It occurs in premontane and montane evergreen forest (Parker et al. 1996, P. G. W. Salaman in litt. 1999), primarily on low, outlying ridges (Schulenberg et al. 2007) and accepts altered habitats as long as forest patches and thickets of secondary growth remain (del Hoyo et al. 1999, Schuchmann et al. 2020). It occurs at elevations between 400-1,200 m (Schuchmann et al. 2020). The species feeds on the nectar of flowers, including flowers from Rubiaceae, Ericaceae (especially Psammisia), and Gesneriaceae species (Schuchmann et al. 2020). It may also feed on insects occasionally. Breeding occurs between December and April (Schuchmann et al. 2020).

Phlogophilus hemileucurus is locally uncommon to common in the Andean foothills of south-west Colombia (west Putumayo, east Cauca, and possibly extending further north of the Caquetá River [Gómez-Bernal et al. 2016]), east Ecuador (west Napo south to Zamora-Chinchipe) and north-east Peru (San Martín and Loreto) at 800-1,500 m, but as low as 400 m in Peru (Hilty and Brown 1986, Sibley and Monroe 1990, Parker et al. 1996, P. G. W. Salaman in litt. 1999, Clements and Shany 2001, Ridgely and Greenfield 2001). Due to agricultural and urban development, the presence of the species further north of the Caquetá River in Colombia requires confirmation (Gómez-Bernal et al. 2016). 

Conservation Actions Underway
CITES Appendix II. It occurs in protected areas, including the Ecuador-Peru East Andes EBA (Schuchmann et al. 2020). 

Conservation Actions Proposed
Attempt to obtain an accurate estimate of its population size and trends. Search for the species in potentially suitable habitat at new sites. Study its ecology and its ability to persist in degraded and fragmented habitats. Monitor populations at strongholds. Quantify the extent of habitat losses.
Effectively protect significant areas of suitable habitat at key sites, in both strictly protected areas and community led multiple use areas.