Basic Information
Common Name: Arroyo Toad
Scientific Name: Anaxyrus californicus
Species Code: ANACAL
Management Category: SO (significant occurrence at risk of loss)
Occurrence Map
Table of Occurrences
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Species Information

MSP Species Background

Goals and Objectives

Goal: Protect and enhance existing significant occurrences of arroyo toad to self-sustaining levels and re-establish occurrences in locations where they previously existed to ensure persistence over the long-term (>100 years).

local NFO 2017, 2018, 2019, 2020, 2021 SO
MON-IMP-IMG ANACAL-1

Management units: 3, 4, 5, 6, 8, 9, 10, 11

Annually inspect known areas occupied by arroyo toad to identify and reduce threats that can be managed at the local scale including road crossings, illegal encroachment, off-road vehicle use, non-native plants, trash dumping, grazing by livestock, and incompatible human recreation. Where possible, restrict access to arroyo toad upland and breeding habitats to help prevent disturbance to all arroyo toad life history stages (eggs, larvae, metamorphs and adults). Activities should be restricted in upland habitat year-round and in breeding habitat during the core of the breeding season (March to July).

Action Statement Action status Projects
IMP-1 Using a regional "IMG" monitoring protocol, annually inspect significant Arroyo toad occurrences to assess status and quantify potential threats to determine management needs. AID_20161229_1831_100 Available for implementation
IMP-2 Roads should be examined for high risk areas for arroyo toad crossing and use. Only slow moving vehicles (<5mph) with an occupant experienced in arroyo toad identification should be allowed on high risk roads after sunset (Zimmitti and Mahrdt 1999). Available for implementation
IMP-3 An education program should be implemented that promotes the value of the arroyo toad and informs the public of restrictions and the importance of not disturbing the wildlife. Available for implementation
IMP-4 Based upon occurrence status and threats, determine management needs including whether routine management or more intensive management is warranted. Available for implementation
IMP-5 Submit monitoring and management recommendations to the MSP web portal Available for implementation
Criteria Deadline year
Annual IMG monitoring of Arroyo toad completed 2021
local NFO 2017, 2018, 2019, 2020, 2021 SO
MGT-IMP-IMG ANACAL-2

Management units: 3, 4, 5, 6, 8, 9, 10, 11

Beginning in 2018, conduct routine management actions for arroyo toad identified through the IMG regional protocol monitoring, including protecting populations from detrimental human use (e.g. ORV, trampling, altered hydrology), removing invasive plants, and removing aquatic predators and exotic species (which compete and/or prey on arroyo toads, primarily young) within the known arroyo toad habitat.

Action Statement Action status Projects
IMP-1 Perform routine management activities such as protecting occurrences from human disturbance, controlling invasive plants, and removing invasive aquatic animals. available for implementation
IMP-2 Submit project metadata and management data to MSP web portal. available for implementation
Criteria Deadline year
Routine Management Completed as Needed Based Upon Monitoring Recommendations 2021
Code Obj. code Statement
ANACAL-1 MON-IMP-IMG Annually inspect known areas occupied by arroyo toad to identify and reduce threats that can be managed at the local scale including road crossings, illegal encroachment, off-road vehicle use, non-native plants, trash dumping, grazing by livestock, and incompatible human recreation. Where possible, restrict access to arroyo toad upland and breeding habitats to help prevent disturbance to all arroyo toad life history stages (eggs, larvae, metamorphs and adults). Activities should be restricted in upland habitat year-round and in breeding habitat during the core of the breeding season (March to July).
regional NFO 2017, 2018, 2019, 2020, 2021 SO
MON-RES-GEN ANACAL-3

Management units: 3, 4, 5, 6, 8, 9, 10, 11

From 2017 to 2021, continue genetic studies of the arroyo toad in San Diego Co. (using genetic material collected during past and present regional surveys) to evaluate the degree of genetic variation within and between populations and to possibly identify genetic bottlenecks or barriers; this information will also be used to determine source populations to use in re-establishing arroyo toads in previously occupied areas.

Action Statement Action status Projects
RES-1 Continue to collect genetic samples during surveys for arroyo toad for use in examining the genetic relationship of arroyo toad in western San Diego County. waiting for precedent action
RES-2 Analyze the genetic samples to evaluate the degree of genetic variation within and between populations and to possibly identify genetic bottlenecks or barriers. waiting for precedent action
RES-3 Prepare management recommendations based upon the genetic analyses that maintain or enhance gene flow and genetic diversity and that identifies source populations. waiting for precedent action
RES-4 Submit project metadata, datasets, and Arroyo Toad Genetics Study report to the MSP Web Portal. Unknown
Criteria Deadline year
Genetic samples collected from studies completed through 2021; Genetic Analysis and Report Completed by 2021. 2021
Threat Name Threat Code
Loss of connectivityLOSCON
Code Obj. code Statement
ANACAL-1 MON-IMP-IMG Annually inspect known areas occupied by arroyo toad to identify and reduce threats that can be managed at the local scale including road crossings, illegal encroachment, off-road vehicle use, non-native plants, trash dumping, grazing by livestock, and incompatible human recreation. Where possible, restrict access to arroyo toad upland and breeding habitats to help prevent disturbance to all arroyo toad life history stages (eggs, larvae, metamorphs and adults). Activities should be restricted in upland habitat year-round and in breeding habitat during the core of the breeding season (March to July).
ANACAL-4 MON-SURV-SPEC In 2020 and 2021 (assuming adequate rainfall levels), conduct comprehensive arroyo toad surveys using USGS survey protocols throughout the MSPA on Conserved Lands in known occupied and potential habitat to determine current distribution and status of arroyo toad, collect data on threats and habitat covariates, and identify management needs.
regional NFO 2020, 2021 SO
MON-SURV-SPEC ANACAL-4

Management units: 3, 4, 5, 6, 8, 9, 10, 11

In 2020 and 2021 (assuming adequate rainfall levels), conduct comprehensive arroyo toad surveys using USGS survey protocols throughout the MSPA on Conserved Lands in known occupied and potential habitat to determine current distribution and status of arroyo toad, collect data on threats and habitat covariates, and identify management needs.

Action Statement Action status Projects
SURV-1 Survey known occupied and potantial habitat on Conserved Lands across the MSPA to determine the distribution and abundance of arroyo toad on Conserved Lands. Available for implementation
SURV-2 Collect data on threats and identify management needs to support self-sustaining occurrences. Available for implementation
SURV-3 Continue to collect genetic samples from all arroyo toads captured. Available for implementation
SURV-4 Submit survey data and management recommendations to MSP web portal Available for implementation
Criteria Deadline year
Comprehensive surveys completed for Arroyo toad by 2021 2021
Code Obj. code Statement
ANACAL-1 MON-IMP-IMG Annually inspect known areas occupied by arroyo toad to identify and reduce threats that can be managed at the local scale including road crossings, illegal encroachment, off-road vehicle use, non-native plants, trash dumping, grazing by livestock, and incompatible human recreation. Where possible, restrict access to arroyo toad upland and breeding habitats to help prevent disturbance to all arroyo toad life history stages (eggs, larvae, metamorphs and adults). Activities should be restricted in upland habitat year-round and in breeding habitat during the core of the breeding season (March to July).
regional NFO 2017, 2018, 2019 SO
MGT-PRP-MGTPL ANACAL-5

Management units: 3, 4, 5, 6, 8, 9, 10, 11

In 2017, continue to convene with the working group of land managers, scientists, wildlife agencies, and local biologists knowledgeable in arroyo toad to review existing conditions of known occurrences on Conserved Lands, to prepare a plan for management of arroyo toad which considers each site, and to develop a regional monitoring strategy.

Action Statement Action status Projects
PRP-1 Convene working group meetings to review existing conditions of known occurrences. in progress
PRP-2 Use habitat models developed by USGS and results from survey and genetic analyses to identify suitable areas for long-term management. in progress
PRP-3 Conduct site visits as necessary to identify appropriate management actions. in progress
PRP-4 Develop an arroyo toad management plan. The plan should prioritize management actions for the next five years and detail tasks, lead entities, responsibilities, timelines, and budgets. in progress
PRP-5 Submit management plan to MSP web portal in progress
Criteria Deadline year
Arroyo toad management plan completed by 2018 2021
Code Obj. code Statement
ANACAL-1 MON-IMP-IMG Annually inspect known areas occupied by arroyo toad to identify and reduce threats that can be managed at the local scale including road crossings, illegal encroachment, off-road vehicle use, non-native plants, trash dumping, grazing by livestock, and incompatible human recreation. Where possible, restrict access to arroyo toad upland and breeding habitats to help prevent disturbance to all arroyo toad life history stages (eggs, larvae, metamorphs and adults). Activities should be restricted in upland habitat year-round and in breeding habitat during the core of the breeding season (March to July).
ANACAL-2 MGT-IMP-IMG Beginning in 2018, conduct routine management actions for arroyo toad identified through the IMG regional protocol monitoring, including protecting populations from detrimental human use (e.g. ORV, trampling, altered hydrology), removing invasive plants, and removing aquatic predators and exotic species (which compete and/or prey on arroyo toads, primarily young) within the known arroyo toad habitat.
ANACAL-3 MON-RES-GEN From 2017 to 2021, continue genetic studies of the arroyo toad in San Diego Co. (using genetic material collected during past and present regional surveys) to evaluate the degree of genetic variation within and between populations and to possibly identify genetic bottlenecks or barriers; this information will also be used to determine source populations to use in re-establishing arroyo toads in previously occupied areas.
ANACAL-4 MON-SURV-SPEC In 2020 and 2021 (assuming adequate rainfall levels), conduct comprehensive arroyo toad surveys using USGS survey protocols throughout the MSPA on Conserved Lands in known occupied and potential habitat to determine current distribution and status of arroyo toad, collect data on threats and habitat covariates, and identify management needs.
regional NFO 2018, 2019, 2020, 2021 SO
MGT-IMP-MGTPL ANACAL-6

Management units: 3, 4, 5, 6, 8, 9, 10, 11

Beginning in 2018, implement high priority actions identified in the Arroyo Toad Management Plan.

Action Statement Action status Projects
IMP-1 Submit project metadata, management actions and report to MSP web portal waiting for precedent action
Criteria Deadline year
High priority management actions implemented for Arroyo toad 2021
Code Obj. code Statement
ANACAL-1 MON-IMP-IMG Annually inspect known areas occupied by arroyo toad to identify and reduce threats that can be managed at the local scale including road crossings, illegal encroachment, off-road vehicle use, non-native plants, trash dumping, grazing by livestock, and incompatible human recreation. Where possible, restrict access to arroyo toad upland and breeding habitats to help prevent disturbance to all arroyo toad life history stages (eggs, larvae, metamorphs and adults). Activities should be restricted in upland habitat year-round and in breeding habitat during the core of the breeding season (March to July).
ANACAL-2 MGT-IMP-IMG Beginning in 2018, conduct routine management actions for arroyo toad identified through the IMG regional protocol monitoring, including protecting populations from detrimental human use (e.g. ORV, trampling, altered hydrology), removing invasive plants, and removing aquatic predators and exotic species (which compete and/or prey on arroyo toads, primarily young) within the known arroyo toad habitat.
ANACAL-3 MON-RES-GEN From 2017 to 2021, continue genetic studies of the arroyo toad in San Diego Co. (using genetic material collected during past and present regional surveys) to evaluate the degree of genetic variation within and between populations and to possibly identify genetic bottlenecks or barriers; this information will also be used to determine source populations to use in re-establishing arroyo toads in previously occupied areas.
ANACAL-4 MON-SURV-SPEC In 2020 and 2021 (assuming adequate rainfall levels), conduct comprehensive arroyo toad surveys using USGS survey protocols throughout the MSPA on Conserved Lands in known occupied and potential habitat to determine current distribution and status of arroyo toad, collect data on threats and habitat covariates, and identify management needs.
ANACAL-5 MGT-PRP-MGTPL In 2017, continue to convene with the working group of land managers, scientists, wildlife agencies, and local biologists knowledgeable in arroyo toad to review existing conditions of known occurrences on Conserved Lands, to prepare a plan for management of arroyo toad which considers each site, and to develop a regional monitoring strategy.
regional NFO 2018, 2019, 2020, 2021 SO
MON-IMP-MGTPL ANACAL-7

Management units: 3, 4, 5, 6, 8, 9, 10, 11

Beginning in 2018, monitor the effectiveness of management actions implemented for the arroyo toad.

Action Statement Action status Projects
IMP-1 Submit project metadata, monitoring data and reports to MSP web portal waiting for precedent action
Criteria Deadline year
Effectiveness of implementing high priority arroyo toad management actions determined 2021
regional PRE 2018, 2019 SO
MGT-PRP-RESCPL ANACAL-8

Management units: 3, 4, 5, 6, 8, 9, 10, 11

Beginning in 2018, establish program and permits to allow emergency management actions for the arroyo toad during or immediately following wildfire events, such as implementation of emergency rescue and temporary translocation, to protect from potential loss or extirpation.

Action Statement Action status Projects
PRP-1 Develop protocols, monitoring standards, and permit process for the rescue of Southwestern pond turtles during wildfire events. Available for implementation
Criteria Deadline year
Wildfire rescue program established for Arroyo toad in 2018 2021
Threat Name Threat Code
Altered fire regimeALTFIR
Altered hydrologyALTHYD
regional SUPP 2019, 2020, 2021 SO
MGT-IMP-RESCPL ANACAL-9

Management units: 3, 4, 5, 6, 8, 9, 10, 11

Beginning in 2019, implement arroyo toad rescue program during wildfire events to protect from loss and/or extirpation.

Action Statement Action status Projects
IMP-1 Submit management data and reports to MSP web portal waiting for precedent action
Criteria Deadline year
Wildfire rescue program implemented for Arroyo toad 2021
Threat Name Threat Code
Altered fire regimeALTFIR
Altered hydrologyALTHYD
regional POST 2019, 2020, 2021 SO
MON-IMP-RESCPL ANACAL-10

Management units: 3, 4, 5, 6, 8, 9, 10, 11

Beginning in 2019, monitor the effectiveness of arroyo toad rescue programs following wildfire events, including both translocation or re-introduction efforts.

Action Statement Action status Projects
IMP-1 Submit monitoring data and report to MSP web portal waiting for precedent action
Criteria Deadline year
Monitoring of post fire rescue programs for Arroyo toad implemented 2021
Threat Name Threat Code
Altered fire regimeALTFIR
Altered hydrologyALTHYD
regional POST 2017, 2018, 2019, 2020, 2021 SO
MGT-IMP-FMGT ANACAL-11

Management units: 3, 4, 5, 6, 8, 9, 10, 11

From 2017 to 2021, implement post fire management actions to ensure the recovery of arroyo toad at occupied sites following wildfire events, including invasive plant and animal control, debris/sediment removal, erosion control or other management actions as needed following a fire.

Action Statement Action status Projects
IMP-1 Implement needed management actions as determined through BAER or other post fire surveys. waiting for precedent action
Criteria Deadline year
Post fire management actions implemented following wildfire events 2021
Threat Name Threat Code
Altered fire regimeALTFIR
Altered hydrologyALTHYD
regional POST 2017, 2018, 2019, 2020, 2021 SO
MON-IMP-FMGT ANACAL-12

Management units: 3, 4, 5, 6, 8, 9, 10, 11

From 2017 to 2021, monitor stream conditions and the effectiveness of management actions implemented to assist in recovery of arroyo toad for 3 years following wildfire events.

Action Statement Action status Projects
IMP-1 Monitor stream flows and water quality post fire, document recovery of arroyo toad populations and habitat, and effectiveness of any management actions for first 3 years after fire. waiting for precedent action
Criteria Deadline year
Monitoring of post fire management actions, stream conditions, and population status for arroyo toads implemented for 3 years post fire 2021
Threat Name Threat Code
Altered fire regimeALTFIR
Altered hydrologyALTHYD

Significant Concern

Overall Condition

Declining

Overall Trend

Moderate

Overall Confidence
Metric Condition Trend Confidence
1. Number of Sites Occupied by Young of the Year

Number of subwatersheds with suitable habitat occupied by young of the year


Significant Concern

Declining

Moderate
2. Water Availability Score

Water availability score for reproduction in suitable habitat by subwatershed


Concern

Unknown

High
3. Invasive Aquatic Species Impact Score

Impact score of invasive aquatic species by subwatershed


Concern

No Change

Moderate
Current Status
The current overall condition status of the Arroyo Toad Species Indicator is Significant Concern based on three metric conditions. As part of a Declining trend, there were only four HUC12 watersheds (15 sites) occupied by arroyo toad young of the year in 2020 compared to 2008 when 22 HUC12s watersheds were occupied (Metric 1), attributed to an increase in drought as well as aseasonal flows in areas affected by urban runoff (Metric 2). Invasive aquatic species (Metric 3) are of concern as predatory invasive animals are found in eight of the 15 occupied watersheds. Additional metrics will be added as more information becomes available.
Metrics Dashboard
Full metric information for this species is available on our Dashboard.
Metrics Dashboard
Post-Fire Monitoring - Arroyo Toad Surveys
The arroyo toad surveys in southern San Diego County are part of an investigation of the impacts of fire on arroyo toads. In 2007, the Witch, Harris and Poomacha fires burned approximately 300,000 acres of wildlands in San Diego County. Many of the burned lands are currently conserved or are planned to be conserved under the San Diego County Multiple Species Conservation Program (MSCP). Riparian areas across four major watersheds were extensively burned during these 2007 fires, many of these streams support arroyo toad populations. The USGS (coordinating with the San Diego Association of Governments, the US Fish and Wildlife Service, California Department of Fish and Wildlife, City of San Diego, and County of San Diego) is investigating how specific target species will respond to these massive fires and resultant changes in stream morphology, vegetation communities, and vegetation structure over a five-year time period. The goal of this study is to provide information that will allow future land management decisions to include considerations of the effects of large wildfires on the biological community structure and function, especially for those species covered by conservation plans such as the San Diego County MSCP.
Regional Grazing Monitoring Plan
This project evaluates using grazing as a management tool for degraded grasslands and coastal sage scrub habitat. Pilot projects will be conducted to look at the efficacy of grazing as management tool and necessary monitoring techniques.
SR 94 Wildlife Infrastructure Plan
Proposed road improvements to SR 94 provide an opportunity to mitigate the potential barrier effects of the highway. This project identifies where improvements to existing infrastructure on SR-94 could improve connectivity across the South County preserves, using Best Management Practices from the scientific literature; recommends wildlife movement monitoring to identify where new crossings are needed; and identifies where additional conservation would enhance the integrity of South County linkages. The review prioritizes infrastructure improvements of 35 existing undercrossings inspected by wildlife experts in the field along 14.6 miles of SR-94 where the highway bisects conserved lands. The majority of the recommendations for infrastructure improvement focus on increasing the diameter, and thus the openness ratio (cross-sectional area divided by length), of the undercrossing itself, removing vegetation and debris blocking the undercrossing, restoring habitat in the approach to the undercrossing, and installing fencing to both (1) keep animals off the highway and (2) funnel wildlife to the undercrossings.
File name Lead Author Year Type
1.03 Responses of arroyo toads to wildfires Brown, Chris 2013 recording
1997 Sensitive Species Survey Results for Pine Creek and Hauser Canyon Wilderness Areas, Descanso Ranger District, Cleveland National Forest, San Diego County, California. Wells, Jeffery M.; Turnbull, Jennifer 1998 report
A New Strategy for Monitoring Arroyo Toad Populations Atkinson, Andrea; Brehme, Cheryl; Fisher, Robert N.; Lovio, John 2004 book/conf proceeding
All species and habitats IAP pages Vinje, Jessie; Spring, Shawn 2024 fact sheet
Amphibian and Reptile Species of Special Concern in California Jennings, Mark; Hayes, Mark 1994 report
Amphibian IBI and Hydrological Impact Score Fisher, Robert N. 2019 powerpoint presentation
Arroy Toad (Bufo californicus) Symposium Natural History and Management Practices 2000 other
ARROYO SOUTHWESTERN TOAD (Bufo microscaphus caiWornicus) RECOVERY PLAN 1999 report
ARROYO TOAD (Bufo californicus) SURVEYS ON SAN DIEGO NATIONAL WILDLIFE REFUGE Martin, John 2005 report
Arroyo Toad and Western Pond Turtle in the San Diego Multiple Species Conservation Program Area, 2002 Meyer, Kathie; Ervin, Edward; Madden-Smith, Melanie; Hathaway, Stacie; Fisher, Robert N. 2003 report
Arroyo Toad Population Monitoring in Southern California; Findings and Trends other
Arroyo toad study design for San Diego County, California Tracey, Jeff; Brehme, Cheryl; Brown, Chris; Rochester, Carlton; Fisher, Robert N. 2020 powerpoint presentation
Arroyo Toad Survey (2002) Davenport, Arthur 2002 field notes/data sheets
Arroyo Toads (Bufo californicus) in MCBCP; Findings from 5 years of Population Monitoring and Program Review Brehme, Cheryl; Fisher, Robert N.; Schuster, Sara L.; Turschak, Greta 2010 powerpoint presentation
Arroyo Toads (Bufo californicus) in Southern California; Findings and Trends from 3 to 10 years of Population Monitoring. not sure
Assessing the Risk of Loveland Dam Operations to the Arroyo Toad (Bufo californicus) in the Sweetwater River Channel, San Diego County, California Madden-Smith, Melanie; Atkinson, Andrea; Fisher, Robert N.; Danskin, Wesley R.; Mendez, Gregory O. 2003 report
Baseline Biodiversity Report Santa Margarita Preserve 2012 report
Baseline Surveys for the Arroyo Toad (Bufo californicus) in the Sweetwater River Channel, San Diego County, California. Madden-Smith, Melanie; Ervin, Edward; Fisher, Robert N. 2005 report
Biological Diversity Baseline Report FOR THE Lawrence and Barbara Daley Preserve County of San Diego 2011 report
County of San Diego MSCP Monitoring Summary Report January 1998 - June 2007 County of San Diego 2007 report
Data Summary for the 2005 Arroyo Toad (Bufo californicus) Surveys Conducted in the San Bernardino National Forest Schuster, Sara L.; Fisher, Robert N.; Hathaway, Stacie; Backlin, Adam R.; Hitchcock, Cynthia J. 2005 report
Daytime Habitat Assessment Survey Protocol for the Arroyo Toad (Bufo californicus) 2003 other
Developing a Countywide Arroyo Toad Monitoring Plan 2020 powerpoint presentation
Distribution and Status of the Arroyo Toad (Bufo californicus) in the San Diego MSCP and Surrounding Areas, 2002-2003. powerpoint presentation
Draft Final: Associations Between Arroyo Toads, Nonnative Species, Drought, and Impervious Surfaces in San Diego County Brown, Chris; Perkins, Emily; Hitchcock, Cynthia J.; Aguilar Duran, Angelica; Grolle, Lizzie; Watson, Elise; Fisher, Robert N. 2020 report
FINAL Baseline Biodiversity Survey for the San Luis Rey River Park 2011 report
Final Report: Ramona Grasslands Preserve Bullfrog Eradication Project 2020 report
Flashcards All species and habitat revisions Vinje, Jessie; Spring, Shawn 2024 fact sheet
Habitat Assessment and Surveys for the Arroyo Toad (Bufo californicus) in Cuyamaca Rancho State Park, 2002 Ervin, Edward; Hathaway, Stacie; Fisher, Robert N. 2002 report
Habitat Assessment and Surveys for the Arroyo Toad (Bufo californicus) in Cuyamaca Rancho State Park, and Lucky 5 Ranch in Anza-Borrego Desert State Park, 2003 Ervin, Edward; Fisher, Robert N. 2003 report
Habitat Restoration Summary 2010 2010 report
Longevity and population age structure of the arroyo southwestern toad (Anaxyrus californicus) with drought implications Brehme, Cheryl; Fisher, Robert N.; Hathaway, Stacie; Hovey, Tim; Stokes, Drew; Warburton, Manna 2018 journal article
MCB Camp Pendleton Arroyo Toad (Bufo californicus) Monitoring Results, 2003 Brehme, Cheryl; Atkinson, Andrea; Fisher, Robert N. 2004 report
MCB Camp Pendleton Arroyo Toad Monitoring Protocol: 1. Summary of results from a workshop on August 27, 2002 2. Monitoring protocol and targeted studies Atkinson, Andrea; Fisher, Robert N.; Ervin, Edward; Yang, Brian S.; Case, Ted J.; Scott, Norman; Shaffer, H. Bradley 2003 report
MCBCP Arroyo Toad Monitoring Program: 3-Year Trend Analyses for 2003- 2005 Brehme, Cheryl; Schuster, Sara L.; Rochester, Carlton; Hathaway, Stacie; Fisher, Robert N. 2006 report
MCBCP Arroyo Toad Monitoring Results for 2006 with Multi-Year Trend Analysis Turschak, Greta; Brehme, Cheryl; Schuster, Sara L.; Rochester, Carlton; Fisher, Robert N. 2008 report
MCBCP Arroyo Toad Monitoring Results for 2009 with Multi-Year Trend Analysis Brehme, Cheryl; Turschak, Greta; Schuster, Sara L.; Fisher, Robert N. 2011 report
MCBCP Arroyo Toad Monitoring Results for 2011 Brehme, Cheryl; Matsuda, Tritia; Fisher, Robert N. 2012 report
MCBCP Arroyo Toad Monitoring Results for 2012 and Multi-Year Trend Analysis from 2003 to 2012 Brehme, Cheryl; Matsuda, Tritia; Fisher, Robert N. 2013 report
MCBCP Arroyo Toad Monitoring Results for 2013 and Multiyear Trend Analysis from 2003 to 2013 Brehme, Cheryl; Matsuda, Tritia; Fisher, Robert N. 2014 report
Multi-scale effects of land cover and urbanization on the habitat suitability of an endangered toad Treglia, Michael ; Landon, Adam C.; Fisher, Robert N.; Gerard, Kyle; Fitzgerald, Lee 2018 journal article
Post-Cedar Fire Arroyo Toad (Bufo californicus) Monitoring Surveys at Cuyamaca Rancho State Park, 2004 Mendelsohn, Mark; Madden-Smith, Melanie; Fisher, Robert N. 2005 report
Post-Cedar Fire Arroyo Toad Monitoring Surveys at CRSP Fisher, Robert N.; Mendelsohn, Mark 2004 powerpoint presentation
Quarry Creek Preserve Management Plan 2011 report
Range-wide persistence of the endangered arroyo toad (Anaxyrus californicus) for 20+ years following a prolonged drough Hitchcock, Cynthia J.; Gallegos, Elizabeth; Backlin, Adam R.; Barabe, Russell; Bloom, Peter; Boss, Kimberly; Brehme, Cheryl; Brown, Chris; Clark, Denise; Clark, Elizabeth, R.; Cooper, Kevin; Donnell, Julie; Ervin, Edward; Famolaro, Pete; Guilliam, Kim, M.; Hancock, Jacquelyn, J.; Hess, Nicholas; Howard, Steven; Hubbartt, Valerie; Lieske, Patrick; Lovich, Robert; Matsuda, Tritia; Meyer-Wilkins, Katherin; Muri, Kamarul; Nerhus, Barry; Nordland, Jeff; Ortega, Brock; Packard, Robert H.; Ramirez, Ruben; Stewart, Sam, C.; Warburton, Manna; Wells, Jeffery M.; Winkleman, Ryan; Winter, Kirsten; Zitt, Brian; Fisher, Robert N. 2022 journal article
Recording - December 2022 SDMMP Annual End-of-Year Management and Monitoring Coordination Meeting Vickers, Winston; Smith, Trish; Smith, Kim; Fisher, Robert N.; Price, Jennifer; McCutcheon, Sarah; Pesce, Courtney; Preston, Kris; Perkins, Emily; Brown, Chris; Bernabe, Annabelle; Roesler, Elizabeth 2022 recording
Residence Tract Surveys For: Mountain Yellow-Legged Frog (Rana muscosa), California Red-Legged Frog (Rana aurora) and Arroyo Toad (Bufo californicus) Backlin, Adam R.; Kahacza, Zsolt; Fisher, Robert N. 2002 report
Responses of Arroyo Toads to Wildfires Brown, Chris; Brehme, Cheryl; Hathaway, Stacie; Fisher, Robert N. powerpoint presentation
Southern California Herpetofaunal Research and Monitoring (1995-1999): Application to Natural Community Conservation Planning Case, Ted J.; Fisher, Robert N. 2000 field notes/data sheets
State of the Regional Preserve System in Western San Diego County Preston, Kris; Perkins, Emily; Brown, Chris; McCutcheon, Sarah; Bernabe, Annabelle; Luciani, Emilie; Kus, Barbara; Wynn, Susan 2022 report
Status of the Arroyo Toad in San Pasqual Valley Results of the 2005 Breeding Season Surveys Haas, William E. 2005 other
Studies of the Arroyo Toad and Coast Range Newt on the Upper San Diego River Watershed - Annual Report Lovio, John; Fleury, Scott; Ervin, Edward; Hathaway, Stacie; Warburton, Manna 2002 report
Survey Results for the Arroyo Toad (Bufo californicus) in the San Bernardino National Forest, 2001 Brown, Chris; Fisher, Robert N. 2002 report
Understanding the Demographics of Arroyo Toad (Bufo californicus) Reproduction to Develop Management Strategies. Fisher, Robert N.; Hathaway, Stacie 2002 other
Using the ARMI Metric, Proportion Area Occupied, for Monitoring Arroyo Toads in Southern California. Brehme, Cheryl 2003 book/conf proceeding

Current Distribution Rangewide

Historically occurred from upper Salinas River system in Monterey County, south through the Santa Ynez, Santa Clara, and Los Angeles River Basins and coastal drainages of Orange, Riverside, and San Diego Counties, to the Arroyo San Simeon system in Baja California, Mexico [1]. Also occurs on desert slopes of the San Gabriel Mountains (in Little Rock Creek in Los Angeles County) and the San Bernardino Mountains (in the Mojave River and in its tributaries in San Bernardino County) [2]. Primarily restricted to headwaters of streams as small, isolated populations, having been extirpated from much of their historic habitat [3].

Known Populations in San Diego County

Occurrences found in Camp Pendleton, Anza Borrego State Park, Fallbrook NWS, Barrett Reservoir Open Space, Marron Valley Mitigation Bank, Cleveland National Forest, Mount Woodson, San Vicente Reservoir Cornerstone Lands, El Capitan Reservoir Open Space, San Pasqual Valley, Boden Canyon Ecological Reserve, Pamo Valley, Ramona Grasslands Preserve, San Dieguito River Park, Santa Ysabel East Open Space, Santa Ysabel West Open Space, Cuyamaca Rancho State Park, Barrett Reservoir Open Space, Dulzura Conduit, Bureau of Land Management, McAlmond Canyon, SDGE Sunrise Powerlink Parcels Long Potre, Lake Morena Regional Park, Canada de Vicente, Sutherland Reservoir Open Space, Hodges Reservoir Open Space, San Luis Rey River Park, Groves Open Space, Faubus Farms, Roncon San Luiseno Band of Mission Indians, and Vista Irrigation District.

List Status

FE, SSC

Habitat Affinities

Found in semi-arid regions near washes or intermittent streams. Habitats include: valley-foothill and desert riparian, desert wash, palm oasis, and Joshua tree, mixed chaparral and sagebrush [4;5;6; all cited from 7]. Breeding habitat consists of slow-moving streams with shallow pools, sandbars, and stream terraces. Breeding habitat is maintained by periodic flooding and scouring that alters stream channels, redistributes sand, opens up the vegetation, and changes the location and configuration of breeding pools [8]. Outside of the breeding season, toads are terrestrial and estivate in underground burrows in upland habitats including: sycamore-cottonwood woodlands, oak woodlands, coastal sage scrub, chaparral, and grassland [9;10; both cited from 3]. Elevational range extends up to 1950 m [7].

Taxonomy and Genetics

Considered a subspecies of the southwestern toad (Bufo microscaphus) at time of listing [9]. Allozyme analyses found each subspecies (B. m. microscaphus, B. m. californicus, and B .m. mexicanus) should be considered a full species and arroyo toad was reclassified as the full species Bufo californicus [11]. Later, the genus Bufo was subdivided into three genera, with the North American clade of Bufo renamed as the genus Anaxyrus [12].

Seasonal Activity

Adults primarily nocturnal but may be diurnal during breeding season. Newly metamorphosed toads are active during the daylight hours and can tolerate much higher temperatures than adults [13, cited in 7]. Active at temperatures between 22-35° C [14]. Adult and subadults seek shelter during the day, by burrowing into upland terraces, along old flood channels, and often in the soils below the canopy edge of willows (Salix spp.) or cottonwoods (Populus fremontii) [8;12;15]. Usually burrow into dry or slightly damp fine sand and may even use burrows constructed by other animals or seek temporary shelter under rocks or debris [16, cited from 8]. Go into estivation in burrows during the non-breeding season when it is hot and dry, starting in the late summer from about August and continuing into January [12;15].

Life History/Reproduction

Breeding typically occurs from February to July on streams with persistent water [9 cited from 3]. Breed and deposit egg masses in shallow, sandy pools that are usually bordered by sand and gravel flood terraces [9;10; both cited from 3]. Adults and subadults spend much of their lives in riparian and upland habitats adjacent to breeding locations [1 cited from 8].

Diet and Foraging

Tadpoles feed on loose organic material such as algae, bacteria, and diatoms [16;17; both cited from 8]. Juveniles feed on ants almost exclusively [16 cited from 8]. Adults feed on snails, Jerusalem crickets, beetles, ants, caterpillars, moths, and occasionally cannibalize newly metamorphosed individuals. Usually feed nocturnally. Individuals walk instead of hop when foraging for food [6;13; both cited from 7].

Dispersal

Move between stream and upland foraging sites, as well as up and down stream corridors to find suitable breeding pools [1 cited from 8]. Movements vary between watersheds or river reaches in response to different hydrological regimes [9 cited from 8]. When searching for suitable egg-laying sites in broad floodplain river systems move across parallel stream channels, such as the lower San Mateo River in San Diego County [8]. For watersheds with relatively narrower, steeper-sided drainages with alternating riffles and pools, tend to move in both up- and downstream directions rather than laterally while searching for breeding pools [9 cited from 8].

Threats

Threatened by habitat destruction and alteration from water storage reservoirs, flood control structures, roads, agriculture, urban development, recreational facilities, and mining activities. Non-native plants, such as tamarisk and Arundo have also altered arroyo toad habitat. Introduced non-native predators (e.g., bullfrogs, green sunfish, and African clawed frogs) and fire are substantial threats as well as chytrid fungus disease and wildfire suppression activities [3].

Literature Sources

[1] Campbell, L. A., T. B. Graham, L. P. Thibault, and P. A. Stine. 1996. The Arroyo Toad (Bufo microscaphus californicus): Ecology, Threats, Recovery Actions, and Research Needs. No. NBS/CSC-96-01. National Biological Service.

[2] Hitchcock, C. J., A. R. Backlin, and R. N. Fisher. 2004. Monitoring arroyo toads (Bufo californicus) in the San Bernardino National Forest. U.S. Geological Survey final report.

[3] U.S. Fish and Wildlife Service. 2009. Arroyo Toad (Bufo californicus [microscaphus]) 5-Year Review: Summary and Evaluation. Ventura Fish and Wildlife Office, Ventura, California, USA.

[4] Stebbins, R. C. 1954. Amphibians and reptiles of western North America. New York, McGraw-Hill.

[5] Stebbins, R.C. 1985. A field guide to western reptiles and amphibians. 2nd ed., revised. Houghton Mifflin, Boston. 336pp.

[6] Behler, J. L. and F. W. King. 1979. The Audubon Society field guide to North American reptiles and amphibians. AA Knopf. Inc., New York, New York.

[7] California Department of Fish and Game. 2005. Arroyo Toad. Sacramento, California, USA.

[8] U.S. Fish and Wildlife Service. 2014. Arroyo Toad Species Report. Ventura Fish and Wildlife Office, Ventura, California, USA.

[9] Griffin, P. C., T. J. Case, and R. N. Fisher. 1999. Radio telemetry study of Bufo californicus, arroyo toad movement patterns and habitat preferences, 66.

[10] Holland, D. C. 1995. Sensitive Species Hydroecological Evaluation–Santa Margarita River: Arroyo Southwestern Toad (Bufo microscaphus californicus) Camp. Camp Pendleton.

[11] Gergus, E. W.A. 1998. Systematics of the Bufo microscaphus complex: allozyme evidence. Herpetologica: 317-325.

[12] Frost, D.R., T. Grant, J. Faivovich, R.H. Bain, A. Haas, C.F.B Haddad, R.O. De Sá. A. Channing, M. Wilkinson, S.C. Donnellan, C.J. Raxworthy, J.A. Campbell, B.L. Blotto, P. Moler, R.C. Drewes, R.A. Nussbaum, J.D. Lynch, D.M. Green, and W.C. Wheeler. 2006. The amphibian tree of life. Bulletin of the American Museum of natural History: 1-291.

[13] Mayhew W.W. 1968. The biology of desert amphibians and reptiles. Pages 195-356 in GW Brown Jr., ed. Desert Biology, Vol. 1. Academic Press, New York. 638pp.

[14] Brattstrom, B. H. 1963. A preliminary review of the thermal requirements of amphibians. Ecology 44, no. 2: 238-255.

[15] Rancho Las Flores Limited Partnership. 2003. Arroyo toad (Bufo californicus) hydrogeomorphic habitat baseline analysis/radio telemetry study-Rancho Las Flores San Bernardino County, California. Prepared by Cadre Environmental, Carlsbad, CA.

[16] Sweet, S. S. 1992. Initial report on the ecology and status of the arroyo toad (Bufo microscaphus californicus) on the Los Padres National Forest of southern California, with management recommendations. Department of Biological Sciences, University of California.

[17] Jennings, M.R. and M.P. Hayes. 1994. Amphibian and reptile species of special concern in California. Report to the California Department of Fish and Game, Inland Fisheries Division, Rancho Cordova, California. 255 pp.