# Presentation: 196867

## Are Tortoise Recovery Actions Effective?

***William I . Boarman***
***USGS, WERC &***
***Conservation Science Research & Consulting***
***William B. Kristan, III***
***CSU, San Marcos***
***Ed LaRue***
***BLM &***
***Circle Mountain Biological Consultants***
***Paul Burgess***
***Redlands Institute***

## Supporters

***Marine Corps (MCAGCC)***
***National Park Service (MNP)***
***US Fish and Wildlife Service (Ventura)***
***Bureau of Land Management (CDD)***

## Goal/Objectives

***Goal:  Evaluate the state of knowledge about effectiveness of tortoise recovery actions.***
***Objective1:  Gather and critically evaluate best available evidence.***
***Objective 2:  Map the extent of effrorts to monitor recovery actions.***

## Questions

- How much information is available to support recovery actions, and what kind of information is it?

- Is the effectiveness of recovery actions well supported by scientific evidence?

- How can tortoise management be improved?

## Caveats

***Evidence of threat ≠ effective recovery***
***Absence of evidence ≠ evidence of absence***
***No new data analyses***
***Focused on California***

## Data Squeeze

***BLM***
- Barstow
- Moreno Valley
- Needles
- Ridgecrest
- Sacramento
***State Parks***
- Red Rock Canyon
***USGS***
- San Diego

***FWS***
- Ventura
- Barstow
- Carlsbad
***NPS***
- JTNP
***DOD***
- MCAGCC
- China Lake NAWS
- Fort Irwin

## Based Evaluation on Several Criteria

***•******	******Individual vs. population***
***•******	******Project vs. action-level***
***Study design***
***Source of information***
***Certainty of recovery***

## Results

***395 documents found***
***107 were relevant***
- 44 were “designed studies”
- 107 were other types of information

## Limit OHV Access

**Limit OHV Access**

- •  Monitored before and after controlled races
- 		Some success demonstrated
- 		Some failures demonstrated
- 		Evaluations were too subjective
- •	Network reductions
- 		Routes/tracks proliferated, but less than outside
- 		Little evidence of effect on diffuse problems

## Limit OHV Access

- •  Vertical mulching
- 		Claimed to work, but no studies.
- •	Needs
- 		Effect of OHV removals on tortoise populations,
- 		weeds, and habitat.
- 		Effect of OHV reductions.
- 		How much degradation can tortoises withstand?
- •	OHV means many things

## Restrict or Eliminate Grazing

**Restrict or Eliminate Grazing**

- •  Some exclosure studies
- 	Improvements noted
- •  Level of impact varies with distance
-      from water source
- •  Needs:
- 	Threshold stocking levels

## Road Mortality and Barrier Fencing

**Road Mortality and ****Barrier Fencing**

- •  Moderately well studied
- 	89% reduction in road kills
- 	Use culverts
- •  Different materials tested
- •  Needs
- 	Population-level effect
- 	Bycatch rate
- 	Culvert design & spacing

## Other Actions We Could Evaluate

***Reserves***
***Construction***
***Habitat Restoration***
***Translocation***
***Predator Management***

## Actions We Could not Evaluate

***Burros***
***Habitat Loss***
***Habitat degradation***
***Disease***
***Control of Invasives***
***Drought***

## Conclusions

***Few studies designed to evaluate effectiveness of recovery actions.***
***Many lost opportunities***
***Managers must often rely on non-scientific information***

## Recommendations

***Coordinate monitoring activities***
***Conduct studies to assess population responses***
- Managers and Stakeholders:  find the funds and  obtain scientific advice on design, implementation, and interpretation
- Scientists:  develop and seek funding for effectiveness studies
- Publish results