Omega-3 fatty acids accelerate fledging in an avian marine predator: a potential role of cognition

Abstract

Consuming omega-3 fatty acids (n3-LCPUFAs) during development improves cognition in mammals, but the effect remains untested in other taxa. In aquatic ecosystems, n3-LCPUFAs are produced by phytoplankton and bioaccumulate in the food web. Alarmingly, the warming and acidification of aquatic systems caused by climate change impair n3-LCPUFA production, with an anticipated decrease of 80% by the year 2100. We tested whether n3-LCPUFA consumption affects the physiology, morphology, behaviour, and cognition of a top marine predator's chicks, the ring-billed gull. Using a colony with little access to n3-LCPUFAs, we supplemented siblings from 22 fenced nests with opposite treatments from hatching until fledging; one sibling received n3-LCPUFA-rich fish oil and the other, a control sucrose solution without n3-LCPUFAs. Halfway through the nestling period, half the chicks receiving fish oil were switched to the sucrose solution to test whether n3-LCPUFA intake remains crucial past the main growth phase (chronic versus transient treatments). Upon fledging, n3-LCPUFAs were elevated in the blood and brains of chicks receiving the chronic treatment, but were comparable to control levels among transient chicks. Across the entire sample, chicks with elevated n3-LCPUFAs in their tissues fledged earlier despite their morphology and activity levels being unrelated to fledging age. Fledging required chicks to escape fences encircling their nest. We therefore interpret fledging age as a possible indicator of cognition, with chicks with improved cognition fledging earlier. These results provide insight into whether declining dietary n3-LCPUFAs will compromise top predators' problem-solving skills, thus, their ability to survive in a rapidly changing world.

Maternal diet influences fecundity in a freshwater turtle undergoing population decline

“…However, this study does not take into account the proportions of inorganic ions such as calcium, sodium, magnesium or iron, which constitute 5% of an eggs composition ( Thompson et al., 2000 ), or the proportions of specific amino or fatty acids ( Speake and Thompson, 1999 ; Thompson et al., 2000 ). Elevated levels of omega-3 fatty acids in particular increased cognitive maturation in ring-billed gulls ( Larus delawarensis ), which led to earlier fledging ( Lamarre et al., 2021 ). Further research should examine the proportion of these additional macro- and micronutrients in eggs to determine whether maternal diet is influencing egg composition and potentially hatchling size and physiology at a scale not studied here.…”

Temporal trends of essential omega-3 fatty acids in Atlantic and Pacific food webs as measured in eggs of Leach’s storm-petrel Oceanodroma leucorhoa

“…Based upon the results presented here, there is no evidence to suggest that declines in n-3 HUFA availability during the period of egg formation has played such a role. Another aspect that needs to be considered, however, is n-3 HUFA availability during the chick growth and fledging periods, as adequate supplies of these essential nutrients are critical for development in birds (Twining et al 2016b, Lamarre et al 2021. Worldwide, many factors are affecting petrel populations and diverse conservation actions are required (Rodríguez et al 2019).…”

Experimental evidence that EPA and DHA are dietary requirements in a migratory shorebird, but they do not affect muscle oxidative capacity

“…We did not separate the lipid fractions of adipose because the fatty acid profile of the total lipids is almost entirely reflective of the neutral lipid fraction ( Klaiman et al, 2009 ). We also analysed fatty acid composition of brain total lipids to maintain continuity with previously published data in birds ( Lamarre et al, 2021 ; Twining et al, 2016 ).…”