikrans Acacia cyclops throughout the Fynbos Biome, South Africa, a recent study reports. Writing in Ibis, Cape Town University scientists Les Underhill and Jan Hofmeyr describe how the birds – typically associated with aerial insect predation – were seen consuming the native Australian plant’s conspicuous and abundant seeds. Because of the large distances covered by swallows, the seeds – once expelled in their own little blob of “fertilizer” – could spread the advance of the unwanted alien plant at an unprecedented rate. Underhill and Hofmeyr emphasize the urgent need to eradicate rooikrans from the Fynbos, even though the data they present are over eighteen years old! Source: Underhill LG & Hofmeyr (2007) Barn swallows Hirundo rustica disperse seeds of Rooikrans Acacia Cyclops, an invasive alien plant in the Fynbos Biome. Ibis DOI: 10.1111/j.1474-919x.2006.00598.x Related story in Conservation magazine: Aliens Among Us Image © Arpad Benedek

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Mar

23

2007
 
 

Our fault again



Left a bit, right a bit, straight on...Bird migration routes don’t chart the spread of avian influenza, roads do Avian influenza H5N1 might be on its way to a farm near you, but the chances are it won’t be delivered by migrating wild birds, according to a review of the evidence published this week in Ibis. Michel Gauthier-Clerc, an ecologist at the Station Biologique de la Tour du Valat, France, and colleagues argue against the hypothesis that “bird ’flu” is spread by migrating birds: the recorded disease outbreaks just don’t match migration routes that take in south-east Asia. Instead, the most likely cause is the movement of poultry – both legal and otherwise – along trade routes. The trafficking of large numbers of wild birds for the pet trade, in particular between Asia and Europe, opens another potentially devastating route for the disease. So ask yourself a question: do you really need that extra pet Steller’s sea eagle? Source: Gauthier-Clerc M, Lebarbenchon C & Thomas F (2007) Recent expansion of highly pathogenic influenza H5N1: a critical review. Ibis DOI: 10.1111/j.1474-919x.2007.00699.x Image © Shane Link Related story in Conservation magazine: No easy way out

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