Different rodent species seem to possess different techniques to handle the seed that they retrieve. For an example, we have observed that a red squirrel prefers to stick to its arboreal nature by dragging the seed towards the canopy away from the ground, a spiny rat prefers the deep dark world below the ground and an agouti prefers to bury the seed just a few centimeters below the surface. Even within agoutis, there are differences in the sites they choose to cache their seeds. We have seeds cached in the stream beds, in the gaps and in the understory of saplings, trees, lianas and vines. In order to know if there are differences in cache sites of agoutis, red squirrels and spiny rats in terms of environmental conditions such as light intensity, soil characteristics and leaf litter depth, Lieneke Bakker, a Master’s student recently completed measurements of microsite characteristics of cache sites. The seeds and fruits of black palm (Astrocaryum standleyanum) are not only preferred by agoutis, spiny rats, red squirrels, peccaries, howler monkeys, spider monkeys, but are also predated upon by insects such as Bruchid beetles and Scotylid beetles. While the fruit is in its early developmental stage, female Bruchid beetle oviposits eggs on the flesh and the newly hatched larvae emerge out of the seed through a perfectly circular hole in the seeds.
We are in the midst of the wet season. Almost every afternoon, dark clouds arrive rolling towards the island and announce rainfall through its thunder and lightning. Rain seeps through tree trunks and between gaps in the palm fronds, the streams swell up with rain water and the soil remains moist under the shadow of leaf litters. We suspect that many transmitters are washed off the magnets after heavy rainfall. But surprisingly, very few transmitters are washed off the magnets. On one hand, the rain makes the surface slippery to walk on; on the other hand it serves as a perfect platform for animal species to leave their footprints. While tracking seeds, we encounter beautiful tracks of ocelots, agoutis, peccaries and deer that decorate the muddy trails. In addition to radio tracking seeds, we are also doing mammal monitoring by using motion sensitive cameras to study the diversity and abundance of terrestrial bird and mammal communities and we recently started the seed excavation project to record the diversity and abundance of palm seeds and seedlings.