Habitat use of urban-nesting lesser black-backed gulls during the breeding season

Abstract

Increasing urbanisation is detrimental for some animal species and potentially advantageous for others. Urban-nesting populations of gulls have undergone rapid population increases worldwide, which has resulted in an increase in human-gull conflicts. In order to inform management and conservation decisions in relation to these populations, more information is needed about the behaviour of these birds in urban settings and how they utilise their environment. This study combined Global Positioning System (GPS) tracking data of 12 urban-nesting lesser black-backed gulls, Larus fuscus , with habitat and behaviour data over three breeding seasons (2016–2018). Despite the proximity of marine areas (~10 km), the birds only made significant use of terrestrial environments, spending two-thirds of their time away from the nest in suburban and urban areas, and one-third in rural green areas. The gulls utilised suburban and urban areas more as their chicks grew and appeared to use diverse foraging strategies to suit different habitats. These results indicate that the range of potential foraging areas available needs to be considered in management decisions and that urban bird populations may not use the resources they are expected to.

Dynamic Space Use of Andalusian Rice Fields by Overwintering Lesser Black-Backed Gulls is Driven by Harvest-Related Flooding

“…From December onwards, many of these LBBG disperse to other areas of Andalusia outside of the rice eld landscape where they forage in land lls and roost in reservoirs and natural lakes (Martín-Vélez et al 2019, 2020, this study). Accelerometer data indicate that the gulls spend most of their overwintering time budget resting in water bodies inside and outside the rice eld complex, at similarly high proportions as gulls in the breeding season (Spelt et al, 2019). This aligns well with other observations that gulls prefer to sleep and rest in open water (Baker, 2009;Clark et al, 2016), although especially during the harvesting phase gulls also often rested on dikes in the rice eld complex.…”

“…The strong selection for rice paddies during active harvest in combination with the presumably unchanging availability of alternative resources (land lls) strongly suggest that changing conditions in rice paddies ( This implies there were no substantial differences in the bird's dietary or metabolic needs during the overwintering season, and that changes in behavior are driven by harvest dynamics and the resulting shifts in resource availability within rice paddies. This consistency in behavioral frequency across the overwintering season also contrasts strongly with studies on breeding gulls, which show substantial shifts in time-activity budgets over the course of the breeding season (Spelt et al, 2019).…”

“…These changes correspond with three phases of the harvest cycle, and the spatiotemporal patterns of abundance. They are likely driven by the availability of spatial resources (i.e., foraging and roost sites), speci cally with respect to the proximity and reliability of food resources, a major driver of LBBG space use in anthropogenic landscapes during the breeding season (Spelt et al, 2019). These patterns were highly consistent among sampled individuals and were strongly supported by eld observations of abundance and behavior during the same and different years.…”

Bird-inspired Velocity Optimization for UAVs in the Urban Environment

“…All work was approved by the University of Bristol Animal Welfare and Ethical Review Body (UIN: UB /15/069). Bird handling and tagging was conducted under BTO permit A /2831, additional details can be found in [11]. Bio-metrics for the individuals were recorded at the time of capture used to characterize the morphology based aerodynamics of an average individual, as found in table 2.…”

“…Birds of comparable size and weight to small SUAVs are able to navigate the complex city wind flows and exploit the environment to reduce the energetic cost of flight. During the breeding season, urban gulls spend up to 40% [11] of their time in flight, flying to and from foraging locations through these complex wind-scapes. Choosing appropriate flight strategies has the potential to substantially reduce their energetic flight costs and could be key for breeding success.…”