above sea level, being particularly common at elevations above 1400 m. The species grows terrestrially in primary montane forest and forest margins. It is not found in the so-called Bonsai Forest, a region of stunted vegetation on the plateau below the summit ridge of Mount Hamiguitan. It typically grows in partial shade and is frequently exposed to heavy downpours. While Mount Hamiguitan is an ultramafic mountain, N. hamiguitanensis does not necessarily grow in an ultramafic substrate, owing to the high humus content of the forest underlayer. At the type locality, N. hamiguitanensis occurs at an average density of around two to three plants per 50 m2, as estimated by eye. Only seedlings and mature, climbing plants have been observed, with no records of larger rosette plants bearing lower pitchers. Nepenthes hamiguitanensis is sympatric with N. justinae (previously identified as N. mindanaoensis) and grows in the same altitudinal range as N. micramphora and N. peltata; the latter two species are typically found in more open areas, where they are exposed to higher levels of incident light. Despite this, no natural hybrids involving N. hamiguitanensis have been observed with certainty; it has been suggested that the flowering times of N. hamiguitanensis and the other Nepenthes species of Mount Hamiguitan may differ. The describing authors assessed the conservation status of N. hamiguitanensis as Vulnerable based on the IUCN criteria. They pointed out that N. hamiguitanensis is far more localised than N. micramphora and N. peltata, which occur at several sites on the mountain and are represented by larger populations. Mount Hamiguitan forms part of the Mount Hamiguitan Range Wildlife Sanctuary National Park and visitors are only permitted to climb the mountain with the assistance of a guide. The future of wild populations of N. hamiguitanensis will be further secured if provincial officials of Davao Oriental are successful in their bid to gain recognition of Mount Hamiguitan as a UNESCO World Heritage Site. Hybrid origin Nepenthes hamiguitanensis was initially assumed to represent a natural hybrid between N. micramphora and N. peltata, both of which are also present on the upper slopes of Mount Hamiguitan. It shares several morphological features with its putative parent species, such as the shape of the pitchers (with N. micramphora) and form of the indumentum (with N. peltata). However, it has distinctive light-coloured upper pitchers that neither of these species possess (N. peltata is not known to produce aerial traps