Cloud cover amplifies the sleep-suppressing effect of artificial light at night in geese.

Sjoerd J Van Hasselt,Giancarlo Allocca,Roelof A Hut,Niels C Rattenborg,Alexei L Vyssotski,Peter Meerlo,Theunis Piersma

doi:10.1016/j.envpol.2021.116444

Abstract

In modern society the night sky is lit up not only by the moon but also by artificial light devices. Both of these light sources can have a major impact on wildlife physiology and behaviour. For example, a number of bird species were found to sleep several hours less under full moon compared to new moon and a similar sleep-suppressing effect has been reported for artificial light at night (ALAN). Cloud cover at night can modulate the light levels perceived by wildlife, yet, in opposite directions for ALAN and moon. While clouds will block moon light, it may reflect and amplify ALAN levels and increases the night glow in urbanized areas. As a consequence, cloud cover may also modulate the sleep-suppressing effects of moon and ALAN in different directions. In this study we therefore measured sleep in barnacle geese (Branta leucopsis) under semi-natural conditions in relation to moon phase, ALAN and cloud cover. Our analysis shows that, during new moon nights stronger cloud cover was indeed associated with increased ALAN levels at our study site. In contrast, light levels during full moon nights were fairly constant, presumably because of moonlight on clear nights or because of reflected artificial light on cloudy nights. Importantly, cloud cover caused an estimated 24.8% reduction in the amount of night-time NREM sleep from nights with medium to full cloud cover, particularly during new moon when sleep was unaffected by moon light. In conclusion, our findings suggest that cloud cover can, in a rather dramatic way, amplify the immediate effects of ALAN on wildlife. Sleep appears to be highly sensitive to ALAN and may therefore be a good indicator of its biological effects.

Highlights

This page was generated automatically upon download from the ETH Zurich Research Collection
An important milestone towards quantum control is the so-called strong coupling regime, which in cavity optomechanics corresponds to an optomechanical coupling strength larger than cavity decay rate and mechanical damping
The trap is mounted on a nano-positioning stage allowing for precise 3D placement of the particle inside the low loss, high finesse Fabry-Pérot cavity with a cavity linewidth κ ≈ 2π × 10 kHz, cavity finesse F = 5.4 × 105 and free spectral range ΔωFSR = πc/Lc = 2π × 5.4 GHz

Summary

Introduction

This page was generated automatically upon download from the ETH Zurich Research Collection. After a decade of experimental and theoretical efforts employing the same techniques[1,2,3,4,5,6,7,8], the motional ground state of levitated silica nanoparticles at room temperature has been reported[9] While this represents an important milestone towards the creation of mesoscopic quantum objects, coherent quantum control of levitated nanoparticles[10,11] still remains elusive. Levitated particles stand out among the plethora of optomechanical systems[12] due to their detachment, and high degree of isolation from the environment Their centre of mass, rotational and vibrational degrees of freedom[13] make them attractive tools for inertial sensing[14], rotational dynamics[15,16,17,18], free fall experiments[19], exploration of dynamic potentials[20], and are envisioned for testing macroscopic quantum phenomena at room temperature[2,10,21,22]. The centre-of-mass motion of a levitated particle has successfully been 3D cooled employing coherent scattering (CS)[8,23]

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Results

Conclusion