Abstract:

Sixty camera traps were set on 32 islands and one terrestrial plot in the Thousand Island Lake region from May 1, 2011 to March 31, 2014. In total, we recorded 23,639 photos that included nine species of large ground-dwelling mammals with a rate of independent photographs of 2.62%. The species-area relationship showed that species richness increased with island area (ha) with a slope, z value, of 0.27. On large islands (> 10 ha), the minimum trapping effort increased with island area. On small islands (< 10 ha), however, there was no clear pattern. The minimum trapping effort was not correlated with island isolation (d.f. = 20, F = 3.067, P = 0.095). Our results suggested that large ground-dwelling mammal populations have disappeared on smaller islands since the lake was formed. Based on these findings, we suggest that large MTE’s are required in islands with large areas when using camera traps in a fragmented landscape. On small islands, researchers should vary trapping efforts according to the island’s attributes, including species resources.

Key words: fragmented habitat, island biogeography, land-bridge islands, ground-dwelling mammals, monitoring