School yards and nature trails: ecology education outside the university.

Ecologists, conservation biologists and other natural historians increasingly recognize the need to become involved in public education. An ecologically literate public may be the 'last best hope' for a sustainable biosphere. Partnerships between ecologists and educators may be the best hope, though not the last, for moving towards an ecologically literate public.

Numerical and functional response of predators to a long-term decline in mammalian prey at a semi-arid Neotropical site.

Occurrence and diet of ten carnivorous predators (four falconiforms, four owls, and two foxes), and population levels of their mammalian prey, were monitored over 45 months at a semi-arid site in north-central Chile. Early in this period, small mammals irrupted and then declined markedly to a density 7% of that at peak. All four falconiforms (Buteo polyosoma, Falco sparverius, Geranoaetus melanoleucus, Parabuteo unicinctus) and one owl (Tyto alba) responded numerically to the decline in mammalian prey by virtually abandoning the study site.

Effects of indiscriminate foraging by tropical hummingbirds on pollination and plant reproductive success: experiments with two tropical treelets (Rubiaceae).

In cloud forest at Monteverde, Costa Rica, two common treelets (Palicourea lasiorrachis and Cephaelis elata, both Rubiaceae) depend simultaneously on one hummingbird population (Lampornis calolaema) for pollination. Both species are distylous and self-incompatible. In laboratory experiments, we examined possible effects of indiscriminate foraging by hummingbirds among flowers of both species, as observed in the field, on pollination of Palicourea.

Disturbance and Predictability of Flowering Patterns in Bird-Pollinated Cloud Forest Plants.

The distribution and flowering patterns of hummingbird-pollinated plants were compared from July 1981 to June 1983 in three patch types in cloud forest at Monteverde, Costa Rica. Study plots were: (1) four recent, large (1100-2500 m ) disturbances ("cutovers") produced by cutting vegetation, (2) six recent, smaller (200-600 m ) disturbances caused by treefalls, and (3) four plots (1600-1800 m ) of canopied forest. Based on published literature dealing with communities that characterize different regimes of disturbance, we tested one assumption and two hypotheses.