Karen A. Johnson

Nocturnal Mammals, Diurnal Lizards, and the Pollination Ecology of the Cryptic Flowering Acrotriche Serrulata (Ericaceae)

Acrotriche serrulata exhibits a complex and uncommon form of flowering. It starts with a male-phase flower that shows secondary pollen presentation on the perianth and follows with a female phase after the corolla is removed or abscissed. We examined the potential for insects, lizards, and mammals to act as pollinators. Observations and experiments on breeding system, phenology, floral scent, flower visitors, and lizard feeding were undertaken in southern Australia. Acrotriche serrulata sets little fruit by autonomous selfing but readily sets fruit after facilitated geitonogamy and xenogamy. Flower anthesis is diurnal and nocturnal. The nectar profile includes acetaldehyde, ethanol, and ethyl acetate. The nocturnal mammals Trichosurus vulpecula and the introduced Rattus rattus were the only visitors observed to actively forage on the flowers. In contrast, the skinks Egernia whitii, Niveoscincus ocellatus, and Niveoscincus metallicus routinely passed flowers full of nectar and foraged only on those presented during feeding observations. Insects visited the flowers but did not behave as pollinators. Acrotriche serrulata is likely to be pollinated by nocturnal mammals attracted to its flowers by scent. Effective pollinators appear to be rare over some of its range. This may have implications for the long-term reproductive success and conservation of A. serrulata.

Bird Pollination of the Climbing Heath Prionotes Cerinthoides (Ericaceae)

Tubular red and pink flowers often indicate bird pollination. Prionotes cerinthoides, a climbing shrub of the temperate rainforest in Tasmania (Australia) and one of only two members of the most primitive clade of the subfamily Styphelioideae (Ericaceae), has such flowers. We tested the hypothesis that P. cerinthoides is bird pollinated using breeding system experiments, observations of flower visitors, and invertebrate trapping. Flowering phenology, nectar availability, and flower damage were also recorded. Prionotes cerinthoides produced little viable seed in the absence of a pollinator but selfed readily when pollination was facilitated. It appears that P. cerinthoides depends largely on the pollination services of a single native bird species, the eastern spinebill (Acanthorhynchus tenuirostris). The only other flower visitor observed to contact anthers and stigma was the introduced bumblebee (Bombus terrestris). The crescent honeyeater (Phylidonyris pyrrhoptera), the introduced honeybee (Apis mellifera), and the bumblebee were nectar robbers.

Are there pollination syndromes in the Australian epacrids (Ericaceae: Styphelioideae)? A novel statistical method to identify key floral traits per syndrome

BACKGROUND AND AIMS Convergent floral traits hypothesized as attracting particular pollinators are known as pollination syndromes. Floral diversity suggests that the Australian epacrid flora may be adapted to pollinator type. Currently there are empirical data on the pollination systems for 87 species (approx. 15 % of Australian epacrids). This provides an opportunity to test for pollination syndromes and their important morphological traits in an iconic element of the Australian flora. METHODS Data on epacrid-pollinator relationships were obtained from published literature and field observation. A multivariate approach was used to test whether epacrid floral attributes related to pollinator profiles. Statistical classification was then used to rank floral attributes according to their predictive value. Data sets excluding mixed pollination systems were used to test the predictive power of statistical classification to identify pollination models. KEY RESULTS Floral attributes are correlated with bird, fly and bee pollination. Using floral attributes identified as correlating with pollinator type, bird pollination is classified with 86 % accuracy, red flowers being the most important predictor. Fly and bee pollination are classified with 78 and 69 % accuracy, but have a lack of individually important floral predictors. Excluding mixed pollination systems improved the accuracy of the prediction of both bee and fly pollination systems. CONCLUSIONS Although most epacrids have generalized pollination systems, a correlation between bird pollination and red, long-tubed epacrids is found. Statistical classification highlights the relative importance of each floral attribute in relation to pollinator type and proves useful in classifying epacrids to bird, fly and bee pollination systems.