scholarly journals Selection on personality in a songbird affects maternal hormone levels tuned to its effect on timing of reproduction

2008 ◽  
Vol 4 (5) ◽  
pp. 465-467 ◽  
Author(s):  
Ton G.G Groothuis ◽  
Claudio Carere ◽  
Joe Lipar ◽  
Piet J Drent ◽  
Hubert Schwabl
Keyword(s):  
Brood Size ◽  
Genetic Selection ◽  
Bird Species ◽  
Brood Reduction ◽  
Correlated Response ◽  
Timing Of Reproduction ◽  
Yolk Androgens ◽  
Laying Sequence ◽  
Food Conditions ◽  
Adaptive Tool

The increase or decrease in yolk androgens over the laying sequence of a clutch in birds may mitigate or enhance, respectively, the disadvantage of the last-hatched chicks, providing a potentially adaptive tool to adjust brood size to food conditions. This variation may involve a genetic component on which Darwinian selection can act. We found that two lines of a wild bird species selected for bold and shy personalities show, respectively, increased and decreased androgen concentrations over the laying sequence. The line showing the increase laid earlier in the season, when food conditions are normally sufficient to raise the whole brood. The line showing the decrease laid later, when food is normally scarce, which may facilitate brood reduction. The results indicate a correlated response in maternal hormone transfer to genetic selection on personality, which relates to ecological conditions.

scholarly journals Corrigendum to: Consequences of genetic selection for environmental impact traits on economically important traits in dairy cows

2018 ◽  
Vol 58 (10) ◽  
pp. 1966
Author(s):  
Purna Kandel ◽  
Sylvie Vanderick ◽  
Marie-Laure Vanrobays ◽  
Hélène Soyeurt ◽  
Nicolas Gengler
Keyword(s):  
Dairy Cows ◽  
Body Condition Score ◽  
Genetic Correlations ◽  
Genetic Selection ◽  
Selection Response ◽  
Direct Selection ◽  
Correlated Response ◽  
Production Traits ◽  
Ch4 Emissions ◽  
Natural Logarithm

Methane (CH4) emission is an important environmental trait in dairy cows. Breeding aiming to mitigate CH4 emissions require the estimation of genetic correlations with other economically important traits and the prediction of their selection response. In this study, test-day CH4 emissions were predicted from milk mid-infrared spectra of Holstein cows. Predicted CH4 emissions (PME) and log-transformed CH4 intensity (LMI) computed as the natural logarithm of PME divided by milk yield (MY). Genetic correlations of PME and LMI with traits used currently were approximated from correlations between estimated breeding values of sires. Values were for PME with MY 0.06, fat yield (FY) 0.09, protein yield (PY) 0.13, fertility 0.17; body condition score (BCS) –0.02; udder health (UDH) 0.22; and longevity 0.22. As expected by its definition, values were negative for LMI with production traits (MY –0.61; FY –0.15 and PY –0.40) and positive with fertility (0.36); BCS (0.20); UDH (0.08) and longevity (0.06). The genetic correlations of 33 type traits with PME ranged from –0.12 to 0.25 and for LMI ranged from –0.22 to 0.18. Without selecting PME and LMI (status quo) the relative genetic change through correlated responses of other traits were in PME by 2% and in LMI by –15%, but only due to the correlated response to MY. Results showed for PME that direct selection of this environmental trait would reduce milk carbon foot print but would also affect negatively fertility. Therefore, more profound changes in current indexes will be required than simply adding environmental traits as these traits also affect the expected progress of other traits.

Time-Energy Budgets During Reproduction and the Evolution of Single Parenting in the Superb Lyrebird

1986 ◽  
Vol 34 (3) ◽  
pp. 351 ◽  
Author(s):  
A Lill
Keyword(s):  
Growth Rate ◽  
Brood Size ◽  
Slow Growth ◽  
Bird Species ◽  
Egg Laying ◽  
Energy Budgets ◽  
Brood Care ◽  
Single Parenting ◽  
Slow Growth Rate ◽  
Small Brood

Estimated expenditures on brood-care by unassisted female superb lyrebirds, obtained through time-energy budgeting, were compared with published values for other bird species. With the exception of nestbuilding, estimated daily expenditures were relatively low, due mainly to the small brood size and low level of parental attentiveness. It is suggested that the traits which reduce daily brood-care expenditures, particularly the small brood size and extremely slow growth rate, may have evolved as adaptations which enabled deserted females operating close to maximal capacity to cope with single-parenting. Male parental involvement could probably increase the growth rate of the young, but not brood size; moreover, egg- laying was sufficiently asynchronous to afford multiple mating opportunities to parentally emancipated males. However, the slow growth rate of the young results in relatively large overall brood-care expenditures for females. Investments by males of up to 50% of daylight hours and 45% of BMR on singing at the height of the mating season were comparable with those of partially emancipated, polygynous males of other species. They probably reflect the high level of competition to control good display areas and to advertise status and quality to widely spaced females.

scholarly journals Maternal yolk androgens stimulate territorial behaviour in black-headed gull chicks

2009 ◽  
Vol 5 (5) ◽  
pp. 586-588 ◽  
Author(s):  
Wendt Müller ◽  
Cor Dijkstra ◽  
Ton G. G. Groothuis
Keyword(s):  
Social Interactions ◽  
Territorial Behaviour ◽  
Social Competition ◽  
Maternal Environment ◽  
Yolk Androgens ◽  
The Social ◽  
Food Conditions ◽  
High Concentrations ◽  
Colonial Breeding ◽  
Parasite Exposure

Avian eggs contain substantial amounts of maternal androgens. The concentrations of these yolk androgens are affected by the maternal environment, such as the level of social competition, parasite exposure or food conditions. Since yolk androgens have been shown to affect a wide array of offspring traits, they may adjust the chicks to the expected post-hatching environment, but experimental evidence is still scarce. We investigate in colonial breeding black-headed gulls whether high concentrations of yolk androgens, such as those found in environments with high numbers of social interactions, facilitate aggressiveness and territorial behaviour of the chicks. Black-headed gulls are highly suitable for this, as the semi-precocial chicks defend the natal territory and food against intruders. We manipulated yolk androgen concentrations and investigated their role in both within-nest and between-nest aggression. We found that chicks hatching from androgen-treated eggs defended the natal territory more often than their nest mates from control eggs, without increasing sibling aggression. This suggests that variation in yolk androgen concentrations in relation to the social environment of the mother may indeed allow adjustment of the offspring's behaviour to the expected frequency of territorial interactions with conspecifics post-hatching.

scholarly journals Seasonal Egg-Mass Variation and Laying Sequence in a Bird With Facultative Brood Reduction

The Auk ◽  
2007 ◽  
Vol 124 (2) ◽  
pp. 643-652 ◽  
Author(s):  
Liliana D'Alba ◽  
Roxana Torres
Keyword(s):  
Reproductive Output ◽  
Brood Reduction ◽  
Laying Date ◽  
Egg Mass ◽  
Chick Survival ◽  
Mass Variation ◽  
Embryo Survival ◽  
Sula Nebouxii ◽  
Laying Order ◽  
Laying Sequence

Abstract Females may maximize their lifetime reproductive output by adjusting their investment in each breeding event to the perceived likelihood of success. The Blue-footed Booby (Sula nebouxii) is a long-lived seabird with facultative siblicide. We examined whether there is differential resource allocation to eggs with laying order and whether greater egg mass increases hatching probability, chick survival, hatching interval, and mass and size at hatching. We found that the relative investment in first and second eggs decreased as the season advanced: second eggs were slightly (1.5%) heavier than first eggs in early clutches; by contrast, first eggs were 2% heavier than second eggs in late clutches. Accordingly, hatching probability increased with laying date for first eggs and decreased for second eggs. The mass of the egg increased hatching probability, and no effect on chick survival was detected. Laying interval increased after a heavier egg was laid, and heavier eggs produced heavier hatchlings. Hatching intervals were positively related to laying intervals, but egg mass was unrelated to the length of the incubation period and the hatching interval. Our results suggest that egg mass influences embryo survival and that Blue-footed Booby females may adaptively allocate resources to eggs of different laying order according to breeding conditions. Variación del Peso de los Huevos y Secuencia de Postura en un Ave con Reducción Facultativa de la Nidada

scholarly journals Migratory constraints on yolk precursors limit yolk androgen deposition and underlie a brood reduction strategy in rockhopper penguins

2012 ◽  
Vol 8 (6) ◽  
pp. 1055-1058 ◽  
Author(s):  
Glenn T. Crossin ◽  
Maud Poisbleau ◽  
Laurent Demongin ◽  
Olivier Chastel ◽  
Tony D. Williams ◽  
...  
Keyword(s):  
Steroid Hormones ◽  
Maternal Effects ◽  
Egg Size ◽  
Hatching Asynchrony ◽  
Brood Reduction ◽  
Size Dimorphism ◽  
Reduction Strategy ◽  
Yolk Androgens ◽  
Linear Relationships ◽  
Androgen Levels

Hormonally mediated maternal effects link maternal phenotype and environmental conditions to offspring phenotype. The production of lipid-rich maternal yolk precursors may provide a mechanism by which lipophilic steroid hormones can be transported to developing yolks, thus predicting a positive correlation between yolk precursors in mothers and androgen levels in eggs. Using rockhopper penguins ( Eudyptes chrysocome ), which produce a two-egg clutch characterized by extreme egg-size dimorphism, reversed hatching asynchrony and brood-reduction, we examined correlations between circulating concentrations of the primary yolk-precursor vitellogenin (VTG) and levels of yolk androgens. Previous work in Eudyptes penguins has shown that egg-size dimorphism is the product of migratory constraints on yolk precursor production. We predicted that if yolk precursors are constrained, androgen transport to developing yolks would be similarly constrained. We reveal positive linear relationships between maternal VTG and androgens in small A-eggs but not larger B-eggs, which is consistent with a migratory constraint operating on the A-egg. Results suggest that intra-clutch variation in total yolk androgen levels depends on the production and uptake of yolk precursors. The brood reduction strategy common to Eudyptes might thus be best described as the result of a migratory constraint.

scholarly journals Consequences of genetic selection for environmental impact traits on economically important traits in dairy cows

2018 ◽  
Vol 58 (10) ◽  
pp. 1779
Author(s):  
Purna Kandel ◽  
Sylvie Vanderick ◽  
Marie-Laure Vanrobays ◽  
Hélène Soyeurt ◽  
Nicolas Gengler
Keyword(s):  
Dairy Cows ◽  
Body Condition Score ◽  
Genetic Correlations ◽  
Genetic Selection ◽  
Selection Response ◽  
Direct Selection ◽  
Correlated Response ◽  
Production Traits ◽  
Ch4 Emissions ◽  
Natural Logarithm

Methane (CH4) emission is an important environmental trait in dairy cows. Breeding aiming to mitigate CH4 emissions require the estimation of genetic correlations with other economically important traits and the prediction of their selection response. In this study, test-day CH4 emissions were predicted from milk mid-infrared spectra of Holstein cows. Predicted CH4 emissions (PME) and log-transformed CH4 intensity (LMI) computed as the natural logarithm of PME divided by milk yield (MY). Genetic correlations of PME and LMI with traits used currently were approximated from correlations between estimated breeding values of sires. Values were for PME with MY 0.06, fat yield (FY) 0.09, protein yield (PY) 0.13, fertility 0.17; body condition score (BCS) –0.02; udder health (UDH) 0.22; and longevity 0.22. As expected by its definition, values were negative for LMI with production traits (MY –0.61; FY –0.15 and PY –0.40) and positive with fertility (0.36); BCS (0.20); UDH (0.08) and longevity (0.06). The genetic correlations of 33 type traits with PME ranged from –0.12 to 0.25 and for LMI ranged from –0.22 to 0.18. Without selecting PME and LMI (status quo) the relative genetic change through correlated responses of other traits were in PME by 2% and in LMI by –15%, but only due to the correlated response to MY. Results showed for PME that direct selection of this environmental trait would reduce milk carbon foot print but would also affect negatively fertility. Therefore, more profound changes in current indexes will be required than simply adding environmental traits as these traits also affect the expected progress of other traits.

Juvenile dispersal in Gray Jays: dominant brood member expels siblings from natal territory

1991 ◽  
Vol 69 (12) ◽  
pp. 2935-2945 ◽  
Author(s):  
Dan Strickland
Keyword(s):  
Sex Ratio ◽  
Weight Distribution ◽  
Brood Size ◽  
Food Storage ◽  
Brood Reduction ◽  
Juvenile Dispersal ◽  
Storage Season ◽  
Unrelated Pair ◽  
Gray Jays ◽  
Perisoreus Canadensis

Breeding pairs of Gray Jays (Perisoreus canadensis) in Quebec and Ontario were accompanied in the autumn significantly more often by one nonbreeder, and less often by none or two, than expected from initial brood size frequencies. Among the rare cases of two nonbreeders accompanying a pair, there was no evidence that both were from the same brood. These observations, and the fact that 30.6% of single nonbreeders closely associated with autumn pairs of known, same-year breeding history were unrelated to those adults, indicated the division of juvenile Gray Jays into "stayers," which remained with their parents at no more than one per pair, and "leavers," which left their natal territory and sometimes joined an unrelated pair. The weight distribution of 62 stayers indicated that about two-thirds were males. Leavers had a more equal sex ratio and showed a strong tendency to associate with failed breeders. Stayers apparently had much higher first-summer survival than leavers but no significant chance to inherit their natal territory. Gray Jay broods broke up in June, through intrabrood aggression, when the young were 55–65 days old. Stayers were the dominant juveniles that forced out the leavers. Partial June dispersal may function as a type of brood reduction that permits the dominant juvenile to have exclusive access to a parental subsidy of stored food that is reliably adequate for the survival of only one extra bird on the territory. The best models describing the origin and winter acquisition of such a subsidy postulate recovery of stored food by memory and require that the expulsion of subordinate siblings occur at the beginning of the food storage season. The models predict that food stored by Gray Jays in June survives in significant enough quantities to enhance winter survival.

scholarly journals Does Traditional Feeding of Outdoor Guard Dogs Provide a Food Resource for Wild Mammals and Birds?

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1198
Author(s):  
Róża Andrzejczak ◽  
Łukasz Dylewski ◽  
Leszek Jerzak ◽  
Branislav Peťko ◽  
Łukasz Myczko
Keyword(s):  
Food Resource ◽  
Bird Species ◽  
Passer Domesticus ◽  
Early Spring ◽  
Camera Traps ◽  
Farm Animals ◽  
Wild Mammals ◽  
Animal Populations ◽  
Food Conditions ◽  
Access To Food

Access to food is crucial in the life of birds and affects reproduction, survival and, consequently, population size. In the case of bird species inhabiting villages, poorer food conditions now exist, mainly because of changes in the lifestyle of rural residents and a reduction in the number of farm animals traditionally housed in backyards. Recent changes have also affected dog populations in villages, and the majority of them are no longer kept outside as guard dogs, but rather inside houses as pets. We investigated how traditional care of dogs impacted rural birds and other animal populations. The study was carried out at the end of winter and early spring in 29 farmsteads in western Poland. Using camera traps, it was found that the food fed to dogs was also taken by seven species of birds and at least three species of mammals. The most numerous species taking dog food was the house sparrow, Passer domesticus, which is declining in Europe. In the case of this species, females were more likely than males to use food given to dogs, with a clear preference for food prepared in the human kitchen. We conclude that the food provided to domestic pets can be an important component of the diet of wild birds and mammals living close to humans.

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