Glossy ibis

The Glossy ibis (Plegadis falcinellus) is a wetland bird species belonging to the Threskiornithidae family. While protected in many jurisdictions due to its conservation status, it is recognized by agronomists as a potential pest in intensive rice cultivation regions, where its feeding habits intersect with human agricultural activities.

The biology of the Glossy ibis is centered on marshy environments. These birds are migratory and colonial breeders. Their life cycle includes nesting in reed beds, followed by a post-breeding dispersal period where large groups of adults and juveniles forage in shallow, waterlogged areas, such as flooded rice paddies, looking for invertebrates and grains.

The damage caused to agriculture is primarily mechanical. As the birds forage, they trample newly emerged rice seedlings and consume germinating seeds. This destruction of the crop stand leads to significant patchiness, reduced plant density, and ultimately lowers the harvest yield of the affected rice fields.

The pest pressure is most intense during the early growth stages of the rice crop. Because the birds are highly mobile and social, a single flock can destroy a substantial portion of a field in a very short amount of time, especially in areas where irrigation canals provide easy access to the paddies.

To mitigate the impact of the Glossy ibis without harming the birds, farmers employ various non-lethal deterrents:

• Deployment of visual deterrents like holographic tape and effigies.
• Use of bioacoustic devices that emit predator calls or distress signals.
• Water level management to make fields less attractive during the germination phase.
• Active field monitoring to prevent large flocks from settling in vulnerable areas.