Pooing pooches point polewards
Stories from Physics
for 11-14
14-16
- Dedicated scientists have observed the body alignment of dogs during defecation (1,893 observations) and urination (5,582 observations) and report that the animals preferred to excrete while aligned in a north-south direction.
- Meanwhile, using images from Google Earth, a team of researchers has claimed that grazing and resting domestic cattle and red and roe deer tend to align their bodies in a roughly north-south direction. The authors report that the biological significance of the alignment is unknown. The results are controversial and other researchers have argued that there is no evidence that cattle align along magnetic field lines.
- A number of organisms including honeybees, bacteria, sharks and pigeons are capable of detecting magnetic fields. Three hypotheses exist for the nature of the mechanism that enables animals to detect magnetic fields:
b) alterations in chemical reactions due to the magnetic field
c) effects due to the presence of permanently magnetic materials in animals’ bodies – for example magnetite, Fe3O4 has been found in the bodies of bees, pigeons and other creatures.

References
S. Begall, J. Červený, J. Neef, O. Vojtčch, & H. Burda, H. (2008). Magnetic alignment in grazing and resting cattle and deer. Proceedings of the National Academy of Sciences. vol. 105, no. 36, 2008, pp. 13451-13455
V. Hart, P. Nováková, E. P. Malkemper, S. Begall, V. Hanzal, M. Ježek, … & J. Červený, Dogs are sensitive to small variations of the Earth’s magnetic field. Frontiers in Zoology, vol. 10, no. 1, 2013, 80, pp. 1-12.
J. Hert, L. Jelinek, L. Pekarek, & A. Pavlicek, No alignment of cattle along geomagnetic field lines found. Journal of Comparative Physiology A, vol. 197, no. 6, 2011, pp. 677-682.
J. L. Kirschvink, & J. L. Gould, Biogenic magnetite as a basis for magnetic field detection in animals. Biosystems, vol. 13, no. 3, 1981, 181-201, p. 181.