Brown Tree Snake
Brown Tree SnakeBrown Tree SnakeBrown Tree SnakeBrown Tree Snake

Brown Tree Snake

Boiga irregularis

Least ConcernNear ThreatenedVulnerableEndangeredCritically Endangered
Insufficient data
overall probability at Blue Mountains National Park
3 Verified records at Blue Mountains National Park
☀️🌙 Day & Night When it's active Active throughout day and night

The brown tree snake (Boiga irregularis), also known as the brown catsnake, is an arboreal rear-fanged colubrid snake native to eastern and northern coastal Australia, eastern Indonesia (Sulawesi to Papua), Papua New Guinea, and many islands in northwestern Melanesia. The snake is slender, which facilitates climbing, and can reach up to 2 metres in length. Its coloration may also vary, some being brown, green, or even red. Brown tree snakes prey on a wide range of animals, from invertebrates to birds and even some small mammals. It is one of the very few colubrids found in Australia, where elapids are more common. Due to an accidental introduction after the events of World War II, this snake is now infamous for being an invasive species responsible for extirpating the majority of the native bird population in Guam. Wikipedia →

Closest Relatives at Blue Mountains National Park

Black Treesnake
LC

Black Treesnake

☀️ Diurnal Reptile

Dendrelaphis punctulatus

5–10% · With luck

📅 Monthly Probability

📊

Fewer than 5 records of Brown Tree Snake at Blue Mountains National Park — not enough to chart months honestly.

☀️🌙 When They're Spotted

Active throughout day and night · across all parks (global)

☀️🌙Day & Night
☀️🌙🌙12am6am12pm6pm12am

Global Distribution

Where this species is recorded worldwide. Restricted to human observations from 2019 onwards — the same kind of record and the same period the probabilities on this page are built from, so collar-tracking studies, camera-trap arrays and museum specimens are excluded. Around Santa Rosa that removes 5,924 GPS fixes from a handful of tagged jaguars.

where this species is recorded (GBIF density — it tracks where observers go, not how likely a sighting is)  ·  parks where it occurs — tap a pin for the sighting probability there

Parks Where Found

# Park Country Probability
1 Litchfield National Park 🇦🇺 Australia
40–50%
2 Daintree National Park 🇦🇺 Australia
30–40%
3 Kakadu National Park 🇦🇺 Australia
20–30%
4 Nitmiluk National Park 🇦🇺 Australia
20–30%
5 Lamington National Park 🇦🇺 Australia
10–20%
6 Springbrook National Park 🇦🇺 Australia
10–20%
7 Noosa National Park 🇦🇺 Australia
Insufficient data
8 Lorentz National Park 🇮🇩 Indonesia
Insufficient data
9 Royal National Park 🇦🇺 Australia
Insufficient data
10 Blue Mountains National Park 🇦🇺 Australia
Insufficient data
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