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Evaluating the potential effects of capturing and handling on subsequent observations of a migratory passerine through individual acoustic monitoring

Citation

Petrusková, Tereza et al. (2021), Evaluating the potential effects of capturing and handling on subsequent observations of a migratory passerine through individual acoustic monitoring, Dryad, Dataset, https://doi.org/10.5061/dryad.cvdncjt3x

Abstract

Ringing is the most common technique used for individual marking of passerine birds, informing understanding of many aspects of their behaviour and ecology. Birds caught for ringing may also be substantially handled before release (e.g., to obtain biometric data, blood or feather samples), and all such procedures may affect the subsequent behaviour of a captured individual. Previous field studies that have assessed the potential effects of capturing and handling birds have nevertheless, to date, lacked an entirely independent unhandled control. In this study, we used individual acoustic monitoring to compare the apparent survival and re-encounter probabilities of male Tree Pipits (Anthus trivialis) that were captured with mist nets and intensively handled (measured, blood-sampled and ringed) with those of a control group of unhandled birds tracked solely by their vocalization. There were no differences between handled and unhandled birds in apparent survival rates, either in simple annual estimates, or in jointly estimated within- and between-breeding season survival estimates. Re-encounter probabilities in the latter analysis peaked at the start of the breeding season, when song activity would be expected to be greatest, but were higher for handled than unhandled birds in mid- to late May. Apart from demonstrating that Tree Pipits were not affected in the long-term by capture and associated handling, our study confirms that individual acoustic monitoring is a valuable non-intrusive method for long-term monitoring studies.

Methods

Indidivual acoustic monitoring (IAM) was used to track territorial Tree Pipit males and evaluate their apparent survival within and between seasons over nine years at a Central European locality. Part of these males were previously caught by mist netting (and further handled, including ringing and blood sampling), part was only tracked by IAM as a control group. No difference in apparent survival between groups was observed.

Usage Notes

Three files described below are provided. This description is also included in README.TXT:

male and observation info.xlsx

This file in MS Excel format contains two sheets:
1: bird info: summary information for each individual Tree Pipit male recorded at the studied locality. For each bird, the following information is provided: male ID, dates of first and last observation based on individual acoustic monitoring (IAM) within the study period (2011-2019), ringing date and ring number (if relevant), years in which the male was recorded at the locality, years and dates when a territory change was observed during the breeding season, and reasons why a particular male was excluded from further analysis (if relevant).

2: observation dates: list of all dates when a particular male was recorded at the locality through IAM.
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MARK-annual.inp

An input file for capture-mark–recapture Cormack–Jolly–Seber analyses in the MARK program, focusing on apparent annual survival. For each year, presence or absence of a particular male at the locality from April 21 to 9 July on is indicated; the males are divided into groups based on their handling status (unhandled/handled).
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MARK-season.inp

An input file for capture-mark–recapture Cormack–Jolly–Seber analyses in the MARK program, focusing on both apparent within-breeding season survival and apparent between-breeding season survival. For each year, presence or absence of a particular male at the locality in four 20-day blocks (21 April–10 May, 11–30 May, 31 May–19 June, 20 June–9 July) is indicated; the males are divided into groups based on their handling status (unhandled/handled).

Funding

Charles University, Award: SVV 260569

Charles University, Award: SVV 260569