A1 Vertaisarvioitu alkuperäisartikkeli tieteellisessä lehdessä
No strong effects of leg-flagged geolocators on return rates or reproduction of a small long-distance migratory shorebird
Tekijät: Veli-Matti Pakanen, Nelli Rönkä, Robert L. Thomson, Kari Koivula
Kustantaja: Birdlife Finland
Julkaisuvuosi: 2015
Journal: Ornis Fennica
Lehden akronyymi: Ornis Fenn
Vuosikerta: 92
Numero: 3
Aloitussivu: 101
Lopetussivu: 111
Sivujen määrä: 11
ISSN: 0030-5685
Verkko-osoite: http://www.ornisfennica.org/pdf/latest/153Pakanen.pdf
Tiivistelmä
Small light-level geolocators have revolutionized research on avian migration and breeding
ecology. However, proper evaluations of their impact on the life history of individuals
compared to control individuals that experience the same conditions are still rare.
Geolocator effects may be species specific and depend on the type of mounting, sex and
size of individuals. While geolocators have been used extensively and without negative
effects on large shorebirds, relatively little is known about their effects on small shorebirds,
especially of those attached on leg-flags.We mounted 30 leg-flagged geolocators
(15 on each sex) on Southern Dunlins (Calidris alpina schinzii) – a small, long distance
migratory shorebird (40–52 grams) – and examined the effects of geolocators on return
rates and reproduction through comparisons to a control group. The whole attachment
weighed 1.5–2% of an individual’s body mass.We found no evidence of lowered return
rates. Out of 30 birds, 22 (73%) returned from both groups. Returning birds had similar
breeding probability, timing of breeding, clutch size and nesting success. The proportion
of unhatched eggs was higher in the geolocator group, but this difference was not significant.
Inspection of unhatched eggs from the treatment group suggested no clear damage to
eggs caused by geolocators. Our results suggest that at least one small wader species can
withstand the extra weight imposed by appropriately sized geolocators. However, our
study lasted only for one year, and long term evaluations that capture the full suite of environmental conditions and assess impact on brood care are needed.
Small light-level geolocators have revolutionized research on avian migration and breeding
ecology. However, proper evaluations of their impact on the life history of individuals
compared to control individuals that experience the same conditions are still rare.
Geolocator effects may be species specific and depend on the type of mounting, sex and
size of individuals. While geolocators have been used extensively and without negative
effects on large shorebirds, relatively little is known about their effects on small shorebirds,
especially of those attached on leg-flags.We mounted 30 leg-flagged geolocators
(15 on each sex) on Southern Dunlins (Calidris alpina schinzii) – a small, long distance
migratory shorebird (40–52 grams) – and examined the effects of geolocators on return
rates and reproduction through comparisons to a control group. The whole attachment
weighed 1.5–2% of an individual’s body mass.We found no evidence of lowered return
rates. Out of 30 birds, 22 (73%) returned from both groups. Returning birds had similar
breeding probability, timing of breeding, clutch size and nesting success. The proportion
of unhatched eggs was higher in the geolocator group, but this difference was not significant.
Inspection of unhatched eggs from the treatment group suggested no clear damage to
eggs caused by geolocators. Our results suggest that at least one small wader species can
withstand the extra weight imposed by appropriately sized geolocators. However, our
study lasted only for one year, and long term evaluations that capture the full suite of environmental conditions and assess impact on brood care are needed.
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