Sex differences in digestive traits in sexually size-dimorphic birds: Insights from an assimilation efficiency experiment on Black-tailed Godwit

Santiago‐Quesada, Francisco; Masero, José A.; Albano, Noelia; Villegas, Auxiliadora; Sánchez‐Guzmán, Juan M.

doi:10.1016/j.cbpa.2009.01.001

Cited by 25 publications

(24 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In black-tailed godwits, females (the larger sex) should experience higher food demands [16] and, despite also having slightly higher energy assimilation efficiency [52], might still need to forage upon more energetic, on larger prey and/or for longer periods than males. Secondly, longer-billed females can access deep-buried prey items that will often be unavailable to males.…”

Section: Discussionmentioning

confidence: 99%

Sex Promotes Spatial and Dietary Segregation in a Migratory Shorebird during the Non-Breeding Season

et al. 2012

View full text Add to dashboard Cite

Several expressions of sexual segregation have been described in animals, especially in those exhibiting conspicuous dimorphism. Outside the breeding season, segregation has been mostly attributed to size or age-mediated dominance or to trophic niche divergence. Regardless of the recognized implications for population dynamics, the ecological causes and consequences of sexual segregation are still poorly understood. We investigate the foraging habits of a shorebird showing reversed sexual dimorphism, the black-tailed godwit Limosa limosa, during the winter season, and found extensive segregation between sexes in spatial distribution, microhabitat use and dietary composition. Males and females exhibited high site-fidelity but differed in their distributions at estuary-scale. Male godwits (shorter-billed) foraged more frequently in exposed mudflats than in patches with higher water levels, and consumed more bivalves and gastropods and fewer polychaetes than females. Females tended to be more frequently involved and to win more aggressive interactions than males. However, the number of aggressions recorded was low, suggesting that sexual dominance plays a lesser role in segregation, although its importance cannot be ruled out. Dimorphism in the feeding apparatus has been used to explain sex differences in foraging ecology and behaviour of many avian species, but few studies confirmed that morphologic characteristics drive individual differences within each sex. We found a relationship between resource use and bill size when pooling data from males and females. However, this relationship did not hold for either sex separately, suggesting that differences in foraging habits of godwits are primarily a function of sex, rather than bill size. Hence, the exact mechanisms through which this segregation operates are still unknown. The recorded differences in spatial distribution and resource use might expose male and female to distinct threats, thus affecting population dynamics through differential mortality. Therefore, population models and effective conservation strategies should increasingly take sex-specific requirements into consideration.

show abstract

Section: Discussionmentioning

confidence: 99%

Sex Promotes Spatial and Dietary Segregation in a Migratory Shorebird during the Non-Breeding Season

et al. 2012

View full text Add to dashboard Cite

show abstract

“…The birds were immediately taken to an outdoor aviary at the University of Extremadura, under natural photoperiod (9 h 31 min to 11 h 14 min duration) and temperature (mean temperature range 6.1-13.5°C) conditions. The birds were randomly distributed into four cages (5 9 2.5 9 2 m 3 ) equipped with freshwater pools (2.5 9 2 m 2 , 5 cm depth) for bathing and drinking (see details in Santiago-Quesada et al 2009). …”

Section: Animalsmentioning

confidence: 99%

Plasma metabolites correlate with weekly body mass changes in migrating black-tailed Godwits Limosa limosa feeding on different diets

et al. 2015

Self Cite

View full text Add to dashboard Cite

The study of variations in plasma metabolite profiles has emerged as a useful physiological tool to assess fuel deposition rates from a single blood sample. Diet may be a key factor in the study of refueling patterns in longdistance migratory birds, but the potential confounding effect of diet on the conclusions drawn from plasma metabolites has rarely been considered. Here, we assessed whether plasma metabolite levels correlate with the weekly increase in body mass of migrating Black-tailed Godwits Limosa limosa, a medium-large shorebird, feeding on two natural diets (insectivorous vs. granivorous) during the refueling period. We found that glycerol and triglycerides successfully explained the weekly natural change in body mass of Black-tailed Godwits. Although the diet type contributed to the change in body mass, all interactions between plasma metabolites and diet treatment were nonsignificant. Our results support the use of plasma metabolite profiling to predict body mass changes on a long-term (weekly) scale in medium-large birds.

show abstract

“…Food available for godwits differed between both habitats: in the rice fields godwits feed on spilled rice seeds (Santiago‐Quesada et al , Lourenço et al ), whilst in the salt pans they feed almost exclusively on chironomid larvae ( Chironomus salinarius ) (Estrella and Masero ). See Santiago‐Quesada et al () for more details on the study sites.…”

Section: Methodsmentioning

confidence: 99%

Why water birds forage at night: a test using black‐tailed godwits Limosa limosa during migratory periods

Santiago‐Quesada

Estrella

Sánchez‐Guzmán

et al. 2014

Journal of Avian Biology

Self Cite

View full text Add to dashboard Cite

Many migratory water birds are known to feed both during day and night outside the breeding season, but the underlying factors and mechanisms determining this foraging pattern are poorly understood. We addressed this topic by comparing both diurnal and nocturnal foraging activity (FA) and metabolizable energy intake rate (MEIR) in migrating black‐tailed godwits Limosa limosa staging in two different habitats, rice fields and coastal salt pans. Black‐tailed godwits staging in rice fields during pre‐breeding migration fed on rice seeds, and only foraged during the daylight period (FA: 81.89 ± 3.03%; MEIR: 1.15 ± 0.03 kJ · min−1). Daily energy consumption (DEC) of godwits relying on seeds was enough to meet the theoretical daily energy expenditure (DEE). In contrast, black‐tailed godwits staging in salt pans during post‐breeding migration fed on chironomid larvae, and they foraged during both daylight (FA: 67.36 ± 4.30%; MEIR: 0.27 ± 0.01 kJ · min−1) and darkness (FA: 69.89 ± 6.89%; MEIR: 0.26 ± 0.00 kJ · min−1). Nocturnal energy intake contributed 31.7% to DEC, the latter being insufficient to fully meet DEE. Our findings give empirical support to the view that diurnal foraging is the norm in many migratory water birds outside the breeding season, and nocturnal foraging occurs when the daily energy requirements are not met during the daylight period, supporting the supplementary food hypothesis.

show abstract

Sex differences in digestive traits in sexually size-dimorphic birds: Insights from an assimilation efficiency experiment on Black-tailed Godwit

Cited by 25 publications

References 37 publications

Sex Promotes Spatial and Dietary Segregation in a Migratory Shorebird during the Non-Breeding Season

Sex Promotes Spatial and Dietary Segregation in a Migratory Shorebird during the Non-Breeding Season

Plasma metabolites correlate with weekly body mass changes in migrating black-tailed Godwits Limosa limosa feeding on different diets

Why water birds forage at night: a test using black‐tailed godwits Limosa limosa during migratory periods

Contact Info

Product

Resources

About