Grey-breasted Spiderhunter (Arachnothera modesta) [XC241643]
by Mike Nelson from Mount Kerinci, West Sumatra, Sumatra, Indonesia (call, song)
Grey-breasted Spiderhunter (Arachnothera modesta) [XC777991]
by Roland Zeidler from Kuala Tahan, Guesthouse besides the mosque, Jerantut District , Pahang, Malaysia (call)
Subspecies
Sometimes considered to form a superspecies with Streaky-breasted Spiderhunter (Arachnothera affinis) as they overlap in range in Borneo, but are segregated by altitude. Present species and nominate subspecies of latter have been treated as conspecific (with subspecies everetti of Streaky-breasted Spiderhunter (Arachnothera affinis) then treated as a separate species). Geographical variation not well marked; caena intergrades with nominate in southern Myanmar (Tenasserim) and southern Thailand and could perhaps be merged with it.
Proposed subspecies heliophilus (described from Loh Sidoh Bay, in north-western Sumatra) considered indistinguishable from concolor.