TY - JOUR

T1 - Weak effects of geolocators on small birds

T2 - a meta-analysis controlled for phylogeny and publication bias

AU - Brlík, Vojtěch

AU - Koleček, Jaroslav

AU - Burgess, Malcolm

AU - Hahn, Steffen

AU - Humple, Diana

AU - Krist, Miloš

AU - Ouwehand, Janne

AU - Weiser, Emily

AU - Adamík, Peter

AU - Alves, José

AU - Arlt, Debora

AU - Barišić, Sanja

AU - Becker, Detlef

AU - Belda, Eduardo

AU - Beran, Václav

AU - Both, Christiaan

AU - Bravo, Susana

AU - Briedis, Martins

AU - Chutný, Bohumír

AU - Ćiković, Davor

AU - Cooper, Nathan

AU - Costa, Joana

AU - Cueto, Víctor

AU - Emmenegger, Tamara

AU - Fraser, Kevin

AU - Gilg, Olivier

AU - Guerrero, Marina

AU - Hallworth, Michael

AU - Hewson, Chris

AU - Johnson, James

AU - Jiguet, Frédéric

AU - Kelly, Tosha

AU - Kishkinev, Dmitry

AU - Leconte, Michel

AU - Lislevand, Terje

AU - Lisovski, Simeon

AU - López, Cosme

AU - McFarland, Kent

AU - Marra, Peter

AU - Matsuoka, Steven

AU - Matyjasiak, Piotr

AU - Meier, Christoph

AU - Metzger, Benjamin

AU - Monrós, Juan

AU - Neumann, Roland

AU - Newman, Amy

AU - Norris, Ryan

AU - Pärt, Tomas

AU - Pavel, Václav

AU - Perlut, Noah

AU - Piha, Markus

AU - Reneerkens, Jeroen

AU - Rimmer, Christopher

AU - Roberto-Charron, Amélie

AU - Scandolara, Chiara

AU - Sokolova, Natasha

AU - Takenaka, Makiko

AU - Tolkmitt, Dirk

AU - van Oosten, Herman

AU - Wellbrock, Arndt

AU - Wheeler, Hazel

AU - van der Winden, Jan

AU - Witte, Klaudia

AU - Woodworth, Brad

AU - Procházka, Petr

PY - 2020/1

Y1 - 2020/1

N2 - 1. Currently, the deployment of tracking devices is one of the most frequently used approaches to study movement ecology of birds. Recent miniaturisation of light-level geolocators enabled studying small bird species whose migratory patterns were widely unknown. However, geolocators may reduce vital rates in tagged birds and may bias obtained movement data. 2. There is a need for a thorough assessment of the potential tag effects on small birds, as previous meta-analyses did not evaluate unpublished data and impact of multiple life-history traits, focused mainly on large species and the number of published studies tagging small birds has increased substantially. 3. We quantitatively reviewed 549 records extracted from 74 published and 48 unpublished studies on over 7,800 tagged and 17,800 control individuals to examine the effects of geolocator tagging on small bird species (body mass <100 g). We calculated the effect of tagging on apparent survival, condition, phenology and breeding performance and identified the most important predictors of the magnitude of effect sizes. 4. Even though the effects were not statistically significant in phylogenetically controlled models, we found a weak negative impact of geolocators on apparent survival. The negative effect on apparent survival was stronger with increasing relative load of the device and with geolocators attached using elastic harnesses. Moreover, tagging effects were stronger in smaller species. 5. In conclusion, we found a weak effect on apparent survival of tagged birds and managed to pinpoint key aspects and drivers of tagging effects. We provide recommendations for establishing matched control group for proper effect size assessment in future studies and outline various aspects of tagging that need further investigation. Finally, our results encourage further use of geolocators on small bird species but the ethical aspects and scientific benefits should always be considered.

AB - 1. Currently, the deployment of tracking devices is one of the most frequently used approaches to study movement ecology of birds. Recent miniaturisation of light-level geolocators enabled studying small bird species whose migratory patterns were widely unknown. However, geolocators may reduce vital rates in tagged birds and may bias obtained movement data. 2. There is a need for a thorough assessment of the potential tag effects on small birds, as previous meta-analyses did not evaluate unpublished data and impact of multiple life-history traits, focused mainly on large species and the number of published studies tagging small birds has increased substantially. 3. We quantitatively reviewed 549 records extracted from 74 published and 48 unpublished studies on over 7,800 tagged and 17,800 control individuals to examine the effects of geolocator tagging on small bird species (body mass <100 g). We calculated the effect of tagging on apparent survival, condition, phenology and breeding performance and identified the most important predictors of the magnitude of effect sizes. 4. Even though the effects were not statistically significant in phylogenetically controlled models, we found a weak negative impact of geolocators on apparent survival. The negative effect on apparent survival was stronger with increasing relative load of the device and with geolocators attached using elastic harnesses. Moreover, tagging effects were stronger in smaller species. 5. In conclusion, we found a weak effect on apparent survival of tagged birds and managed to pinpoint key aspects and drivers of tagging effects. We provide recommendations for establishing matched control group for proper effect size assessment in future studies and outline various aspects of tagging that need further investigation. Finally, our results encourage further use of geolocators on small bird species but the ethical aspects and scientific benefits should always be considered.

KW - condition

KW - migration

KW - phenology

KW - reproduction

KW - return rate

KW - survival

KW - tracking device

KW - tag effect

U2 - 10.1111/1365-2656.12962

DO - 10.1111/1365-2656.12962

M3 - Article

VL - 89

SP - 207

EP - 220

JO - Journal of Animal Ecology

JF - Journal of Animal Ecology

SN - 0021-8790

IS - 1

ER -