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Biotic interactions have been considered as an important feature in species distribution modeling, but little is known about the effect of including different types of interactions or performing different strategies of integrating biotic interactions in species distribution modelling. This study compares different methods for including interspecific interactions in species distribution models for bees, their cleptoparasites, and the plants they pollinate. Hostparasite interactions among bumble bees (genus Bombus: generalist pollinators and brood parasites) and specialist plant-pollinator interactions between Centris bees and Krameria flowers were used as case studies. We used 7 different modelling algorithms available in the BIOMOD R package. Adding biotic information to present day predictions of potential occurrence significantly improved the cross-validated area under the receiver operating characteristic curve (AUC), a measure often applied to estimate model accuracy. Different species and types of interaction showed different AUC results in line with data quality, level of biological linkage and interdependence of each interaction. Furthermore, the species that presented the best improvement of AUC was projected under future climate scenarios. The results showed marked differences when using abiotic data only, and when including biotic interactions of various types. The results show that choosing the correct biotic information, based on biological and ecological knowledge, is critical to improve the accuracy of species distribution models, and also to forecast distribution change.

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Colour is one of the most obvious advertisements of flowers, and occurs in a huge diversity among the angiosperms. Flower colour is responsible for attraction from a distance, whereas contrasting colour patterns within flowers aid orientation of flower visitors after approaching the flowers. Due to the striking differences in colour vision systems and neural processing across animal taxa, flower colours evoke specific behavioural responses by different flower visitors. We tested whether and how yellow flowers differ in their spectral reflectance depending on the main pollinator. We focused on bees and birds and examined whether the presence or absence of the widespread UV reflectance pattern of yellow flowers predicts the main pollinator. Most bee-pollinated flowers displayed a pattern with UV-absorbing centres and UV-reflecting peripheries, whereas the majority of bird-pollinated flowers are entirely UV- absorbing. In choice experiments we found that bees did not show consistent preferences for any colour or pattern types. However, all tested bee species made their first antennal contact preferably at the UV-absorbing area of the artificial flower, irrespective of its spatial position within the flower. The appearance of UV patterns within flowers is the main difference in spectral reflectance between yellow bee- and bird-pollinated flowers, and affects the foraging behaviour of flower visitors. The results support the hypothesis that flower colours and the visual capabilities of their efficient pollinators are adapted to each other.

-A survey of the bee fauna of Araucaria Forest was performed in the border of a fragment in the district of Porto União, in Santa Catarina State. Samples were carried on monthly between October/2005 and October/2006 with hand nets directly on the fl owers, besides three types of traps: chemical baits, trap nests and pantraps. A total of 1711 bees were captured belonging to 164 species, distributed in fi ve families of bees that occur in Brazil. From the total 1339 bees of 130 species were sampled with the hand net, 346 individuals of 72 species were collected in pantraps, 24 bees of nine species were caught in the trap nests and two specimens of one species were sampled with baits. At most 48 species were common to two or more sample methods. Dialictus, with 27 species, was the most representative genus in the area. The exotic Apis mellifera L. was the most abundant species, representing 49.6% of the sampled bees, following by Dialictus sp.11 with 3.2%. The results show evidences of a seasonal pattern of activity of the bees and the importance of the use of complementary methods to survey the fauna. The composition of the bee fauna was similar to many inventories performed in the Araucaria Forest, being Halictidae the most diverse family followed by Apidae.