Nest trampling and ground nesting birds: Quantifying temporal and spatial overlap between cattle activity and...

Area of Science:

• Ecological management
• Avian conservation
• Livestock grazing impacts

Background:

• Common redshank (Tringa totanus) populations on UK saltmarshes have declined over 50% since 1985, linked to grazing management changes.
• Light grazing (<1 cattle/ha) is recommended for conservation, but can cause significant nest trampling.
• Livestock distribution, not just density, impacts nest trampling rates, especially when concentrated in breeding areas.

Purpose of the Study:

• To quantify cattle spatial-temporal distribution relative to redshank nesting habitats.
• To assess nest trampling rates based on livestock presence and habitat use.
• To inform grazing management strategies for redshank conservation on saltmarshes.

Main Methods:

• GPS tracking of cattle on saltmarshes to monitor their distribution.
• Deployment of dummy nests to quantify trampling rates.
• Analysis of livestock movement patterns in relation to redshank breeding zones.

Main Results:

• Cattle distribution varied significantly by season and saltmarsh, utilizing 3-42% of area and favoring higher elevations near sea walls.
• Cattle moved further onto saltmarshes as the season progressed, coinciding with redshank nesting periods.
• Nest trampling probability was up to six times higher in redshank breeding areas due to spatial-temporal overlap with cattle.

Conclusions:

• Standard cattle density measures underestimate nest trampling risk in redshank breeding habitats.
• Grazing management must consider livestock distribution to mitigate nest trampling.
• Delaying grazing or implementing rotational systems to avoid mid-April to mid-July nesting periods is crucial for redshank conservation.