Home range- and colony-scale habitat models for Pinyon Jays in piñon-juniper woodlands of New Mexico, USA

Despite the Pinyon Jay's (Gymnorhinus cyanocephalus) importance as a pinon tree seed disperser and its long-term population declines, pinon-juniper habitat use by Pinyon Jays has been little studied. We created home range- and colony-scale habitat suitability models for Pinyon Jays in pinon-juniper woodlands at Kirtland Air Force Base and White Sands Missile Range, New Mexico, USA. Home range-scale models included mainly Juniper Woodland and Savanna, Pinon-Juniper, and Pinon Woodland vegetation types. Although home range-scale models at the two study sites contained similar vegetation types, we found differences between colony-scale models in habitat use and within-site diversity. Because of topographic and vegetation differences, colony-scale modeling incorporated fewer vegetation types and topographic classes for the White Sands Missile Range Study site than at Kirtland Air Force Base. Predictive colony-scale models overlapped validation colonies by 75.9% and 100% at the two study sites, indicating good model predictability. The large sizes of Pinyon Jay home ranges make year-round, home range-scale habitat management challenging. Habitat conservation focused at more limited spatial, i.e., colony, and temporal scales, revealed by multiscale modeling, could be more feasible and potentially more effective than management at the larger home range scale.Original Abstract: Malgre l'importance du Geai des pinedes (Gymnorhinus cyanocephalus) en tant que vecteur de dispersion de graines du pin pignon et la baisse de longue date de ses effectifs, l'utilisation de l'habitat de pins-genevriers par ce geai a ete peu etudiee. Nous avons elabore des modeles de la qualite de l'habitat aux echelles du domaine vital et de la colonie chez le Geai des pinedes dans les boises composes de pins et de genevriers a la Kirtland Air Force Base et au White Sands Missile Range au Nouveau-Mexique, Etats-Unis. Les modeles a l'echelle du domaine vital incorporaient essentiellement les types de vegetation allant des boises et des savanes domines par les genevriers, aux boises mixtes de pins-genevriers et aux pinedes. Meme si les modeles a l'echelle du domaine vital comportaient des types de vegetation semblables aux deux sites d'etude, nous avons trouve des differences entre les modeles a l'echelle de la colonie pour ce qui est de l'utilisation de l'habitat et la diversite a l'interieur d'un meme site. En raison de differences sur le plan de la topographie et de la vegetation, la model