California Special-Status Species Survey Timeline

This timeline is a general guideline for survey season requirements for selected special-status species. Some federally listed species require a 15-day notice to USFWS prior to commencing surveys within the survey periods identified on this calendar; some require USFWS approval to begin. For current regulations regarding complete survey requirements, get in touch!

Our more than 60 full-time biologists deliver thorough, defensible biological assessments and reports using our understanding of federal and state regulations and policies, diverse species and habitats, and the latest survey protocols and technology. We provide a depth of biological expertise, geographic breadth, regulatory contacts, and experience to meet the needs of any project.

All Species

2020
January 1

San Bernardino kangaroo rat

San Bernardino kangaroo rat

Dipodomys merriami parvus

Habitat: Alluvial, scrub; elevation below 4,500 feet

Survey Window: Year-round
• Minimum five consecutive trapping nights, unless captured sooner
• Trapping may not be conducted if nightly low temperatures are forecast to fall below 50ºF

January 1

Stephens’ kangaroo rat

Stephens’ kangaroo rat

Dipodomys stephensi

Habitat: Grasslands, open; elevation 180–4,100 feet

Survey Window: Year-round
• Minimum five consecutive trapping nights, unless captured sooner
• Trapping may not be conducted if nightly low temperatures are forecast to fall below 50ºF

January 1

Fairy shrimp

Fairy shrimp

Branchinecta spp. and Streptocephalus woottoni

Habitat: Vernal pools/playas

Survey Window: Year-round

• Conduct one wet-season (winter/spring) and one dry-season survey (summer/fall, soil collection)
• Wet season survey: sample all 3-centimeter-deep pools that last 24 hours

January 1

Swainson’s hawk

Swainson’s hawk

Buteo swainsoni

Habitat: Woodlands, grasslands

Survey Window: Jan 1–Aug 31

• Jan 1–Apr 15: Survey for potential nest sites
• Apr 20–Jun 9: Do not survey unless nest monitoring, then 2–3 surveys April 20 to mid-May and 2–3 surveys mid-May to June 9

• Jul–Aug 31: 2–3 surveys

January 1

California red-legged frog

California red-legged frog

Rana draytonii

Habitat: Riparian, pond; elevation up to 4,500 feet

Survey Window: Jan 1-Sep 30

• At least one survey before August 15 with a minimum 6-week survey period

• Jan 1-Jun 30: 2 diurnal surveys and 4 nocturnal surveys

• Jul 1-Sep 30: 1 diurnal survey and 1 nocturnal survey
• One-week interval between surveys

February 15

Ridgway’s rail

Ridgway’s rail

Rallus obsoletus levipes

Habitat: Salt marsh, coastal emergent wetlands

Survey Window: Feb 15–Apr 30
• Six diurnal surveys, at least one at dusk and one at dawn
• Minimum 7-day interval between surveys

February 15

Western burrowing owl

Western burrowing owl

Athene cunicularia hypugaea

Habitat: Grasslands, open; elevation up to 5,300 feet

Survey Window: Feb 15–Jul 15
• Four crepuscular (dawn and dusk) surveys, 500-foot buffer as legally able, 7- to 10-meter transects
• Feb 15–Apr 15: One survey
• Apr 16–Jul 15: Three surveys with 3-week interval between surveys
• Pre-construction surveys required in suitable habitat within 30 days of ground disturbing activities

February 15

Brown-headed cowbird

Brown-headed cowbird

Molothrus ater

Habitat: Woodlands, grasslands

Survey Window: Feb 15–Aug 30

• Trap throughout breeding season or as required by permit

• Generally, maintain up to three males and two wing-clipped females in trap

• Check traps daily to release non-target captures

February 15

Belding’s savannah sparrow

Belding’s savannah sparrow

Passerculus sandwichensis beldingi

Habitat: Salt marsh

Survey Window: Feb 15–Apr 30
• Five diurnal surveys
• General season, weather conditions may alter survey season

February 18

Quino checkerspot butterfly

Quino checkerspot butterfly

Euphydryas editha quino

Habitat: Open; elevation below 5,000 feet
Survey Window: Third week of February–second Saturday in May
• If detected, minimum 5 diurnal surveys; otherwise, at least 13 surveys
• Minimum 4-day interval between surveys
• Weather conditions may alter survey season
• Survey period and number may be altered with USFWS coordination (usually related to elevation)

March 1

Mohave ground squirrel

Mohave ground squirrel

Xerospermophilus mohavensis

Habitat: Desert scrub

Survey Window: Mar 1–Jul 15

Mar 1–Apr 15: Diurnal visual surveys

Mar 1–Apr 30: First 5-day trapping period

May 1–May 30: Second 5-day trapping period

Jun 1–Jul 15: Third 5-day trapping period

March 1

California tiger salamander

California tiger salamander

Ambystoma californiense

Habitat: Grasslands, vernal pools/playas

Survey Window: Mar 1-May 30; October 1-March 15
• Larval survey: Three surveys, one each in March, April, and May; 10-day interval between surveys
• Drift fence survey: October 15-March 15; surround ponds and additional fences equaling 90% of site perimeter; traps open at night during rainy or humid weather; 20 trap nights per location

March 15

Coastal California gnatcatcher

Coastal California gnatcatcher

Polioptila californica californica

Habitat: Scrub; elevation up to 2,000 feet

Breeding Survey Window: Mar 15-Jun 30

Non-Breeding Survey Window: Jul 1-March 14
• Within Natural Community Conservation Plan (NCCP) area: Three diurnal surveys with seven-day interval between surveys, year round
• Outside NCCP area: Mar 15–Jun 30: Six diurnal surveys with seven-day interval between surveys; Jul 1–Mar 14: Nine diurnal surveys with 14-day interval between surveys

March 15

Arroyo toad

Arroyo toad

Anaxyrus californicus

Habitat: Alluvial, scrub, riparian; elevation 1,000–4,500 feet

Survey Window: Mar 15–Jun 30

• At least one survey in April, May, and June
• Six paired nocturnal/diurnal surveys
• Minimum 7-day interval between surveys
• Surveys should not occur during or near full moon period

March 20

Mojave desert tortoise

Mojave desert tortoise

Gopherus agassizii

Habitat: Desert; elevation up to 5,000 feet

Survey Window: Mar–May 30; Sep 1–Oct 31 (Presence/Absence)
• One diurnal survey
• Project area and zone of influence is surveyed
• General season, weather conditions may alter survey season, per USFWS

April 1

Thorne’s hairstreak butterfly

Thorne’s hairstreak butterfly

Callophrys thornei

Habitat: Cypress woodlands, chaparral; elevation 1,000–4,500 feet

Survey Window: Determined by emergence of species (approx. Apr 1–May 30
• Five weekly diurnal surveys

April 1

Pacific pocket mouse

Pacific pocket mouse

Perognathus longimembris pacificus

Habitat: Grasslands, scrub, generally within 5 miles of coast

Survey Window: Apr 1–Sep 30
• Minimum five consecutive trapping nights, unless captured sooner
• Trapping may not be conducted if nightly low temperatures are forecast to fall below 50ºF

April 10

Least Bell’s vireo

Least Bell’s vireo

Vireo bellii pusillus

Habitat: Riparian; elevation below 4,000 feet

Survey Window: Apr 10–Jul 31
• Eight diurnal surveys
• Ten-day interval between surveys

April 15

Laguna Mountains skipper

Laguna Mountains skipper

Pyrgus ruralis lagunae

Habitat: Meadow; elevation 3,900–6,000 feet

Survey Window: Apr 15–Jul 31
• Two-year survey
• Weekly visits during entire season (19 surveys)

April 15

Western pond turtle

Western pond turtle

Actinemys marmorata

Habitat: Riparian, Pond; elevation below 6,000 feet

Survey Window: Apr 15–Sep 15
• No official survey method
• Five surveys recommended
• General season, weather conditions may alter survey season

May 1

Southwestern willow flycatcher

Southwestern willow flycatcher

Empidonax traillii extimus

Habitat: Riparian; elevation below 8,500 feet

Survey Window: May 1–Jul 31

• May: 1 diurnal survey; June: 2 diurnal surveys; July: 2 diurnal surveys

• Five-day minimum interval between any survey

• When surveying for both southwestern willow flycatcher and least Bell’s vireo, separate surveys must occur with flycatcher surveys performed first

May 1

Mountain yellow-legged frog

Mountain yellow-legged frog

Rana muscosa

Habitat: Riparian, pond; elevation 1,000–6,900 feet

Survey Window: May 1–Aug 30
• Three diurnal surveys
• Each survey separated by minimum 7 days

May 19

Hermes copper butterfly

Hermes copper butterfly

Lycaena hermes

Habitat: Woodlands, chaparral, coastal sage scrub; elevation 200–4,000 feet

Survey Window: third full week of May–first full week of July
• Four diurnal surveys; 8- to 14-day intervals
• Look for spiny redberry associated with buckwheat that occurs within 15 feet

• Learn more about critical habitat and ESA considerations

June 1

Harbison’s dun skipper

Harbison’s dun skipper

Euphyes vestris harbisoni

Habitat: Oak woodlands, wooded riparian

Survey Window: Determined by emergence of species (approx. late spring–early summer
• Five weekly diurnal surveys
• Alternatively, year-round, perform single-pass survey of patches of Carex spissa for evidence of grazing or characteristic tent structures

July 1

Delhi sands flower-loving fly

Delhi sands flower-loving fly

Rhaphiomidas terminatus abdominalis

Habitat: Delhi sand and dune substrates in western Riverside and
San Bernardino Counties

Survey Window: Jul 1–Sep 20
• Two-year survey
• Two visits per week (1618 visits)
• Survey season may be altered by USFWS

December 1

Western spadefoot

Western spadefoot

Spea hammondii

Habitat: Grasslands, vernal pools/playas; elevation up to 4,500 feet

Survey Window: Dec 1–Mar 31
• Three nocturnal surveys, each survey conducted after/during rain event of 0.25 inches or greater
• Approximate 10-meter transects
• General season, weather conditions may alter survey season

Ready to find out more? Let’s talk about what you need!