Exploring the consequences of reducing survey effort for detecting individual and temporal variability in survival

Lahoz-Monfort, Jose J. and Harris, Michael P. and Morgan, Byron J. T. and Freeman, Stephen N. and Wanless, Sarah (2014) Exploring the consequences of reducing survey effort for detecting individual and temporal variability in survival. Journal of Applied Ecology, 51 (2). pp. 534-543. ISSN 0021-8901. (doi:https://doi.org/10.1111/1365-2664.12214) (The full text of this publication is not currently available from this repository. You may be able to access a copy if URLs are provided)

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Official URL
http://dx.doi.org/10.1111/1365-2664.12214

Abstract

1. Long-term monitoring programmes often involve substantial input of skilled staff time. In mark–recapture studies, considerable effort is usually devoted to both marking and recaptur- ing/resighting individuals. Given increasing budgetary constraints, it is essential to streamline field protocols to minimize data redundancy while still achieving targets such as detecting trends or ecological effects. 2. We evaluated different levels of field effort investment in marking and resighting individu- als by resampling existing mark–recapture–recovery data to construct plausible scenarios of changes in field protocols. We demonstrate the method with 26 years data from a common guillemot Uria aalge monitoring programme at a major North Sea colony. We also assess the impact of stopping the ringing of chicks on our ability to study population demography using integrated population models (IPM) fitted to data including information on breeding adults. Different data sets were removed artificially to explore the ability to compensate for missing data. 3. Current ringing effort at this colony appears adequate but resighting effort could be halved while still maintaining the capacity to monitor first-year survival and detect the effect of hatch date on survival prospects. 4. The IPM appears robust for estimating survival, productivity or abundance of the breed- ing population, but has limited capacity to recover year-specific first-year survival when chick data are omitted. If productivity were not monitored, the inclusion of chick data would be essential to estimate it, albeit imprecisely. 5. Synthesis and applications. Post-study evaluation can help streamline existing long-term environmental monitoring programmes. To our knowledge, this study is the first use of data thinning of existing mark–recapture–recovery data to identify potential field effort reductions. We also highlight how alternative monitoring scenarios can be evaluated with integrated pop- ulation models when data are collected on different aspects of demography and abundance. When effort reduction is necessary, both approaches provide decision-support tools for adjusting field protocols to collect demographic data. The framework has broad applicability to other taxa and demographic parameters, provided suitable long-term data are available, and we discuss its use in different contexts.

Item Type: Article
Uncontrolled keywords: data thinning, hidden parameters, individual covariates, integrated population model, juvenile survival, long-term monitoring, mark–recapture–recovery, productivity, survey design, Uria aalge
Subjects: Q Science > QA Mathematics (inc Computing science) > QA276 Mathematical statistics
Q Science > QH Natural history > QH541 Ecology
Q Science > QL Zoology
Divisions: Faculties > Sciences > School of Mathematics Statistics and Actuarial Science
Faculties > Sciences > School of Mathematics Statistics and Actuarial Science > Statistics
Depositing User: Byron Morgan
Date Deposited: 30 May 2014 12:41 UTC
Last Modified: 02 Jun 2014 11:21 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/41240 (The current URI for this page, for reference purposes)
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