Gordon H Rodda (Former Employee)

We conducted a physical simulation experiment to test the efficacy of harmonic direction finding for remotely detecting locomotor activity in animals. The ability to remotely detect movement helps to avoid disturbing natural movement behavior. Remote detection implies that the observer can sense only a change in signal bearing. In our simulated movements, small changes in bearing (

Since 1937, thirteen species of non-indigenous anurans have made their way to Guam. Of these, at least six have established breeding populations. Various pathways led to the introduction of these species to the island. The only anuran intentionally introduced was Chaunus marinus (formerly Bufo marinus), which was brought to Guam as a biocontrol agent. Kaloula picta, K. pulchra...

Eight anuran species were recorded for the first time in Guam in the period May 2003-December 2005, all apparently the result of arrivals to the island since 2000. Three of the eight species (Rana guentheri, Polypedates megacephalus, and Eleutherodactylus planirostris) had well-established breeding populations by 2005. A further three (Fejevarya cf. livinocharis, Fejervarya cancrivora...

Since their introduction to Guam shortly after World War II, brown tree snakes, Boiga irregularis (Merrem), have seriously impacted the biota and human population of the island. Understanding the biology of this exotic species will likely be important to the success of control programs. We compared the reproductive biology of 782 B. irregularis caught on Guam during the 1980s with...

The effectiveness of methyl bromide as a fumigant for brown treesnake (Boiga irregularis) management was evaluated on Guam. Eighteen snakes in secured cloth bags were randomly positioned in a 47.7-m3 tarpaulin-covered cargo container for each fumigation treatment. Methyl bromide treatments tested were: 24 g m−3 and and 12 g m−3, both for 2-h and 1-h exposures. All treatments, except for...

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Aim Some species reach extraordinary densities on islands. Island assemblages have fewer species, however, and it is possible that island species differ from their mainland counterparts in average mass. Island assemblages could be partitioned differently (fewer species or smaller individuals) from mainland sites without differing in aggregate biomass (density compensation). Our objective...

No abstract available.

No abstract available.

An understanding of the abundance of organisms is central to understanding ecology, but many population density estimates are unrepresentative because they were obtained from study areas chosen for the high abundance of the target species. For example, from a pool of 1072 lizard density estimates that we compiled from the literature, we sampled 303 estimates and scored each for its...