Northern Philippine cobra , Philippine spitting cobra, Northern philippine cobra
The Philippine cobra (Naja philippinensis ) is a highly venomous spitting cobra that defensively shoots its venom directly from its fangs. It was described by American herpetologist Edward Harrison Taylor in 1922.
The Philippine cobra has a fairly stocky build. Adult snakes are uniformly light to medium brown, while the juveniles tend to be a darker brown in color. The head is elliptical, depressed, slightly distinct from the neck with a short, rounded snout and large nostrils. The eyes are moderate in size with dark brown and round pupils.
Philippine cobras occur mostly in the northern regions of the Philippines. They can be found on the islands of Luzon, Mindoro, Catanduanes, Azria, and Masbate. These snakes can be found in low-lying plains and forested regions, along with open fields, grasslands, dense jungle, agricultural fields, and human settlements. Philippine cobras are particularly fond of water, so they can be found very close to ponds, rivers, or large puddles of water.
Philippine cobras are solitary and only come together to mate. They are mainly terrestrial spending most of the time on the ground. These snakes are active during the night and hide in burrows, holes, rocks, and under vegetation during the midday heat. Philippine cobras are ambush predators; being extremely fast and agile they strike from their hiding spots with amazing speed and subdue their prey with ease. When threatened, these snakes will rise upwards and produce their hood; they are capable of accurately spitting their venom at a target up to 3 meters (9.8 ft) away.
The venom of the Philippine cobra is a potent postsynaptic neurotoxin which affects respiratory function and can cause neurotoxicity and respiratory paralysis, as the neurotoxins interrupt the transmission of nerve signals by binding to the neuromuscular junctions near the muscles. Research has shown its venom is purely a neurotoxin, with no apparent necrotizing components and no cardiotoxins. These snakes are capable of accurately spitting their venom at a target up to 3 metres (9.8 ft) away. The symptoms of a bite might include headache, nausea, vomiting, abdominal pain, diarrhea, dizziness, and difficulty breathing. Bites by the Philippine cobra produce prominent neurotoxicity with minimal to no local signs. A study of 39 patients envenomed by the Philippine cobra was conducted in 1988. Neurotoxicity occurred in 38 cases and was the predominant clinical feature. Complete Respiratory failure developed in 19 patients, and was often rapid in onset; in three cases, apnea occurred within just 30 minutes of the bite. There were two deaths, both in patients who were moribund upon arrival at the hospital. Three patients developed necrosis, and 14 individuals with systemic symptoms had no local swelling at all. Both cardiotoxicity and reliable nonspecific signs of envenoming were absent. Bites by the Philippine cobra produce a distinctive clinical picture characterized by severe neurotoxicity of rapid onset and minimal local tissue damage.
Although venom toxicity values can vary greatly even among specimens of the same species, the Philippine cobra is considered to possess one of the most toxic venom among all of the Naja (cobra) species based on murine LD50, according to most toxinology studies. The average subcutaneous LD50 for this species is 0.18 mg/kg (0.11-0.3 mg/kg), and the average venom yield per bite is 90–100 mg. Only the Caspian cobra (Naja oxiana ) has produced a more potent venom, producing an average of 0.14 mg/kg (0.067-0.21 mg/kg).
Philippine cobras are carnivores. They feed predominantly on small mammals, frogs, and even other snakes. Small rodents such as mice and small rats are their preferred prey and make up the majority of their diets. However, they will also eat small lizards, eggs, and when the opportunity arises, small birds.
The breeding season of Philippine cobras occurs year-round. After the mating females lay 10 to 20 eggs which are incubated about 70-90 days. When hatched, the young are completely independent and are able to fend for themselves.
The biggest threats to Philippine cobras include habitat destruction and poaching. These snakes are often collected for the exotic food trade or for the pet trade and also suffer persecution in agricultural areas.
The IUCN Red List and other sources don’t provide the number of the Philippine cobra total population size. Currently, this species is classified as Near Threatened (NT) on the IUCN Red List and its numbers today are decreasing.
