Many animal species, which live at higher latitudes, have an endogenous circannual clock to time reproduction, migration and/or hibernation. This ensures that the offspring is born during the most favourable seasons and that the harsh winter conditions can be bridged. I investigate how the circannual clock stays in synchrony with the environmental annual cycle and how it can be disturbed by light pollution and climate change. In humans, seasonal rhythms are documented in many parameters from diseases to school attendance, but proof for a circannual clock is lacking.
My main model species is the European hamster (Cricetus cricetus). This species lives predominantly on farmland and has a huge distribution area covering most parts of the temperate zones of the Eurasian continent. In my current project, I want to investigate why such a formerly superabundant widespread species is now worldwide at the brink of extinction. The population has declined since the 60’s by at least 70% all over its huge distribution area.
Such a global decline in the hamster’s population can only partially be explained by a worsening of the biotopes (the spatial structure of the environment), i.e. the farmlands, since this would only have regional effects. My hypothesis is that the decline is due to a change in the chronotope (the temporal structure of the environment), for example by light pollution or climate change. Such disturbances act on the global scale and would affect the endogenous circannual clock. Indeed, in recent years, we have observed a marked delay in the onset and thus a shortening of the reproductive phase in hamsters. As a consequence, the yearly offspring of a female has reduced by 77%. This alone will lead to extinction of the species within the shortest of time. In this project the reasons for the delay in the reproduction phase should be elucidated.
The moon is the most complex zeitgeber for organisms on earth giving rise to rhythms with different period lengths: the 12.4h tidal rhythms, the 14.76d cycle of spring and neap tides, moreover, each 27.32d the moon adopts the same relative position to fixed stars (tropic month), the moon needs 27.56 d (anomalistic month) to rotate around the earth, full moons appear each 29.53d (synodical month) and supermoons each 206d when the moon is very close to the earth. We know that many animal species use the moon as zeitgeber for reproduction. In a collaboration with the University of Wurzburg we investigate whether these cycles are reflected in women’s menstruation cycles.
Zerbini G, van der Vinne V, Otto LKM, Monecke S, Kantermann T, and Merrow M (2019) Tardiness Increases in Winter: Evidence for Annual Rhythms in Humans. Journal of Biological Rhythms. https://doi.org/10.1177/0748730419876781
Sáenz de Miera C, Sage-Ciocca D, Simonneaux V, Pévet P, and Monecke S (2018) Melatonin-independent Photoperiodic Entrainment of the Circannual TSH Rhythm in the Pars Tuberalis of the European Hamster. Journal of Biological Rhythms 33:302-317, https://journals.sagepub.com/doi/abs/10.1177/0748730418766601?journalCode=jbra.
Pévet P, Bouaouda H, Monecke S, Mendoza J, El Allali K, Challet E (2016) Control of seasonality by photoperiodic changes: Are the Arcuate nuclei involved? In: Haldar, C (ed) Updates on Integrative Physiology and Comparative Endocrinology. Banaras Hindu University Press, Vârânasî (India)
Feature article: Surov A, Banaszek A, Bogomolov PL, Feoktistova N, Monecke S (2016) Dramatic global decrease in the range and reproduction rate of the European hamster Cricetus cricetus. Endanger Species Research 31:119-145 http://www.int-res.com/articles/feature/n031p119.pdf
Könnicke S, Faber M, Monecke S, Stefen C (2016) Methods of postmortal age-determination in Cricetus cricetus. Mammalian Biology - Zeitschrift für Säugetierkunde 81, Supplement:11 http://www.sciencedirect.com/science/article/pii/S1616504716300842
Invited review: Monecke S, Wollnik F and Pévet P (2014) The circannual clock in the European hamster – how is it synchronized by photoperiodic changes? In: Annual, Lunar and Tidal Clocks: Patterns and Mechanisms of Nature’s Enigmatic Rhythms. Numata H, Helm B (eds) Springer
Sáenz de Miera C, Monecke S, Laran-Chich MP, Bartzen-Sprauer J, Hazlerigg D, Pévet P, Simonneaux V (2014) The circannual clock drives expression of genes central for seasonal reproduction. Curr Biol 24:1500-1506. http://www.sciencedirect.com/science/article/pii/S0960982214005491
Monecke S, Amann B, Lemuth K, and Wollnik F (2014) Dual control of seasonal time keeping in male and female juvenile European hamsters. PhysiolBehav 130:66-74 http://www.sciencedirect.com/science/article/pii/S0031938414001541