What does the western spadefoot toad, northwestern pond turtle and tricolored blackbird have in common? All could live on Travis Air Force Base, California, and all could become federally listed under the Endangered Species Act.
A project team from the Center for Integrated Research on the Environment at the University of Montana, is surveying several areas on base for the toad, including the former aero club, Union Creek south of the Navy detachment and the Castle Terrace conservation area.
The team is also surveying areas where the turtle and blackbird were previously sited, said Kirsten Christopherson, wildlife biologist with the Air Force Civil Engineer Center Installation Support Team at Travis.
Through a cooperative agreement between the U.S. Army Corps of Engineers and the CIRE, the Air Force awarded federally-listed species surveys at multiple bases nationwide, including Travis and Beale AFB, California.
“By doing habitat assessments and surveys for these species now, the Air Force is posturing to adjust to any new legal requirements associated with those species and thereby, minimize delays in the base's future construction projects,” said Christopherson.
Christopherson explained that the Endangered Species Act requires federal agencies to consult with U.S. Fish and Wildlife Service or National Marine Fisheries Service to ensure any project “they approve, fund, or carry out will not jeopardize the continued existence of a listed species, or destroy or adversely modify designated critical habitats.”
California already lists the western spadefoot toad and the northwestern pond turtle as species of concern. The state lists the tricolored blackbird as a “candidate” species, meaning it will be added to the state’s threatened and endangered species list in the future.
The western spadefoot toad has been found in California’s central valley and coastal ranges as well as the coastal lowlands from the San Francisco Bay south to Mexico. Although they are primarily terrestrial, they require aquatic habitats for breeding.
The pond turtle has been split into two subspecies, one that prefers the northern region – from the Bay Area into Washington – and one that is restricted to the central coast range – south of the Bay Area. Primarily an aquatic animal, the turtle requires terrestrial habitat in the winter and for reproduction.
The tricolored blackbird spends the winter in the Sacramento to San Joaquin River delta and along the coast. The largest population is located in the central valley and surrounding foothills though they have been seen as far north as Oregon and as far east as Nevada.
“We want to find out where these species are, record their numbers and determine their habitat characteristics,” said Winsor Lowe, CIRE project principal investigator and associate professor of amphibious reptiles. Lowe and two other project leads met with Air Force project managers at Travis in November 2016 to review the work plan and schedule survey dates.
When they visited in January, the team conducted aquatic surveys for the toad, which involved visual scans of pool surfaces for egg clusters. They also installed song meters at several locations, including the duck pond, to detect nighttime toad vocalizations.
The team returned Feb. 13 to download the song meter data and collect water samples. The water will be filtered, dried and stored until funds are available for “species specific primers” that allow the toad’s DNA to be detected and sequenced, said Penn Craig, 60th Civil Engineer Squadron biological scientist and natural and cultural resource manager.
“Currently, primers are not available for this species and species-specific primers are expensive,” said Craig.
The team plans to return in April to set hoop traps for the pond turtle.
“A tube allows the turtle to enter (the trap) but a door shuts so it can’t get out. Part of the submersible trap sticks out of the water so the turtles don’t drown,” said Brett Addis, team field coordinator.
In April, the team also will conduct blackbird surveys.
The birds breed from March to early August, said Craig. Although there can be as many as 200,000 blackbirds in a colony, fewer than 2,000 have been seen at Travis.
The project team is expected to complete all field work by May, according to Christopherson.
“We expect to receive a draft report in August and then finalize the report by December. The final results will then be incorporated into the next update of the Travis AFB Integrated Natural Resources Management Plan. Also, if any of these species are detected, their presence will be documented in a statewide database (California Natural Diversity Database) for future use by other scientists doing work in the region.”
Travis is already home to the California tiger salamander, vernal pool fairy shrimp, vernal pool tadpole and the Contra Costa goldfield, an annual flower, that live in or near the more than 800 areas with vernal pool and wetland features on base. Those areas are off limits to most personnel.
No additional areas have been declared off-limits while the project team conducts surveys but people should not touch or remove any of their equipment, which is clearly marked with AFCEC’s information, said Christopherson.
Anyone witnessing theft or tampering with the equipment should call security forces at 707-424-2800.
“If the tricolored blackbird gets listed by U.S. Fish and Wildlife Service, we’ll have the needed data to suggest conservation efforts and how to manage the species,” said Christopherson. She said USFWS will make a final decision on each species by 2021 “depending on the priority of the species and existing scientific data.”
At Travis, the CIRE is also providing a comprehensive plan for overall management of invasive species and a non-native species control plan for bird airstrike hazard reduction and storm water compliance.