TY - JOUR
T1 - Magnetic compass orientation research with migratory songbirds at Stensoffa Ecological Field Station in southern Sweden
T2 - why is it so difficult to obtain seasonally appropriate orientation?
AU - Muheim, Rachel
AU - Åkesson, Susanne
AU - Bäckman, Johan
AU - Sjöberg, Sissel
PY - 2017/1/1
Y1 - 2017/1/1
N2 - More than three decades ago, Thomas Alerstam initiated the study of orientation and navigation of migratory songbirds in southern Sweden. Stensoffa Ecological Field Station, located approx. 20 km east of Lund, has since been a primary location for orientation experiments. However, it has often been difficult to record well-oriented behaviour in the seasonal appropriate migratory directions, in particular in magnetic orientation experiments under simulated overcast or indoors. Here, we summarise all available experiments testing magnetic compass orientation in migratory songbirds in southern Sweden, and review possible explanations for the poor magnetic compass orientation found in many studies. Most of the factors proposed can be essentially excluded, such as difficulties to extract magnetic compass information at high latitudes, methodological or experimenter biases, holding duration and repeated testing of individual birds, effects of magnetic anomalies and temporal variations of the ambient magnetic field, as well as anthropogenic electromagnetic disturbances. Possibly, the geographic location of southern Sweden where many birds captured and/or tested at coastal sites are confronted with the sea, might explain some of the variation that we see in the orientation behaviour of birds. Still, further investigations are needed to conclusively identify the factors responsible for why birds are not better oriented in the seasonal appropriate migratory direction at Stensoffa.
AB - More than three decades ago, Thomas Alerstam initiated the study of orientation and navigation of migratory songbirds in southern Sweden. Stensoffa Ecological Field Station, located approx. 20 km east of Lund, has since been a primary location for orientation experiments. However, it has often been difficult to record well-oriented behaviour in the seasonal appropriate migratory directions, in particular in magnetic orientation experiments under simulated overcast or indoors. Here, we summarise all available experiments testing magnetic compass orientation in migratory songbirds in southern Sweden, and review possible explanations for the poor magnetic compass orientation found in many studies. Most of the factors proposed can be essentially excluded, such as difficulties to extract magnetic compass information at high latitudes, methodological or experimenter biases, holding duration and repeated testing of individual birds, effects of magnetic anomalies and temporal variations of the ambient magnetic field, as well as anthropogenic electromagnetic disturbances. Possibly, the geographic location of southern Sweden where many birds captured and/or tested at coastal sites are confronted with the sea, might explain some of the variation that we see in the orientation behaviour of birds. Still, further investigations are needed to conclusively identify the factors responsible for why birds are not better oriented in the seasonal appropriate migratory direction at Stensoffa.
UR - http://www.scopus.com/inward/record.url?scp=85012160032&partnerID=8YFLogxK
U2 - 10.1111/jav.01303
DO - 10.1111/jav.01303
M3 - Review article
AN - SCOPUS:85012160032
SN - 0908-8857
VL - 48
SP - 6
EP - 18
JO - Journal of Avian Biology
JF - Journal of Avian Biology
IS - 1
ER -