Photoperiodic and physiological adaptations regulating avian breeding cycles and their ecological significance

Lofts, B.; Murton, R. K.

doi:10.1111/j.1469-7998.1968.tb03056.x

Cited by 246 publications

(74 citation statements)

References 219 publications

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“…Stokkan et al 1986Stokkan et al , 1988. In contrast, regulation of breeding and moult appear to be independent of photoperiod in the rock dove (Lofts & Murton 1968). Finite stage diversity may help identify where possible differences, or similarities, in environmental and endocrine mechanisms may exist, and also indicate what experiments need to be performed.…”

Section: Implications For Endocrine Control Mechanismsmentioning

confidence: 99%

Organization of vertebrate annual cycles: implications for control mechanisms

Wingfield

2007

Phil. Trans. R. Soc. B

211

199

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The majority of vertebrates have a life span of greater than one year. Therefore individuals must be able to adapt to the annual cycle of changing conditions by adjusting morphology, physiology and behaviour. Phenotypic flexibility, in which an individual switches from one life history stage to another, is one way to maximize fitness in a changing environment. When environmental variation is low, few life history stages are needed. If environmental variation is large, there are more life history stages. Each life history stage has a characteristic set of sub-stages that can be expressed in various combinations and patterns to determine state at any point in the life of the individual. Thus individuals have a finite number of states that can be expressed over the spectrum of environmental conditions in their life spans. Life history stages have three phases-development, mature capability (when characteristic sub-stages can be expressed) and termination. Expression of a stage is time dependent (probably a minimum of one month), and termination of one stage overlaps development of the next stage. It follows that the more life history stages an individual expresses, the less flexibility it will have in timing those stages. Having fewer life history stages increases flexibility in timing, but less tolerance of variation in environmental conditions. To varying degrees it is possible to overlap mature capability of some life history stages to effectively reduce 'finite stage diversity' and maximize flexibility in timing. Theoretical ways by which this can be done, and the implications for neuroendocrine and endocrine control mechanisms are discussed. Twelve testable hypotheses are posed that relate directly to control mechanisms.

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Section: Implications For Endocrine Control Mechanismsmentioning

confidence: 99%

Organization of vertebrate annual cycles: implications for control mechanisms

Wingfield

2007

Phil. Trans. R. Soc. B

211

199

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“…However, because maintaining functional gonads throughout the year is energetically costly and because birds have high energy turnover relative to body weight and are unable to store large amounts of resources, they are income breeders tightly dependent on food availability (Martin 1987). Several studies suggest that the onset of the breeding season in tropical birds is triggered by rainfall and its associated pulses in food abundance (e.g., Lofts 1964;Lofts and Murton 1968;Poulin et al 1992;Hau et al 2008). Thus, one expects individuals dispersing into a population with a distinct precipitation regime to experience reduced fitness owing to a mismatch in breeding condition with respect to local individuals.…”

Section: Introductionmentioning

confidence: 99%

Asynchrony of Seasons: Genetic Differentiation Associated with Geographic Variation in Climatic Seasonality and Reproductive Phenology

Quintero

González‐Caro

Zalamea

et al. 2014

The American Naturalist

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JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. abstract: Many organisms exhibit distinct breeding seasons tracking food availability. If conspecific populations inhabit areas that experience different temporal cycles in food availability spurred by variation in precipitation regimes, then they should display asynchronous breeding seasons. Thus, such populations might exhibit a temporal barrier to gene flow, which may potentially promote genetic differentiation. We test a central prediction of this hypothesis, namely, that individuals living in areas with more asynchronous precipitation regimes should be more genetically differentiated than individuals living in areas with more similar precipitation regimes. Using mitochondrial DNA sequences, climatic data, and geographical/ecological distances between individuals of 57 New World bird species mostly from the tropics, we examined the effect of asynchronous precipitation (a proxy for asynchronous resource availability) on genetic differentiation. We found evidence for a positive and significant cross-species effect of precipitation asynchrony on genetic distance after accounting for geographical/ecological distances, suggesting that current climatic conditions may play a role in population differentiation. Spatial asynchrony in climate may thus drive evolutionary divergence in the absence of overt geographic barriers to gene flow; this mechanism contrasts with those invoked by most models of biotic diversification emphasizing physical or ecological changes to the landscape as drivers of divergence.

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“…(e.g. [1][2][3][4][5]). Thus, animals avoid the overlapping of life-history stages that are energetically expensive and could affect fitness negatively.…”

Section: Introductionmentioning

confidence: 99%

How birds cope physiologically and behaviourally with extreme climatic events

Wingfield

Pérez

Krause

et al. 2017

Phil. Trans. R. Soc. B

103

114

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One contribution of 14 to a theme issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. As global climate change progresses, the occurrence of potentially disruptive climatic events such as storms are increasing in frequency, duration and intensity resulting in higher mortality and reduced reproductive success. What constitutes an extreme climatic event? First we point out that extreme climatic events in biological contexts can occur in any environment. Focusing on field and laboratory data on wild birds we propose a mechanistic approach to defining and investigating what extreme climatic events are and how animals cope with them at physiological and behavioural levels. The life cycle of birds is made up of life-history stages such as migration, breeding and moult that evolved to match a range of environmental conditions an individual might expect during the year. When environmental conditions deteriorate and deviate from the expected range then the individual must trigger coping mechanisms (emergency life-history stage) that will disrupt the temporal progression of life-history stages, but enhance survival. Using the framework of allostasis, we argue that an extreme climatic event in biological contexts can be defined as when the cumulative resources available to an individual are exceeded by the sum of its energetic costs-a state called allostatic overload. This allostatic overload triggers the emergency life-history stage that temporarily allows the individual to cease regular activities in an attempt to survive extreme conditions. We propose that glucocorticoid hormones play a major role in orchestrating coping mechanisms and are critical for enduring extreme climatic events.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'.

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Photoperiodic and physiological adaptations regulating avian breeding cycles and their ecological significance

Cited by 246 publications

References 219 publications

Organization of vertebrate annual cycles: implications for control mechanisms

Organization of vertebrate annual cycles: implications for control mechanisms

Asynchrony of Seasons: Genetic Differentiation Associated with Geographic Variation in Climatic Seasonality and Reproductive Phenology

How birds cope physiologically and behaviourally with extreme climatic events

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