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

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.

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The peak load reduction hypothesis for avian hatching asynchrony

Evolutionary Ecology ◽

10.1007/bf02214333 ◽

1990 ◽

Vol 4 (3) ◽

pp. 249-260 ◽

Cited By ~ 32

Author(s):

Douglas W. Mock ◽

P. L. Schwagmeyer

Keyword(s):

Peak Load ◽

Hatching Asynchrony ◽

Load Reduction

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Environmental and Intrinsic Control of Filtering and Feeding Rates in Arctic Daphnia

Journal of the Fisheries Research Board of Canada ◽

10.1139/f75-018 ◽

1975 ◽

Vol 32 (2) ◽

pp. 219-226 ◽

Cited By ~ 21

Author(s):

S. W. Chisholm ◽

Raymond G. Stross ◽

Paul A. Nobbs

Keyword(s):

Feeding Rate ◽

Functional Relationship ◽

Time Of Day ◽

Temperature Cycle ◽

Food Density ◽

Feeding Rates ◽

Daily Food ◽

Filtering Rate ◽

Daphnia Middendorffiana ◽

The Mean

Filtering and feeding rates of Daphnia middendorffiana at Point Barrow, Alaska were measured as a function of temperature, food density, animal length, and time of day.The functional relationship between feeding rate and food density followed the hyperbolic pattern typical for filter feeders. Daphnia middendorffiana was found to have comparatively high filtering capabilities at its temperature optimum (around 11 C), with filtering rate increasing with length according to the equation F =.458L3.17. The exponent of this equation was found to be a function of temperature, and the coefficient a function of food density.A bimodal diel rhythm in feeding rate was found in this species in experiments where the animals were held under constant conditions. Feeding rates were maximum at 1400 and 2400, the time of day when the temperature cycle in the ponds passes through the mean daily temperature, which is optimum for feeding in D. middendorffiana. Thus the timing of the rhythm may serve to maximize the daily food gathering ability of this species.

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Regular monitoring of breast-feeding rates: feasible and sustainable. The Emilia-Romagna experience

Public Health Nutrition ◽

10.1017/s136898001700074x ◽

2017 ◽

Vol 20 (11) ◽

pp. 1895-1902 ◽

Cited By ~ 3

Author(s):

Simona Di Mario ◽

Silvana Borsari ◽

Eleonora Verdini ◽

Sergio Battaglia ◽

Luca Cisbani ◽

...

Keyword(s):

Monitoring System ◽

Breast Feeding ◽

Record Linkage ◽

Feeding Rate ◽

Local Health ◽

Feeding Rates ◽

Regional Survey ◽

Health Authorities ◽

The Mean ◽

Local Health Authorities

AbstractObjectiveAn efficient breast-feeding monitoring system should be in place in every country to assist policy makers and health professionals plan activities to reach optimal breast-feeding rates.Design/Setting/SubjectsFrom March to June 2015, breast-feeding rates at 3 and 5 months of age were monitored in Emilia-Romagna, an Italian region, using four questions added to a newly developed paediatric immunization database with single records for each individual. Data were collected at primary-care centres. Breast-feeding definitions and 24 h recall as recommended by the WHO were used. Direct age standardization was applied to breast-feeding rates. Record linkage with the medical birth database was attempted to identify maternal, pregnancy and delivery factors associated with full breast-feeding rates at 3 and 5 months of age.ResultsData on breast-feeding were collected for 14044 infants. The mean regional full breast-feeding rate at 3 months was 52 %; differences between local health authorities ranged from 42 to 62 %. At 5 months of age, the mean regional full breast-feeding rate dropped to 33 % (range between local health authorities: 26 to 46 %). Record linkage with the birth certificate database was successful for 93 % of records. Total observations more than doubled with respect to the previous regional survey.ConclusionsThe new monitoring system implemented in 2015 in Emilia-Romagna region, totally integrated with the immunization database, has proved to be feasible, sustainable and more efficient than the previous one. This system can be a model for other regions and countries where the vast majority of mothers obtain vaccinations from public health facilities and that already have an immunization database in place.

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

Ethology ◽

10.1111/eth.12229 ◽

2014 ◽

Vol 120 (6) ◽

pp. 577-585 ◽

Cited By ~ 2

Author(s):

Mark C. Mainwaring ◽

David Lucy ◽

Ian R. Hartley

Keyword(s):

Parental Care ◽

Peak Load ◽

Empirical Support ◽

Hatching Asynchrony ◽

Load Reduction ◽

Zebra Finches

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Abundance and Consumption Rate of Glassy-Winged Sharpshooter (Hemiptera: Cicadellidae) on Peaches and Plums

Journal of Entomological Science ◽

10.18474/0749-8004-43.4.394 ◽

2008 ◽

Vol 43 (4) ◽

pp. 394-407 ◽

Cited By ~ 4

Author(s):

Peter C. Andersen ◽

Russell F. Mizell ◽

Brent V. Brodbeck ◽

Thomas G. Beckman ◽

Gerard Krewer

Keyword(s):

Feeding Rate ◽

Consumption Rate ◽

Prunus Persica ◽

Feeding Rates ◽

Homalodisca Vitripennis ◽

Prunus Salicina ◽

Nocturnal Feeding ◽

Primary Vector ◽

The Mean ◽

Nighttime Feeding

Homalodisca vitripennis (Germar), the glassy-winged sharpshooter, is a primary vector of phony peach and plum leaf scald diseases caused by Xylella fastidiosa Wells et al. A survey of H. vitripennis on peach [Prunus persica (L.) Batsch] varieties established that leafhopper abundances varied from 0–13 per tree. Prunus persica cvs. Flordaking and June Gold and Prunus salicina Lindl. (cvs. Methley and Santa Rosa) were then budded on each of 3 P. persica rootstocks (cvs. Aldrighi, Lovell and Nemaguard). Leafhopper abundance was monitored on each of the two scions budded on each rootstock and on non budded rootstocks over a 2-yr period. The genotypes were container-grown in Year 1 and were planted in the field in Year 2. For both years leafhopper abundance was greatest during early June and on Methley and Santa Rosa cultivars compared with the peach genotypes. The feeding rates of leafhoppers were substantially higher on plum scions than on peach scions, and nocturnal feeding rates were often higher than daytime feeding rates. Mean leafhopper feeding rates were correlated with leafhopper abundance on Prunus genotypes from 3–8 June in a quadratic manner (F = 53.8; df = 2,12; R2 = 0.90; P < 0.0001); the mean nighttime feeding rate was best correlated linearly to mean cumulative leafhopper abundance (F= 446.9; df = 1,13; R2 = 0.972; P < 0.0001).

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Hatching asynchrony, chick care, and adoption in the common tern: can disadvantaged chicks win?

Canadian Journal of Zoology ◽

10.1139/z91-097 ◽

1991 ◽

Vol 69 (3) ◽

pp. 661-668 ◽

Cited By ~ 21

Author(s):

Ralph D. Morris ◽

Michelle Woulfe ◽

G. D. Wichert

Keyword(s):

Foster Parents ◽

Hatching Asynchrony ◽

Common Tern ◽

Sterna Hirundo ◽

Feeding Rates ◽

Chick Survival ◽

Viable Option ◽

Fledging Success ◽

Significant Survival ◽

The Common

In 1987 and 1988, common tern (Sterna hirundo) chicks at a colony near Port Colborne, Ontario, were individually colour banded according to known hatch order. Intraclutch hatch intervals produced size disparities among chicks at brood completion; third-hatched chicks were significantly lighter and at a significant survival disadvantage compared with their earlier-hatched siblings. There were differences in feeding rates according to hatch order and many third-hatched chicks obtained fewer or no feedings during our periods of observation. Sixty-five chicks known to have abandoned their home broods gained acceptance into foreign broods. Chicks that remained in the foreign brood for more than 2 days (average residency 11.9 ± 5.3 days; n = 26) were fed and brooded by the foster parents, were on average older than the youngest resident chick, but were not always the last hatched in their home brood. Conversely, chicks that were in a foreign brood for less than 2 days were no different in age from the youngest resident chick. Survival and fledging success was highest for chicks accepted into two chick broods in which they were older than the resident second chick; in effect, the adoptee became the second chick. Parents that accepted a foreign chick for more than 2 days experienced a seasonal fitness loss compared with nonadopting parents. As the only viable option available to them, selection favours movement away from home broods by chicks that may be disadvantaged there.

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Maguari Stork Nesting: Juvenile Growth and Behavior

The Auk ◽

10.2307/4086908 ◽

1984 ◽

Vol 101 (4) ◽

pp. 812-823 ◽

Cited By ~ 8

Author(s):

Betsy Trent Thomas

Keyword(s):

South America ◽

Clutch Size ◽

Breeding Biology ◽

Brood Reduction ◽

Juvenile Growth ◽

Fledging Success ◽

Wide Range ◽

The Mean ◽

And Behavior ◽

Tropical South America

Abstract Although it has a wide range in tropical South America, the Maguari Stork (Ciconia maguari) is poorly known. In an 11-yr study of its breeding biology in the llanos of Venezuela I found the mean clutch size for 3 yr to be 3.2 eggs. The young hatched asynchronously at 29-32 days and usually made their first flight at 60-72 days. Data on egg sizes, weights, and a probable dump egg are given. The weight and growth of two siblings, plumage succession, and nestling and fledgling behaviors are described. The fledging success of eggs from 55 nests, over 9 yr, was 61%. Loss of eggs (presumably from snake predation) was higher than nestling loss. Although the asynchronously hatched young in a clutch varied greatly in weight and continued this difference throughout nestling life, no case of brood reduction was found in 123 nests during the study. Nestlings were fed mainly frogs and tadpoles, fish, eels, and aquatic rats; food classes and food sizes brought by adults varied with the age of their young. Maguari Stork nestlings do not grasp with their hallux and so are confined to their nests until they can fly. I suggest that the two black plumages of nestlings, between the white hatching down and the white first basic plumage, are for crypsis of the nest-bound young.

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