Streaming Media
Start Date
3-2-2021 11:45 AM
End Date
3-2-2021 11:51 AM
Abstract
Native bees are threatened by habitat loss through urbanization, however there is increasing interest in creating bee nesting habitat in urban areas. Although about a third of our native bees use cavity nests, few studies have examined the role of nest height or cavity size in attracting our lesser known native cavity-nesting bees, or even determined what species are present in the region. To determine what species were present, and whether they showed preferences for nesting at a certain height or cavity diameter, we set up artificial wooden cavity nest blocks across fourteen locations in the greater Portland, OR area. Wooden posts were erected with nest blocks at 3 different heights (0.5, 1.5, and 2.3 meters), and to accommodate a diversity of bee species, cavity diameters ranged from 3.0 to 10.0 mm. The nests were retrieved at the end of the season and the bees and wasps reared in the lab. We found that bees occupied 14% of the cavities, with a total occupancy rate of 27.5% by all bee and wasp occupants. Fifteen species of bees used the nest blocks, including 8 genera of Megachilidae and one species of Colletidae. The diameter most occupied by bees was the 5.0 mm size at 60.2% and included 9 bee species, and the different nest heights used varied across species. Nesting preference data will be used to better inform residents of greater Portland how best to provide nesting habitat for cavity nesting bees, and the solitary wasps that use similar nesting sites.
Subjects
Conservation biology, Habitat assessment, Wildlife biology
Persistent Identifier
https://archives.pdx.edu/ds/psu/35500
Nest Preferences of solitary cavity nesting bees in Portland, OR
Native bees are threatened by habitat loss through urbanization, however there is increasing interest in creating bee nesting habitat in urban areas. Although about a third of our native bees use cavity nests, few studies have examined the role of nest height or cavity size in attracting our lesser known native cavity-nesting bees, or even determined what species are present in the region. To determine what species were present, and whether they showed preferences for nesting at a certain height or cavity diameter, we set up artificial wooden cavity nest blocks across fourteen locations in the greater Portland, OR area. Wooden posts were erected with nest blocks at 3 different heights (0.5, 1.5, and 2.3 meters), and to accommodate a diversity of bee species, cavity diameters ranged from 3.0 to 10.0 mm. The nests were retrieved at the end of the season and the bees and wasps reared in the lab. We found that bees occupied 14% of the cavities, with a total occupancy rate of 27.5% by all bee and wasp occupants. Fifteen species of bees used the nest blocks, including 8 genera of Megachilidae and one species of Colletidae. The diameter most occupied by bees was the 5.0 mm size at 60.2% and included 9 bee species, and the different nest heights used varied across species. Nesting preference data will be used to better inform residents of greater Portland how best to provide nesting habitat for cavity nesting bees, and the solitary wasps that use similar nesting sites.
