Temporal patterns in natality and mortality of three threatened antelope species in North Africa: Oryx dammah, Addax nasomaculatus and Nanger dama

Abstract

Long‐term population studies on large mammals are rare. Here, we have examined the threatened scimitar‐horned oryx, addax and dama gazelle's populations over the last 20 years in Bou Hedma National Park. Using monthly count data of the three studied species collected since 1995, we examined their population trends. Using autocorrelation analyses, we discovered endogenous natural cyclical fluctuations in the numbers of each species, with a periodicity of approximately 3 years. For all three studied species which seem to be opportunistic breeders, births and deaths occurred throughout the year, although with notable seasonality. By means of cross‐correlation, we discovered that during the first 7 years for which data were available, addax numbers were positively correlated with those of dama and inversely correlated with numbers of oryx. This pattern reversed during the following 4‐year period. The number of oryx was negatively correlated with dama during the first 4 years and then became positively correlated during the subsequent 7‐year period. Thus, we draw attention to difference in response to environmental and anthropogenic factors. Incorporating fundamental long‐term population data into developing management approaches, especially for potentially competitive species, is vital for their future long‐term survival and the success of conservation actions.

The environment matters: season and female contact affect the behavior of captive Addax nasomaculatus male antelope

“…Thus, aggression and marking behaviors that occurred in winter would not be mainly associated with feeding competition. In addax, calving is mainly concentrated in winter and spring (Northern hemisphere: Densmore and Kraemer 1986;Hizem et al 2019), which coincides with historical reports at the Parque Lecocq (data not published), and gestation length is around 8 months (Dittrich 1972;Spevak 2015). Thus, in the present study, the females' estrus cycles (i.e., the rut) may have occurred more frequently between the end of the spring and the summer.…”

“…A moderate reproductive seasonality has been described in wild and captive addax, with births concentrated in winter and spring (Densmore and Kraemer 1986;Hizem et al 2019). Thus, it is expected that the frequencies of courtship and mating behaviors vary throughout the year in accordance with the females' reproductive activity.…”

Habitat selection and foraging preference of the endangered addax (Addax nasomaculatus) in a fenced wildlife reserve within its historic range: insights for supporting effective reintroduction

“…As a direct result of these changes, the species disappeared from Tunisia in the early 1930s (Bel Haj Kacem et al 1994; Jebali 2008). A restoration programme for addax was initiated with semi-captive animals in the Bouhedma National Park (aka Bou-Hedma National Park) in 1985 (Bel Haj Kacem et al 1994), which were then translocated to Jbil National Park in 2006 (Hizem et al 2019). This protected area, located in the south-western quarter of the country, is made up of sand dunes and would be particularly suitable for an in situ captive breeding programme for addax.…”