NEWS107
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here are two tree frogs in Europe,
though they look so similar that lay-
men can't usually tell them apart. These
frogs have attracted the attention of
people since time immemorial.Tree frogs
were purportedly kept in the temples of
Apollo, aGreek andRomangodwhowas
responsible for, inter alia, healing, light,
spring, and the fine arts, andwere suppo-
sed toprophesyall sortsof things there.So
just as thewill of thegods and the future
couldbe read from the flight of birds, the
same couldbe effectedwith tree frogs. If
the frogshidaway that indicated that there
wouldbebadweather,but if on theother
hand the frogs sat clearly visible among
the branches then that was supposed to
meangoodweatheron theway.
T
The frogsof Europe inhabit swampy, inhospitable terrain -withoneexception: tree frogs.These smart littlecreatures,
whichgrow toaround,5cm insize, live inbushes,where their freshgreencolorationprovidesexcellentcamouflage.
Aweather-forecastingfrogfromNorthAmerica
byVolker Ennenbach
Hylacinerea
, theCarolinaTreeFrog.
All photos:FrankSchäfer
Can tree frogs forecast theweather?
This interpretationofanimalbehavior isn't
inherentlywrong,although it isn'tveryac-
curate either. Essentially tree frogs, being
poikilotherm creatures, have a body tem-
perature thatmatches theambient tempe-
rature.At the same time theiractivity tem-
perature is higher than that of other,
ground-dwelling frogs. If the weather is
very cool and rainy then youwill see very
little of tree frogs. By contrast, on mild
springdays they canevenbe seenduring
the day (these frogs aremore inclined to
be crepuscular andnocturnal) when they
sunbathe.That typeof springdayalsoen-
ticesushumansoutside,weareveryplea-
sedwhen thewinter is finallyoverandNa-
ture re-awakens into life. So the tree frog
has a very positive emotional quality and
its appearance has become associated
with fineweather.In theMiddleAges there
was a superstitious belief that a live frog
kept in the cellar would bring the occu-
pants of the house good luck and well-
being. The combination of beliefs in the
prophetic powers of tree frogs, handed
down fromdays of yore,of observationof
nature, and of themedieval superstition
probably eventually led topeople (presu-
mably in the Biedermeier, starting 1815)
beginning to keep frogs in jars with lad-
ders asweather forecasters. If the frog sat
on the bottom that meant bad weather,
but if it climbed up the ladder then that
meant good weather. Only the arrival of
terrariumstudyat theendof the19thcen-
Amphibians
