Reproduction and survival of suricates (Suricata suricatta) in the southern Kalahari

Abstract

SummaryIn most respects, the demography of Kalahari suricates (Suricata suricatta) resembles that of other social mongooses. Average group size varies from four to nine, and groups typically include several mature females, of which one is responsible for the majority of breeding attempts. Breeding females show a postpartum oestrus; gestation is around 60 days; litter size is three to five pups at emergence and females rarely breed before the age of 24 months. In contrast, annual survival rates (0.20 for pups and 0.43 for animals over one year old) are lower than those recorded in other species. Breeding frequency is related to rainfall and breeding can cease altogether when rainfall is unusually low. In a year when this occurred, group size eroded rapidly and over 60% of groups became extinct. Total numbers were slow to recover during the following year because emigration by females was infrequent and new groups did not form in vacant ranges created by the extinction of groups. High rates of group extinction have been found in other cooperative breeders and may occur because breeding success and survival show inverse density dependence. Key words: cooperative breeding, population dynamics, suricates RésuméPar bien des aspects, la démographie des suricates du Kalahari (Suricata suricatta) ressemble à celle des autres mangoustes sociales. La taille moyenne des groupes varie de quatre à neuf, et les groupes comprennent typiquement plusieurs femelles mâtures dont une est responsable de la majorité des tentatives de reproduction. Les femelles reproductrices présentent un oestrus de post-partum; la gestation dure environ 60 jours; la portée compte de trois á cinq jeunes á la naissance, et les femelles se reproduisent rarement avent l'âge de 24 mois. Par contre, les taux de survie annuels (0,20 pour les petits et 0,43 pour les animaux de plus d'un an) sont plus faibles que ceux des autres espèces. La fréquence des reproductions est liée aux chutes de pluie, et elles peuvent même s'arrêter quand les pluies sont extraordinairement rares. Une année où ceci est arrivé, la taille des groupes s'est réduite rapidement et plus de 60% des groupes ont disparu. Le nombre total a mis du temps à remonter l'année suivante

Infanticide and expulsion of females in a cooperative mammal

“…Both study areas experienced a hot, wet summer (October^April), followed by a cold, dry winter (May^September) (Mills 1990). Breeding occurred most frequently during the summer months (November^March) but, over the ¢ve years of the study, births were observed in all months of the year (Clutton-Brock et al 1999a). For the purpose of these analyses, we de¢ned the breeding season as the period between 1 September and 31 March.…”

Life histories and the evolution of cooperative breeding in mammals

“…We used averages when multiple values for a given parameter for a given species were available. Data on annual adult survival were collected from reviews [26][27][28], and we searched for additional survival values from the primary literature specifically to increase the sample of cooperative breeders [29][30][31]. Continuous variables were log-transformed prior to analyses.…”

Dispersal, Eviction, and Conflict in Meerkats (Suricata suricatta): An Evolutionarily Stable Strategy Model

“…Data on survival, fecundity, and emigration behavior of meerkats have been extensively analyzed and are presented elsewhere (e.g., Clutton-Brock et al 1999a, 1999b, 2001bRussell et al 2002Russell et al , 2003a. We analyzed the current data set specifically to provide the parameters necessary for our dispersal model.…”

“…Details of the habitat and climate during the study period are provided elsewhere (Clutton-Brock et al 1999b;. Up to 28 groups were identified during the study period (1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001), but for the life-history data presented below, only data from the 14 most intensively studied groups were used.…”