Mammals

Grassland fauna can be impacted by fire in a number of ways. Grazers and browsers may experience short-term displacement and need to seek other sources of food and shelter in nearby unburned areas. Conversely, animals that burrow underground, such as voles and deer mice, are more likely to access shelter during and after burn events (Reiner, 2007; Gifford-Gonzalez et al., 2013). Despite any immediate challenges with fire, grassland plant vegetation quickly regenerates, providing nutrient-rich forage from the minerals deposited by ash for species such as deer, coyotes, and sheep (van Mantgem et al., 2015) and allows animal populations to quickly rebound. Most grassland rodents and small mammals recolonize within one year upon the arrival of the first seed-bearing plants (Lee and Tietje, 2005; Vreeland and Tietje, 2002). Fire is also effective at improving habitat for animals that rely on open habitat, as burning maintains herbaceous vegetation and reduces woody shrub encroachment (Halstead et al., 2019).

Birds

Insect-eating birds, such as swallows and Swainson’s hawks, benefit from burning as smoke cues them to feed in burned patches where invertebrates emerge from the ground (Reiner, 2007). Other grassland species of birds, including the horned lark, burrowing owls, and mountain plovers, can benefit from grasslands when herbaceous cover is kept low enough by fire and/or grazing. (Reiner, 2007). The timing of burns can be an important factor for ground nesting birds, as some of these species can lose eggs and/or offspring when fires occur during the breeding/nesting season (Reiner, 2007).

Reptiles and Amphibians

Few studies have evaluated the effects of burning on reptile and amphibian populations. Halstead et al. (2019) monitored the endangered San Francisco garter snake (Thamnophis sirtalis tetrataenia) pre- and post-burn in a coastal prairie in San Mateo County. This species is predicted to benefit from burning, as reducing woody encroachment with prescribed fire enhances habitat for snake brumation (seasonal hibernation) and hunting for amphibians. The study did not find a significant effect of fire on snake mortality and there was a weak trend in snakes transitioning to reside in burned sites. They encourage the use of low-severity prescribed fire in the fall to maintain T. sirtalis tetrataenia, particularly if the snake population is robust enough at the onset and a wet winter is forecasted that can increase prey abundance. A broader review on the effects of wildfire on amphibian populations reportedd that high severity fires can harm habitat and decrease populations, particularly if aquatic breeding sites are impacted (Hossack and Pilliod, 2011). However, more studies are needed to determine if this is the same for prescribed fire.

Invertebrates

Certain beneficial insects, such as seed harvesting ants and native earthworms, increase post-fire when there is a reduction in thatch and regeneration of forbs (Underwood and Christian, 2009; Callaham et al., 2003). This increase in insects enhances food availability for larger predatory invertebrate and vertebrate communities. Further, burning can create favorable conditions for rare species such as the Ohlone tiger beetle (Cicindela ohlone), as fire promotes bare ground which is necessary for its persistence (Cornelisse et al., 2013). Fire can also negatively impact many insects, especially those that live with close proximity to the soil surface (~3 cm), as burning can cause lethal temperatures. However, a study on the endangered Taylor’s checkerspot butterfly (Euphydryas editha taylori) found that burns occurring during cool and moist conditions can create lower severity fires that enhance survival of such species, encouraging thoughtful timing and seasonality of the prescribed fire (Hill et al., 2017). Another study found that seed-harvesting ants decreased after a fall burn, whereas omnivore ants increased after a spring burn (Reiner 2007), reiterating the generalization that prescribed burning has mixed effects on insects.