Data from: Crossing the (Wallace) line: local abundance and distribution of mammals across biogeographic barriers

Past and ongoing vertebrate introductions threaten to
rearrange ecological communities in the Indo-Malay Archipelago, one of
Earth’s most biodiverse regions. But the consequences of these
translocations are difficult to predict. We compared local abundance
and distributions in four tropical mammal lineages that have crossed
from Asia to Wallacea or New Guinea. The local abundance of macaques
(Macaca spp.), which naturally crossed Wallace’s Line, was higher in
Sulawesi (east of the line; mean = 3.7 individuals per camera station,
95% CI = 2.2 : 5.1) than in Borneo (west of the line; mean = 1.1, CI =
0.8 : 1.4), but the local abundance of Malay civets (Viverra
tangalunga), Rusa deer, and Sus pigs was similar in their native
ranges and where they had been introduced by humans east of Wallace’s
Line. Proximity to rivers increased Malay Civet local abundance and
decreased the local abundance of pigs in parts of their introduced
ranges (Maluku and New Guinea, respectively), while having no effect
on local abundance in their native ranges (Borneo) or other areas
where they have been introduced (Sulawesi). That local abundance was
higher east of Wallace’s Line in just one out of four mammal lineages
is consistent with findings from plant invasions, where most species
have similar abundance in their native and introduced ranges. However,
species’ ecology may change as they enter new communities, for example
their patterns of abundance at local scales. This could make it
difficult to predict community structure in the face of ongoing
species introductions.