Estimating the Suitability for the Reintroduced Arabian Oryx (Oryx leucoryx, Pallas 1777) of Two Desert Environments by NIRS-Aided Fecal Chemistry

Serge Yan Landau,Ido Isler,David Saltz,Amir Arnon,Benny Shalmon,Levana Dvash

doi:10.3390/rs13101876

Abstract

The re-introduction paradigm is that Arabian Oryx (Oryx leucoryx) herds adjust the size of their home ranges depending on the availability of vegetation, which is directly related to rainfall. In Israel, Arabian oryx were released in two hyper-arid sites: the Arava Valley and in the Paran wilderness, belonging to the Sudanese and the Saharo–Arabian biogeographic zones, respectively. While post-release survival was similar in both, reproductive success in the Paran wilderness reintroduction site was extremely low, resulting in an acute decline of the reintroduced population over time. The hypothesis that impaired nutrition might be associated with this finding was assessed with near-infrared spectroscopy (NIRS)-aided chemistry of monthly sampled fecal pellets, used as remote sensing evidence of ingested diets, throughout a year. Fecal nitrogen (FN), used as an estimate of nutritional status, was consistently higher in the Arava. Grass was never the sole or even a major dietary component. The dietary contribution of tannin-rich browse was high and steady all year-round in the Arava and increased steadily in Paran from winter to summer, corresponding to the period of availability of Acacia raddiana pods in both regions. The oryx in Paran had a home-range that was ten-fold, compared to the Arava, suggesting less feed availability. Acacia browsing may mitigate the effects of temporal variance in primary production. Under such conditions, oryx should be preferably released in areas that support significant acacia stands.

Highlights

The Arabian oryx (Oryx leucoryx, Pallas 1777), a specialized desert ungulate of the Bovidae family, once roamed hyper-arid zones in the Arabian Peninsula, southern Israel, and parts of the Sinai desert, but became extinct in the wild by 1972 due to the fact of uncontrolled hunting
We did not use a repeated measurement procedure, because there was no evidence that the feces collected in different months were dropped by the same animals; rather, we considered samples to have been defecated by random animals from the whole herd at each of the two locations
A major difference was found between sites: a significant rain downpour occurred on 28 October 2004 in the Arava

Summary

Introduction

The Arabian oryx (Oryx leucoryx, Pallas 1777), a specialized desert ungulate of the Bovidae family, once roamed hyper-arid zones in the Arabian Peninsula, southern Israel, and parts of the Sinai desert, but became extinct in the wild by 1972 due to the fact of uncontrolled hunting. Several reintroduction programs have established wild populations in Oman, Bahrain, Saudi Arabia, and Israel, but the Arabian oryx is still classified as vulnerable on the IUCN Red List Kleiman et al [2] suggested 13 criteria to plan and proceed with species reintroduction, one of which is that the habitat is sufficiently protected and a quality food resource exists. Based on the experience of oryx reintroduction in Saudi Arabia, the reintroduction schedule should imperatively take into account the quality and unpredictability of food resources in arid environments [3]. Often reintroductions take place in areas where extirpation occurred before any on-site nutritional- and habitat-preference studies took place

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