The blue duiker (Philantomba monticola) is a small antelope found in central, southern and eastern Africa.

The blue duiker feeds on fallen fruits, foliage, flowers and pieces of bark, provided mainly by the forest canopies in their habitat.

Forests are preferred as these provide the animal with shelter through the dense understory and forage through the canopy.

[3][5] While the generic name Philantomba has no clear origin, the specific name monticola has been derived from the Latin words montis (mountain) and colo (meaning "I cultivate" or "I inhabit"), in reference to its montane habitat.

[8] In 2012, Anne R. Johnston (of the University of Orleans) and colleagues constructed a cladogram of the subfamily Cephalophinae (duiker), that includes the three genera Cephalophus, Philantomba and Sylvicapra, based on mitochondrial analysis.

Marc Colyn (of the University of Rennes 1) and colleagues, who had discovered this species in 2010, had prepared a similar cladogram (below) that included it.

[7][14] A row of minute pores surrounded by a few hairs in the preorbital glands (near the eyes) secrete an opaque liquid consisting of 45 volatile compounds.

The grey-legged northern subspecies show a grey to brown coloration, with a posterior stripe that marks a transition from the rump to the buttocks.

The diminutive P. m. melanorheus stands apart as well, with black dorsal parts, pinkish grey sides, and long thick fur.

The paler P. m. defriensi is grey in the middle portion of the back, with red to fawn sides, and dark rump and tail.

P. m. monticola, light grey to fawn with a reddish rump, is darker than P. m. bicolor, that has reddish-orange flanks.

P. m. simpsoni is distinguished by a facial stripe with white ventral parts; the rump is redder than the flanks.

[7] The diet consists of fallen fruits, foliage, flowers and pieces of bark, provided mainly by the forest canopies in their habitat.

[14] Fungi, resin, particularly exudates from Albizia species[7] and animal matter such as ants (which are licked from the ground)[17] may also be included in the diet.

[7] A 1990 study analysed 12 stomachs and determined the content of dicotyledonous leaves to be 70%, while fruits and seeds comprised 23% of the diets and fresh foliage was plenty and perennial.

Forests are preferred as these provide the animal with shelter through the dense understory and forage through canopy.

[14] They can also be found in pockets of degraded and regenerated forests from the sea level up to an altitude of 3,000 metres (9,800 ft).

This duiker can be found in several countries in the western, southern and eastern parts of Africa: Angola, Cameroon, Central African Republic, The Democratic Republic of Congo, Equatorial Guinea, Gabon, Kenya, Malawi, Mozambique, Nigeria, Rwanda, South Africa, South Sudan, Tanzania, Uganda, Zambia and Zimbabwe.

It is listed in Appendix II of the Convention on International Trade in Endangered Species (CITES).

While the population trend is reasonably stable, the blue duiker is threatened by extensive bushmeat hunting across its range.

Wilson claimed that the blue duiker has the greatest economic as well as ecological significance of any African ungulate .