Factors Affecting Habitat Use and Distribution of Desert Mule Deer in an Arid Environment

Abstract

We studied habitat use by desert mule deer (Odocoileus hemionus eremicus) in the Sonoran Desert to understand the relative importance of vegetation, terrain characteristics, human disturbances, and water sources in determining their distribution. We located 44 radiocollared female mule deer weekly over 5 years. In spring, when water was most scarce, deer were in areas with lower elevations, shallower slopes, and greater normalized difference vegetation index (NDVI) rates, when compared to random locations. Use of water developments (i.e., catchments) during spring was evident but their effect on deer distribution was small relative to other factors, and their importance varied by animal. More deer locations were recorded in areas of higher NDVI rate in spring, summer, and autumn, but they were also further from washes in autumn. The deer we monitored used lower elevations in spring and higher elevations during the rest of the year. The effect of slope was strong in all seasons. However, deer tended to select shallow slopes in spring and steep slopes during the rest of the year. Deer avoided roads in summer and autumn but were closer to them in winter. They avoided rivers or canals in summer but were closer to those features in autumn. Our results suggest that terrain characteristics in all seasons (slope and elevation), as well as forage quality in 3 of 4 seasons (as indexed by NDVI rate) were most important in determining distribution of deer. Concomitantly water catchments had a measurable, but minor, role during hot, dry conditions. We recommend investigators continue to evaluate the importance of water developments relative to other habitat factors, particularly via the use of multivariate studies, global positioning system technology, adaptive management, and temporary closure of water developments known to be used by radiocollared deer.

The Normalized Difference Vegetation Index (NDVI): unforeseen successes in animal ecology

“…NDVI was also successfully used to monitor the vegetation response to rainfall in both Egypt and Israel (Dall'Olmo & Karnieli 2002). This again scales up to the level of consumers: desert mule deer Odocoileus hemionus eremicus distribution in the Sonoran Desert was shown to correlate with high NDVI values in 3 out of 4 seasons (Marshal et al 2006); likewise the dynamics of great gerbils Rhombomys opimus in the arid Kazakhstan steppe was shown to be influenced by annual variability captured by spring NDVI (Kausrud et al 2007). …”

Selección del terreno de escape y cobertura vegetal del borrego cimarrón (Ovis canadensis cremnobates) en Baja California, mediante Técnicas de Teledetección Satelital

“…Los resultados obtenidos coinciden con lo reportado para otras especies de ungulados silvestres, como el Odocoileus hemionus (Marshal et al 2006), Damaliscus lunatus (Bro-Jørgensen et al 2008, Procapra gutturosa (Mueller et al 2008) y Aepyceros melampus (VanBommel et al 2006). Estas especies también dependen de la visibilidad para la detección de sus depredadores y seleccionan hábitats con valores similares de NDVI a los obtenidos en este estudio.…”

“…Los objetivos de esta investigación fueron: 1) Determinar la disponibilidad del terreno de escape, para lo que se utilizó un modelo de rugosidad del terreno en cuatro categorías (plano, sierras bajas, cañones y sierras altas). 2) Evaluar la disponibilidad de la cobertura vegetal mediante un Índice de Vegetación de Diferencia Normalizada (NDVI), que en estudios recientes ha sido útil para explicar la distribución de ungulados silvestres en zonas áridas, e. g. el venado bura (Marshal et al 2006), el impala (VanBommel et al 2006) y el borrego cimarrón (Sesnie et al 2012;Hoglander et al 2015), y 3) Analizar las preferencias de uso y la selección que hace el borrego cimarrón de las variables del hábitat. Esta es la primera evaluación de preferencia de hábitat del borrego cimarrón en Baja California.…”

Urbanization Alters the Influence of Weather and an Index of Forest Productivity on Avian Community Richness and Guild Abundance in the Seattle Metropolitan Area

“…The severity of the extremes and local habitat conditions dictate which species will thrive and which will decline. Numerous recent studies have found primary productivity or available energy, as measured by satellite based remote sensing, to be a good predictor of species richness at various spatial scales (Laurent et al, 2005;Luck, 2006;Marshal et al, 2006;Goetz et al, 2007;Bino et al, 2008). However, there are relatively few published reports investigating the use of productivity as a predictor of avian species richness in urban landscapes (Gottschalk et al, 2005) and fewer yet that relate this to the effects of climate.…”