Reproductive conflict between laying workers in the ant Aphaenogaster senilis

The hypothesis that proximal factors associated with high worker density in a bumble bee (Bombus terricola) colony trigger laying of male eggs by the queen was examined in a series of four experiments. Neither the age of workers, the presence or absence of laying workers, nor the amount of pollen available to the colony affected the date of first male egg laying. Moreover, queens that had begun laying male eggs did not revert to laying female eggs after being removed from their colonies and placed in isolation. Instead, onset of male egg production appeared to be associated with the date of attainment of a critical worker/larva ratio in the colony. Functional considerations lead to the new hypothesis that queens monitor their egg-laying performance and begin to lay male eggs when it can be predicted that their female eggs will be raised as young queens.

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A long post-reproductive lifespan is a shared trait among genetically distinct killer whale populations

10.22541/au.161460887.74001987/v1 ◽

2021 ◽

Author(s):

Mia Nielsen ◽

Samuel Ellis ◽

Jared Towers ◽

Thomas Doniol-Valcroze ◽

Daniel Franks ◽

...

Keyword(s):

Social Structure ◽

Killer Whale ◽

Demographic Data ◽

Reproductive Period ◽

Substantial Variation ◽

Killer Whales ◽

Reproductive Conflict ◽

Demographic Patterns ◽

General Prediction

The extended female post-reproductive lifespan found in humans and some toothed whales remains an evolutionary puzzle. Theory predicts demographic patterns resulting in increased female relatedness with age (kinship dynamics) can select for a prolonged post-reproductive lifespan due to the combined costs of inter-generational reproductive conflict and benefits of late-life helping. Here we test this prediction using >40 years of longitudinal demographic data from the sympatric yet genetically distinct killer whale ecotypes: resident and Bigg’s killer whales. The female relatedness with age is predicted to increase in both ecotypes, but with a less steep increase in Bigg’s due to their different social structure. Here, we show that there is a significant post-reproductive lifespan in both ecotypes with >30% of adult female years being lived as post-reproductive, supporting the general prediction that an increase in local relatedness with age predisposes the evolution of a post-reproductive lifespan. Differences in the magnitude of kinship dynamics however, did not influence the timing or duration of the post-reproductive lifespan with females in both ecotypes terminating reproduction before their mid-40s followed by an expected post-reproductive period of ~20 years. Our results highlight the important role of kinship dynamics in the evolution of a long post-reproductive lifespan in long-lived mammals, while further implying that the timing of menopause may be a robust trait that is persistent despite substantial variation in demographic patterns among population.

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Life history and demography of an uncooperative Australian passerine, the brown thornbill

Australian Journal of Zoology ◽

10.1071/zo99052 ◽

1999 ◽

Vol 47 (6) ◽

pp. 633 ◽

Cited By ~ 25

Author(s):

David J. Green ◽

Andrew Cockburn

Keyword(s):

Phylogenetic Analysis ◽

Life History ◽

Breeding Season ◽

Cooperative Breeding ◽

Mating Systems ◽

Survival Rates ◽

Reproductive Conflict ◽

Annual Survival ◽

Shed Light ◽

C 63

The genus Acanthiza may be important in understanding the evolution of avian mating systems because while brown thornbills, Acanthiza pusilla, are thought to breed only in pairs, a recent phylogenetic analysis suggests that cooperative breeding is the ancestral trait within this genus. We provide a detailed account of the breeding biology of the brown thornbill, confirm that they breed exclusively in pairs, and compare their population demography with what is known for other members of the Pardalotidae. We found that brown thornbills produced small clutches (3 eggs) with a two-day laying interval, had a long incubation period (declining from 19 to 16 days through the season), and had a long breeding season (4.0 months) that allowed females to occasionally raise two successful broods. Brown thornbills, in our study, produced an average of 1.57 fledglings per pair and had relatively high annual survival rates (c. 63%). We found no evidence to suggest that the evolution of pair-breeding within the Pardalotidae is associated with a reduction in annual survival rates, a short breeding season with reduced productivity, or high levels of predation post-fledging. Since there also appear to be no ecological correlates with mating system in the Pardalotidae we suggest that examination of reproductive conflict between parents and young may shed light on the evolution of pairbreeding in this family.

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Reproductive conflict in animal societies: hierarchy length increases with colony size in queenless ponerine ants

Behavioral Ecology and Sociobiology ◽

10.1007/s00265-003-0600-9 ◽

2003 ◽

Vol 54 (1) ◽

pp. 71-79 ◽

Cited By ~ 24

Author(s):

Thibaud Monnin ◽

Francis L. W. Ratnieks ◽

Carlos R. F. Brand�o

Keyword(s):

Colony Size ◽

Reproductive Conflict ◽

Ponerine Ants ◽

Hierarchy Length ◽

Animal Societies

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THE ROLE OF NUTRITION AND TEMPERATURE IN THE OVARIAN DEVELOPMENT OF THE WORKER HONEY BEE (APIS MELLIFERA)

The Canadian Entomologist ◽

10.4039/ent130883-6 ◽

1998 ◽

Vol 130 (6) ◽

pp. 883-891 ◽

Cited By ~ 32

Author(s):

Huarong Lin ◽

Mark L. Winston

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Nutritive Value ◽

Royal Jelly ◽

Ovarian Development ◽

Egg Laying ◽

Brood Chamber ◽

Laying Workers

AbstractQueenless, caged, newly emerged worker bees (Apis mellifera L.) were fed honey, 22 and 40% pollen in honey, and 22 and 40% royal jelly in honey for 14 days. Workers fed royal jelly, pollen, and honey had large, medium, and small ovaries, respectively. Royal jelly had higher nutritive value for workers’ ovarian development than did pollen, possibly because royal jelly is predigested by nurse bees and easily used by adult and larval bees. These results suggest that nurse bees could mediate workers’ ovarian development in colonies via trophallactic exchange of royal jelly. Six levels of royal jelly in honey, 0, 20, 40, 60, 80, and 100% (royal jelly without honey), were tested for their effects on workers’ ovarian development and mortality for 10 days. High levels of royal jelly increased ovarian development, but also increased worker mortality. All caged bees treated with 100% royal jelly died within 3 days. When workers were incubated at 20, 27, and 34 °C for 10 days, only bees at 34 °C developed ovaries. These findings suggest that nurse bees functioning as units which digest pollen and produce royal jelly may feed some potentially egg-laying workers in a brood chamber with royal jelly when a queen is lost in a colony. Feeding workers a diet of 50% royal jelly in honey and incubating at 34 °C for 10 days is recommended for tests of ovarian development.

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Power and punishment influence negotiations over parental care

Behavioral Ecology ◽

10.1093/beheco/araa034 ◽

2020 ◽

Vol 31 (4) ◽

pp. 911-921 ◽

Cited By ~ 1

Author(s):

Tina A Barbasch ◽

Suzanne H Alonzo ◽

Peter M Buston

Keyword(s):

Social Interactions ◽

Behavioral Response ◽

Social Groups ◽

The Other ◽

Reproductive Conflict ◽

Negotiation Model ◽

Rank 2 ◽

Evolutionary Consequences ◽

Total Effort ◽

Partial Compensation

Abstract Asymmetries in power (the ability to influence the outcome of conflict) are ubiquitous in social interactions because interacting individuals are rarely identical. It is well documented that asymmetries in power influence the outcome of reproductive conflict in social groups. Yet power asymmetries have received little attention in the context of negotiations between caring parents, which is surprising given that parents are often markedly different in size. Here we built on an existing negotiation model to examine how power and punishment influence negotiations over care. We incorporated power asymmetry by allowing the more-powerful parent, rank 1, to inflict punishment on the less-powerful parent, rank 2. We then determined when punishment will be favored by selection and how it would affect the negotiated behavioral response of each parent. We found that with power and punishment, a reduction in one parent’s effort results in partial compensation by the other parent. However, the degree of compensation is asymmetric: the rank 2 compensates more than the rank 1. As a result, the fitness of rank 1 increases and the fitness of rank 2 decreases, relative to the original negotiation model. Furthermore, because power and punishment enable one parent to extract greater effort from the other, offspring can do better, that is, receive more total effort, when there is power and punishment involved in negotiations over care. These results reveal how power and punishment alter the outcome of conflict between parents and affect offspring, providing insights into the evolutionary consequences of exerting power in negotiations.

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