Fruit Preference Criteria by Avian Frugivores: Their Implications for the Evolution of Clutch Size in Solanum pubescens

AbstractGlucocorticoid hormones may mediate trade-offs between current and future reproduction. However, understanding their role is complicated by predation risk, which simultaneously affects the value of the current reproductive investment and elevates glucocorticoid levels. Here, we shed light on these issues in long-lived female Eiders (Somateria mollissima) by investigating how current reproductive investment (clutch size) and hatching success relate to faecal glucocorticoid metabolite [fGCM] level and residual reproductive value (minimum years of breeding experience, body condition, relative telomere length) under spatially variable predation risk. Our results showed a positive relationship between colony-specific predation risk and mean colony-specific fGCM levels. Clutch size and female fGCM were negatively correlated only under high nest predation and in females in good body condition, previously shown to have a longer life expectancy. We also found that younger females with longer telomeres had smaller clutches. The drop in hatching success with increasing fGCM levels was least pronounced under high nest predation risk, suggesting that elevated fGCM levels may allow females to ensure some reproductive success under such conditions. Hatching success was positively associated with female body condition, with relative telomere length, particularly in younger females, and with female minimum age, particularly under low predation risk, showing the utility of these metrics as indicators of individual quality. In line with a trade-off between current and future reproduction, our results show that high potential for future breeding prospects and increased predation risk shift the balance toward investment in future reproduction, with glucocorticoids playing a role in the resolution of this trade-off.

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Temporal changes in reproductive success and optimal breeding decisions in a long-distance migratory bird

Scientific Reports ◽

10.1038/s41598-020-78565-y ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Cynthia Reséndiz-Infante ◽

Gilles Gauthier

Keyword(s):

Reproductive Success ◽

Clutch Size ◽

Environmental Changes ◽

Migratory Bird ◽

Laying Date ◽

Negative Consequences ◽

Breeding Phenology ◽

Additional Time ◽

Long Distance ◽

Seasonal Decline

AbstractMany avian migrants have not adjusted breeding phenology to climate warming resulting in negative consequences for their offspring. We studied seasonal changes in reproductive success of the greater snow goose (Anser caerulescens atlantica), a long-distance migrant. As the climate warms and plant phenology advances, the mismatch between the timing of gosling hatch and peak nutritive quality of plants will increase. We predicted that optimal laying date yielding highest reproductive success occurred earlier over time and that the seasonal decline in reproductive success increased. Over 25 years, reproductive success of early breeders increased by 42%, producing a steeper seasonal decline in reproductive success. The difference between the laying date producing highest reproductive success and the median laying date of the population increased, which suggests an increase in the selection pressure for that trait. Observed clutch size was lower than clutch size yielding the highest reproductive success for most laying dates. However, at the individual level, clutch size could still be optimal if the additional time required to acquire nutrients to lay extra eggs is compensated by a reduction in reproductive success due to a delayed laying date. Nonetheless, breeding phenology may not respond sufficiently to meet future environmental changes induced by warming temperatures.

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Clutch Size in the Scincid Genus Emoia

Copeia ◽

10.2307/1441777 ◽

1968 ◽

Vol 1968 (2) ◽

pp. 417 ◽

Cited By ~ 3

Author(s):

Allen E. Greer

Keyword(s):

Clutch Size

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Impacts of ambient temperature and clutch size on incubation behaviour onset in a female‐only incubator songbird

Ibis ◽

10.1111/ibi.12937 ◽

2021 ◽

Author(s):

David Diez‐Méndez ◽

Juan José Sanz ◽

Emilio Barba

Keyword(s):

Ambient Temperature ◽

Clutch Size ◽

Incubation Behaviour

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One or two eggs: what underlies clutch size variation within a gecko species?

Zoology ◽

10.1016/j.zool.2021.125911 ◽

2021 ◽

pp. 125911

Author(s):

Osamu Sakai

Keyword(s):

Clutch Size ◽

Size Variation

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The relationship among host plant species, egg clutch size, and level of parasitism for the sharpshooter Tapajosa rubromarginata

Entomologia Experimentalis et Applicata ◽

10.1111/eea.12988 ◽

2020 ◽

Vol 168 (12) ◽

pp. 900-910

Author(s):

Eduardo G. Virla ◽

María B. Aguirre ◽

Guido A. Van Nieuwenhove ◽

Erica B. Luft Albarracin ◽

Guillermo A. Logarzo

Keyword(s):

Host Plant ◽

Clutch Size ◽

Plant Species ◽

Host Plant Species ◽

The Relationship

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First evidence for a latitudinal body mass effect in extant Crocodylia and the relationships of their reproductive characters

Biological Journal of the Linnean Society ◽

10.1093/biolinnean/blz208 ◽

2020 ◽

Vol 129 (4) ◽

pp. 875-887

Author(s):

Rebecca J Lakin ◽

Paul M Barrett ◽

Colin Stevenson ◽

Robert J Thomas ◽

Matthew A Wills

Keyword(s):

Clutch Size ◽

Body Mass ◽

Linear Models ◽

Incubation Temperature ◽

Mass Effect ◽

Distribution Patterns ◽

Egg Mass ◽

Phylogenetically Independent Contrasts ◽

Extant Species ◽

Female Body Mass

Abstract Relationships between distribution patterns and body size have been documented in many endothermic taxa. However, the evidence for these trends in ectotherms generally is equivocal, and there have been no studies of effects in crocodylians specifically. Here, we examine the relationship between latitudinal distribution and body mass in 20 extant species of crocodylians, as well as the relationships between seven important reproductive variables. Using phylogenetically independent contrasts to inform generalized linear models, we provide the first evidence of a latitudinal effect on adult female body mass in crocodylians. In addition, we explore the relationships between reproductive variables including egg mass, hatchling mass and clutch size. We report no correlation between egg mass and clutch size, upholding previously reported within-species trends. We also find no evidence of a correlation between measures of latitudinal range and incubation temperature, contrasting with the trends found in turtles.

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