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THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 124. No. 3. September 2012 
spatial variation in the magnetic field has an 
important role in migratory orientation of adults 
that is likely involved in geographic positioning. 
ACKNOWLEDGMENTS 
We lhank H. A. Ford and the Zoology Department for 
hosting MED’s visit to the University of New England. 
Mark Stewart from Geophysical Technology Ltd. for 
providing technical support and access to the magnetom¬ 
eter. D. C. Droney for statistical advice in analyzing activity 
and concentration data. Rachel Muheim for assistance in 
creating Figure I and for comments on the manuscript, and 
R. C. Season and C. D. Galvani for editorial assistance. We 
also thank Wolfgang and Roswitha Wiltschko for discuss¬ 
ing the interpretation of our experimental findings. Funding 
was provided by a grant from the National Science 
Foundation to .IBP (1BN02-I6957). The experiments 
comply with the current laws of Australia and we followed 
the 1991 “Guidelines for the use of animals in research" 
(Animal Behaviour 41:183-186). 
LITERATURE CITED 
Akesson. s.. J. Morin. R. Muheim, and U. Ottosson. 
2005. Dramatic orientation shift of White-crowned 
Sparrows displaced across longitudes in the high 
arctic. Current Biology 15:1591-1597. 
Batsckelet, E. 1981. Circular statistics in biology. 
Academic Press. London. United Kingdom. 
Beason, R C. and P. Semm. 1996, Does the avian 
ophthalmic nerve carry magnetic navigational infor¬ 
mation'.' Journal of Experimental Biology 199 P4I- 
1244. 
Beck, W and W. Wiltschko. 1988. Magnetic factors 
control the migratory direction of Pied Flycatchers, 
Fideeula hypoleuca. Proceedings of the International 
Ornithological Congress 19:1955-1962. 
Bert hold. P. 1990a. Genetics of migration. Pages 269-280 
in Bird migration: physiology and ccophysiology (E. 
Gwinner. Editor). Springer-Verlag, Berlin. Germany. 
Berthold, P 1990b. Spatiotemporal programs and genet¬ 
ics of orientation. Experientia 46:363-371. 
Chernetsov. N„ D. KiSHKtNEV. AND H. Mouritskn. 2008. 
A long-distance avian migrant compensates for 
longitudinal displacement during spring migration 
Current Biology 18:1-3. 
Emlen, S. T. and J. T. EMLEN. 1966. A technique for 
recording migratory orientation in captive birds. Auk 
Falkenberg. C.. g. Fleissn.:*, K. Schuchardt, M. 
Kl-ehbacher. P. Thalau. H. Mol ritsen. D. Hevers 
C.- WEl LENREimiER. AND G. Fl LISSNER. 2010. Avian 
magnetoreception: elaborate iron mineral containing 
dendrites in the upper beak seem to be a common 
feature ol birds. PLoS One 5 (e923l):|-9 
^MaJe, H " l; ' MUNRa AN,) J - PH.UJPS. 2003. 
M.^nuK- navigation by an avian migrant? Pages 423 - 
E W V,an . m,8ra r nn (P - Bcr,ho,d ’ E. Gwinner. and 
Germa ny Cn SC 10 '" ^ ^^r-Ver,ag. Berlin' 
Fransson, T.. S. Jakobsson. P. Johansson, C. Kullberg, 
J. Lind, and A. VALLIN. 2001. Magnetic cues trigger 
extensive refuelling. Nature 414:35-36. 
Freakk. M. J.. R. Muheim, and J. B Phillips. 2006. 
Magnetic maps in animals u theory comes of age? 
Quarterly Review of Biology 81:327-347. 
Funnell. J. 2007. A comparison of annual patterns of 
behaviour and physiology between partially migrator} 
and non-migratory subspecies of the Australian 
Silvereyc. Zosterops lateralis, in captivity. Disserta¬ 
tion. University of Technology. Sydney. Australia. 
FUNNELL. J. AND l . Mijnro. 2007. Orientation in captive 
migratory and sedentary Australian Silvereyes Zoster- 
ops lateralis. Behavioral Ecology and Sociobiology 
61:337-345. 
Gould. J. L. 1980. I he case for magnetic sensitivity in 
birds and bees (such as it is). American Scientist 
68:256-267. 
Griffin. D. R. 1952. Bird navigation. Biological Reviews 
27:359-400. 
Gkifi ioen. P. A. and M. F, Clarke. 2002. Large-scale bird 
movement patterns evident in eastern Australian atlas 
data. Emu 102:99-125. 
Hklhici. A. .1 1991. Inheritance of migratory direction in 
bird species: a cross-breeding with SE- and SW- 
migraiing Blackcaps (Sylvia airicapilla). Behavioral 
Ecology and Sociobiology 28:9-12. 
Hi .1 mu. A. J. 1996. Genetic basis, mode of inheritance and 
evolutionary changes in migratory directions in 
palcarctic warblers (Aves: Sylviidae). Journal of 
Experimental Biology 199:49-55. 
Helhig, A, J.. p. Berthold. and w wiltschko. 1989. 
Migratory orientation of Blackcaps. Sylvia airicapilla- 
population specific shifts of direction during the 
autumn. Ethology 82:307-315. 
Henshaw, I.. T. Fransson, S. Jakobsson. anti C. 
Kullberg. 2010. Geomagnetic field affects spring 
migratory direction in a long distance migrant. 
Behavioral Ecology and Sociobiology 64:1317-1323- 
Kikschvink. J. L. 1992. Uniform magnetic fields and 
double-wrapped coil systems: improved techniques for 
the design of bioelectromagnetic experiments. Bioe¬ 
lectromagnetics 13:401 -411. 
Kullberg. C.. j. Lind. T. Fransson. S. Jakobsson. and 
A. VALLIN. 2003. Magnetic cues and time of season 
alfeet luel deposition in migratory Thrush Nightin¬ 
gales (Lnscinia luscinia). Proceedings of the Royal 
Society of London, Series B 270:373-378. 
Lane. S. G. and H. Battam. |971. Silvereyc movements 
in eastern Australia. Australian Bird Bander 9:80-82. 
Moore, B, R. 1980. Is the homing pigeon’s map 
geomagnetic? Nature 285:69-70. 
MoURlTSEN, H. 1998. Modelling migration: the clock-and- 
compass model can explain the distribution of ringing 
recoveries. Animal Behaviour 56:899-907. 
Mouritsf.n, FI. 2001. Ringing recoveries contain hidden 
intormalion about orientation mechanisms. Ardea 
89:31-42. 
Mill RITSEN. H. 2003. Spatiotemporal orientation strategies 
ol long-distance migranLs. Pages 493-513 in Avian 
