Treating hummingbirds as feathered bees : a case of ethological cross-pollination

Hummingbirds feed from hundreds of flowers every day. The properties of these flowers provide these birds with a wealth of information about colour, space and time to guide how they forage. To understand how hummingbirds might use this information, researchers have adapted established laboratory paradigms for use in the field. In recent years, however, experimental inspiration has come less from other birds, and more from looking at other nectar-feeders, particularly honeybees and bumblebees, which have been models for foraging behaviour and cognition for over a century. In a world in which the cognitive abilities of bees regularly make the news, research on the influence of ecology and sensory systems on bee behaviour is leading to novel insights in hummingbird cognition. As methods designed to study insects in the laboratory are being applied to hummingbirds in the field, converging methods can help us identify and understand convergence in cognition, behaviour and ecology.PostprintPeer reviewe

The Egg of \u3ci\u3eStylogaster Neglecta\u3c/i\u3e Williston (Diptera: Conopidae)

Adults of both sexes and the previously unknown eggs of the parasitoid conopid fly Stylogaster neglecta Williston are illustrated and measurements are provided, including the total clutch size and the lengths and widths of eggs from random samples

Morphometric sexing of little spiderhunter (Arachnothera longirostra) in Peninsular Malaysia

Sexual dimorphism is often directly linked to sexual selection, mating systems and resource partitioning, which are crucial in species conservation and management. Many avian species, including pollinator birds, are sexually dimorphic with respect to size and colour, yet, such differences may be subtle for some species. In this study, molecular sexing was performed in addition to determining morphological parameters that can aid in future sex determination of a common forest pollinator, the little spiderhunter (Arachnothera longirostra), in Peninsular Malaysia. Based on 23 captures made in four forests, two out of seven body measurements (i.e. wing and tail lengths) were useful in predicting the sexes of the bird with 100% accuracy. In addition, significant differences were found in the head, bill, and total body lengths. Such findings will facilitate more effective sex identification in future field studies, particularly in the case of juveniles

Breeding systems and pollination modes of understorey shrubs in a medium elevation wet evergreen forest, southern Western Ghats, India

This study on the reproductive biology and pollination modes of 22 species of understorey shrubs in 11 families was conducted in a medium elevation wet evergreen forest in the southern Western Ghats of India from 1994 to 1997. We evaluated whether this assemblage was predominantly outcrossing as in other tropical forests, and whether mating systems are related to pollination mode. We assessed whether species were hermaphrodites, dioecious or monecious. We assessed the breeding systems of each species with hand self pollinations. About 55% of the species produced small white and inconspicuous flowers. The majority of the flowers opened at dawn and was visited by diurnal pollinators. The proportion of dioecious and monoecious species was lower than for other tropical forests. Among the hermaphrodites, the majority had mixed mating systems. Therefore the overall levels of obligate outcrossers (37%) were low compared with other tropical forests. We recognized 7 pollination modes: social bees, solitary bees, diverse insects, flies, sunbird, sphingid moth and Xylocopa sp. Among these the social bees, flies and diverse insects visited more species than the other groups. Species pollinated by flies and diverse insects tended to be significantly more outcrossing than those pollinated by bees and other solitary pollinators

Butterfly genome reveals promiscuous exchange of mimicry adaptations among species.

Author's manuscript, Europe PMC version. Published in final edited form as: Nature. 2012 July 5; 487(7405): 94–98. doi:10.1038/nature11041.The evolutionary importance of hybridization and introgression has long been debated. Hybrids are usually rare and unfit, but even infrequent hybridization can aid adaptation by transferring beneficial traits between species. Here we use genomic tools to investigate introgression in Heliconius, a rapidly radiating genus of neotropical butterflies widely used in studies of ecology, behaviour, mimicry and speciation. We sequenced the genome of Heliconius melpomene and compared it with other taxa to investigate chromosomal evolution in Lepidoptera and gene flow among multiple Heliconius species and races. Among 12,669 predicted genes, biologically important expansions of families of chemosensory and Hox genes are particularly noteworthy. Chromosomal organization has remained broadly conserved since the Cretaceous period, when butterflies split from the Bombyx (silkmoth) lineage. Using genomic resequencing, we show hybrid exchange of genes between three co-mimics, Heliconius melpomene, Heliconius timareta and Heliconius elevatus, especially at two genomic regions that control mimicry pattern. We infer that closely related Heliconius species exchange protective colour-pattern genes promiscuously, implying that hybridization has an important role in adaptive radiation

Comparative genetics of seven plants endemic to Florida’s Lake Wales Ridge

Here we submit that mathematical tools used in population viability analysis can be used in conjunction with floristic and faunistic surveys to predict changes in biogeographic range. We illustrate our point by summarizing the results of a demographic study of Lobelia boykinii. In this study we used deterministic and stochastic matrix models to estimate the growth rate and to predict the time to extinction for three populations growing in the Carolina bays. The stochastic model better discriminated among the fates of the three populations. It predicted extinction for two populations in the next 25 years but no extinction of the third population for at least 50 years. Probability of extinction is likely correlated with hydrologic regime and fire frequency of the bay in which a population is found. The stochastic model could be combined with information about the geographic distribution of L. boykinii habitats to predict short-term biogeographic change

The diversification of Heliconius butterflies: what have we learned in 150 years?

Research into Heliconius butterflies has made a significant contribution to evolutionary biology. Here, we review our understanding of the diversification of these butterflies, covering recent advances and a vast foundation of earlier work. Whereas no single group of organisms can be sufficient for understanding life's diversity, after years of intensive study, research into Heliconius has addressed a wide variety of evolutionary questions. We first discuss evidence for widespread gene flow between Heliconius species and what this reveals about the nature of species. We then address the evolution and diversity of warning patterns, both as the target of selection and with respect to their underlying genetic basis. The identification of major genes involved in mimetic shifts, and homology at these loci between distantly related taxa, has revealed a surprising predictability in the genetic basis of evolution. In the final sections, we consider the evolution of warning patterns, and Heliconius diversity more generally, within a broader context of ecological and sexual selection. We consider how different traits and modes of selection can interact and influence the evolution of reproductive isolation.RMM is funded by a Junior Research Fellowship at King’s College, Cambridge. KMK is supported by the Balfour Studentship, University of Cambridge, SHMa by a Research Fellowship at St John's College, Cambridge, and SHMo by a Research Fellowship from the Royal Commission for the Exhibition of 1851. Our work on Heliconius has been additionally supported by the Agence Nationale de la Recherche (France), the Biology and Biotechnology Research Council (UK), the British Ecological Society, the European Research Council, the Natural Environment Research Council (UK), and the Smithsonian Tropical Research Institute.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1111/jeb.1267

Heliconiini butterflies can learn time-dependent reward associations.

For many pollinators, flowers provide predictable temporal schedules of resource availability, meaning an ability to learn time-dependent information could be widely beneficial. However, this ability has only been demonstrated in a handful of species. Observations of Heliconius butterflies suggest that they may have an ability to form time-dependent foraging preferences. Heliconius are unique among butterflies in actively collecting pollen, a dietary behaviour linked to spatio-temporally faithful 'trap-line' foraging. Time dependency of foraging preferences is hypothesized to allow Heliconius to exploit temporal predictability in alternative pollen resources. Here, we provide the first experimental evidence in support of this hypothesis, demonstrating that Heliconius hecale can learn opposing colour preferences in two time periods. This shift in preference is robust to the order of presentation, suggesting that preference is tied to the time of day and not due to ordinal or interval learning. However, this ability is not limited to Heliconius, as previously hypothesized, but also present in a related genus of non-pollen feeding butterflies. This demonstrates time learning likely pre-dates the origin of pollen feeding and may be prevalent across butterflies with less specialized foraging behaviours

The Glass is Half-Full: Overestimating the Quality of a Novel Environment is Advantageous

According to optimal foraging theory, foraging decisions are based on the forager's current estimate of the quality of its environment. However, in a novel environment, a forager does not possess information regarding the quality of the environment, and may make a decision based on a biased estimate. We show, using a simple simulation model, that when facing uncertainty in heterogeneous environments it is better to overestimate the quality of the environment (to be an “optimist”) than underestimate it, as optimistic animals learn the true value of the environment faster due to higher exploration rate. Moreover, we show that when the animal has the capacity to remember the location and quality of resource patches, having a positively biased estimate of the environment leads to higher fitness gains than having an unbiased estimate, due to the benefits of exploration. Our study demonstrates how a simple model of foraging with incomplete information, derived directly from optimal foraging theory, can produce well documented complex space-use patterns of exploring animals