Hatching Asynchrony Decreases the Magnitude of Parental Care in Domesticated Zebra Finches: Empirical Support for the Peak Load Reduction Hypothesis

Ethology ◽  
2014 ◽  
Vol 120 (6) ◽  
pp. 577-585 ◽  
Author(s):  
Mark C. Mainwaring ◽  
David Lucy ◽  
Ian R. Hartley
Keyword(s):  
Parental Care ◽  
Peak Load ◽  
Empirical Support ◽  
Hatching Asynchrony ◽  
Load Reduction ◽  
Zebra Finches

Hatching asynchrony and food stress in Ring-billed Gulls: an experimental study

1999 ◽  
Vol 77 (4) ◽  
pp. 515-523 ◽  
Author(s):  
Percy N Hébert ◽  
Raymond McNeil
Keyword(s):  
Feeding Rate ◽  
Peak Load ◽  
Adaptive Significance ◽  
Hatching Asynchrony ◽  
Brood Reduction ◽  
Load Reduction ◽  
Feeding Rates ◽  
Fledging Success ◽  
Clutch Initiation ◽  
The Mean

We examined predictions derived from three hypotheses (hurry-up, peak-load reduction, and brood reduction) regarding the adaptive significance of hatching asynchrony. The study was conducted, in 1991 and 1992, in a colony of Ring-billed Gulls (Larus delawarensis) on l'île de la Couvée, Montréal, Québec, Canada. The hypotheses were examined by comparing the mass and size of 18- to 20-day-old chicks from broods that hatched asynchronously (unmanipulated) and synchronously (manipulated). We also compared feeding rates and fledging success between asynchronous and synchronous broods. Also, in 1992, a sample of asynchronous and synchronous broods was experimentally food stressed by providing them with an additional chick when the oldest resident chick was 4 or 5 days old. Consistent with the hurry-up hypothesis, hatch spreads were significantly shorter in 1991 when the mean clutch initiation date was significantly earlier compared with 1992. Also consistent with the hypothesis, hatch spreads increased significantly through the breeding season. In agreement with the peak-load-reduction hypothesis, feeding rates were significantly lower in asynchronous broods compared with synchronous broods. Contrary to the hypothesis, however, the feeding rate was similar for food-stressed asynchronous and food-stressed synchronous broods. As predicted by the brood-reduction hypothesis, survivorship was higher for first-hatched chicks in asynchronous broods compared with chicks in synchronous broods. Total brood loss as a result of starvation tended to occur less often in asynchronous broods compared with synchronous broods. Likewise, fledging success was higher in asynchronous broods compared with synchronous broods. However, contrary to the brood-reduction hypothesis, survival rate of first-hatched chicks, total brood loss, and fledging success were similar in food-stressed asynchronous and synchronous broods. The above results indicate that several benefits accure to Ring-billed Gulls from hatching asynchrony.

The peak load reduction hypothesis for avian hatching asynchrony

1990 ◽  
Vol 4 (3) ◽  
pp. 249-260 ◽  
Author(s):  
Douglas W. Mock ◽  
P. L. Schwagmeyer
Keyword(s):  
Peak Load ◽  
Hatching Asynchrony ◽  
Load Reduction

Peak Load Reduction in a Smart Building Integrating Microgrid and V2B-Based Demand Response Scheme

2019 ◽  
Vol 13 (3) ◽  
pp. 3274-3282 ◽  
Author(s):  
Hanane Dagdougui ◽  
Ahmed Ouammi ◽  
Louis A. Dessaint
Keyword(s):  
Demand Response ◽  
Peak Load ◽  
Load Reduction ◽  
Smart Building ◽  
Response Scheme

Optimal Energy Management of EV Parking Lots Under Peak Load Reduction Based DR Programs Considering Uncertainty

2019 ◽  
Vol 10 (3) ◽  
pp. 1034-1043 ◽  
Author(s):  
Ibrahim Sengor ◽  
Ozan Erdinc ◽  
Baris Yener ◽  
Akin Tascikaraoglu ◽  
Joao P. S. Catalao
Keyword(s):  
Energy Management ◽  
Peak Load ◽  
Load Reduction ◽  
Parking Lots ◽  
Optimal Energy ◽  
Optimal Energy Management

Division of parental duties confirms a need for bi-parental care in a precocial bird, the mute swan Cygnus olor

2015 ◽  
Vol 65 (2) ◽  
pp. 163-176 ◽  
Author(s):  
Radosław Włodarczyk ◽  
Piotr Minias
Keyword(s):  
Parental Care ◽  
Breeding Season ◽  
Time Budget ◽  
Empirical Support ◽  
European Population ◽  
Mute Swan ◽  
Cygnus Olor ◽  
Territory Defence ◽  
Male Activity ◽  
Reproductive Activities

Parental investment is much reduced in precocial species when compared with altricial species, which may explain a predominance of uni-parental care in this group of birds. In precocial wildfowl, bi-parental care is mostly restricted to arctic-breeding species, where the short reproductive season forces mates to cooperate in caring for the young, but a temperate breeding mute swan Cygnus olor is one of the few notable exceptions. In order to explain a need for bi-parental care in this species, we collected data on the time-budget of eleven swan breeding pairs from a Central European population. We found sex-related differences in the mean time allocated to incubation, movement, feeding, resting and aggression. Others behaviours (nest maintenance, alert and comfort) changed along the breeding season, but did not differ between sexes. Females were primarily responsible for providing care to the brood, whereas male activity focused on territory defence and family guarding. Females were exclusively responsible for incubation and they covered 85% of the total time allocated by parents to feeding cygnets. Nearly constant incubation in females limited possibilities for other activities, including foraging. Males allocated significantly more time than females to aggressive interactions, directed mainly towards other breeding pairs and non-breeders. A clear division of parental duties between sexes gave empirical support for the presence of bi-parental care in the mute swan, despite the fact that reproductive activities of this species are not constrained by the short length of the breeding season, as in arctic-breeding wildfowl.

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