Biology Reference
In-Depth Information
(B)
(A)
Plate 4.85
(A and B) A brown tree snake (
Boiga irregularis
) preying on birds nested
(A) or electrocuted (B) on high power lines, Guam.
The predilection of
B. irregularis
for
mating and searching for avian prey on high power lines has resulted in repetitive “brown
outs” on Guam due to the occasional electrocution of these snakes. This has caused significant
economic loss on the island.
Photos copyright to Gordon Rodda.
(
www.mesc.usgs.gov
). As an example, from 1989 to 1994, 206 well-documented
cases were recorded. In this series, 82% of the victims were bitten while sleep-
ing, and 52% of these victims were younger than 5 years old (
www.mesc.usgs.gov/
resources/education/bts
)
. This is reminiscent of some common features of krait
(
Bungarus
spp.) envenoming in India and Sri Lanka (Warrell, 1995a). A published
series of cases included three pediatric patients (mean age
2.9 months) that report-
edly exhibited ptosis, respiratory failure, and spasticity (Fritts and McCoid, 1994).
Retrospective medical expert review of these presumed neurotoxic effects was equiv-
ocal (SA Minton, personal verbal communication with SAW, June 1995).
The majority of patients included in a retrospective review of 446
B. irregularis
bites recorded at Guam Memorial Hospital, 1987-2004, were asymptomatic or exhib-
ited mild local effects (Morocco et al., 2006). Several patients (most commonly chil-
dren) developed more extensive local effects including bleb (blister) formation. These
authors identified “systemic toxicity” (“generalized weakness,” respiratory difficulty,
and ptosis) in several victims, all younger than 1 year old (Morocco et al., 2006). The
more severe effects in infants were ascribed to the introduction of larger “doses of
venom” due to protracted bites/chewing inflicted on victims unable to disengage the
