Post by L Roebuck on Jan 4, 2006 9:22:38 GMT -5
OTIA III State Bridge Delivery Program: Web Brief:
ODOT: Building Better Homes for Bats
Bat habitat and populations in Oregon have been in decline for the past few decades, and now ODOT is in a good position to help.
Many bats use the narrow spaces between beams under highway bridges and other structures as nesting and roosting habitats. During the day, these shelters protect bats from predators and weather conditions. At night, the structures offer bats a place to rest and digest their food between nocturnal feedings. And in spring, bats give birth to and raise their young in these safe shelters.
Now, through the OTIA III State Bridge Delivery Program, ODOT is helping to make and keep bridges even more bat-friendly.
Currently, only 1 percent of American highway structures provide ideal day roost conditions, but minor modifications in the design and construction of future structures can easily provide homes for millions of bats. Bats actually prefer concrete—an excellent heat conductor—as roosting material. However, modern bridge structures use precast concrete that, although more cost-effective and efficient, lacks the texture and crevices bats need to be able to roost safely and comfortably.
ODOT biologists, in collaboration with Oregon Department of Fish and Wildlife (ODFW) and U.S. Forest Service biologists, have developed bat habitat performance standards to help bridge engineers plan construction with bat habitats in mind. With maximum forethought and minimal or no increased cost, bridge program contractors are modifying many new designs to remain bat-friendly.
Engineers lay grit sandpaper in the plywood forms to create a textured surface in the concrete that bats can more easily grip during night roosting. They space girders to encourage day roosting so the bats can adjust to rising and falling temperatures, and they introduced an innovation called the “Oregon wedge,” aninexpensive method of retrofitting bridges or culverts with day-roost habitats. The wedge is made from an exterior-grade plywood panel with wood strips attached along the top and sides, leaving an opening along the bottom.
This attention to preserving and building bat habitats can be considered a form of repayment to bats for controlling the insect populations that “bug” humans.
www.oregon.gov/ODOT/HWY/OTIA/news_bats.shtml
ODOT: Building Better Homes for Bats
Bat habitat and populations in Oregon have been in decline for the past few decades, and now ODOT is in a good position to help.
Many bats use the narrow spaces between beams under highway bridges and other structures as nesting and roosting habitats. During the day, these shelters protect bats from predators and weather conditions. At night, the structures offer bats a place to rest and digest their food between nocturnal feedings. And in spring, bats give birth to and raise their young in these safe shelters.
Now, through the OTIA III State Bridge Delivery Program, ODOT is helping to make and keep bridges even more bat-friendly.
Currently, only 1 percent of American highway structures provide ideal day roost conditions, but minor modifications in the design and construction of future structures can easily provide homes for millions of bats. Bats actually prefer concrete—an excellent heat conductor—as roosting material. However, modern bridge structures use precast concrete that, although more cost-effective and efficient, lacks the texture and crevices bats need to be able to roost safely and comfortably.
ODOT biologists, in collaboration with Oregon Department of Fish and Wildlife (ODFW) and U.S. Forest Service biologists, have developed bat habitat performance standards to help bridge engineers plan construction with bat habitats in mind. With maximum forethought and minimal or no increased cost, bridge program contractors are modifying many new designs to remain bat-friendly.
Engineers lay grit sandpaper in the plywood forms to create a textured surface in the concrete that bats can more easily grip during night roosting. They space girders to encourage day roosting so the bats can adjust to rising and falling temperatures, and they introduced an innovation called the “Oregon wedge,” aninexpensive method of retrofitting bridges or culverts with day-roost habitats. The wedge is made from an exterior-grade plywood panel with wood strips attached along the top and sides, leaving an opening along the bottom.
This attention to preserving and building bat habitats can be considered a form of repayment to bats for controlling the insect populations that “bug” humans.
www.oregon.gov/ODOT/HWY/OTIA/news_bats.shtml