Observation: Photinus pyralis
Primary Observer:
Seth Rogers
Event Date:
2025-05-11
Status:
Unreviewed

Survey
Site Name:
San Gabriel Fireflies
Province/State:
Texas
Event Date:
2025-05-11
Time of Day:
Night-Time
Start Time:
20:15
End Time:
22:00
Number of Observers:
2
Primary Observer:
Seth Rogers
Additional Observers:
Amanda Patterson
Target Species Genus:
Photinus
Target Species Species:
pyralis
Location and Habitat
Location Accuracy (meters):
50-100
Habitat Type:
Riparian - Areas Along lake or stream
Habitat Type Notes:
Wild grass, white flowers, natural habitat trees, river with minor algae growth, fireflies stayed close to overgrowth and trees until nightfall due to birds.
Elevation (meters):
250
Area Searched (hectares):
2 hectares, closest to san Gabriel river
Artificial Light Sources
Vehicles: No
Street Lights: Yes
Buildings: Yes
Street Lights: Yes
Buildings: Yes
Artificial Light Types
Sky Glow (diffuse illumination in the sky): Yes
Light Trespass (light cast on surfaces beyond its intended target): No
Glare (bright light causing visual discomfort): No
Light Trespass (light cast on surfaces beyond its intended target): No
Glare (bright light causing visual discomfort): No
Artificial Light Notes:
Relative low light, sources from nearby buildings and warm, lower bulb lights from nearby clubhouse
Observation
Observation Type:
Flashing
Number Observed:
11-50
Genus:
Photinus
Species:
pyralis
Observation Notes:
Habitat was a small river near San-Gabriel in Georgetown, TX. Species was likely Photinus pyralis as it flashed and flew in a J pattern. Some Species were observed flying upwards and flashing together in synchronization, my partner observed the motion at this link (the file wouldn't properly upload on this platform): https://photos.google.com/share/AF1QipMwFqYAahwjbTpR5ScW6mdyzeTnd5T-KxddJQKKff1GMhA0hF6kki9sqD_cOrOSLw/photo/AF1QipOUKIQx8KCsZ5ucrUoY9Fo1eEHs7KXj-2pMbXJF?key=Y1lEZkUxRlJUZHVhLWhNU2VjelR0Sy13VzBnR0Rn
Specimen Voucher Number:
Flash Behavior
First Flash Time:
20:00
Last Flash Time:
22:00
First Flash Temp (F):
83
Last Flash Temp (F):
72
Flashes in Pattern:
4
Flash Color:
Yellow
Flash Pattern Period:
3
Flash Duration:
5-10 seconds
Flash Interval:
5-10 seconds
Male Height Zone:
Low (0-3 ft), Moderate (3-8 ft)
Flash Location:
Flashes were observed in Tree-line, relatively few were over the water, some were in grasslands near the paved trail path.
Male Flash Behavior:
Males were following a J pattern until near a female, then flew in an upwards motion.
Female Flash Behavior:
Females were relatively stationary near a wooded area.