Cognitive Research on a Well-known, but not Well-liked Waterbird: the Seagull

Hi, my name is Lucas, a 4th-year B.Sc. (Honours) student in Psychology at the Memorial University of Newfoundland. Throughout my degree, I have gained a passion for animal behaviour, a fascinating field of psychology that many students have not heard of. In the summer before the 3rd year of my degree, I started a summer research position with Dr. David Wilson, Department of Psychology, and Ms. Jessika Lamarre, Cognitive and Behavioural Ecology Program, who exposed me to the wonders of animal cognition in seabirds. And, ever since, I have been hooked on seabird research. 

Lucas and the Nesting Ring-billed Gulls in Spaniard’s Bay, NL.

Many waterbirds have been noted to engage in behaviours indicative of higher cognitive abilities, such as tool use. Tools, in animal behaviour, are inanimate objects that are not of internal manufacture and are used to alter the position or form of an object in the environment.  For example, Henry and Aznar (2006) noted tool use in Herring gulls (Larus argentatus). The researchers observed a Herring gull engaging in bait-fishing, in which the animal used bread to attract and kill a Goldfish (Carassius auratus). Moreover, Lamarre and Wilson (2021) observed that 25% (26/104) of Ring-billed gulls (Larus delawarensis) successfully solved a simplistic string-pull test, a foraging puzzle in which food is visible to an animal but can only be obtained by pulling a string attached to the food reward.

The String-Pull test Set-up Utilized by Lamarre and Wilson (2021). The Puzzle Depicted in (a) was used by Dr. Wilson and myself for the First Six Trials we Conducted.

This summer, Dr. Wilson and I conducted field research on four colonies of Ring-billed gulls (Larus delawarensis) in Newfoundland. The four colonies are divided into two broad categories: urban and rural. Notably, birds nesting in urban colonies feed on anthropogenic food sources, such as garbage and agricultural waste; however, birds nesting in rural colonies tend to feed on fish and aquatic invertebrates (Lamarre and Wilson, 2021). In May, Dr. Wilson and I collected the first laid egg in two-egg nests to analyze omega-3 and stress hormone contents within the egg yolk and quantify the eggs’ colours using a spectrophotometer, an instrument designed for physical sample analysis through full spectrum colour measurement.

Eggs Collected from Two-egg Nests in Spaniard’s Bay, NL. Note the Variety in Colour!

Then, we conducted 18 string-pull tests on each nest we took eggs from to assess the cognitive abilities of the gulls. We performed three forms of the string pull test: each retaining six trials and increasing problem-solving difficulty. The first form consisted of a single string attached to a single food reward in a petri dish. The second form consisted of two petri dishes, one with a food reward and one without, and two uncrossed strings. Lastly, the third form resembled the second form; however, the strings attached to the petri dishes were crossed. The results of the string-pull tests were exciting; as some birds solved the puzzle instantly, others learned to solve it, and many did not even attempt to solve the puzzle. Ultimately, our goal is to test the relationship between the eggs’ contents and colours and the parental unit’s cognitive abilities.

Observing the birds in their breeding colonies with hundreds of nesting neighbours significantly changed my perspective on seagulls and their importance in aquatic environments. Many people consider seagulls pests; however, in their natural habitat, they are elegant creatures who display complex behaviours.

Headshot of a Ring-billed gull Nesting in Long Pond, CBS, NL.

For example, they do not hesitate to mob, swoop, and ‘scream’ at predators near their nests. There were many occasions when I was almost hit by an angry gull. Furthermore, the Ring-billed gulls are cannibalistic and will depredate eggs of neighbouring nests and freshly born chicks. Despite their cannibalistic tendencies, their chicks are adorable and fluffy. Coming back to the colony daily and seeing a new chick in a nest always made me smile and appreciate their role in the ecosystem.

Three Newborn Ring-billed Gull Chicks from the Colony on Old Perlican Island, NL.

References

Henry, P.-Y., & Aznar, J.-C. (2006). Tool-use in charadrii: Active bait-fishing by a herring gull. Waterbirds, 29(2), 233–234. https://doi.org/10.1675/1524-4695(2006)29[233:ticabb]2.0.co;2

Lamarre, J., & Wilson, D. R. (2021). Waterbird solves the string-pull test. Royal Society Open Science, 8(12). https://doi.org/10.1098/rsos.211343

Other Readings

Lamarre, J., Cheema, S. K., Robertson, G. J., & Wilson, D. R. (2021). Omega-3 fatty acids accelerate fledging in an avian marine predator: A potential role of cognition. Journal of Experimental Biology, 224(4). https://doi.org/10.1242/jeb.235929

Lucas is participating in and prepared this blog post for our CaNOE Currents program. For more info on how to get involved in CaNOE Currents head to https://oceanliteracy.ca/canoe-currents/