Black-tailed gull

The Black-tailed gull (Larus crassirostris) is a species of the order Charadriiformes, family Laridae. While primarily marine feeders, these birds are known to invade agricultural landscapes in coastal areas, effectively becoming pests that disrupt local farming practices and threaten agricultural output.

These gulls target various crops, with a specific preference for young sprouts of grain crops, corn, and sunflowers. By foraging in agricultural fields, they can deplete entire rows of crops, particularly during the critical germination phase, leading to significant stand reduction and potential economic losses for farmers.

The biological cycle of the Black-tailed gull involves intensive nesting and chick-rearing periods. During these stages, the birds' energy requirements increase significantly, driving them to forage in fields near their colonies. Their gregarious social structure means that when a flock finds an attractive food source, the damage to the field can occur rapidly.

The nature of the damage is twofold: direct consumption of seeds and sprouts, and physical damage caused by the gulls trampling over crops during feeding. This reduces the density of the crop stand, necessitating replanting and leading to uneven maturation of the crop. Additionally, their droppings can impact soil chemistry in localized areas.

Management strategies for controlling these birds focus on deterrence rather than eradication. Common methods include the use of bioacoustic devices that broadcast predator distress calls and the installation of visual deterrents such as silhouettes of birds of prey or kite-based scarecrows. Regular monitoring of flock patterns is essential for the timely implementation of these protection measures.