Food shortage for breeding Black-billed Magpies (Pica pica): an experiment using supplemental food

1987 ◽  
Vol 65 (5) ◽  
pp. 1270-1274 ◽  
Author(s):  
Wesley M. Hochachka ◽  
David A. Boag
Keyword(s):  
Breeding Population ◽  
Egg Laying ◽  
Food Shortage ◽  
Laying Date ◽  
Food Supplementation ◽  
Natural Food ◽  
Supplemental Feeding ◽  
Pica Pica ◽  
Supplemental Food ◽  
Before And After

Supplemental food was provided to a breeding population of Black-billed Magpies (Pica pica), starting before and after eggs were laid, to determine if and when natural food was limited. The production of fledgling magpies was increased only when supplemental feeding was begun before laying. Laying date was also advanced when supplemental feeding began before laying, but clutch and egg size were not significantly changed. Because the two feeding treatments were conducted in different years, we cannot conclude whether natural food was limiting before or after egg laying. However, out data suggest that the former may have been the case. An improved design for food supplementation experiments, which can be used to determine the time of food shortage, is suggested.

Variation in laying date, clutch size, egg size, and egg composition of yellow-headed blackbirds (Xanthocephalus xanthocephalus): a supplemental feeding experiment

1992 ◽  
Vol 70 (10) ◽  
pp. 1904-1911 ◽  
Author(s):  
Todd W. Arnold
Keyword(s):  
Food Availability ◽  
Egg Production ◽  
Egg Size ◽  
Energy Content ◽  
Laying Date ◽  
Food Supplementation ◽  
Supplemental Feeding ◽  
Xanthocephalus Xanthocephalus ◽  
Egg Composition ◽  
Nest Initiation

I studied the effects of food availability, habitat quality, and timing of breeding on egg production in yellow-headed blackbirds (Xanthocephalus xanthocephalus). Food availability was experimentally manipulated by providing females on six wetlands with supplemental food; six additional wetlands served as unsupplemented controls. Mean nest initiation dates varied by up to 6 d among wetlands, and supplementally fed blackbirds initiated nests 2 d earlier than controls, on average (although this latter difference was not quite significant; P = 0.07). Clutch size declined with laying date, but was unaffected by wetland location, food supplementation, or interactions between these two factors and laying date. Although egg size did not vary among wetlands or in relation to supplemental feeding, egg composition varied with both of these factors. All egg components except wet and dry shell and dry albumen varied among wetlands, whereas total water, wet yolk, and lean yolk were the only components that varied with food supplementation. Large blackbird eggs contained proportionately more water and albumen, but proportionately less yolk and shell. These patterns were somewhat compensatory, such that proportional protein and energy content did not vary with egg size; however, large eggs contained proportionately less fat than did small eggs. Proportional egg composition varied among wetlands (yolk and energy content), but was not affected by supplemental feeding. In general, egg production by yellow-headed blackbirds was not greatly affected by food availability. This may have been due to any of the following four factors: (1) inaccessibility of food supplements owing to competition between male and female blackbirds, (2) insufficient time for females to respond to food supplements, owing to rapid settlement and nest initiation, (3) a nutritionally inappropriate food supplement (i.e., protein availability may not have been enhanced among fed birds), or (4) superabundance of natural foods such that food availability was not limiting egg production.

scholarly journals Effect of Food Availability on Arrival and Departure Decisions of Harlequin Ducks at Diurnal Feeding Grounds

The Condor ◽  
2001 ◽  
Vol 103 (4) ◽  
pp. 870-874 ◽  
Author(s):  
Michael S. Rodway ◽  
Fred Cooke
Keyword(s):  
Food Availability ◽  
Food Supplementation ◽  
Natural Food ◽  
Clupea Pallasi ◽  
Histrionicus Histrionicus ◽  
Before And After ◽  
Harlequin Ducks ◽  
Near Shore ◽  
Effect Of Food ◽  
Departure Decisions

Abstract We investigated three types of decisions made by Harlequin Ducks (Histrionicus histrionicus) in moving between nearshore feeding and offshore resting areas: when to move, whether to move synchronously, and whether to form dense flocks on the roosting grounds. We used the spawning of Pacific herring (Clupea pallasi) as a natural food-supplementation experiment. Birds arrived at nearshore feeding areas a few minutes later and departed almost an hour earlier relative to sunrise and sunset when spawn was available than before and after. Cloud cover and high winds resulted in earlier departures, especially during spawning. Arriving, departing, and offshore groups consisted most frequently of two ducks, and birds showed little tendency to synchronize movements or to form dense flocks when resting. Results indicate that Harlequin Ducks avoid crepuscular and nocturnal periods near shore when not constrained by food availability and the length of daylight in which to feed. Efecto de la Disponibilidad de Alimento en las Decisiones de Arribo y Partida de Histrionicus histrionicus en Áreas de Alimentación Diurna Resumen. Investigamos tres tipos de decisiones hechas por Histrionicus histrionicus (Pato Arlequín) al moverse entre áreas de alimentación cercanas a la costa y áreas de reposo mar adentro: cuándo moverse, si se mueven de modo sincrónico, y si forman bandadas densas en las áreas de reposo. Utilizamos el desove del arenque del Pacífico (Clupea pallasi) como un experimento de suplemento de alimento natural. En relación al amanecer y anochecer, las aves llegaron a las áreas de alimentación cercanas a la costa unos minutos después y se fueron casi una hora más temprano cuando los huevos de peces estuvieron disponibles que cuando no lo estuvieron, ya sea antes o después. Cobertura de nubes y fuertes vientos trajeron aparejadas partidas más tempranas, especialmente durante la etapa de desove. Los grupos que llegaban, partían y los que se encontraban mar adentro estuvieron en su mayoría conformados por dos patos, y las aves en general no tendieron a sincronizar sus movimientos o a formar grupos densos durante el reposo. Los resultados indican que H. histrionicus evita permanecer cerca de la costa durante períodos crepusculares y nocturnos cuando no se haya limitado por la disponibilidad de alimentos y por la cantidad de horas de luz para alimentarse.

The effect of food supply on the composition of Black-billed Magpie eggs

1988 ◽  
Vol 66 (3) ◽  
pp. 692-695 ◽  
Author(s):  
Wesley M. Hochachka
Keyword(s):  
Water Content ◽  
Food Supply ◽  
Egg Size ◽  
Supplemental Feeding ◽  
Pica Pica ◽  
Shell Mass ◽  
Supplemental Food ◽  
Effect Of Food ◽  
Egg Composition ◽  
And Control

Viability of hatching birds may be affected by the composition of the eggs from which they come. Egg composition may be influenced by the diet of the female. I examined whether wild Black-billed Magpies (Pica pica) varied the composition of their eggs in response to differences in food supply. Supplemental food was provided on some territories, and the composition of eggs from control and food-supplemented territories was compared. Supplemental feeding had few effects on egg composition. Egg size – water content relationships differed between eggs from food-supplemented and control territories and there was a greater variability in yolk and shell mass within clutches from food-supplemented territories. These results show that food supply to the female can affect the composition of an egg relative both to other eggs in the same clutch and to eggs in other clutches. However, it is not clear whether the observed variation in egg composition would have an effect on the viability of the eggs.

scholarly journals The Role of Food, Nest Predation, and Climate in Timing of Wrentit Reproductive Activities

The Condor ◽  
2006 ◽  
Vol 108 (4) ◽  
pp. 832-841 ◽  
Author(s):  
Kristine L. Preston ◽  
John T. Rotenberry
Keyword(s):  
Breeding Season ◽  
Nest Predation ◽  
Climatic Conditions ◽  
Egg Laying ◽  
Laying Date ◽  
Supplemental Food ◽  
Fitness Consequences ◽  
Average Rainfall ◽  
Reproductive Activities

Abstract Abstract Timing of breeding activities by birds hasimportant fitness consequences, as deciding when tonest can affect nest success. For three breedingseasons, we provided supplemental food to Wrentits(Chamaeafasciata) inhabitingsemiarid shrublands. We tested the effects of foodsupplementation on timing of initial egg laying,number of nests attempted, timing of fledging, andlength of the breeding season. We also evaluatedwhether Wrentits timed nest initiation to avoidperiods of greatest predation risk. Our study wasconducted during a period of high interannualvariation in precipitation. Supplemental food didnot advance laying date in Wrentits. During adrought, even Wrentits given supplemental fooddelayed nesting, initiated fewer nesting attempts,fledged young earlier, and reduced the length ofthe breeding season. In a year of average rainfall,supplemental food allowed pairs to continuerenesting late into the summer, after repeated nestlosses from predation. Wrentits did not timenesting to avoid periods of greatest predationrisk. In timing initial breeding, Wrentits appearedto be responding to climatic conditions and toindirect cues that predicted environmentalconditions later in the breeding season rather thanto food availability at the time of egg laying.

Food supplementation experiments revisited: verifying that supplemental food is used by its intended recipients

2007 ◽  
Vol 85 (6) ◽  
pp. 679-685 ◽  
Author(s):  
A.J. Wirsing ◽  
D.L. Murray
Keyword(s):  
Population Level ◽  
Food Supplementation ◽  
Natural Food ◽  
Supplemental Food ◽  
Snowshoe Hares ◽  
Extra Food ◽  
Study Sites ◽  
Natural Foods ◽  
And Control ◽  
Free Ranging

Field-based food supplementation experiments can determine whether populations are limited by natural food availability. However, they may yield spurious results if added food is hoarded by dominants, exploited by immigrants, or delivered ineffectively. Surprisingly, population-level approaches accounting for these potential sources of bias have not been established. We explored responses of free-ranging snowshoe hares ( Lepus americanus Erxleben, 1777) to food supplementation by contrasting per capita browsing rates on three study sites with added food with those on three control sites during two winters. Food augmentation reduced foraging pressure by hares; this reduction was significant when browse species of high dietary importance were considered. By implication, hares on manipulated sites switched from favored natural foods to supplemental food, meaning that the extra food found its mark and was not heavily exploited by immigrants or hoarded by dominants. Demographic responses to food addition were not detected on the manipulated sites, indicating that the study population was not food limited. Given the success with which we detected the signal of supplementation and eliminated potential confounding factors, we suggest that future studies using food addition in the context of herbivore population dynamics would benefit from a more mechanistic approach; this may involve measurement of browsing rates on manipulated and control sites.

Experimental increase in female mass during the fertile phase leads to enhanced extra-pair paternity in pied flycatchers Ficedula hypoleuca

2019 ◽  
Author(s):  
Mireia Plaza ◽  
Alejandro Cantarero ◽  
Juan Moreno
Keyword(s):  
Negative Relationship ◽  
Ficedula Hypoleuca ◽  
Egg Laying ◽  
Female Dominance ◽  
Laying Date ◽  
Control Group ◽  
Wing Loading ◽  
Potential Fecundity ◽  
Fertile Phase ◽  
Extra Pair Paternity

Female mass in most altricial birds reaches its maximum during breeding at egg-laying, which coincides temporally with the fertile phase when extra-pair paternity (EPP) is determined. Higher mass at laying may have two different effects on EPP intensity. On the one hand, it would lead to increased wing loading (body mass/wing area), which may impair flight efficiency and thereby reduce female’s capacity to resist unwanted extra-pair male approaches (sexual conflict hypothesis). On the other hand, it would enhance female condition, favouring her capacity to evade mate-guarding and to search for extra-pair mates (female choice hypothesis). In both cases, higher female mass at laying may lead to enhanced EPP. To test this prediction, we reduced nest building effort by adding a completely constructed nest in an experimental group of female pied flycatchers (Ficedula hypoleuca). Our treatment caused an increase in mass and thereby wing loading and this was translated into a significantly higher EPP in the manipulated group compared with the control group as expected. There was also a significant negative relationship between EPP and laying date and the extent of the white wing patch, an index of female dominance. More body reserves at laying mean not only a higher potential fecundity but a higher level of EPP as well. This interaction had not previously received due attention but should be considered in future studies of avian breeding strategies.

scholarly journals Rearing Drones in Queen Cells of Apis mellifera Honey Bees

2016 ◽  
Vol 60 (2) ◽  
pp. 119-128
Author(s):  
Georgios Goras ◽  
Chrysoula Tananaki ◽  
Sofia Gounari ◽  
Elissavet Lazaridou ◽  
Dimitrios Kanelis ◽  
...  
Keyword(s):  
Apis Mellifera ◽  
Larval Development ◽  
Honey Bees ◽  
Royal Jelly ◽  
Early Stage ◽  
Egg Laying ◽  
Horizontal Position ◽  
Before And After ◽  
Queen Larvae ◽  
As If

Abstract We investigated the rearing of drone larvae grafted in queen cells. From the 1200 drone larvae that were grafted during spring and autumn, 875 were accepted (72.9%) and reared as queens. Drone larvae in false queen cells received royal jelly of the same composition and of the same amounts as queen larvae. Workers capped the queen cells as if they were drones, 9-10 days after the egg laying. Out of 60 accepted false queen cells, 21 (35%) were capped. The shape of false queen cells with drone larvae is unusually long with a characteristically elongate tip which is probably due to the falling of larvae. Bees start the destruction of the cells when the larvae were 3 days old and maximised it before and after capping. Protecting false queen cells in the colony by wrapping, reversing them upside down, or placing in a horizontal position, did not help. The only adult drones that emerged from the false queen cells were those protected in an incubator and in push-in cages. Adult drones from false queen cells had smaller wings, legs, and proboscis than regular drones. The results of this study verify previous reports that the bees do not recognise the different sex of the larvae at least at the early stage of larval development. The late destruction of false queen cells, the similarity in quality and quantity of the produced royal jelly, and the bigger drone cells, allow for the use of drone larvae in cups for the production of royal jelly.

scholarly journals Efektivitas Pemberian Makanan Tambahan (PMT) Pemulihan Pada Status Gizi Balita di Wilayah Kerja Puskesmas Simomulyo, Surabaya

2020 ◽  
Vol 4 (1) ◽  
pp. 58
Author(s):  
Arum Sekar Rahayuning Putri ◽  
Trias Mahmudiono
Keyword(s):  
Nutritional Status ◽  
Health Center ◽  
Supplemental Feeding ◽  
Cross Sectional ◽  
Significance Level ◽  
Supplementary Food ◽  
Children Under Five ◽  
Under Five ◽  
Before And After ◽  
Nutritional Status Of Children

Background: One of the efforts made in overcoming malnutrition in the toddler age group is by implementing a Recovery Supplementary Feeding program.Objectives: The purpose of this study was to analyze the differences in nutritional status of children based on weight for height before and after the Supplementary Food Recovery and differences in nutritional status of children after Supplementary Food Recovery and when they had not received Supplementary Food Recovery in the Simomulyo Community Health Center work area.Methods: This study was observational study using case-control design. A total of 38 toddlers with history of obtaining Supplemental Feeding Recovery (PMT) Program in the working area of Simomulyo Health Center were randomly selected. Nutritional status of toddlers is obtained using anthropometric methods of body weight and height / body length. Statistically tested using t-test paired with a significance level of <0.05.Results: After not getting Supplemental Feeding Recovery, it was found that 2.6% of children under five severely wasting, 34.2% wasting, and 63.2% had normal nutritional status. There was a decrease in the percentage of infants with normal nutritional status compared to after completing PMT Recovery program from 68.4% to 63.2%. There were no significant differences in nutritional status of children before and after the program (p=0.585). There was no difference between the nutritional status of children under five after the program and when they had not received the program (p=0.430)Conclusions: There was no difference in nutritional status of children (weight-for-height) before and after Supplemental Feeding Recovery Program.ABSTRAK  Latar Belakang: Upaya yang dilakukan dalam mengatasi kekurangan gizi pada kelompok usia balita adalah program Pemberian Makanan Tambahan (PMT) Pemulihan.Tujuan: Penelitian ini dilakukan bertujuan untuk menganalisis adanya perbedaan pada status gizi balita berasarkan BB/TB sebelum dan setelah Pemberian Makanan Tambahan (PMT) Pemulihan serta perbedaan status gizi balita setelah PMT Pemulihan dan saat sudah tidak mendapat PMT Pemulihan di wilayah kerja Puskesmas Simomulyo.Metode: Penelitian ini adalah peneitian observasional dengan desain penelitan cross sectional. Lokasi penelitian adalah di wilayah kerja Puskemas Simomulyo, Surabaya. Sebanyak 38 balita dengan riwayat mendapat PMT Pemulihan dipilih secara acak menggunakan metode simple random sampling. Status gizi balita didapat menggunakan metode antropometri berat badan dan tinggi/panjang badan. Indeks BB/TB digunakan dalam penilaian status gizi dengan alasan sasaran utama PMT Pemulihan adalah balita dengan status gizi kurus.  Uji secara statistik dilakukan menggunakan uji t berpasangan dengan tingkat signifikansi <0,05.Hasil: Setelah 3 bulan mendapat PMT Pemulihan ada peningkatan persentase balita dengan status gizi normal dari 65,8% menjadi 68,4%. Setelah tidak mendapat PMT Pemulihan ada penurunan persentase balita dengan status gizi normal menjadi 63,2%. Tidak ada perbedaan yang bermakna status gizi balita berasarkan BB/TB sebelum dan setelah PMT Pemulihan (p=0,585). Tidak ada perbedaan pada status gizi dapat disebabkan oleh konsumsi PMT yang belum optimal. Begitu juga diketahui tidak ada perbedaan yang bermakana status gizi balita setelah PMT Pemulihan dan saat sudah tidak mendapat PMT Pemulihan (p=0,430).Kesimpulan: Tidak ada perbedaan pada status gizi balita dengan indeks antropometri BB/TB saat sebelum PMT Pemulihan dan setelah PMT Pemulihan.

Supplemental Food and Laying Date in the European Starling

The Condor ◽  
1993 ◽  
Vol 95 (4) ◽  
pp. 1031-1034 ◽  
Author(s):  
Johnny Karlsson
Keyword(s):  
European Starling ◽  
Laying Date ◽  
Supplemental Food

Effects of Supplemental Food on the Behaviour and Paternity Status of Male Indigo Buntings (Passerina CyaNea)

2018 ◽  
Vol 11 (2) ◽  
pp. 67-73
Author(s):  
Brad T. McLeod ◽  
Gary Ritchison
Keyword(s):  
Time Budget ◽  
Mate Guarding ◽  
Breeding Birds ◽  
Food Supplementation ◽  
Time Budgets ◽  
Blood Samples ◽  
Supplemental Food ◽  
Extra Pair Paternity ◽  
Passerina Cyanea ◽  
And Control

Breeding is energetically costly and, if energy-limited, birds may alter their time budgets, spending less time engaged in some activities and more time in others. Investigators who have provided breeding birds with supplemental food have noted changes in time budgets, but the extent and types of changes have been found to vary among species. Our objective was to determine how food supplementation might influence the time budgets and paternity status of male Indigo Buntings (Passerina cyanea). We studied Indigo Buntings from 8 May to 15 August 2009 in Madison County, Kentucky. Territories of male Indigo Buntings (n=30) were randomly assigned as either food supplemented (n=8) or controls (n=22). During time-budget observations, all behaviours were noted. To determine paternity status, blood samples were collected from adults and nestlings at 16 nests. Males with feeders in their territories spent significantly less time foraging and more time vocalising (chip notes) than males without feeders. Time spent singing and mate guarding by treatment and control males did not differ. Differences in the proportion of extra-pair young did not differ between nests in territories with and without supplemental food. Our results suggest that, when provided with supplemental food, male Indigo Buntings spend less time foraging and more time engaged in other activities. However, neither the presence of supplemental food nor differences in the behaviour of males in food-supplemented versus non-supplemented territories affected rates of extra-pair paternity.

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