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Providing evidence to improve practice

Individual study: The effects of reseeding on the use of grasslands by wintering barnacle geese Branta leucopsis at Loch Gruinart RSPB reserve, Islay, Strathclyde, Scotland

Published source details

Percival S.M. (1993) The effects of reseeding, fertilizer application and disturbance on the use of grasslands by barnacle geese, and the implications for refuge management. Journal of Applied Ecology, 30, 437-443


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Re-seed grasslands Bird Conservation

A replicated, controlled trial in 1984-7 on a reserve on the island of Islay, west Scotland (Percival 1993), found that more barnacle geese Branta leucopsis used wet pasture fields if they were reseeded, compared to if they were fertilised or untreated (reseeding increased dropping density by 60-135%; fertilisation by 17-42%, but not in all fields or years). The effect of reseeding declined over time, and as the overall area of rotational grassland on the reserve increased. Reseeding consisted of ploughing fields and sowing with a perennial rye-grass Lolium perenne dominated seed mix in May.

 

Provide ‘sacrificial’ grasslands to reduce the impact of wild geese on crops Bird Conservation

A replicated, controlled trial in 1984-7 on a reserve on the island of Islay, west Scotland (Percival 1993), found more barnacle geese Branta leucopsis used wet pasture fields if they were re-seeded or fertilised than if they were unmanaged. However, increases were due to a redistribution of local birds, rather than new birds visiting the reserve. The author therefore suggests that improving the reserve grasslands will only minimally reduce conflict with farmers elsewhere on the island. The details of management interventions are discussed in ‘Re-seed grasslands’ and ‘Fertilise grasslands’.

 

Fertilize artificial grasslands Bird Conservation

A replicated, controlled study in 1984-1987 on a reserve on the island of Islay, west Scotland (Percival 1993), found that more barnacle geese Branta leucopsis used wet pasture fields if they were fertilised, compared to control fields (17-42% higher dropping densities in fertilised fields, but not in all fields or years). However, fewer geese used fertilised fields than re-seeded ones. Fertilisers were either 34.5% nitrogen in pellet form (at 125 kg/ha), or ‘Nitrochalk’ – 25% nitrogen in granular form – (at 175 kg/ha) and spread in October (wet and dry fields) and March (dry fields only).

 

Provide 'sacrificial' grasslands to reduce the impact of wild geese on crops Farmland Conservation

A replicated, controlled trial in 1984-1987 on a reserve on the island of Islay, west Scotland (Percival 1993) found more barnacle geese Branta leucopsis used wet pasture fields if they were re-seeded or fertilized than if they were unmanaged. However, fewer geese used fertilized fields than re-seeded ones. Fertilizers were either 34.5% nitrogen in pellet form (at 125 kg/ha), or ‘nitrochalk’ – 25% nitrogen in granular form – (at 175 kg/ha) and spread in October (wet and dry fields) and March (dry fields only). However, increases in barnacle geese were due to a redistribution of local birds, rather than new birds visiting the reserve. The author therefore suggests that improving the reserve grasslands will only minimally reduce conflict with farmers elsewhere on the island.