Speaker
Description
Bees vary greatly in their dietary span, ranging from highly specialized species that collect floral rewards (e.g., pollen, nectar, or oil) from very few plant taxa to generalists that utilize a variety of floral hosts. Such diet specialization is hypothesized to constrain both the abundance and distribution of a species, with specialist species having lower abundance and smaller distribution ranges compared to generalist counterparts. Several studies have shown that diet specialization can increase species’ risk of local extinction. Understanding how diet is linked to the the abundance and distribution of bees is thus critical for conservation. Here, we examined whether diet specialization affects the abundance and distribution of oil-collecting Centris bees, key pollinators of a global biodiversity hotspot, the Brazilian Cerrado. Using museum data from the Federal District of Brazil, we analyzed the abundance and distribution, on a local scale, of 15 Centris species across six decades (from 1970 to 2022). By controlling for time and unequal sampling effort, we found that generalist species had higher abundance (x̄ = 10) than specialists (x̄ = 6) and specialist species showed higher variation in their abundance than those of generalists. Using the number of grid cells (10 x 10 km) as a proxy for distribution range, generalist species occupied more grid cells (x̄ = 9) than specialist species (x̄ = 6). Despite both abundance and distribution results being non-significant, the pattern may support the hypothesis that diet seems to play a role in shaping the abundance and distribution of those bees, albeit other ecological characteristics be equally important.
| Status Group | Doctoral Researcher |
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