In search of forage: predicting dynamic habitats of Mongolian gazelles using satellite‐based estimates of vegetation productivity

Abstract

Summary 1.Temporal variability in habitat suitability has important conservation and ecological implications. In grasslands, changes in resource availability can occur at broad spatial scales and enlarge area requirements of ungulate populations, which increases their vulnerability to habitat loss and fragmentation. Understanding and predicting these dynamics, although critical, has received little attention so far. 2. We investigated habitat dynamics for Mongolian gazelles ( Procapra gutturosa Pallas) in the eastern steppes of Mongolia. We quantified the distribution of gazelles at four different time periods and tracked primary productivity using Normalized Difference Vegetation Index (NDVI) data from satellite imagery. 3. A second-order logistic model showed that NDVI was an efficient predictor of gazelle presence. We tested the predictive power of the model with independent data from a gazelle telemetry study: 85% of all relocations were found within the predicted area. 4. Gazelles preferred an intermediate range of vegetation productivity, presumably facing quality quantity trade-offs where areas with low NDVI are limited by low ingestion rates, and areas with high NDVI are limited by the low digestibility of mature forage. 5. Spatiotemporal variation of gazelle habitat areas was high. Only 15% of the study area was consistently gazelle habitat throughout all survey periods, indicating that gazelles need to range over vast areas in search of food. Only 1% of the gazelle habitats were consistently located inside protected areas. 6. Synthesis and applications. Habitat variability in grasslands often leads to area requirements of ungulates that prevent effective conservation within single protected areas. They require landscapelevel management plans, but dynamic habitat predictions to inform such plans are difficult to implement and are often unavailable. We showed that satellite estimates of vegetation productivity can be used successfully to generate dynamic habitat models in landscapes with highly variable resources, and demonstrated that intermediate NDVI values were critical to predict occurrence of Mongolian gazelles.

Biogeographical patterns of the diet of Palearctic badger: Is badger an earthworm specialist predator?

“…Primary productivity is also an important variable for predicting distribution of herbivores and carnivores. Mongolian gazelles (Procapra gutturosa) preferred habitat with intermediate primary productivity [39]. Primary productivity also affects the body mass of roe deer (Capreolus capreolus) in low primary productivity area [40].…”

Mapping and navigating mammalian conservation: from analysis to action

“…Though often phrased in these absolute terms, the balance between, and combining of, these two approaches depends on the species in question [43], the nature of the larger landscape and how this landscape is used. For some species, such as Caribou (Rangifer tarandus) or nomadic Mongolian Gazelle (Procapra gutturosa), existing protected areas will never be large enough to conserve populations and conservation must focus on the larger area used during migration or other large-scale movements [44]. For other species, the landscape context within which conservation efforts take place is a more important variable in influencing the relative importance of a protected area or matrix.…”

Migration timing and stopover selection for barnacle geese Branta leucopsis

“…They preferred areas with an intermediate range of plant biomass, and thereby made a trade-off between forage quality and quantity. Areas with a low GWI (< 20%), where the ingestion rate is limited, and with a high GWI (> 80%), where the energy intake rate decreases because of the low nutritional value and digestibility of mature forage (Mueller et al, 2008;Wilmshurst et al, 2000), were both avoided by the barnacle geese during their spring migration. Thus, their migratory behaviour was consistent with the prediction derived from the green wave hypothesis -that avian herbivores follow the successive spring flushes of plants along their northward migration route.…”

“…For example, Mueller et al (2008) examined the relationship between vegetation productivity and animal habitat utilization, and they found that the intermediate range of NDVI was significantly associated with the highest food quality and resource availability for herbivores like Mongolian gazelles (Procapra gutturosa). Hamel et al (2009) assessed the relationship between two NDVI indices and the date of peaks in fecal crude protein, which represents temporal variability in the high-quality vegetation available for alpine ungulates.…”

“…Thus, NDVI time series have been used to link plant quality with herbivore habitat use (Hamel et al, 2009;Marshal et al, 2006;Mueller et al, 2008;Tveraa et al, 2013). In a study conducted by Doiron et al (2013) on Bylot Island, Canada, NDVI temporal changes were related to the date of peak nitrogen concentration in above-ground graminoid plants (grasses and grass-like plants, rushes, sedges).…”