Begging form and growth pattern of nestlings correlate with parental food-allocation patterns in the Horned Lark (Eremophilaalpestris)

2015 ◽  
Vol 93 (4) ◽  
pp. 273-279 ◽  
Author(s):  
Bo Du ◽  
Chang-Jing Liu ◽  
Shi-Jie Bao
Keyword(s):  
Reproductive Success ◽  
Growth Pattern ◽  
Brood Size ◽  
Life History Theory ◽  
Reproductive Value ◽  
Behavioral Strategies ◽  
Tarsus Length ◽  
Food Allocation ◽  
Allocation Patterns ◽  
Horned Lark

Life-history theory assumes that selection favors parents that can maximize their reproductive success via behavioral strategies. As brood size determines the reproductive value of each nestling, parents may adjust their food-allocation patterns according to brood size. We test this assumption in the Horned Lark (Eremophila alpestris (L., 1758)). Our findings revealed that nestling begging forms varied with brood size, by gaping in one-chick broods and postural activity in two- and three-chick broods. Accordingly, parental food-allocation patterns differed in different-sized broods. In one-chick broods, parents increased feeding rates with the gaping duration of nestling. In two-chick broods, parents did not change food-allocation patterns according to nestlings’ begging. In three-chick broods, however, they fed later-hatched nestlings more even when early-hatched nestlings begged more intensely. Horned Larks exhibited obvious sexual differences in parenting style and ability, which resulted in nestlings from two- and three-chick broods changing their begging intensity according to the sex of the provisioning adult. Furthermore, nestling growth pattern diverged with brood sizes, with body mass growing faster in one-chick broods than in two- and three-chick broods. Growth rate of beak gape and tarsus length did not differ significantly among brood sizes, but beak gape was larger and tarsus length was shorter in one-chick broods than in larger broods at fledging. Our results thus support the idea that parents may use food allocation to regulate sibling rivalry, which in turn cause nestlings to beg food in different forms and grow in different patterns so that their reproductive success can be enhanced.

The costs of reproduction in tree swallows (Tachycineta bicolor)

1991 ◽  
Vol 69 (10) ◽  
pp. 2540-2547 ◽  
Author(s):  
Nathaniel T. Wheelwright ◽  
Joanna Leary ◽  
Caragh Fitzgerald
Keyword(s):  
Life History ◽  
Clutch Size ◽  
Brood Size ◽  
Life History Theory ◽  
Tachycineta Bicolor ◽  
Laying Date ◽  
Tree Swallows ◽  
Costs Of Reproduction ◽  
Return Rates ◽  
Trade Offs

We investigated the effect of brood size on nestling growth and survival, parental survival, and future fecundity in tree swallows (Tachycineta bicolor) over a 4-year period (1987–1990) in an effort to understand whether reproductive trade-offs limit clutch size in birds. In addition to examining naturally varying brood sizes in a population on Kent Island, New Brunswick, Canada, we experimentally modified brood sizes, increasing or decreasing the reproductive burdens of females by two offspring. Unlike previous studies, broods of the same females were enlarged or reduced in up to 3 successive years in a search for evidence of cumulative costs of reproduction that might go undetected by a single brood manipulation. Neither observation nor experiment supported the existence of a trade-off between offspring quality and quantity, in contrast with the predictions of life-history theory. Nestling wing length, mass, and tarsus length were unrelated to brood size. Although differences between means were in the direction predicted, few differences were statistically significant, despite large sample sizes. Nestlings from small broods were no more likely to return as breeding adults than nestlings from large broods, but return rates of both groups were very low. Parental return rates were also independent of brood size, and there was no evidence of a negative effect of brood size on future fecundity (laying date, clutch size). Reproductive success, nestling size, and survival did not differ between treatments for females whose broods were manipulated in successive years. Within the range of brood sizes observed in this study, the life-history costs of feeding one or two additional nestlings in tree swallows appear to be slight and cannot explain observed clutch sizes. Costs not measured in this study, such as the production of eggs or postfledging parental care, may be more important in limiting clutch size in birds.

Effects of an introduced, novel prey on diet and reproduction in the diet-specialist European Starling (Sturnus vulgaris)

2019 ◽  
Vol 97 (3) ◽  
pp. 225-231
Author(s):  
T.D. Williams ◽  
A. Cornell ◽  
C. Gillespie ◽  
A. Hura ◽  
M. Serota
Keyword(s):  
Prey Item ◽  
Brood Size ◽  
Natural Experiment ◽  
Prey Species ◽  
Sturnus Vulgaris ◽  
European Starling ◽  
Tarsus Length ◽  
Negative Effects ◽  
Diet Specialization ◽  
Specialized Diet

Diet specialization has important consequences for how individuals or species deal with environmental change that causes changes in availability of prey species. We took advantage of a “natural experiment” — establishment of a commercial insect farm — that introduced a novel prey item, black soldier flies (Hermetia illucens (Linnaeus, 1758)), to the diet-specialist European Starling (Sturnus vulgaris Linnaeus, 1758). We investigated evidence for individual diet specialization (IDS) and the consequences of diet specialization and exploitation of novel prey on breeding productivity. In all 4 years of our study, tipulid larvae were the most common prey item. Soldier flies were not recorded in diets in 2013–2014; however, coincident with the establishment of the commercial insect farming operation, they comprised 22% and 30% of all prey items in the diets of European Starling females and males, respectively, in 2015. There was marked individual variation in use of soldier flies (4%–48% and 2%–70% in females and males, respectively), but we found little evidence of dichotomous IDS, i.e., where only some individuals have a specialized diet. We found no evidence for negative effects of use of soldier flies on breeding productivity: brood size at fledging and chick quality (mass, tarsus length) were independent of the number and proportion (%) of soldier flies returned to the nest.

scholarly journals Serial monogamy benefits both sexes in the biparental convict cichlid

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e6535 ◽  
Author(s):  
Jennifer L. Snekser ◽  
Murray Itzkowitz
Keyword(s):  
Reproductive Success ◽  
Brood Size ◽  
Parental Behavior ◽  
Convict Cichlid ◽  
Costs And Benefits ◽  
Serial Monogamy ◽  
Convict Cichlids ◽  
Amatitlania Nigrofasciata ◽  
Males And Females

Monogamy can be either long-term or serial, with new pairs formed with each breeding bout. Costs and benefits are associated with each strategy. Because biparental convict cichlids (Amatitlania nigrofasciata) typically switch mates, exhibiting serial monogamy, we tested for the costs associated with forcing individuals to remain with the same mate. Convict cichlids were observed over two successive breeding bouts, either with the same or a new, equally experienced, mate. Parental behavior did not differ between breeding bouts, nor did brood size. Surprisingly, fish that remained with their original partner for a second bout took significantly longer to produce a brood compared to fish that paired with new partners. New partners were also more likely to successfully produce a second brood than re-mated partners. This is in contrast to the majority of bird studies that show many benefits to staying with the same partner for multiple broods. In convict cichlids, there seems to be no benefit associated with remaining with the same partner and switching mates reduces duration between broods for both males and females, potentially increasing overall reproductive success.

scholarly journals Effects of manipulated levels of predation threat on parental provisioning and nestling begging

2019 ◽  
Vol 30 (4) ◽  
pp. 1123-1135 ◽  
Author(s):  
Ariane Mutzel ◽  
Anne-Lise Olsen ◽  
Kimberley J Mathot ◽  
Yimen G Araya-Ajoy ◽  
Marion Nicolaus ◽  
...  
Keyword(s):  
Life History Theory ◽  
Parus Major ◽  
Reproductive Value ◽  
Predation Threat ◽  
Growth And Survival ◽  
Provisioning Behavior ◽  
Parental Provisioning ◽  
Nestling Begging ◽  
Predator Model ◽  
Future Work

AbstractParental provisioning behavior is a major determinant of offspring growth and survival, but high provisioning rates might come at the cost of increased predation threat. Parents should thus adjust provisioning activity according to current predation threat levels. Moreover, life-history theory predicts that response to predation threat should be correlated with investment in current reproduction. We experimentally manipulated perceived predation threat in free-living great tits (Parus major) by presenting parents with a nest predator model while monitoring different aspects of provisioning behavior and nestling begging. Experiments were conducted in 2 years differing greatly in ecological conditions, including food availability. We further quantified male territorial aggressiveness and male and female exploratory tendency. Parents adjusted provisioning according to current levels of threat in an apparently adaptive way. They delayed nest visits during periods of elevated perceived predation threat and subsequently compensated for lost feeding opportunities by increasing provisioning once the immediate threat had diminished. Nestling begging increased after elevated levels of predation threat, but returned to baseline levels by the end of the experiment, suggesting that parents had fully compensated for lost feeding opportunities. There was no evidence for a link between male exploration behavior or aggressiveness and provisioning behavior. In contrast, fast-exploring females provisioned at higher rates, but only in the year with poor environmental conditions, which might indicate a greater willingness to invest in current reproduction in general. Future work should assess whether these personality-related differences in delivery rates under harsher conditions came at a cost of reduced residual reproductive value.

scholarly journals Evo–devo of child growth II: human life history and transition between its phases

2009 ◽  
Vol 160 (2) ◽  
pp. 135-141 ◽  
Author(s):  
Ze'ev Hochberg
Keyword(s):  
Body Composition ◽  
Life History ◽  
Life History Theory ◽  
Human Life ◽  
Child Growth ◽  
Social Needs ◽  
Adaptive Plasticity ◽  
Environmental Cues ◽  
Behavioral Strategies ◽  
The Times

This review attempts to use evolutionary life-history theory in understanding child growth in a broad evolutionary perspective. It uses the data and theory of evolutionary predictive adaptive strategies for transition from one life-history phase to the next, and the inherent adaptive plasticity in the timing of such transitions. Humans evolved to withstand energy crises by decreasing their body size, and evolutionary short-term adaptations to energy crises utilize a plasticity that modifies the timing of transition from infancy into childhood, culminating in short stature at the time of an energy crisis. Transition to juvenility is part of a strategy of conversion from a period of total dependence on the family and tribe for provision and security to self-supply, and a degree of adaptive plasticity is provided and determines body composition. Transition to adolescence entails plasticity in adapting to energy resources, other environmental cues, and the social needs of the maturing adolescent to determine lifespan and the period of fecundity and fertility.ConclusionLife-history transitions are the times when the child adaptively responds to environmental cues in order to enhance growth–body composition–lifespan–fecundity schedules and behavioral strategies that yield the highest fitness in a given environment.

Body mass influences maternal allocation more than parity status for a long-lived cervid mother

2019 ◽  
Vol 100 (5) ◽  
pp. 1459-1465 ◽  
Author(s):  
Eric S Michel ◽  
Stephen Demarais ◽  
Bronson K Strickland ◽  
Jerrold L Belant ◽  
Larry E Castle
Keyword(s):  
Reproductive Success ◽  
Body Mass ◽  
Litter Size ◽  
Reproductive Value ◽  
Lifetime Reproductive Success ◽  
Reproductive Tactics ◽  
High Quality ◽  
Maternal Body ◽  
Individual Offspring ◽  
Maternal Allocation

Abstract Mothers should balance the risk and reward of allocating resources to offspring to optimize the reproductive value of both offspring and mother while maximizing lifetime reproductive success by producing high-quality litters. The reproductive restraint hypothesis suggests maternal allocation should peak for prime-aged mothers and be less for younger mothers such that body condition is not diminished to a level that would jeopardize their survival or future reproductive events. We assessed if reproductive tactics varied by maternal body mass and parity status in captive female white-tailed deer (Odocoileus virginianus) to determine if prime-aged mothers allocate relatively more resources to reproduction than primiparous mothers. Maternal body mass, not parity status, positively affected maternal allocation, with heavier mothers producing both heavy litters and heavy individual offspring. Conversely, maternal body mass alone did not affect litter size, rather the interaction between maternal body mass and parity status positively affected litter size such that maternal body mass displayed a greater effect on litter size for primiparous than multiparous mothers. Our results suggest that heavy white-tailed deer mothers allocate additional resources to current year reproduction, which may be an adaptation allowing mothers to produce high-quality litters and increase their annual reproductive success because survival to the next reproductive attempt is not certain.

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