NEWS107
31
turyput anend to this cruel formofmain-
tenance: a tree frog cannot live long in a
glass jar. The upright form of the jar pre-
vents sufficient fresh air entering via the
opening, so the creature in the jar would
oftenbeon theedgeof suffocation. If the
roombecame somewhat warmer and af-
fected the frog's "operating temperature",
then itwouldclimbas farupaspossible to
where the freshest air was.On cool, rainy
days (don't forget,therewasvery littlehea-
tingandwhat therewasusually restricted
to individual rooms), the poor creature
wouldhunchon thebottom,half suffoca-
tedandbarelyable tomove.Inaddition,at
timesof lowatmosphericpressure thesub-
strate in the jar releaseda fogof foul-smel-
linggases that immediatelyprevented the
frog from lifting itself from thebottom.
Thequestionofwhether tree frogscan fo-
recast theweathermust thusbeanswered
with an unequivocal "No", they simply
react toexistingweatherconditions.Hence
even themost nostalgic frog fan should
never countenance the idea of keeping
tree frogs ina jar.
Europevs.NorthAmerica
As alreadymentioned there are two tree
frog species in Europe,
Hyla arborea
and
theMediterranean
Hylameridionalis
, and
they are alsowidespread inGermany (alt-
hough theyhavebecome raredue tobio-
topedestruction).The taxonomic statusof
additional described forms, for example
theCretanTree Frog and the IberianTree
Frog, ishotlydisputedamong scientists in
the field, but of no further interest here.
Until the 1970s these tree frogswere the
species usually kept in the terrarium, as
they are very attractive and easy tomain-
tain. But then all European frog species
came under a banon trading inwild ani-
mals (this was termed conservation) and
they slowly but surely slipped into obli-
vion.Obviously tree frogscanbebredvery
easilyandeffectively,butnaturallycaptive-
bred specimens are significantlymoreex-
pensive thanwild-caught,and for this rea-
sonnowadays it is the CarolinaTree Frog
(
Hyla cinerea
),which is very common and
widespread in the south-east of theUSA,
that is the commonest and cheapest tree
frog species available in the trade. The
maindifference incolorationbetween the
CarolinaTree Frog and the European spe-
cies is that the flank stripe inH. cinerea is
always snow-whiteasopposed toblack in
theEuropeans.
Note that the tradebanhashadnodetec-
table beneficial effect on populations of
the European tree frogs. Populations con-
tinue todecline inplaceswhere theirhabi-
tats havebeendestroyed, and in addition
there is theworldwide frogdie-off.Aheal-
thy frogpopulationcannotbeendangered
by the removal of small numbersof speci-
mens - relative to population numbers
overall - for the livestock trade.
TheCarolinaTreeFrog
This attractiveandvery characteristic tree
frogwasdescribedas longagoas1799. Its
distribution in thesouth-eastof theUSA is
as follows: from southernTexas eastwards
across thecoastalplain to theFloridapen-
insula and Delaware; from eastern Texas
andwesternTennessee north to theMis-
sissippi drainage and south-eastMissouri,
central, eastern, and southern Arkansas,
southern Illinois,westernKentucky,and the
extremesouth-westof Indiana.Thespecies
hasbeen introduced tonorth-westernPu-
ertoRico.
The coloration of the species varies to
somedegree.Usually these frogs are light
greenandhaveawhite stripeon the side,
extending along the upper jaw and the
flank.This stripe can, however, sometimes
be absent. Sometimes these frogs have
small, dark-bordered, goldendots on the
back.For some timeanorthern (
Hylacine-
reaevittata
) anda southern subspecies (
H.
cinerea cinerea
) were distinguished, with
Likemany tree frogs,
Hylacinerea
can turnbrowndependingon itsmood.
