An Overview of Proximate Factors Affecting Reproductive Success in Colonial Birds: Concluding Remarks and Summary of Panel Discussion

1982 ◽  
Vol 5 ◽  
pp. 58 ◽  
Author(s):  
Joanna Burger
Keyword(s):  
Reproductive Success ◽  
Panel Discussion ◽  
Factors Affecting ◽  
Colonial Birds ◽  
Proximate Factors

scholarly journals A comparative study on the reproductive success of two rewarding Habenaria species (Orchidaceae) occurring in roadside verge habitats

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Wenliu Zhang ◽  
Jiangyun Gao
Keyword(s):  
Reproductive Success ◽  
Fruit Set ◽  
Plant Density ◽  
Flowering Plant ◽  
Floral Display ◽  
Pollinator Behaviour ◽  
Factors Affecting ◽  
Nectar Sugar ◽  
Viable Seeds ◽  
Viable Embryo

Abstract Background Most orchid species have been shown to be severely pollination limited, and the factors affecting reproductive success have been widely studied. However, the factors determining the reproductive success vary from species to species. Habenaria species typically produce nectar but exhibit variable fruit set and reproductive success among species. Here, we investigated the influence of the flowering plant density, inflorescence size, breeding system, and pollinator behaviour on the reproductive success of two rewarding Habenaria species. Results Our observations indicated that Habenaria limprichtii and H. petelotii co-occur in roadside verge habitats and present overlapping flowering periods. Both species were pollination limited, although H. limprichtii produced more fruits than H. petelotii under natural conditions during the 3-year investigation. H. petelotii individuals formed distinct patches along roadsides, while nearly all H. limprichtii individuals clustered together. The bigger floral display and higher nectar sugar concentration in H. limprichtii resulted in increased attraction and visits from pollinators. Three species of effective moths pollinated for H. limprichtii, while Thinopteryx delectans (Geometridae) was the exclusive pollinator of H. petelotii. The percentage of viable seeds was significantly lower for hand geitonogamy than for hand cross-pollination in both species. However, H. limprichtii may often be geitonogamously pollinated based on the behaviours of the pollinators and viable embryo assessment. Conclusions In anthropogenic interference habitats, the behaviours and abundance of pollinators influence the fruit set of the two studied species. The different pollinator assemblages in H. limprichtii can alleviate pollinator specificity and ensure reproductive success, whereas the more viable embryos of natural fruit seeds in H. petelotii suggested reducing geitonogamy by pollinators in the field. Our results indicate that a quantity-quality trade-off must occur between species with different breeding strategies so that they can fully exploit the existing given resources.

Factors affecting pollinator visitation and reproductive success in Sonneratia caseolaris and Aegiceras corniculatum in a mangrove forest in India

2001 ◽  
Vol 17 (3) ◽  
pp. 431-447 ◽  
Author(s):  
SHALINI PANDIT ◽  
B. C. CHOUDHURY
Keyword(s):  
Reproductive Success ◽  
Mangrove Forest ◽  
Time Of Day ◽  
Pollinator Visitation ◽  
Aegiceras Corniculatum ◽  
Factors Affecting ◽  
Plant Reproductive Success ◽  
Sonneratia Caseolaris ◽  
Exclusion Experiments ◽  
Selfing Species

Pollinator visitation to, and the reproductive success of, Sonneratia caseolaris (Sonneratiaceae) and Aegiceras corniculatum (Myrsinaceae) was investigated in a mangrove forest in India. S. caseolaris was shown to be primarily outcrossed and A. corniculatum was shown to be a selfing species. The flowers of both plant species attracted several diurnal and nocturnal visitors. Earlier reports had indicated that S. caseolaris flowered for one night and was exclusively night-pollinated. But flowers of this species were found to be in bloom both at night and during the day, and diurnal visitors to the flowers were more diverse and frequent than nocturnal ones. This was related to the higher volume and energy value of nectar in the morning. The effects of time of day and temperature on visitation rates were quantified. The importance of visitors to plant reproductive success was investigated via controlled visitor-exclusion experiments. Pollinators were expected to be more important for the outcrossing species than for the selfing species, and this was confirmed by the results of the exclusion experiments. In S. caseolaris reproductive success was determined both by pollinator availability and the intensity of flower and fruit predation, while in A. corniculatum it is likely to be resource limited.

Factors affecting brood abandonment in gadwalls (Anas strepera)

2000 ◽  
Vol 78 (2) ◽  
pp. 327-331 ◽  
Author(s):  
Michel Gendron ◽  
Robert G Clark
Keyword(s):  
Body Condition ◽  
Brood Size ◽  
Female Body ◽  
Confounding Factor ◽  
Factors Affecting ◽  
Proximate Factors ◽  
Anas Strepera ◽  
Brood Desertion ◽  
Brood Success

Brood desertion by radio-equipped female gadwalls (Anas strepera) was examined to test three hypotheses regarding proximate factors responsible for post hatch brood abandonment in waterfowl. Gadwall broods with the greatest duckling mortality, independent of brood size, were more likely to be abandoned, providing support for the "brood-success" hypothesis. Our results do not support the "brood-size" hypothesis, as the size of broods immediately prior to female abandonment was no smaller than the size of broods not abandoned. Although brood fate was not related to female body condition, the "salvage-strategy" hypothesis could not be rejected, because experience was a confounding factor and could not be sampled adequately; younger, possibly less-experienced females were more likely to abandon their broods than older females. Further studies, preferably involving experimental manipulations, are needed to adequately address the full array of hypotheses.

Proximate Factors Affecting Male Elk Hunting Mortality in Northern Idaho

2002 ◽  
Vol 66 (2) ◽  
pp. 491 ◽  
Author(s):  
Stephen G. Hayes ◽  
David J. Leptich ◽  
Peter Zager
Keyword(s):  
Factors Affecting ◽  
Proximate Factors ◽  
Hunting Mortality ◽  
Elk Hunting ◽  
Northern Idaho

Passing the baton

2016 ◽  
Vol 24 (3) ◽  
pp. 35-37 ◽  
Author(s):  
Pauline Drury
Keyword(s):  
Family Business ◽  
Succession Planning ◽  
Family Firms ◽  
Longitudinal Research ◽  
Panel Discussion ◽  
Psychological Impact ◽  
Food Group ◽  
Content Type ◽  
Factors Affecting ◽  
The Family

Purpose The purpose of this paper is to consider the factors affecting the success of succession planning in family businesses. Design/methodology/approach The study reports on a panel discussion in which the former chairman of the William Jackson Food Group describes the processes put in place to manage succession at this family firm and his own experience of handing over to his successor. Findings Once upon a time, saying that you were going into the family business marked the end of any career discussion. Now it’s just the beginning – interest in family firms has never been greater. Succession planning is a subject guaranteed to generate questions – everyone wants to know how to get it right. Fortunately, it’s an area where some are happy to share their experience. Research limitations/implications The paper highlights the need for more longitudinal research on family firms. Practical implications This paper provides a practical guide to structures and processes that can facilitate succession planning in family firms. Social implications It draws attention to the emotional and psychological impact of succession on the retiring individual and the need to create life structures to replace former business involvement. Originality/value This paper aims to present a frank discussion of the approach to succession planning taken by one family business and the broader research questions that it raises.

Factors affecting the reproductive success of common tern (Sterna hirundo) colonies on the lower Great Lakes during the summer of 1972

1976 ◽  
Vol 54 (11) ◽  
pp. 1850-1862 ◽  
Author(s):  
Ralph D. Morris ◽  
Rodger A. Hunter ◽  
James F. McElman
Keyword(s):  
Reproductive Success ◽  
Great Lakes ◽  
Clutch Size ◽  
Relative Proportion ◽  
Common Tern ◽  
Sterna Hirundo ◽  
Success Rates ◽  
Factors Affecting ◽  
Fledging Success ◽  
Egg Failure

The breeding biology of five common tern (Sterna hirundo) colonies in the lower Great Lakes was studied between May and August 1972. Frequent visits were made to each colony and data collected on nests within large artificially enclosed areas. The objective was to identify factors that influence the reproductive success of common tern colonies on the Great Lakes. Hatching success was significantly dependent on clutch size and time of clutch initiation, whereas fledging success was independent of clutch size. The most common category of egg failure was disappearance from the nest. One colony (Port Colborne) realized a significantly higher hatching and fledging success than the others, among which there were no significant differences in prehatch or posthatch success rates. Factors that contributed to differences in reproductive success are presented and their relative contributions to the reproductive success of the tern colonies are discussed. The factors include the relative proportion of three-egg clutches, incubation time as a measure of 'parent attentiveness,' numerical size of the colony, predation, competition for nesting sites by gulls, food availability, flooding, and toxic chemicals. We conclude that no single factor can be readily correlated with reproductive success and suggest that caution should be exercised when considering the relationships between reproductive success and factors influencing it.

Factors affecting the reproductive success of dominant male meerkats

2008 ◽  
Vol 17 (9) ◽  
pp. 2287-2299 ◽  
Author(s):  
GÖRAN F. SPONG ◽  
SARAH J. HODGE ◽  
ANDREW J. YOUNG ◽  
TIM H. CLUTTON-BROCK
Keyword(s):  
Reproductive Success ◽  
Dominant Male ◽  
Factors Affecting
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