title: Thermal physiology. Keeping cool: Enhanced optical reflection and radiative heat dissipation in Saharan silver ants.
abstract: Saharan silver ants, Cataglyphis bombycina, forage under extreme temperature conditions in the African desert. We show that the ants' conspicuous silvery appearance is created by a dense array of triangular hairs with two thermoregulatory effects. They enhance not only the reflectivity of the ant's body surface in the visible and near-infrared range of the spectrum, where solar radiation culminates, but also the emissivity of the ant in the mid-infrared. The latter effect enables the animals to efficiently dissipate heat back to the surroundings via blackbody radiation under full daylight conditions. This biological solution for a thermoregulatory problem may lead to the development of biomimetic coatings for passive radiative cooling of objects.
authors.affiliation: Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA.
authors.forename: Norman Nan
authors.initials: NN
authors.lastname: Shi
authors.affiliation: Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA.
authors.forename: Cheng-Chia
authors.initials: CC
authors.lastname: Tsai
authors.affiliation: Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, NY, USA.
authors.forename: Fernando
authors.initials: F
authors.lastname: Camino
authors.affiliation: Department of Electrical Engineering, University of Washington, Seattle, WA, USA.
authors.forename: Gary D
authors.initials: GD
authors.lastname: Bernard
authors.affiliation: Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA. ny2214@columbia.edu rwehner@zool.uzh.ch.
authors.forename: Nanfang
authors.initials: N
authors.lastname: Yu
authors.affiliation: Brain Research Institute, University of Zürich, Zürich, Switzerland. ny2214@columbia.edu rwehner@zool.uzh.ch.
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Wehner
mesh_terms: D000352:Africa, Northern; D000818:Animals; D001000:Ants / Q000033:anatomy & histology / Q000502:physiology* / Q000648:ultrastructure; D001833:Body Temperature Regulation; D003889:Desert Climate; D006358:Hot Temperature; D013816:Thermodynamics