Endocrine Control of Life-Cycle Stages: A Constraint on Response to the Environment?

Abstract Most organisms live in seasonal environments that fluctuate on a predictable schedule and sometimes unpredictably. Individuals must, therefore, adjust so as to maximize their survival and reproductive success over a wide range of environmental conditions. In birds, as in other vertebrates,...

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Published in:The Condor
Main Authors: Jacobs, Jerry D., Wingfield, John C.
Format: Article in Journal/Newspaper
Language:English
Published: Oxford University Press (OUP) 2000
Subjects:
Online Access:http://dx.doi.org/10.1093/condor/102.1.35
http://academic.oup.com/condor/article-pdf/102/1/35/29709650/condor0035.pdf
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spelling croxfordunivpr:10.1093/condor/102.1.35 2024-09-15T17:52:18+00:00 Endocrine Control of Life-Cycle Stages: A Constraint on Response to the Environment? Jacobs, Jerry D. Wingfield, John C. 2000 http://dx.doi.org/10.1093/condor/102.1.35 http://academic.oup.com/condor/article-pdf/102/1/35/29709650/condor0035.pdf en eng Oxford University Press (OUP) The Condor volume 102, issue 1, page 35-51 ISSN 0010-5422 1938-5129 journal-article 2000 croxfordunivpr https://doi.org/10.1093/condor/102.1.35 2024-08-12T04:24:06Z Abstract Most organisms live in seasonal environments that fluctuate on a predictable schedule and sometimes unpredictably. Individuals must, therefore, adjust so as to maximize their survival and reproductive success over a wide range of environmental conditions. In birds, as in other vertebrates, endocrine secretions regulate morphological, physiological, and behavioral changes in anticipation of future events. The individual thus prepares for predictable fluctuations in its environment by changing life-cycle stages. We have applied finite-state machine theory to define and compare different life-history cycles. The ability of birds to respond to predictable and unpredictable regimes of environmental variation may be constrained by the adaptability of their endocrine control systems. We have applied several theoretical approaches to natural history data of birds to compare the complexity of life cycles, the degree of plasticity of timing of stages within the cycle, and to determine whether endocrine control mechanisms influence the way birds respond to their environments. The interactions of environmental cues on the timing of life-history stages are not uniform in all populations. Taking the reproductive life-history stage as an example, arctic birds that have short breeding seasons in severe environments appear to use one reliable environmental cue to time reproduction and they ignore other factors. Birds having longer breeding seasons exhibit greater plasticity of onset and termination and appear to integrate several environmental cues. Theoretical approaches may allow us to predict how individuals respond to their environment at the proximate level and, conversely, predict how constraints imposed by endocrine control systems may limit the complexity of life cycles. Article in Journal/Newspaper Arctic birds Oxford University Press The Condor 102 1 35 51
institution Open Polar
collection Oxford University Press
op_collection_id croxfordunivpr
language English
description Abstract Most organisms live in seasonal environments that fluctuate on a predictable schedule and sometimes unpredictably. Individuals must, therefore, adjust so as to maximize their survival and reproductive success over a wide range of environmental conditions. In birds, as in other vertebrates, endocrine secretions regulate morphological, physiological, and behavioral changes in anticipation of future events. The individual thus prepares for predictable fluctuations in its environment by changing life-cycle stages. We have applied finite-state machine theory to define and compare different life-history cycles. The ability of birds to respond to predictable and unpredictable regimes of environmental variation may be constrained by the adaptability of their endocrine control systems. We have applied several theoretical approaches to natural history data of birds to compare the complexity of life cycles, the degree of plasticity of timing of stages within the cycle, and to determine whether endocrine control mechanisms influence the way birds respond to their environments. The interactions of environmental cues on the timing of life-history stages are not uniform in all populations. Taking the reproductive life-history stage as an example, arctic birds that have short breeding seasons in severe environments appear to use one reliable environmental cue to time reproduction and they ignore other factors. Birds having longer breeding seasons exhibit greater plasticity of onset and termination and appear to integrate several environmental cues. Theoretical approaches may allow us to predict how individuals respond to their environment at the proximate level and, conversely, predict how constraints imposed by endocrine control systems may limit the complexity of life cycles.
format Article in Journal/Newspaper
author Jacobs, Jerry D.
Wingfield, John C.
spellingShingle Jacobs, Jerry D.
Wingfield, John C.
Endocrine Control of Life-Cycle Stages: A Constraint on Response to the Environment?
author_facet Jacobs, Jerry D.
Wingfield, John C.
author_sort Jacobs, Jerry D.
title Endocrine Control of Life-Cycle Stages: A Constraint on Response to the Environment?
title_short Endocrine Control of Life-Cycle Stages: A Constraint on Response to the Environment?
title_full Endocrine Control of Life-Cycle Stages: A Constraint on Response to the Environment?
title_fullStr Endocrine Control of Life-Cycle Stages: A Constraint on Response to the Environment?
title_full_unstemmed Endocrine Control of Life-Cycle Stages: A Constraint on Response to the Environment?
title_sort endocrine control of life-cycle stages: a constraint on response to the environment?
publisher Oxford University Press (OUP)
publishDate 2000
url http://dx.doi.org/10.1093/condor/102.1.35
http://academic.oup.com/condor/article-pdf/102/1/35/29709650/condor0035.pdf
genre Arctic birds
genre_facet Arctic birds
op_source The Condor
volume 102, issue 1, page 35-51
ISSN 0010-5422 1938-5129
op_doi https://doi.org/10.1093/condor/102.1.35
container_title The Condor
container_volume 102
container_issue 1
container_start_page 35
op_container_end_page 51
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