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Parental self-feeding effects on parental care levels and time allocation in Palestine sunbirds.

Markman S - PLoS ONE (2014)

Bottom Line: Until now the effect of food consumption by parent birds on their food delivery to their young as well as other parental activities has rarely been studied.Nestling food intake and growth rate increased with increasing food quality of parents and decreasing brood size.These results imply that increasing the nutrient content of foods consumed by parent sunbirds allow them to increase the rate at which other foods are delivered to their young and to increase the time spent on other parental care activities.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology and Environment, University of Haifa - Oranim, Tivon, Israel.

ABSTRACT
The trade-off between parents feeding themselves and their young is an important life history problem that can be considered in terms of optimal behavioral strategies. Recent studies on birds have tested how parents allocate the food between themselves and their young. Until now the effect of food consumption by parent birds on their food delivery to their young as well as other parental activities has rarely been studied. I have previously shown that parent Palestine sunbirds (Nectarinia osea) will consume nectar and liquidized arthropods from artificial feeders. However, they will only feed their young with whole arthropods. This provided a unique opportunity to experimentally manipulate the food eaten by parents independent of that fed to their offspring. Here, I hypothesized that parents invest in their current young according to the quality of food that they themselves consume. Breeding pairs with two or three nestlings were provided with feeders containing water (control), sucrose solution (0.75 mol) or liquidized mealworms mixed with sucrose solution (0.75 mol). As food quality in feeders increased (from water up to liquidized mealworms mixed with sucrose solution): 1) Parents (especially females) increased their food delivery of whole arthropod prey to their young. 2) Only males increased their nest guarding effort. Nestling food intake and growth rate increased with increasing food quality of parents and decreasing brood size. These results imply that increasing the nutrient content of foods consumed by parent sunbirds allow them to increase the rate at which other foods are delivered to their young and to increase the time spent on other parental care activities.

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Time spent mobbing near the nest per hour (means ± SE) by Palestine sunbirds plotted against brood size (2 or 3 nestlings), quality of food available in an artificial feeder, which was either water (Water), sucrose solution (Sugar) or sucrose and mealworm solution (Sugar and worms), and parental sex (blank: males; cross hatched: females).The values consist of the average for the whole seven days of the manipulation period (from nestlings being 7 days of age until 13 days of age) for each parent.
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pone-0113890-g003: Time spent mobbing near the nest per hour (means ± SE) by Palestine sunbirds plotted against brood size (2 or 3 nestlings), quality of food available in an artificial feeder, which was either water (Water), sucrose solution (Sugar) or sucrose and mealworm solution (Sugar and worms), and parental sex (blank: males; cross hatched: females).The values consist of the average for the whole seven days of the manipulation period (from nestlings being 7 days of age until 13 days of age) for each parent.

Mentions: Parental sex and food treatment both affected mobbing effort. The time that males spent mobbing was significantly greater than for females (Table 2c, Fig. 3). As predicted, males significantly increased their mobbing time with increasing nutritional quality of food offered (Fig. 3), while females did not (all Tukey HSD tests for females: p>0.05). As a result, there was a significant parental sex by food treatment interaction term (Table 2c). There was also a significant effect of brood size on mobbing time, with more mobbing effort for larger broods (Table 2c). However, as indicated by the significant parental sex by brood size interaction term, only the males, and not the females, increased their mobbing time when they reared larger broods (all Tukey HSD tests for females: p>0.05).


Parental self-feeding effects on parental care levels and time allocation in Palestine sunbirds.

Markman S - PLoS ONE (2014)

Time spent mobbing near the nest per hour (means ± SE) by Palestine sunbirds plotted against brood size (2 or 3 nestlings), quality of food available in an artificial feeder, which was either water (Water), sucrose solution (Sugar) or sucrose and mealworm solution (Sugar and worms), and parental sex (blank: males; cross hatched: females).The values consist of the average for the whole seven days of the manipulation period (from nestlings being 7 days of age until 13 days of age) for each parent.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4256214&req=5

pone-0113890-g003: Time spent mobbing near the nest per hour (means ± SE) by Palestine sunbirds plotted against brood size (2 or 3 nestlings), quality of food available in an artificial feeder, which was either water (Water), sucrose solution (Sugar) or sucrose and mealworm solution (Sugar and worms), and parental sex (blank: males; cross hatched: females).The values consist of the average for the whole seven days of the manipulation period (from nestlings being 7 days of age until 13 days of age) for each parent.
Mentions: Parental sex and food treatment both affected mobbing effort. The time that males spent mobbing was significantly greater than for females (Table 2c, Fig. 3). As predicted, males significantly increased their mobbing time with increasing nutritional quality of food offered (Fig. 3), while females did not (all Tukey HSD tests for females: p>0.05). As a result, there was a significant parental sex by food treatment interaction term (Table 2c). There was also a significant effect of brood size on mobbing time, with more mobbing effort for larger broods (Table 2c). However, as indicated by the significant parental sex by brood size interaction term, only the males, and not the females, increased their mobbing time when they reared larger broods (all Tukey HSD tests for females: p>0.05).

Bottom Line: Until now the effect of food consumption by parent birds on their food delivery to their young as well as other parental activities has rarely been studied.Nestling food intake and growth rate increased with increasing food quality of parents and decreasing brood size.These results imply that increasing the nutrient content of foods consumed by parent sunbirds allow them to increase the rate at which other foods are delivered to their young and to increase the time spent on other parental care activities.

View Article: PubMed Central - PubMed

Affiliation: Department of Biology and Environment, University of Haifa - Oranim, Tivon, Israel.

ABSTRACT
The trade-off between parents feeding themselves and their young is an important life history problem that can be considered in terms of optimal behavioral strategies. Recent studies on birds have tested how parents allocate the food between themselves and their young. Until now the effect of food consumption by parent birds on their food delivery to their young as well as other parental activities has rarely been studied. I have previously shown that parent Palestine sunbirds (Nectarinia osea) will consume nectar and liquidized arthropods from artificial feeders. However, they will only feed their young with whole arthropods. This provided a unique opportunity to experimentally manipulate the food eaten by parents independent of that fed to their offspring. Here, I hypothesized that parents invest in their current young according to the quality of food that they themselves consume. Breeding pairs with two or three nestlings were provided with feeders containing water (control), sucrose solution (0.75 mol) or liquidized mealworms mixed with sucrose solution (0.75 mol). As food quality in feeders increased (from water up to liquidized mealworms mixed with sucrose solution): 1) Parents (especially females) increased their food delivery of whole arthropod prey to their young. 2) Only males increased their nest guarding effort. Nestling food intake and growth rate increased with increasing food quality of parents and decreasing brood size. These results imply that increasing the nutrient content of foods consumed by parent sunbirds allow them to increase the rate at which other foods are delivered to their young and to increase the time spent on other parental care activities.

Show MeSH