Investigating the cognitive underpinnings, behavioural development and fitness consequences of urban life in herring gulls

Lead Research Organisation: University of Exeter
Department Name: Biosciences

Abstract

Human-wildlife conflict is rife in coastal towns such as Falmouth and St. Ives, where herring gulls are often perceived to cause major disturbances in the form of noise, excrement and human food theft. While herring gull populations are in national decline, the public perception is that they are thriving in coastal towns. Surprisingly, it is not known whether herring gulls that breed and forage in coastal towns are actually thriving, or just making the best of a bad situation. In addition, to date no research has been conducted on whether and how gulls may learn to exploit human foods, whether this is a specialist and adaptive, or merely opportunistic and last-resort type of foraging strategy, and whether urban dwellers produce urban-dwelling offspring. This project will investigate the cognitive underpinnings, behavioural development and fitness consequences of urban life in herring gulls - a species considered a pest while of major conservation concern in the UK.

This PhD project will increase our understanding of how behavioural plasticity and cognitive adaptations allow herring gulls to survive and thrive in anthropogenic habitats by addressing the following questions:
a) How do herring gulls adjust their behaviour to exploit human food sources? Do gulls change their foraging movements to match fluctuations in human food availability? For example, do gulls switch from foraging at sea to towns during the tourist season or on rubbish collection days, and do they pay attention to human identity and gaze direction when attempting to steal food? These questions will be addressed by using GPS tags to quantify daily and seasonal foraging routines, and by conducting individual-level cognitive tests of memory and learning about anthropogenic cues.
b) How do herring gulls acquire their foraging strategies? Do gull chicks copy their parents by following them after fledging, do they learn about foods through parental provisioning in the nest, and/or is the egg yolk composition of urban gulls different from those of rural gulls? These questions will be addressed by comparing urban and rural egg yolk and chick feather composition through stable isotope analyses, and conducting cross-fostering experiments to test the relative contributions of genetic and environmental factors in driving foraging strategies. The student will also conduct social learning experiments to test whether juveniles copy their parents' solutions to novel food puzzles.
c) How do herring gull foraging strategies affect their survival and reproductive success? Do urban herring gulls have higher or lower reproductive success than those breeding in more natural habitats, and is this influenced by dietary intake of human foods? These questions will be addressed by tracking the reproductive success of gulls in urban and rural areas and relating individuals' foraging strategies to their reproductive output.

Publications

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