Megafire forces a declining prairie grouse into more marginal landscapes providing fine‐scale habitat

Abstract Megafires (wildfire >10,000 ha) are increasing worldwide and pose a novel threat to wildlife in fragmented landscapes. Within the southern Great Plains, 70% of grasslands have been lost to conversion to row‐crop agriculture, energy development, and invasive woody species. Multiple contemporary megafires have burned remaining large grassland tracts that provide high‐quality habitat for lesser prairie‐chickens ( Tympanuchus pallidicintus ). Grasslands and wildlife in this region evolved with fire, and studies demonstrate benefits of smaller fires for lesser prairie‐chickens. However, wildlife response to the scale and severity of megafire in contemporary fragmented grasslands remains undocumented. We used a hierarchical approach to assess lesser prairie‐chicken response to megafire, evaluating individual space use, habitat selection, and lek attendance in relation to landscape habitat features for 2 years before (2014−2015) and 2 years after (2018−2019) a 2017 megafire in the mixed‐grass prairie of south‐central Kansas, USA (Starbuck fire ~266,000 ha). The area used by individual lesser prairie‐chickens did not differ in size before (828 ± 110 ha SE) and after (720 ± 101 ha) the fire based on 95% isopleth Brownian bridge home ranges, but lesser prairie‐chickens shifted the location of home ranges to include 4 times more cover of United States Department of Agriculture Conservation Reserve Program (CRP) fields after the fire. Individual habitat selection revealed lesser prairie‐chickens selected more overall grassland (β = 0.19 ± 0.04) and avoided cropland (β = −0.18 ± 0.03) post fire. However, at the population level, male lek attendance was greater in landscapes (7,854 ha) with more cropland post fire, opposite of trends before the fire. Lesser prairie‐chickens avoided more severely burned areas during the 3 years post fire across all analyses. Both individual‐ and population‐level analyses suggested that more marginal CRP and cropland landscapes provided refugia following the megafire. Increased megafire risk may reduce lesser prairie‐chicken habitat and drive dispersal to lower quality, marginal, fragmented landscapes. Habitat in more marginal landscapes may play an important role in wildlife resilience and resistance to novel disturbance in contemporary fragmented grasslands.