|
| |
|
REPTILIA:
SQUAMATA: VARANIDAE: Varanus
|
|
Varanus doreanus (Meyer, 1874)
Bluetail monitor
Text & photos by Dr. Robert Sprackland.
|
|
|
Range: Much of coastal and
lowland interior New Guinea.
|
|
Diagnosis: A member of the
mangrove monitor group (subgenus Euprepiosaurus) that differs
from all similar species in having a predominantly yellow tongue,
distinct black and yellow bars on the lips and throat, and having a
high, slightly bulbous (vs. depressed) snout tip. The tail is
generally blue, blue-gray, or gray banded. The only other known
mangrove monitor with a yellow tongue tip is Varanus yuwonoi,
from which the blue-tailed monitor differs in having large yellow
spots over the entire (vs. only posterior) dorsum, no temporal
stripe, barred lips, and a higher snout tip profile. Varanus
yuwonoi lacks any light markings on the head or nape.
The intense blue coloring of the tail
is seen in juvenile monitors. Adults may retain blue
coloration,
but it tends to be less intense, and becomes more of a blue-gray in
large specimens.
|
|
Description: A monitor with
a yellow tongue, black-barred throat, and a generally pale to
turquoise blue-banded tail. There is no dark temporal stripe. The
lips are barred, though bars may become indistinct in large adults.
There are often extensive black reticulations on the belly,
particularly in young lizards. Grows to at least 1.2 meters/ 4 feet.
Upper photo shows a yearling
blue-tail monitor; below, the same lizard two years later as an
adult. at the San Diego Zoo.
|
| Natural
History: So far this is a poorly
known species with few field observations available. Stomach
contents indicate that natural diets include lizard eggs, beetles,
and small lizards such as tree skinks. |
|
Reproduction: Egg-layer,
details unknown.
|
|
Taxonomy & Relationships:
The specific name refers to the type locality on the west coast of
the Vogelkopf Peninsula of Indonesian Irian Jaya. The old name for
the settlement was "Dore" or "Doreh." This
species was named in 1874, but overlooked for 120 years in part
because the diagnostic blue tail coloring fades very quickly when
animals are preserved. This species most closely resembles the
metaspecies Varanus indicus* and Varanus jobiensis,
both of which are sympatric.
Böhme et alia (1994) named a subspecies, Varanus
doreanus finschi which was subsequently raised to species status
by Sprackland (1995, 1997).
|
| Variation:
This species is variable in pattern and
coloration. The dorsum may have well defined yellow rosettes or
instead have numerous pinpoint light spots. The tail, though always
banded, may vary fro bright turquoise blue to a dirty gray to nearly
white (in juveniles). |
|
Neotype: ZFMK 52922,
Sarong, Irian Jaya, Indonesia.
|
|
Literature:
Böhme, Wolfgang, Hans-Georg Horn &
Thomas Ziegler. 1994. Zur taxonomie der Pazifikwarane (Varanus
indicus-Komplex): Revalidierung von Varanus doreanus (A.B.
Meyer, 1874) mit Beschreibung einer neuen Unterart. Salamandra
30(2): 119-142.
Sprackland, Robert. 1997. Mangrove monitor
lizards. Reptiles March: 48-63.
Sprackland, Robert. 1995. Evolution,
systematics, and variation in Pacific mangrove monitor lizards.
Unpublished Ph.D. Thesis, University College London.
|
|
|
