Whenever someone asks me about my coolest wildlife encounters, I usually refer to one of the many events that occurred while I was radio tracking King cobras in Agumbe, India. It’s usually a toss up between two moments. Either while we had just followed the male into the forest as night was falling and searched a tree base where the signal was coming from, we looked up to see him suspiciously eyeing us from above. Or when we were out walking along the river and stumbled across an untracked king cobra which we followed as it swam upriver before catching and eating an Indian ratsnake (Ptyas mucosa) hiding in an overhanging shrub.

The King cobra (Ophiophagus hannah) is a species that's unique in many different ways. It’s the world’s longest venomous snake (up to 6m!), the sole member of the Ophiophagus genus, and the only snake species known to build a nest and defend it. They range from India in the West to the Philippines in the East, Nepal and China in the North and South to Indonesia. Despite this huge range, they are listed as Vulnerable by the IUCN due to habitat loss and exploitation.

Raja, or M5, the big male King cobra (Ophiophagus hannah) that we were tracking

King cobras have been studied in some detail, especially with regards to their movement patterns. This has been studied in the Western Ghats in India (where I was) and in Thailand. Research from Thailand has found the average home range of a king cobra is 493 hectares, with a range from 52 to 1073 across all studied cobras. I’ve put that into context for you using a few useless examples:

  • 690 football pitches.

  • The combined extent of 14 European badger territories.

  • 23,664 double-decker buses parked next to each other with no gaps.

Quite large areas for a reptile. King cobras are active foragers and predominantly eat other snakes that naturally exist in low densities, which could explain this usage pattern. The amount of space used by the snakes, particularly males, also changes dramatically with seasonal shifts. This is likely a result of males searching for females during the breeding season.