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Dogs Point North-South When They Pee and Poop

Dogs Point North-South

Dogs point North-South when they pee and poop. They use the Earth’s magnetic field when urinating and defecating, aligning their bodies in the N-S axis.

If I wrote this on April 1st, everyone would take that for an April Fool’s prank. It is not. It is the conclusion of a scientific project conducted by Hart et al. and involving researchers from the Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, and the Faculty of Biology, University of Duisburg-Essen in Germany (Hart et al. 2013).

 

Dogs Register Small Variations in Earth’s Magnetic Field

The study concludes dogs (Canis lupus familiaris) register small variations in Earth’s magnetic field after examining the behavior of 70 individuals (28 males and 42 females) belonging to 37 breeds, collected by 37 dog owners/reporters.

The researchers collected data on alignment during defecation (n = 1,893 observations, 55 dogs) and urination (n = 5,582, 59 dogs) from December 2011 through July 2013 in the Czech Republic and in Germany.

Under calm magnetic field conditions, dogs preferred to defecate with their bodies aligned along the north-south axis, even when sometimes facing south. Dogs not only favored N-S but also avoid E-W.

The data shows that larger and faster changes in magnetic conditions result in a random distribution of body alignments, i.e., a lowering of the preferences and ceasing of the avoidances, which may result from the magnetic disturbance or the intentional shutdown of the magnetoreception mechanism.

To avert any bias, all dogs moved in a free-roaming environment, off-lead and not restricted by walls or roads that would influence their movements. The routes of walks changed to exclude or limit pseudo-replication caused by the dogs defecating and urinating in the same few places.

The researchers also excluded the sun, polarized light, and the wind as determining factors for the body alignment of the dogs.

 

No Differences Between Males and Females

The study found no differences in the alignment of males and females during defecation and of the latter during urination. They all assume similar postures during defecation and females’ urination. Urinating males showed slightly different preferences to the females’ choices. The male leg lifting posture, while urinating, could explain these discrepancies.

 

No Answer to Why Dogs Prefer the North-South Axis

We have no answer to why dogs prefer the north-south axis and avoid east-west. It may be intentional, in which case they must perceive the magnetic field with one of their senses (as a haptic stimulus), or maybe they feel more comfortable aligning them in a particular direction (controlled at the vegetative level).

 

New Perspectives

Earlier studies confirmed that the natural fluctuations of the Earth’s magnetic field may disturb orientation in birds, bees, whales, and even affect vegetative functions and behavior in humans.

Studies on the wolves’ (Canis lupus lupus) homing are inconclusive. We cannot rule out the possible influence of an inherent sense of direction. There may be critical periods during a wolf’s life during which specific elements of its environment may imprint on it. In a study, the simplest hypothesis that explained the movement of four wolves was responses to visual, olfactory, and auditory cues with the latter probably being the most important. The wolves seemed driven to return to familiar territory, using the strongest learned exogenous cues (Henshaw and Stephenson 1974). Magnetoreception could have been a homing aid.

The findings of Hart et al. open new perspectives on how organisms use magnetic fields for direction.

References

Begall, S., Malkemper, P., Burda, H. 2014. Magnetoreception in mammals. Advances in the Study of Behavior, 2014. pp 45-79.

Dimitrova, S., Stoilova, I., and Cholakov, I. 2004. Influence of local geomagnetic storms on arterial blood pressure. Bioelectromagnetics 2004, 25:408–414. https://doi.org/10.1002/bem.20009.

Hart V, Malkemper EP, Kušta T, Begall S, Nováková P, Hanzal V, Pleskač L, Ježek M, Policht R, Husinec V, Červený J, Burda H: Directional compass preference for landing in water birds. Frontiers Zool 2013, 10:38. https://doi.org/10.1186/1742-9994-10-38.

Hart, V. et al. 2013. Dogs are sensitive to small variations of the Earth’s magnetic field. Frontiers in Zoology 2013, 10:80.

Henshaw, R.E., and Stephenson, R.O. 1974. Homing in the gray wolf (Canis lupus). J Mammal 1974, 55:234–237.

Southern, W.E. 1978. Orientation Responses of Ring-Billed Gull Chicks: A Re-Evaluation. In Schmidt-Koenig K., Keeton W.T. (eds) Animal Migration, Navigation, and Homing. Proceedings in Life Sciences. Springer, Berlin, Heidelberg, pp 311-317.

Featured illustration by Anton Antonsen.

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Canine Epigenetics

Canine-Epigenetics

Epigenetics [Greek epi– ἐπι- = above, over, on, in addition to] is the study of heritable gene functions that cause stable phenotypic variations without affecting the DNA sequence of the organism.

Conrad Waddington coined the term in 1942 before we knew that DNA was the molecular basis of genes. He proposed that genes are differentially turned on and off by another level of “epigenetic” processes to produce different cells in the developing embryo.

 

Epigenetics, Environment, Phenotypic Plasticity

Behavioral epigenetics studies the role of epigenetics in forming behavior. It seeks to explain how nurture may shape nature. It attempts to provide a framework for understanding how the environment may influence gene expression to produce individual differences in behavior.

However, we must be careful with the term ‘environment’. To a geneticist, the environment is everything that isn’t the cellular environment of the DNA. To a social scientist, the environment catches everything from parental care to the stock market climate. That the cellular environment might be essential for understanding gene expression does not imply that one’s housing conditions have a similar impact.

The environment influences particular changes in gene action. For example, in alligators and specific turtles, egg incubation temperature affects the gene expression defining the sex of the individual. In these cases, the state of the gene passes down through cell divisions within a single organism, but it resets in eggs or sperm most times, so it does not transfer between generations. Thus, the mechanism does not influence evolution. An epigenetic state must carry over into the progeny to have any evolutionary relevance. For instance, molecules that bind to DNA and transfer to the offspring partially control the coat color of mice, Rattus norvegicus.

We must not confuse ‘epigenetics’ with ‘phenotypic plasticity,’ i.e., the capacity of one genotype of producing different phenotypes depending on the environment.

 

Belyayev’s Experiments

Belyayev’s experimented with silver foxes, Vulpes vulpes, which he bred based on a selection for tameness. He tested the animals, gave them a tameness score, and placed them in one of three groups. By the 20th generation, 35 percent of the animals were in the higher class, the ‘elite’ group; and as of 2009, ‘elite foxes’ made up 70 to 80 percent of the population. In addition, the changes in the tame foxes over the generations were not only behavioral but also physiological.

Belayev didn’t prove the effect of epigenetics in domestication. He proved the probability of domestication having occurred through selective breeding. In his own words, “It seems possible that the high frequency of the star mutation is due to strong selection intentionally applied for behavior.” (Belyaev et al. 1981). His experiments are a unique resource for studying the genetics of domestication.

The question of epigenetics goes deeper. Genes controlling plasma glucocorticoids were probably the targets during selection for tameness and the effects showed at all levels from phenotypic parameters to the gene expression of the corticotropin-releasing hormone (CRH), proopiomelanocortin (POMC), and the glucocorticoid receptor (GCR). Trut et al. conclude that “It appears plausible that the phenotypic novelties in the experimental fox population could be due to changes in gene activity, largely in its epigenetic modification.” (Trut et al. 2009).

If environmental conditions prefer a gene expression which parents pass to their progeny, and which, in turn, is more environmental independent than in the previous generation, then we can talk of a genuine epigenetic effect. If it is not, then we are talking about phenotypic plasticity and not epigenetics.

Most epigenetic changes occur only within the course of one individual organism’s lifetime—and that’s it. They can, though, pass to the organism’s offspring (transgenerational epigenetic inheritance). Also, if gene inactivation occurs in a sperm or egg cell that results in fertilization, this epigenetic modification may transfer to the next generation.

 

Conclusions

Do epigenetics make Lamarck right and Darwin wrong? To answer that, we must determine whether usage or selection causes epigenetic effects. Evidence supports the latter. Thus, epigenetic factors are yet another source of heritable natural variation. Darwin would have appreciated it. In fact, in 1868 he cautiously proposed ‘Pangenesis’ to cover the possibility that acquired characters might transfer to the progeny (whereby gemmules passed from somatic to reproductive cells). Modern discoveries seem to confirm that Darwin was right again.

At the time of writing, I have not found conclusive studies showing the effect of epigenetics on canine (Canis lupus familiaris) behavior, although Belyayev’s and subsequent studies make it plausible. I would appreciate if my reader has relevant information that may clarify this topic.

In popular writings appealing to the broad public, epigenetics seems to be everything that is not in the genes. However, that is not the scientific view, one requirement being that an effect is only epigenetic if it impacts the evolution of a trait. Therefore, I would recommend prudence when analyzing any statement claiming ‘epigenetic’ effects. These days, the term ‘epigenetic’ (like ‘quantum’) is prone to arouse the fantasy of quacksalvers.

References

Belyayev, D.K., Ruvinsky, A.O., and Trut, L N. 1981. Inherited activation/inactivation of the star gene in foxes. Journal of Heredity, 72: 264-274.

Chandler, V.L. 2007. Paramutation: from maize to mice. Cell. 128 (4): 641–45. doi:10.1016/j.cell.2007.02.007. PMID 17320501.

Cimarelli, G., Virányi, Z., Turcsán B., Rónai, Z., Sasvári-Székely, M., Bánlaki, Z. 2017. Social Behavior of Pet Dogs Is Associated with Peripheral OXTR Methylation. Front Psychol. 2017 Apr 10;8:549. doi: 10.3389/fpsyg.2017.00549.

Darwin, C. R. 1868. The variation of animals and plants under domestication. London: John Murray. 1st edition, second issue. Volume 1.

Dias, B.G., & Ressler, K.J. 2014. Parental olfactory experience influences behavior and neural structure in subsequent generations. Nature Neuroscience, 17(1), 89-98. doi: 10.1038/nn.3594.

Dupont C., Armant D.R., Brenner, C.A. 2009. Epigenetics: definition, mechanisms and clinical perspective. Seminars in Reproductive Medicine. 27 (5): 351–57. doi:10.1055/s-0029-1237423. PMC 2791696. PMID 19711245.

Florean, C. 2014. Food that shapes you: how diet can change your epigenome. Science in School, Issue 28.

Hughes, V. 2014. Epigenetics: the sins of the father. Nature, 507, 22-24.

Kaplan, G. 2017. Why is my dog this way, does it matter if we know, and what can we do? IAABC journal.

Pörtt, D., Jung, C. 2017. Is dog domestication due to epigenetic modulation in brain? Dog Behavior. Vol 3, No 2 (2017). ISSN 2421-5678.

Trut, L.N. 1996. Sex ratio in silver foxes: effects of domestication and the star gene. Theor Appl Genet (1996)92:109-115. ISSN
1432-2242.

Trut, L., Oskina, I., and Kharlamova, A. 2009. Animal evolution during domestication: the domesticated fox as a model. Bioessays. 2009 Mar; 31(3): 349–360.

Featured image by Anton Antonsen, photo by Hitdelight.

Featured Course of the Week

Agonistic Behavior Agonistic Behavior is all forms of aggression, threat, fear, pacifying behavior, fight or flight, arising from confrontations between individuals of the same species. This course gives you the scientific definitions and facts.

Featured Price: € 168.00 € 98.00

 

Learn more in our course Ethology. Ethology studies the behavior of animals in their natural environment. It is fundamental knowledge for the dedicated student of animal behavior as well as for any competent animal trainer. Roger Abrantes wrote the textbook included in the online course as a beautiful flip page book. Learn ethology from a leading ethologist.

EthologyCourse