How to get fat: nutritional mechanisms of seasonal fat accumulation in migratory songbirds

Abstract

Many migratory birds accumulate large amounts of lipids as the prime energy source for their long-distance flights. This fat accumulation is mostly under endogenous control, reflecting genetically programmed temporal shifts of the body mass set point. It is accompanied by an increase in daily food intake and food utilisation efficiency and by a seasonal shift in food selection. In particular, seasonal frugivory appears to play a key role in many migrants. Fruits have a high content of fatty acids indispensable for building up the specific depot lipids. In addition, plant secondary compounds seem to play some kind of supportive role, but the mechanisms are not yet known. The effect of being fat on the metabolic situation in migrant birds appears to be similar to the metabolic syndrome in obese humans. The fat migratory bird provides a model through which to study nutritional factors as well as the biochemical and endocrine regulation of food intake, body mass and obesity.

Characterization of meat from two game birds: thrush (Turdus philomelos) and turtle dove (Streptopelia turtur) Caracterización de la carne de dos aves de caza: zorzal (Turdus philomelos) y tórtola (Streptopelia turtur)

“…This is probably because the thrush and the turtle dove are migratory birds and these birds accumulate large amounts of lipids as the prime energy source for their long-distance flights (Bairlein, 2002). Notas: NS, no significativo; ND, no detectado; SFA, a´cidos grasos saturados; MUFA, a´cidos grasos monoinsaturados; PUFA, a´cidos grasos poliinsaturdos.…”

Obese super athletes: fat-fueled migration in birds and bats

“…The deposition of fat and the alteration of the fatty acid composition of fat stores of migratory birds are achieved through changes in both physiology and behavior (Bairlein, 2002;Berthold, 1993;Biebach, 1996;Newton, 2008). During the migratory phase, birds become hyperphagic, typically eating 20-40% more food than maintenance levels (Bairlein, 2002) and gaining mass at a rate of ∼1-7% of lean body mass per day (Alerstam and Lindström, 1990;Lindström, 1991).…”

“…During the migratory phase, birds become hyperphagic, typically eating 20-40% more food than maintenance levels (Bairlein, 2002) and gaining mass at a rate of ∼1-7% of lean body mass per day (Alerstam and Lindström, 1990;Lindström, 1991). However, when food and foraging time are unlimited, migratory birds are capable of increasing food intake by three-to fivefold, reaching a gluttonous energy assimilation rate of up to 10 times BMR and gaining mass at a rate of 15% or more of lean body mass per day Lindström, 2000, 2003).…”

“…Many excellent reviews summarize aspects of fat storage and utilization in migratory birds (Bairlein, 2002;Berthold, 1993;Biebach, 1996;Blem, 1976Blem, , 1980Guglielmo, 2010;Jenni and Jenni-Eiermann, 1998;McWilliams et al, 2004;Newton, 2008;Pierce and McWilliams, 2014;Price, 2010;Ramenofsky, 1990;Weber, 2009), with occasional information on bats (Blem, 1980;Fleming and Eby, 2003;McGuire and Guglielmo, 2009). The purpose of this Review is to use recent findings to compare the role of fat as a fuel for migration of birds and bats.…”

Time trends (1993–1997) and seasonal variation in body mass index and waist circumference in the Netherlands

“…From a Northern, cross-sectional study, it was suggested that seasonal variation in testosterone levels may be associated with seasonal differences in abdominal obesity, although the potential aetiology was not clear. 28 Animal studies suggest a role of daylight via the neurohormone melatonin, 29,30 and also leptin, PPRg 31 and cholecystokinin 32 may have a photosensitive influence on food intake. However, the seasonal variation in body weight in animals is opposite to the variation in body weight found in affluent human populations who have a yearlong access to foods.…”