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Productivity (mean + s.e.) of Fed and Unfed nests from 1996 to 2006. The smallest differences in productivity between Fed and Unfed nests were observed from 2000 through to 2003, a period when natural food availability was high.
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Supplementation of food to wild animals is extensively applied as a conservation tool to increase local production of young. However, in long-lived migratory animals, the carry-over effects of food supplementation early in life on the subsequent recruitment of individuals into natal populations and their lifetime reproductive success are largely un...
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Intradialytic oral nutrition (ION) has been shown to improve many clinical outcomes, including lowering mortality, in hemodialysis (HD) patients. Despite the benefits, ION is underused in many countries.
Objective:
The objective of our study was to determine the perception of health-care professionals (HCP) in our environment of the...
Citations
... Moreover, food availability significantly influences the fledging success of avian species. Several studies, have demonstrated that the quantity of prey, rather than its quality, servers as the primary determinant of reproductive success in birds such as the Black-throated Blue Warbler Setophaga caerulescens [48], the Eastern Brown Pelican Pelecanus occidentalis [49], and the European Pied Flycatcher Ficedula hypoleuca [50]. However, in present study, nestling success (86.1%) of Asian Openbill indicates better nestling success attributed to attentive parental care during feeding. ...
Nutrition plays a crucial role in avian development, growth, and health. Inadequate nutrition can have an impact on immune systems and increase susceptibility to diseases. However, there is a paucity of studies that quantify the nutrition provided to young birds. We studied the nutrients delivered to six nests, especially to the hatchling and nestling stages of the Asian Openbill (Anastomus oscitans), using CCTV cameras and spotting scope in Eastern Nepal. Simultaneously, we collected the major food of the Asian Openbill, specifically Filopaludina and Pila spp., and assessed their nutrient content value to estimate the amount of nutrients delivered to the young birds. Asian Openbills feed Filopaludina spp. to hatchlings and both Filopaludina and Pila species to nestlings across all nests. The amount of food supplied to each nest during the nestling stage (272.4 to 386.4 g/day) was approximately three times higher than that during the hatchling stage (87.7 to 128.01 g/day). Energy was primarily derived from protein, followed by fat, and carbohydrate, with variations observed between both nesting stages. Our study provides baseline data on nutrient delivery patterns during two nesting stages of the Asian Openbill in Eastern Nepal, highlighting their adaptability and flexibility in meeting nutritional requirements.
... One major difference between the populations is diet. Although supplemental food is provided, wild parrots also consume native food plants that could be nutritionally advantageous to nestlings (Saunders, 1986;Vincenzi et al., 2015;Stojanovic et al., 2020b). Alternatively, there could be differences in the growth rates of wild and captive orange-bellied parrots. ...
Conservation breeding programs are an increasingly important tool to help supplement declining wild populations, but captive‐bred animals generally do not survive well post‐release. Early life in captivity has the potential to influence growth and development, with impacts carrying over to affect survival. Understanding carry‐over effects of captivity and consequences on survival is critically important for conservation efforts globally but remains poorly understood. We examined the relationship between early‐life environment, physical condition, and juvenile survival of wild and captive‐bred critically endangered orange‐bellied parrots (Neophema chrysogaster). Using nestling growth models, we calculated a body condition index for 1,039 wild and captive‐bred orange‐bellied parrots hatched over six breeding seasons. Nestling body condition varied with year, provenance, and brood position. Wild nestlings had consistently higher body condition than captive‐bred nestlings, and first‐hatched nestlings were typically heavier than later hatched siblings. We then investigated first‐year survival for 298 wild‐born and captive‐bred released parrots in the wild. Overall, first‐year survival was 27.5%, and individual body condition was more influential than provenance in predicting survival. Our findings could be used to aid the selection of individuals for release that have the best prospects of surviving in the wild. This study addresses important questions about the post‐release fitness of captive‐bred animals, and our metric of assessing physical condition provides a straightforward tool for other conservation breeding programs to adapt management techniques to improve survival outcomes.
... "Fed" birds could take as many of these as they wished, "unfed" birds were given none under controlled conditions. These manipulations affected adult birds in numerous ways, including the sex ratio of offspring (Merkling et al., 2012), their fledging success (Vincenzi, Hatch, Merkling, & Kitaysky, 2015), and in the (Merkling et al., 2016) study, seemingly in the higher aggressiveness of the α chicks of the unfed adults. ...
The Black-legged Kittiwake gull (Rissa tridactyla) is noted for its suite of evolutionary adaptations to its extreme cliff-nesting habitat (Cullen, 1957) which distinguish it behaviourally in a number of ways from other gulls (Laridae). One such behaviour we observed was siblicide, the death of one chick from falling out of the nest as a consequence of agonistic harassment by the other (Dickins et al., 1985). This harassment involved what we termed “siblicidal pecks” inflicted by the dominant chick on its younger sib, not in the context of feeding. These we distinguished observationally from “punishing pecks”, also made by the dominant chick on its brood mate, specifically when the latter was begging for food from a parent, causing it to stop this behaviour in the short term.
Though the evolution of siblicide initially seemed to present a paradox for Inclusive fitness theory it was soon seen to be a logical corollary thereof (O’Connor, 1978) (D. Mock & Parker, 1998), and dependent upon key ecological variables. A number of subsequent studies of these factors in the kittiwake, largely from the ecological and ornithological literature, are here collated, and it is considered how these might be integrated with the application of concepts from operant psychology to chick and parent behaviours (Reed, 2015), to give a full account.
... Here, we investigated whether differences in sex and hatching order are associated with variation in the fitness consequences of MHC class-II diversity during the nestling stage in a wild population of the monogamous black-legged kittiwakes (Rissa tridactyla). In kittiwakes, female and second-hatched chicks are smaller, grow slower (Merkling et al., 2012;Vincenzi, Hatch, Mangel, & Kitaysky, 2013;Vincenzi, Hatch, Merkling, & Kitaysky, 2015) and suffer more from sibling aggressions (Delaunay, 2018;White, Leclaire, et al., 2010) than other chicks, suggesting that they are less competitive for food and in poorer condition. In several other species, including birds, food shortage and reduced condition have been linked to reduced immune responses via energy trade-offs (Beldomenico & Begon, 2010;Brzek & Konarzewski, 2007) or chronic stress (Glaser & Kiecolt-Glaser, 2005). ...
... We tested several fitness-related traits, namely survival in the nest, growth rate and tick infection during the nestling stage. Growth rate is an important component of fitness in kittiwakes because faster growing chicks are more likely to recruit as breeders (Vincenzi et al., 2015). Ticks can have strong deleterious effects on kittiwake chicks by reducing growth rate when food is scarce (McCoy, Boulinier, Schjorring, & Michalakis, 2002), potentially leading to death in the case of hyperinfestation (Chastel, Monnat, Lelay, & Balouet, 1987). ...
Genes of the major histocompatibility complex (MHC) play a pivotal role in parasite resistance, and their allelic diversity has been associated with fitness variations in several taxa. However, studies report inconsistencies in the direction of this association, with either positive, quadratic or no association being described. These discrepancies may arise because the fitness costs and benefits of MHC‐diversity differ among individuals depending on their exposure and immune responses to parasites. Here, we investigated in black‐legged kittiwake (Rissa tridactyla) chicks whether associations between MHC class‐II diversity and fitness vary with sex and hatching order. MHC‐II diversity was positively associated with growth and tick clearance in female chicks, but not in male chicks. Our data also revealed a positive association between MHC‐II diversity and survival in second‐hatched female chicks (two eggs being the typical clutch size). These findings may result from condition‐dependent parasite infections differentially impacting sexes in relation to hatching order. We thus suggest that it may be important to account for individual heterogeneities in traits that potentially exert selective pressures on MHC‐diversity in order to properly predict MHC‐fitness associations.
... In kittiwakes, female and second-hatched chicks are smaller, grow slower (T. Vincenzi, Hatch, Mangel, & Kitaysky, 2013;Vincenzi, Hatch, Merkling, & Kitaysky, 2015) and suffer more from sibling aggressions (Delaunay, 2018; than other chicks, suggesting that they are less competitive for food and in poorer condition. In several other species, including birds, food shortage and reduced condition have been linked to reduced immune responses via energy trade-offs (Beldomenico & Begon, 2010;Brzek & Konarzewski, 2007) or chronic stress (Glaser & Kiecolt-Glaser, 2005). ...
... Growth rate is an important component of fitness in kittiwakes because faster growing chicks are more likely to recruit as breeders (Vincenzi et al., 2015). Ticks can have strong deleterious effects on kittiwake chicks by reducing growth rate when food is scarce (McCoy et al., 2002), potentially leading to death in case of hyper-infestation (Chastel et al., 1987). ...
... We investigated MHC-based sex allocation decision in the genetically monogamous black-legged kittiwake (Rissa tridactyla), a species in which MHC-II diversity is positively associated with growth and tick loss in female chicks, but not male chicks (this thesis, chapter 1). Both growth rate (Vincenzi et al., 2015) and tick infection (Chastel et al., 1987;McCoy et al., 2002) are known to strongly affect fitness in this species. Additionally, MHC-II diversity is positively associated with survival in second-hatched female chicks (two eggs being the typical clutch size in kittiwakes) while it is not associated with survival in any other sex-rank chick categories (this thesis, chapter 1). ...
Parents are expected to adjust their reproductive decisions depending on the future advantages they will gain. These advantages include increased offspring fitness through acquisition of genetic benefits from mates. However, constraints may force individuals to mate with suboptimal partners. The costs of suboptimal pairing should have created selective pressures inducing the evolution of counter strategies. In this thesis, I investigated whether individuals adjust some reproductive post-pairing decisions depending on the prospective genetic characteristics of their offspring, along with the fitness consequences of these genetic characteristics, using a monogamous seabird species, the black-legged kittiwake (Rissa tridactyla). First, I found that chick functional diversity at major histocompatibility complex class II (MHC-II) genes, which play a pivotal role in vertebrate immunity, was positively associated with fitness-related traits in females, but not in males. Accordingly, parents with functionally similar MHC-II, that were more likely to produce chicks with low MHC-II-diversity, overproduced sons, in line with sex allocation theory expectations. Second, I report experimental evidence that genome-wide genetic similarity between mates decreased egg hatchability when the fertilizing sperm was old. In line with our expectations, genetically-similar pairs performed behaviors allowing avoidance of fertilization by old sperm. Overall, this thesis provides evidence that parents flexibly adapt some reproductive decisions in response to within-pair genetic similarity at key functional genes and over the whole genome, thereby partly compensating the detrimental consequences of suboptimal pairing.
... Supplemental feeding in kittiwakes had strong effects on wing growth, mass gain and antioxidant levels. Growth rates are often linked to food availability in seabirds (Lyons & Roby, 2011;Ricklefs, Duffy, & Coulter, 1984;Romano, Piatt, & Roby, 2006;Shea & Ricklefs, 1985), and in this study system, this finding has been extensively documented, along with effects on adult reproductive success and recruitment of fed and unfed chicks (Gill & Hatch, 2002;Vincenzi, Hatch, Merkling, & Kitaysky, 2015;Welcker et al., 2015). As this relationship between food availability and growth is well described in this system, and our findings in this study corroborate the relationship, we refrain from discussing these effects further here. ...
Early-life conditions can drive ageing patterns and life history strategies throughout the lifespan. Certain social, genetic, and nutritional developmental conditions are more likely to produce high-quality offspring: those with good likelihood of recruitment and productivity. Here we call such conditions "favored states" and explore their relationship with physiological variables during development in a long-lived seabird, the black-legged kittiwake (Rissa tridactyla). Two favored states were experimentally generated by manipulation of food availability and brood size, while hatching order and sex were also explored as naturally generating favored states. Thus, the favored states we explored were high food availability, lower levels of sibling competition, hatching first, and male sex. We tested the effects of favored developmental conditions on growth, stress, telomere length (a molecular marker associated with lifespan), and nestling survival. Generation of favored states through manipulation of both the nutritional and social environments furthered our understanding of their relative contributions to development and phenotype: increased food availability led to larger body size, reduced stress, and higher antioxidant status, while lower sibling competition (social environment) led to lower telomere loss and longer telomere lengths in fledglings. Telomere length predicted nestling survival, and wing growth was also positively correlated with telomere length, supporting the idea that telomeres may indicate individual quality, mediated by favored states. This article is protected by copyright. All rights reserved.
... Hence, we expected environmental conditions to be on the right side of Figure 1, but with the Fed group obviously representing higher food availability than the Unfed group. Pairs experimentally fed throughout the breeding season (i.e., mimicking exceptionally good conditions) indeed have a consistently higher productivity than control pairs (0.4 more fledglings/nest in average: Vincenzi et al. 2015). We thus hypothesized that the Unfed group was situated on the right of the parent-senior chick conflict zone of Figure 1, whereas the Fed group was situated in the zone of nonconflict on the right of Figure 1. ...
Maternal effects occur when the mother’s phenotype influences her offspring’s phenotype. In birds, differential allocation in egg yolk components can allow mothers to compensate for the competitive disadvantage of junior chicks. We hypothesise that the parent-older chick conflict peaks at intermediate conditions: parents benefit from the younger chick(s) survival, but its death benefits the older chick in terms of growth and survival. We thus expect maternal compensation to follow a bell-shaped pattern in relation to environmental conditions. We studied a black-legged kittiwake (Rissa tridactyla) population where previous results revealed increased allocation of yolk testosterone in younger as compared to older chicks in intermediate conditions, in line with our theoretical framework. We therefore predicted a maternally-induced increase in aggressiveness, growth and survival for younger chicks born in intermediate environmental conditions. Controlling for parental effects and chick sex, we manipulated food availability before egg-laying to create a situation with intermediate (Unfed group) and good (Fed group) environmental conditions. Within each feeding treatment, we further created experimental broods where the natural hatching order was reversed to maximise our chances to observe an effect of feeding treatment on the younger chicks’ aggressiveness. As predicted, we found that chick aggressiveness was higher in younger chicks born from the Unfed group (i.e. in intermediate environmental conditions), but only when they were put in a senior position, in reversed broods. Predictions on growth and survival were not confirmed. Mothers thus seem to favour the competitiveness of their younger chick in intermediate conditions via egg yolk components, but our study also suggests that hatching asynchrony need to be small for maternal compensation to be efficient. We emphasise the need for further studies investigating other chick behaviours (e.g., begging) and focusing on the relative role of different yolk components in shaping parent-offspring conflict over sibling competition.
Sex allocation studies among birds and mammals are notoriously inconsistent with theoretical predictions. One explanation is the difficulty of collecting data on costs and benefits of sex-ratio adjustments, which prevents the investigation of underlying assumptions. Some predictions may thus have been tested in species where they should not have been expected. Here, we focus on the “cost of reproduction hypothesis”, which states that parents with low investment capacity should avoid producing the most expensive sex to minimise the decrease in their residual reproductive value. In the black-legged kittiwake (Rissa tridactyla), sons are energetically more expensive than daughters. Using 10 years of data (1172 chicks from 790 broods) from a long-term feeding experiment, we predicted a stronger decrease in the probability of producing a son with deteriorating environmental conditions among Control than among supplementally Fed parents. To test this prediction, we used three proxies of environmental conditions and a recent sliding window approach. We found no support for our prediction. Hence, we investigated between-year sex-ratio variation in relation to feeding status to detect a response to an unmeasured environmental variable. There was no interaction between year and feeding status, nor any effect of feeding status itself. However, the probability of producing a male increased with time, which could be a response to an oceanic regime shift that occurred around our colony, but that our proxies failed to capture. Our study further highlights the difficulty of explaining sex-ratio variation in long-lived species with complex life-histories where multiple selective pressures can occur simultaneously.
To maximise the effectiveness of conservation interventions, it is crucial to have an understanding of how intra‐specific variation determines the relative importance of potential limiting factors. For bird populations, limiting factors include nest‐site availability and foraging resources, with the former often addressed through the provision of artificial nest‐boxes. However, the effectiveness of artificial nest‐boxes depends on the relative importance of nest‐site versus foraging resource limitation. Here, we investigate factors driving variation in breeding density, nest‐box occupation and productivity in two contrasting study populations of the European Roller Coracias garrulus, an obligate cavity‐nesting insectivorous bird. Breeding density was more than 4 times higher at the French study site than at the Latvian site, and there was a positive relationship between breeding density (at the 1‐km² scale) and nest‐site availability in France, but between breeding density and foraging resource availability in Latvia. Similarly, the probability of a nest‐box being occupied increased with predicted foraging resource availability in Latvia, but not in France. We detected no positive effect of foraging resource availability on productivity at either site, with most variation in breeding success driven by temporal effects; a seasonal decline in France, and strong inter‐annual fluctuations in Latvia. Our results indicate that the factors limiting local breeding density can vary across a species’ range, resulting in different conservation priorities. Nest‐box provisioning is a sufficient short‐term conservation solution at our French study site, where foraging resources are typically abundant, but in Latvia the restoration of foraging habitat may be more important.
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Individuals must trade‐off between energetically costly activities to maximize their fitness. However, the underlying physiological mechanism remains elusive. Oxidative stress, the imbalance between reactive oxygen species production and antioxidant and/or repair activities, has been suggested to underlie life‐history trade‐offs: greater investment in reproduction supposedly generating higher oxidative damage, thus reducing life span.
While most studies used natural or experimental variation in offspring number to examine how reproduction affects oxidative stress, none studied the impact of offspring sex, although it could influence physiological costs and fitness, if the sexes differ in terms of energetic cost.
Here, we aim at further understanding how reproduction (in terms of offspring sex, experimentally manipulated and number, not manipulated) influences oxidative stress in a wild seabird, where sons are energetically costlier than daughters. We did so by conducting a chick fostering experiment (to disentangle foster and produced sex ratio) and using four oxidative stress markers plus baseline corticosterone.
First, the results suggest that individual physiological state before laying modulates upcoming reproductive effort. Individuals with higher pre‐laying baseline corticosterone and lower antioxidant activity, estimated by their superoxide dismutase activity, subsequently invested more in reproduction, estimated by the cumulative number of days spent rearing chicks. Hence, it seems that only individuals that could afford to invest heavily in reproduction did so.
Then, we examined the effects of reproductive effort on individual physiological state at the end of the breeding season. Higher reproductive effort seemed to imply higher physiological costs. Oxidative stress, estimated by the ratio of oxidized over reduced glutathione, increased with more male‐biased foster sex ratio among mothers but not among fathers, whereas baseline corticosterone did so in both sexes. Similarly, lipid oxidative damage to red blood cells increased with increasing cumulative number of days spent rearing chicks.
Our study provides the first evidence that brood sex ratio variation can affect oxidative balance, potentially in a sex‐specific way, although more studies are needed to understand whether the observed physiological costs could lead to fitness costs. It also highlights the need to consider sex ratio in future studies investigating the role of oxidative stress in life‐history trade‐offs.
A lay summary is available for this article.
