The common term “seagull” is not a specific biological species but rather a colloquial name used to describe numerous bird species within the Laridae family, generally referred to as gulls. This family encompasses roughly 50 different species worldwide, and their conservation status is complex and varies significantly by species and geographic location. While many gulls are abundant, most are currently not endangered. However, many populations are experiencing substantial declines that contradict the public perception of them as overly numerous birds.
The Conservation Status of Gulls
The official conservation status of gulls is assessed by the International Union for Conservation of Nature (IUCN) Red List, which uses scientific criteria to categorize species globally. The majority of the world’s gull species, including widely distributed ones like the Ring-billed Gull and the common Herring Gull, are categorized as “Least Concern.” This designation suggests that these populations are stable enough worldwide to not face an immediate threat of extinction.
However, conservation status is highly species-specific and geographically dependent. Only one species, the Black-billed Gull, is listed as “Endangered” globally, while a small number of others, such as Audouin’s Gull, are classified as “Vulnerable” or “Near Threatened.” The global status often masks significant regional crises; the Herring Gull, despite its global “Least Concern” rating, has been placed on the Red List in the UK due to severe population crashes.
Key Factors Driving Population Shifts
The widespread declines observed in many gull populations are driven by large-scale ecological changes affecting their traditional marine and coastal habitats. A major pressure is the reduced availability of natural food sources, often linked to changes in commercial fishing practices. Gulls historically relied heavily on discarded fish scraps and offal, but stricter regulations and more efficient processing at sea have eliminated much of this reliable food source.
Habitat destruction and shifting land use are also impacting nesting and foraging grounds. The continued development of coastal areas reduces the number of safe, undisturbed sites where gulls can breed successfully. Climate change represents a long-term threat, as warming ocean waters alter the distribution and abundance of the small, surface-schooling fish that form the base of many gulls’ diets.
Disease outbreaks have recently contributed to sharp population drops in several species. Highly pathogenic avian influenza (HPAI), or bird flu, has caused mass mortality events in some colonies. Research comparing pre- and post-outbreak surveys shows significant local declines resulting from these broad environmental and health pressures.
The Relationship Between Gulls and Human Environments
The public often perceives gulls as ubiquitous due to the artificial boost in certain populations that have adapted to human-dominated environments. These generalist species, such as Herring Gulls and Lesser Black-backed Gulls, utilize urban areas for two primary advantages: a steady, accessible food source and safe nesting sites. They have become expert scavengers, exploiting waste at open landfills, harbors, and city streets.
Many gulls have capitalized on man-made structures for breeding. They nest on rooftops in towns and cities, which offer a secure platform free from ground predators like foxes and rats that might plague coastal colonies. This shift to urban nesting has led to localized population increases and high visibility, even as the species’ overall numbers are falling in their traditional coastal habitats.
This adaptation, however, creates a new type of vulnerability when local management strategies change. The closure of open landfills, for example, removes a major, reliable food source for urban-adapted gulls, forcing them to increase their foraging effort or abandon the area entirely. This can lead to decreased body condition and reduced breeding success, demonstrating that the abundance of gulls in cities is often a fragile, human-subsidized phenomenon.