The role of male nest building in post-mating sexual selection in the monogamous red-necked grebe

Behaviour ◽  
2012 ◽  
Vol 149 (1) ◽  
pp. 81-98 ◽  
Author(s):  
Michał Gąska ◽  
Przemysław Grela ◽  
Janusz Kloskowski
Keyword(s):  
Interspecific Interactions ◽  
Egg Laying ◽  
Nest Building ◽  
Nest Size ◽  
Breeding Cycle ◽  
Nest Construction ◽  
Time Activity ◽  
Relative Contribution ◽  
Podiceps Grisegena

AbstractIn monogamous birds, early male parental effort, such as nest building, may serve as a post-mating sexually-selected display allowing female assessment of male quality. We examined the functional significance of male nest building and the potential role of nest size as a sexually-selected signal in the red-necked grebe ( Podiceps grisegena), a species with high mate fidelity. Time-activity budgets showed that no behaviour was performed exclusively by one sex in the pre-laying period, but males spent significantly more time nest building and were more often involved in aggressive intra- and interspecific interactions. Nest building in pairs attempting a second brood was also performed predominantly by males. Greater participation in nest construction by males allowed females to allocate more time to self-maintenance activities in the period prior to egg-laying. The positive relationship found between the relative contribution of males to nest building and later to brood provisioning indicates that male nest building is an honest indicator of future paternal effort. Males obtained copulations solicited by females proportionally to the time spent on nest building, and the extent of male participation in nest construction was of importance for explaining variation in clutch size. Nest size itself is not very likely to be sexually selected in red-necked grebes, as it was found to depend on nest site conditions such as water depth and exposure to wave action. We suggest that greater investment of males in energetically demanding pre-laying activities is functionally similar to post-mating courtship feeding; it constitutes males’ indirect contribution to clutch production and may help to negotiate the relative investment each sex makes in the different stages of the breeding cycle. The results support the idea that, in monogamous birds, naturally selected male characters related to parental care may evolve into important sexual signals to females, although not into extreme displays.

The role of estrogen and progesterone in the regulation of reproductive behaviour in female ring doves (Streptopelia risoria) under long vs. short photoperiods

1976 ◽  
Vol 54 (9) ◽  
pp. 1409-1422 ◽  
Author(s):  
N. R. Liley
Keyword(s):  
Hormone Treatment ◽  
Reproductive Behaviour ◽  
Egg Laying ◽  
Nest Building ◽  
Short Photoperiod ◽  
Streptopelia Risoria ◽  
Ring Doves ◽  
Long Photoperiod ◽  
Marked Tendency

Female ring doves held under long (16 h per day) or short (8 h per day) photoperiods were treated daily for 15 days with saline, estrogen, or progesterone, alone or in combination. Seven days after the start of hormone therapy females were placed with reproductively active males for 4 h per day for 9 days. There was no difference in egg-laying, courtship, and nest-building by control birds under the two photoregimes.Ovarian follicles remained small in all birds receiving hormone treatment. Oviducts of birds receiving progesterone alone remained small in the short-photoperiod group, but at long photoperiods oviducts became enlarged. Estrogen stimulated oviduct growth at both photoperiods. The combined hormone treatment resulted in considerably greater oviduct development than estrogen alone, and in this case the oviducts of birds under long photoperiod were significantly heavier than those of short-photoperiod birds.Female soliciting and nest-building activity remained low in progesterone-treated females under short photoperiod, but increased rapidly under long photoperiod. Birds treated with estrogen and estrogen and progesterone performed considerable soliciting and nest-building. There was a marked tendency for birds under long-photoperiod conditions to be more active in nest-oriented behaviour. Copulatory behaviour by the female (begging and sexual crouch) occurred infrequently in all hormone-treated birds.

scholarly journals Nests Without Eggs: Abandonment or Cryptic Predation?

The Auk ◽  
2006 ◽  
Vol 123 (1) ◽  
pp. 135-140
Author(s):  
J. Dylan Maddox ◽  
Patrick J. Weatherhead
Keyword(s):  
Breeding Season ◽  
Nest Predation ◽  
Egg Laying ◽  
Nest Building ◽  
Nest Construction ◽  
Accurate Identification ◽  
Video Cameras ◽  
Detailed Observation ◽  
Mate Switching ◽  
Predation Rates

AbstractWe determined whether nests that did not receive eggs was attributable to cryptic nest predation (i.e. predation of eggs laid between nest checks) or nest abandonment in Common Grackles (Quiscalus quiscula). Nest predation was extremely low (∼2%), whereas more than 44% of 427 nests found during nest building never received an egg; this indicates that nest abandonment accounted for most nests without eggs. Nest construction was completed for 32% of nests that were abandoned. Few nests known to have received eggs were abandoned. As the breeding season progressed, both nest abandonment and time from nest completion to first egg decreased. It has been proposed that the delay in egg laying early in the season allows females to optimize timing of egg laying. Nest abandonment may also serve this purpose, but seems an unnecessarily expensive mechanism. Alternatively, nest abandonment could be involved with mate switching. Understanding why nests are abandoned requires data on the associated ecological circumstances, in addition to accurate identification of instances of abandonment. The latter requires distinguishing abandonment from cryptic predation. Rates of nest abandonment can be estimated for populations by using rates of known nest predation during egg laying. For individual nests, however, distinguishing abandonment from cryptic predation requires detailed observation (e.g. video cameras), except in circumstances such as ours, where predation is extremely low.Nidos sin Huevos:?Abandono o Depredación Críptica?

scholarly journals Repeatability of nest morphology in African weaver birds

2009 ◽  
Vol 6 (2) ◽  
pp. 149-151 ◽  
Author(s):  
Patrick T. Walsh ◽  
Mike Hansell ◽  
Wendy D. Borello ◽  
Susan D. Healy
Keyword(s):  
Body Size ◽  
Breeding Season ◽  
Nest Building ◽  
Genetic Component ◽  
Nest Construction ◽  
The Village

It is generally assumed that birds build nests according to a genetic ‘template’, little influenced by learning or memory. One way to confirm the role of genetics in nest building is to assess the repeatability of nest morphology with repeated nest attempts. Solitary weaver birds, which build multiple nests in a single breeding season, are a useful group with which to do this. Here we show that repeatability of nest morphology was low, but significant, in male Southern Masked weaver birds and not significant in the Village weavers. The larger bodied Village weavers built larger nests than did Southern Masked weavers, but body size did not explain variation in Southern Masked weaver nest dimensions. Nests built by the same male in both species got shorter and lighter as more nests were constructed. While these data demonstrate the potential for a genetic component of variation in nest building in solitary weavers, it is also clear that there remains plenty of scope in both of these species for experience to shape nest construction.

scholarly journals Nest-Building Effort is Not An Indicator of Male Quality In Bonelli’s Eagles, Aquila fasciata

2021 ◽  
Author(s):  
José E. Martínez ◽  
Íñigo Zuberogoitia ◽  
José F. Calvo ◽  
Mario Álvarez ◽  
Antoni Margalida
Keyword(s):  
Breeding Success ◽  
Egg Laying ◽  
Nest Building ◽  
Male Quality ◽  
Honest Signal ◽  
Parental Quality ◽  
Relative Contribution ◽  
Sex Type ◽  
Aquila Fasciata ◽  
Building Behaviour

Abstract Raptors often use a variety of materials to build their nests (natural, such as branches, but also non-natural objects), presumably due to their insulating properties, their suitability to advertise occupancy of the nest, and to decrease pathogen and parasite loads. The amount of branches used in a nest is an indicator of parental quality and is often associated with increased breeding success. However, in raptors where both sexes collaborate in nest construction, it is unclear whether the effort expended by males (taking the amount of material carried to the nest as the potential predictor) could constitute an honest signal of parental quality to female conspecifics. We examined data on sex, type of material brought to the nest, breeding experience, timing, and nest-building investment prior to egg-laying from 32 identifiable Bonelli’s Eagles (Aquila fasciata) during the pre-laying period to investigate the relative contribution of the sexes to the amount of nest material gathered. We asked: (1) whether the nest-building investment of males could provide information to the females about their quality; and (2) whether the amount of material delivered to the nest by the male was related to breeding success. Despite the considerable investment of males in nest-building during the pre-laying period, our results indicate that this effort is not a consistent indicator of male quality to the female. Therefore, male nest-building behaviour and investment by Bonelli’s Eagles cannot be considered as an extended expression of their phenotype (an extended phenotypic signal). Nest-building behaviour by males in the early and late stages of nest-building, and the fact that males were not significantly more active builders, are discussed in the contexts of signaling nest occupancy to conspecifics and competitors, the decrease of parasite loads, and the strengthening of the pair-bond during the pre-laying period.

A study of distress calls of song, swamp, and white-throated sparrows (Aves: Fringillidae). I. Intraspecific responses and functions

1972 ◽  
Vol 50 (12) ◽  
pp. 1501-1512 ◽  
Author(s):  
Raymond A. Stefanski ◽  
J. Bruce Falls
Keyword(s):  
Close Approach ◽  
Egg Laying ◽  
Nest Building ◽  
Alarm Calls ◽  
Breeding Cycle ◽  
Major Peak ◽  
Red Squirrel ◽  
Latent Time ◽  
Distress Calls ◽  
Intraspecific Responses

Distress calls, recorded from birds captured in mist nets, were played to territorial pairs in successive stages of the breeding cycle. Responses included approach, movement about the speaker, alarm calls, and displays. Latent time to response, closeness of approach, and numbers of movements and calls were measured.Males of all three species responded strongly in the nest building and egg-laying stage and weakly in the incubation and early nestling stage, when behavior is generally cryptic. A major peak of response, characterized by close approach and distraction displays, occurred in the late nestling and fledgling stage, when young are capable of emitting distress calls. Responses declined as juveniles became independent.Responses of females were generally weaker and more variable but the major peak was still evident.When a red squirrel or blue jay was exposed during playback to white-throated sparrows in the late nestling and fledgling stage, diving attacks and distraction displays were directed toward the "predator."Distress calls, normally given by a bird seized by a predator, may startle the predator and elicit harassment and distraction behavior from other birds. A responding individual learns the characteristics and location of the predator and may facilitate the escape of its mate or young.

A Developmental Perspective on the Genetic Basis of Alcohol Use Disorder

2018 ◽  
Author(s):  
Elisa M. Trucco ◽  
Gabriel L. Schlomer ◽  
Brian M. Hicks
Keyword(s):  
Alcohol Use ◽  
Alcohol Use Disorder ◽  
Developmental Perspective ◽  
Relative Contribution ◽  
Intermediate Phenotypes ◽  
Problematic Alcohol ◽  
Age Related ◽  
Genetic And Environmental Factors ◽  
Problematic Alcohol Use

Approximately 48–66% of the variation in alcohol use disorders is heritable. This chapter provides an overview of the genetic influences that contribute to alcohol use disorder within a developmental perspective. Namely, risk for problematic alcohol use is framed as a function of age-related changes in the relative contribution of genetic and environmental factors and an end state of developmental processes. This chapter discusses the role of development in the association between genes and the environment on risk for alcohol use disorder. Designs used to identify genetic factors relevant to problematic alcohol use are discussed. Studies examining developmental pathways to alcohol use disorder with a focus on endophenotypes and intermediate phenotypes are reviewed. Finally, areas for further investigation are offered.

Sexual dimorphism in size and plumage of the polyandrous Dotterel (Charadrius morinellus): sex roles and constraints on sexual selection

1988 ◽  
Vol 66 (6) ◽  
pp. 1334-1341
Author(s):  
John Atle Kålås
Keyword(s):  
Sexual Dimorphism ◽  
Wing Length ◽  
Pair Formation ◽  
Egg Laying ◽  
Published Data ◽  
Museum Specimens ◽  
Time Activity ◽  
Monogamous Species ◽  
First Clutch ◽  
Behaviour Data

Data on live birds and previously published data reveal that female Dotterel (Charadrius morinellus) were on average larger than males for all measurements. However, sexual dimorphism on the basis of size appears weaker than expected when Dotterel are compared with closely related monogamous species. Female museum specimens have less disrupted (brighter) plumage colours than males, and dimorphism in plumage is more pronounced than it is in size. A discriminant analysis based on plumage characters did not separate the sexes totally, however. Females moult earlier in the spring than males, but summer plumage is still not fully developed for all females by the first period of pair formation, suggesting that female plumage is most important in reproduction only after the first clutch is complete. No significant differences were evident in wing length and plumage colour between 1882–1917 and 1957–1982. Time–activity studies on the polyandrous Dotterel during the arrival, prelaying, and egg-laying periods showed small differences between the sexes in the amount of time devoted to agonistic and courtship behaviour. Data from prelaying periods showed no difference between the sexes as to who initiates bouts of courtship and agonistic behaviour. The behaviour of paired birds was highly synchronized. Three hypotheses on the slight sexual dimorphism in size and plumage of this polyandrous species are presented and discussed.

Leading Sustainable CSR Efforts: A Case of Sneha Opportunity School by NLCIL

2021 ◽  
pp. 097468622110070
Author(s):  
R Vikraman ◽  
Shulagna Sarkar ◽  
K Vishnukumar ◽  
A Selvarasu
Keyword(s):  
Qualitative Data ◽  
The Self ◽  
Responsible Leadership ◽  
Time Activity ◽  
Individual Interviews

CSR is not a new practice and has been existing since ages; yet the role of a leader in driving responsible and sustainable CSR efforts is crucial. CSR is not just one-time activity and holds a high responsibility in ensuring the self-sustenance of the effort. There are very few organisations which guides its CSR efforts being sustainable. NLC India limited is one such organisation which believes in sustainable CSR efforts. The article explains the role of responsible leadership in being the drive behind enabling need based sustainable CSR efforts. The article shares the case of Sneha Opportunity School (SOS) at Neyveli, which is successful in its effort with the visionary leaders exhibiting responsible leadership over the years. Qualitative data has been collected using individual interviews of various stakeholders of the CSR initiative of SOS. The qualitative data shares perspectives on responsible leadership and SOS operations. The article also presents a model of responsible leadership in organisations leading to sustainable CSR efforts.

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