California Species Survey Timeline
This timeline is a general guideline for California species survey requirements for selected plant and animal 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 your California species survey needs on any project.
All Species
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
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
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
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
Swainson’s hawk
Buteo swainsoni
Habitat: Woodlands, grasslands, scrub, agricultural land
Antelope Valley (Los Angeles and Kern counties)
Conduct surveys within 5 miles radius
At minimum, complete 2 survey periods before project initiation; complete Periods 2, 3, and 4 before environmental review
Survey potential nesting trees within a 5-mile radius for presence of nests
- Period 1: (optional; pre-arrival) Jan–Mar 31; all day; 1 pass
- Period 2: (arrival/nest building) Apr 1–Apr 30; all day; 3 passes
- Period 3: (as needed for monitoring known nest sites; egg laying/incubation) May 1–May 30; daylight hours
- Period 4: (fledgling) Jun 1–Jul 15; sunrise to 1200 and 1600 to sunset; 3 passes
Central Valley
Conduct surveys within a half-mile radius
At minimum, complete 2 survey periods before project initiation. Periods 2, 3, and 5 always recommended
- Period 1: (recommended/optional) Jan–Mar 20; all day; 1 pass
- Period 2: (arrival/courtship/territorial) Mar 21–Apr 5; sunrise–10:00/16:00–sunset; 3 passes
- Period 3: (nest building/copulation/territorial/courtship) Apr 5–Apr 20; sunrise–12:00 and 16:30–sunset; 3 passes
- Period 4: (only for monitoring known nest sites) Apr 21–Jun 10
- Period 5: (post-fledgling) Jun 11–Jul 30; sunrise–12:00 and 16:00–sunset; 3 passes
Nesting Birds (General)
Habitat: All habitats
Survey Window: Feb–Aug
- Occurs if there is a potential for nesting birds
- Number and frequency of visits varies by project
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)
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
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
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
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
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
White-tailed kite
Elanus leucurus
Habitat: Grassland, agricultural, wetland, riparian, woodlands, savannah
Survey Window: Mar 1–Jun 15
- Surveys follow California Coastal Commission protocol
- Five morning surveys spaced at least one week apart
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
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
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
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
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
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
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
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)
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
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
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
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
Western snowy plover
Charadrius nivosus nivosus
Habitat: Coastal beaches, shores of inland ponds/lakes
Breeding Season Survey Window: Late May–Mid June
Winter Season Survey Window: Dec 1–Jan 31
- One survey pass with one surveyor for beaches <50 meters wide; two surveyors for beaches
>50 meters wide
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
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 (16–18 visits)
• Survey season may be altered by USFWS
Western spadefoot toad
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
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