Very little information on the behavior of White-throated Mountain-gem has been published. Most observers have noted that this species feeds at different strata, visiting epiphytic flowers in forest canopy as well as shrubs at forest edge and gaps in the forest (Stiles and Skutch 1989).
Male White-throated Mountain-gems defend classical feeding territories at flower clusters (Stiles and Skutch 1989, Stiles 1999).
Little information. White-throated Mountain-gem presumably is polygynous, as are most if not all species of hummingbirds (Schuchmann 1999: 509). Likewise, it is not known if previously-mated pairs re-unite for successive breeding seasons after nonbreeding periods.
Social and interspecific behavior
Not much information available for White-throated Mountain-gem. Normally this species is solitary, but it is expected that males and females come together, at least for a short period, during the breeding season. Males are quite aggressive, against individuals of their own species or different species, when defending a large patch of flowers (Stiles 1999), but are subordinate to the larger Fiery-throated Hummingbird (Panterpe insignis) (Stiles and Skutch 1989).
There is no published information on predation of this species.