Relationship of greater sage‐grouse to natural and assisted recovery of key vegetation types following wildfire: insights from scat

Abstract

Megafires are creating severe conservation problems worldwide for wildlife that have obligate dependencies on plant species that are foundational but fire‐intolerant. Wildfire‐induced loss of native perennials and increases in exotic annual grasses threaten greater sage‐grouse (GRSG, Centrocercus urophasianus) in its sagebrush steppe habitat in western North America. Post‐fire restoration using herbicides, seeding, and planting of native perennials such as sagebrush are common, but there are few assessments of GRSG response to the treatments. We measured the presence of GRSG scat and modeled the probability of GRSG presence (PrGRSG‐scat) in relation to variation in plot‐level and landscape‐level predictors, and land treatments, in an intensive, repeat sampling from 2017 to 2020 of 113,000 ha area burned in 2015 in the Soda Megafire (Oregon and Idaho, U.S.A.). GRSG scat was present in less than 200 of more than 8,000 observations, as would be expected for a philopatric species (i.e. high fidelity to home site) returning to degraded habitat. PrGRSG‐scat was positively associated with sagebrush presence at the plot level and was positively related to elevation, lower‐angle slopes, and proximity to sagebrush seedling outplant islands. The statistical significance of relationships of PrGRSG‐scat to restoration treatments was marginal at best, with the largest effect being a positive response of PrGRSG‐scat to pre‐emergent herbicide sprayed to reduce exotic annual grasses. More time may be required for restored sagebrush steppe to meet GRSG needs or for GRSG to “adopt” the restored vegetation. Moreover, whereas scat is a convenient and non‐invasive method to monitor GRSG, its post‐fire scarcity weakens the strength of statistical inference on GRSG recovery patterns and response to restoration.

Using individual‐based habitat selection analyses to understand the nuances of habitat use in an anthropogenic landscape: a case study using greater sage‐grouse trying to raise young in an oil and gas field

“…Therefore, it is likely the reclamation surfaces in our study were not selected by females with chicks because of the lack of a shrub overstory that acts as concealment cover (Thompson et al 2006, Hagen 2011). For example, in a post‐fire landscape, Germino et al (2023) found that sage‐grouse use, as measured by the density of scat, was greater near sagebrush seedling outplantings when compared to burned areas without sagebrush. Mitigating the impacts of energy development through reclamation is a long‐term strategy, and other approaches to mitigation (e.g.…”

Trimming the hedges in a hurricane: Endangered Species lack research on the outcomes of conservation action

“…For example, if an action involved restoring habitat for Sage Grouse (Centrocercus urophasianus), the study had to demonstrate that it had a measurable effect on Sage Grouse, not just the vegetation. This is because habitat restoration does not always have a demonstrable positive effect on the target species, even when habitat quality targets are met (Germino et al, 2023). Simulation studies were not included for similar reasons.…”

“…Other approaches to estimate species' responses to conservation actions when empirical data are not available also demonstrate shortcomings. For example, predicted population growth rates based on simulated responses to action can overestimate true responses (Olsen et al, 2021), and using proxies such as habitat quality can be misleading if restoring habitat fails to yield meaningful improvements in species abundances (e.g., (Germino et al, 2023;Tattersall et al, 2020).…”