Great shearwater

The Great shearwater (Ardenna gravis, formerly Puffinus gravis) is a seabird belonging to the order Procellariiformes, family Procellariidae. While primarily an oceanic species, its interaction with coastal agricultural lands in certain regions creates specific management challenges for local farmers and agronomists.

In an agronomic context, the damage is primarily physical. During the breeding season, great shearwaters dig burrows in soft soils, which undermines root systems of young crops and grasses. This activity leads to uneven soil compaction and creates surface instability, which hampers the efficiency of heavy agricultural machinery used in field cultivation.

The biology of the species involves high colony site fidelity. During the nesting period, the sheer density of birds leads to an excessive accumulation of guano. This high nitrogen concentration can cause chemical stress or phytotoxicity in delicate crop species, negatively affecting the overall vigor and physiological development of the plants.

The damage profile includes both direct mechanical destruction and indirect chemical degradation of the soil profile. Fields adjacent to major nesting colonies are particularly at risk, experiencing stunted growth and reduced yields. The localized nature of these colonies means that damage is often concentrated in specific zones, requiring targeted interventions.

• Installing exclusion fencing to prevent bird movement.
• Deploying acoustic deterrents and predator decoys.
• Implementing buffer zones between nesting grounds and crops.
• Regular soil testing to manage nitrogen levels caused by guano.

Control measures must be carefully managed to adhere to conservation regulations while protecting agricultural productivity. Integrated pest management (IPM) strategies for this species focus on site-specific physical barriers and non-lethal deterrents, ensuring that farms remain operational without disrupting the wider ecological balance of the coastal area.