- Raptor Monitoring Update for May to June 2019
(posted: Jun 19, 2019)
The breeding raptor season is in full swing at Pinnacles National Park, with many species finishing up their nesting efforts. Here is an update on raptor activity through May and June.
Unexpected Closing of the Bear Gulch Cave
posted: September 15, 2006
Pinnacles National Monument has closed the Bear Gulch Cave because of an uncharacteristic movement by a maternity colony of Townsend's big-eared bats. The bats moved into the lower portion of the cave, which was open to the public, Labor Day weekend. The park is unsure why the colony has moved from the closed portion's quiet recesses to the open portion of the cave on such a busy weekend. "One possible explanation is that someone entered the closed portion of the cave and disturbed them," suggested Paul Johnson, Pinnacles Wildlife Biologist. "People illegally enter the closed part of the cave. This can cause major disruptions for the bats as they attempt to raise their young and are especially sensitive to human disturbance. We appreciate everyone's cooperation as the park manages this sensitive resource. Although we may never know, it's quite likely that the colony was ousted from its preferred location in the upper portion of the cave by human intrusion." The park will conduct surveys twice per week to monitor the presence and movement of the bats. When the colony has moved out of the lower portion of the cave, it will reopen.
2006 marks the 10th season for the maternity colony of Townsend Big-eared bats at Pinnacles National Monument. Though it is difficult to obtain the exact number in the maternity colony, park biologists have counted more than 350 during the hibernation season.
In October of 2004, the park installed a set of gates allowing the lower section of the cave to be enjoyed for approximately 10 months of the year. The entire cave is open each March and October for about one and up to four weeks, depending on the presence of the Townsend's Bigeared bat colony. The bats, which are listed by the state of California as a species of special concern, raise their young (pups) and hibernate in the cave. The entire cave is normally closedfrom mid May through mid July to allow the bats to raise their young. Cave openings are not fixed dates and depend solely on the habits of the bats.
When visiting the cave, please remember that it is the home of a sensitive species. To avoid disturbing the bats, please keep voices down and refrain from flash photography. If you happen to see a bat in either of the park's caves, please do not disturb it or shine your light directly on it.
The Bear Gulch Cave (closer to the east entrance of the park) and the Balconies Cave (closer to the west entrance) both offer the opportunity to explore a talus cave. Please remember to bring water, flashlights, and wear sturdy shoes. Seasonal streams run through both caves, and the rocks can be slippery when the stream is flowing. Check the park's web page or call the Bear Gulch Visitor Center for updates remembering that at any time a closure could occur if the bats alter their habits. Additional information about the park's talus caves and the bats who call them home, please visit the park's Bat Web pages
General park information can be obtained by visiting www.nps.gov/pinn or by calling 831- 389-4485 extension 0.