In this document, we attempt to identify landscape, site, and patch habitat features used by breeding streaked horned larks (Eremophila alpestris strigata). We provide this information in a hierarchical framework from weakest to strongest evidence of suitable habitat to help inform where to focus potential survey effort. We relied primarily on quantitative assessments to describe lark habitat but also use descriptions of occupied habitats and expert opinion where necessary.
When using this document, it is important to consider that we had little to no information on the relative influence of different habitat conditions on lark reproduction and survival. In addition, larks readily use landscapes recently modified by humans (e.g., airfields, expanses of dredged material, agricultural fields), which indicates that the landscapes used by larks today are not necessarily reflective of those used in the past. Thus, we don’t discuss the fitness consequences of habitat selection to larks.
Finally, because larks tend to use early successional habitats and vegetation conditions may change rapidly within and between seasons, habitat suitability may change over time depending on the site, the type of vegetation, and the nature of past and ongoing human disturbance. Because of these changing conditions, it may be necessary to periodically re-evaluate a site’s suitability. Our descriptions of landscape, site, and patch characteristics do not include information on the habitat used by larks historically or in portions of its range that are no longer occupied.
This document is not regulatory. It is up to regulatory agencies to determine if and how to use the information in this report. Our goal is to help focus monitoring and surveys in areas that are more likely to supporting nesting larks. Streaked horned larks are federally listed as Threatened under the Endangered Species Act, which is regulated and enforced by the US Fish and Wildlife Service. If readers have questions about habitat suitability or the need to conduct surveys, they should contact their local US Fish and Wildlife Service office for guidance.