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Assessing California’s mitigation guidelines for burrowing owls impacted by development: better science, better conservation, better economic outcomes
Transcript of Assessing California’s Mitigation Guidelines for … › carlsbad › TribalRelations › Sept...
Assessing California’s mitigation guidelines for burrowing owls impacted by development:
better science, better conservation, better economic outcomes
Presenter
Presentation Notes
We understand that Tribal Nations are not beholden to state laws. Tribes do recognize federal laws, including MBTA. The burrowing owl is a species protected by the MBTA. Also, the burrowing owl is going to be petitioned for listing in the near future, either by state and/or federal. Brief overview of the buow research that the Service and the San Diego Zoo Institute for Conservation Research are conducting. This is a grant funded study that is evaluating the impacts of mitigation methods currently used for buow impacted by development. Hopefully you will be interested in partnering with us by including any owls that are on your lands in our study. There is no cost for projects/developers that allow their owls in the study.
Collaborators
Presenter
Presentation Notes
No room to insert all of our partners, but want to give thanks to Sonny Bono National Wildlife Refuge. Our work has been discussed and reviewed by a who’s who of BUOW researchers throughout North America (such as Jim Belthoff, Courtney Conway, Troy Wellicome, Lynn Trulio), who we now rely on for as-needed discussions. We also have a C.E.C. Technical Advisory Committee, which meets semi-annually for additional review and guidance: Alberto Abreu, Sempra Energy Kelly Bishop, Imperial Irrigation District Bobby Brock, Imperial Valley Community Foundation Jennifer Brown, USFWS Migratory Birds Esther Burkett, CDFW Chris Gregory, USFWS Andy Horne, Imperial County Dan Rosenberg, Oregon Wildlife Institute, OSU Harry Sandoval, Riverside County
Issue 1: Reclining Declining Burrowing Owls and Loss of Habitat
Status of Burrowing Owl Populations
San Diego County Bird Atlas, 2004
May soon be petitioned for listing under California Endangered Species Act
Presenter
Presentation Notes
Right map from Birds of NA. Imperial Valley alone contains estimated 50% of NA western population and 70% of CA population. Estimated 21-58% decline (Klute et al. 2003). Example of this decline in SD County shown in left image. This pattern is being observed in other Counties including western Riverside and San Bernardino Counties. We assume petition will go to CDFW, but it could also be (or only be) to FWS.
Habitat Changes, Loss of Ground Squirrels
Good Habitat
Best Habitat
Habitat Loss
Urban Development
Presenter
Presentation Notes
Sarah (et al.) used existing BUOW occurrence records to develop a regional suitability model for SoCal. General results from that are that there would be lots of suitable habitat (based mainly on abiotic factors) but that nearly all the suitable sites are unavailable due to development. The sites that are good for BUOW are also desirable for people. This is a trend seen in many species at risk (e.g., gopher tortoise in Florida). Even if existing grassland habitat is undeveloped, there are additional factors that make the habitat unavailable to BUOW. One factor is changes to habitat structure resulting from invasive annual grasses like Avena (wild oats). The second is widespread declines in ground squirrel abundance, since squirrels provide the needed burrow habitat.
Issue 2: Owl Mitigation Options
Presenter
Presentation Notes
When BUOWs coincide with development, there are some options to avoid take of BUOWs. These options are based on the CDFW Guidelines (2012) but MBTA relies on some of these options as well. Aside from the first choice which is avoidance and buffers, the 2 main options include passive relocation (or eviction) and active relocation (sometimes also called translocation)
Passive Relocation • Install artificial burrows in desired settlement location
(ideally within 100 m)
• Exclude owl from burrow (see picture)
• Collapse burrow once owls are absent
• In California, most common method used
Presenter
Presentation Notes
Define passive relocation here. BUOWs are expected to move on their own and find another burrow, after their burrow is blocked using a one-way door. BUOWs don’t dig their own burrow – must find another existing one made by another animal. Artificial burrows may be installed (not always), ideally near their original burrow or at least within their home range (~ 1 km)
Active Relocation • Capture owl
• Move offsite to a temporary holding cage
• New site is a Conserved area
• Release owl after an acclimation period (establishes new site fidelity)
• Additional installation of artificial burrows to encourage retention
CA: uncommon mitigation strategy as it is not currently recommended by CDFW, citing a lack of scientific study
Presenter
Presentation Notes
Define active relocation. It is allowed for with a scientific purpose and/or within a HCP
Mitigation Measures: Active vs. Passive Relocation • Unknown efficacy - Demographic and behavioral
consequences have never been compared or evaluated.
Presenter
Presentation Notes
State has 2 methods as options to avoid owl take. Neither have been systematically evaluated to understand how well they do or do not work, what their success is. There are very few studies that have evaluated select aspects of each of these methods but none with consistent methodologies, and none compared the methods simultaneously. There are different theories or hypotheses about the effectiveness of each method yet no one really knows. Benefits of better translocation methods More efficient: current cost $20,000 per active relocation More effective: avoid exacerbating population losses Development of proven methods will reduce risk that important energy projects may be halted Lower costs for ratepayers Bring projects into conformance with California conservation strategies
Issue 3: Forced dispersal-related effects
Presenter
Presentation Notes
A concern with either relocation method is that both rely on forcing owls to move or disperse. This can have different effects on animals. Bad�Post-release movements can greatly exceed species-typical dispersal distances: high-risk period (Stamps & Swaisgood [2007] Appl Anim Behav Sci) (stress, unknown/uncertain food resources, predators, conspecifics). Mortality risk may be higher. Ultimately, may affect reproductive success after relocation - may not breed at all or may breed unsuccessfully. Good (Social) animals translocated with familiar conspecifics settle & survive better (Armstrong 1995; Shier 2007): 500% increase in survival (important to understand the details that make a relocation successful or not)
Ultimate Goals • Improve wildlife mitigation actions used for BUOW impacted by
development to reduce negative effects on this species • Provide data on BUOW movements and habitat use to inform risk
models and site selection decisions
Primary Objectives • Record and evaluate Burrowing Owl dispersal, mortality, and
reproductive output in response to passive and active relocations Capture owls & attach satellite transmitters
• Determine if there is a most effective mitigation method used for Burrowing Owl and recommend improvements for both methods
Issue 4: Objectives and Goals of the Study
Presenter
Presentation Notes
Capturing and telemetering a lot of owls, recording even more data, and using our results to help wildlife managers make better choices with their mitigation options. BUOWs can disperse far distances. Telemetry is the only effective method to track or follow owls to answer this question.
Study Design
Group Conspecific cues
No cues
Passive relocation 12 12 Active relocation 12 12 Resident control - 18
• Riverside, San Bernardino, Imperial and San Diego Counties
• Prioritize owls impacted by development
Presenter
Presentation Notes
Total of 66 owls. Three Groups: Passive relocation group, active relocation group, control group Discussion of ‘Cues vs. No Cues’ - only briefly mention for this talk.
Capturing Owls: one-way door trap or bow net with decoy, mouse bait, and call/playback
Presenter
Presentation Notes
We need to catch owls to fit them with telemetry equipment. The 2 main trap methods are burrow traps (one-way door) and bow nets baited with either a decoy or a mouse and acoustic calls
Installation of Artificial Burrows
2 burrows per owl or owl pair
Presenter
Presentation Notes
We are installing artificial burrows at passive (where possible) and active relocation sites. Could use backhoe for installation, but not necessary. However, easier and more efficient with backhoe. Cultural monitor used for digging of burrows on Tribe lands.
Holding Cages: Active Translocations Only
Presenter
Presentation Notes
Installing hacking cages for active relocations. Artificial burrows would be installed as well. One burrow is inside the hacking cage. The rest are spaced 5-7 meters apart. Cages are removed after a 30-day acclimation period.
GPS Transmitters • Lotek PinPoint Argos Solar • Solar rechargeable backpack-style satellite GPS transmitter • ~20 points per cycle, customizable schedule, remote data download • ~5.5 g tag + 0.5 g harness attachment • 1 owl per pair receives transmitter
Presenter
Presentation Notes
This study relies on satellite telemetry to gain the primary dispersal movement/settlement location information. Been working with BUOW researchers in Canada who have used satellite tags in the past (since 2010 for first units in the 5 gram range). Designs and methods have been refined. We have benefitted from collaborating with others to use the best available technology. We have used similar units in the past, haven’t had problems (Microwave Telemetry, Inc. units) Discuss GPS PinPoints (1st pic) – limited battery life, have to recapture owls to retrieve data – not an option for dispersers or migratory birds. Microwave Telemetry Inc. units – solar and satellite uploading but only Argos capable (no GPS so large error ; several hundred meters to several km) Our units – Lotek – GPS accuracy similar to your handheld GPS units For experimental groups, offsetting stressors by applying a week ahead of moving
GPS Transmitters
Presenter
Presentation Notes
Satellite data is downloaded. We receive GPS locations with an accuracy of ~ 5 meters Resident control owls at El Sol Conservation Area in Western Riverside MSHCP. Migrant owls that moved north to breed after release from active relocation cage. Tracking owls that show this much movement is possible with satellite transmitters.
Project Timeline
CEC kickoff meeting July 11, 2016
Begin site selection and prep (July 2016)
Final CEC/LAG presentations and reports (mid-2019); Final publications (late 2019)
“2016” translocations, monitoring, habitat assessments (Jan 2017–July 2018)
“2017” translocations, monitoring, habitat assessments (Sept 2017–July 2019)
2017–19 monitoring and data analysis
Presenter
Presentation Notes
We are starting the second season of the study – nonbreeding season started September 1. We have owls from 29 Palms entered into the study. Each owl is followed for at least 18 months (to include at least 2 breeding seasons post-relocation) Study is running through 2019, but may be extended if additional money is obtained
Do You Have Burrowing Owls?
Presenter
Presentation Notes
Please think of us if you have any BUOWs on your lands or in your upcoming projects. No additional cost to developers! We have been coordinating and reaching out to local, state, federal agencies and planners (e.g., Riverside, Imperial Co., CDFW)
Contacts
Lisa Nordstrom [email protected] 760-796-5692
Chris Gregory, USFWS [email protected] 760-322-2070, ext. 412
Noelle Ronan [email protected] 760-322-2070, ext. 407
Presenter
Presentation Notes
Easiest to speak in-house to FWS employees listed here. But if you pass this outside of the FWS, Lisa (or any contact) is appropriate.
Questions?
