Reproduction and Recruitment Patterns in Warthog (Phacochoerus Aethiopicus) Populations

Abstract

La reproduction et le taux de rcnouvellement des populations de phacochores ont eto otudics dans le pörimetre de lütte antitsetso de Nagupande (Rhodosie) et compares avcc d'autres observations effectuees en Afrique du Sud et avec cclles existant dans la litterature.A Nagupande le rut sc situe en mal et la mise-bas en octobrc ou novembre. L'allaitement du re 3 a 4 mois, mais n'a probablement qu'une importance rlduite apres les 8*9 premieres scmaines. La maturite sexuelle intervicnt a la fin de la premiere annce chez les fcmcllcs ct a la fin de la seconde chez les males. Le taux de fcconditc s'clcvait a Nagupande a 72 % des fcmcllcs adultcs ct la moyenne des jcuncs par portccs ctait dc 3,76. En tenant compte de ccs proportions et de la mortalite fcrtale on a pu calculer un potentiel rcproductif maximum a la conception de 316 jeuncs pour 100 femellcs adultes. Dans la memo region la mortalitc juvenile ctait de 70 a 80 % contrc plus dc 95 % pour une population en dcclin et moins de 60 % pour unc autre en pleine expansion.La relation entre la pcriode de reproduction ct le cycle des saisons cst examinee, ainsi que la signification de la maturation sexuelle plus lentc des males dans cette espcce monogame oü le nombre des femelles reproductriccs est equivalent ä celui des males feconds.

Observations on the Biology of Tsessebe, Damaliscus Lunatus Lunatus, in Northern Botswana

“…13 suggests a rapid build up in the weight of the testicles in adults from a low in August to a peak just before the rut. Similar seasonal fluctuations in impala (Kerr, 1965 ;Child, 1968) and warthog (Child et α Ζ., 1968) are associated with differences in the amount of spermatogenesis. If this also applies in tsessebe, it would infer that, as in the other two species, the timing of the reproductive cycle is to some extent dependent on the seasonal synchronization of gamete production in both sexes.…”

“…Acacia woodland occurs on some of the sandiest soils, while open grassland is associated with areas of impeded drainage. A more detailed account of the topography and vegetation of the Chobe National Park is given by Child (1968 a).…”

“…The wedge of deciduous woodland is dominated by mopane veld consisting of three dominant growth forms which Child (1968 ) has termed Cnn, to include single boled trees and saplings, Cm 2 in which the trees are multiple stemmed and Cms which consists of multiple stemmed scrub with a well developed ground level coppice. Associated with the mopane veld there are sandy areas Brought to you by | University of Queensland -UQ Library Authenticated Download Date | 6/13/15 7:33 PM in which Terminalia cericia is the most conspicuous tree or bush, and some old Mood plains are characterized by Acacia tree savannah.…”

Rainfall extremes explain interannual shifts in timing and synchrony of calving in topi and warthog

“…Accordingly, calving in topi in the Mara and Serengeti (Sinclair et al 2000) is synchronized, but less so than in its congenerics in Southern Africa, with one rainy season (Fairall 1968;Du Plessis 1972;David 1975), but is bimodal in some equatorial populations (Estes and Estes 1979). Timing of breeding in warthog also varies considerably geographically with distinct farrowing seasons reported for parts of Eastern (Child et al 1968;Leuthold and Leuthold 1975;Boshe 1981;Rodgers 1984;Sinclair et al 2000) and Southern (Mason 1986) Africa, and bimodal or continuous breeding for Zaire and Congo Braziville, with high rainfall year-round (Brown 1936). If breeding in ungulates is determined by the quantity and quality of forage (Sadleir 1969), then onset of births should be delayed in dry and advanced in wet relative to an average year.…”

“…Timing of conception in African savanna ungulates appears determined by rainfall (Child et al 1968;Boshe 1981) acting through maternal body condition, because high rainfall improves forage quantity and quality (Desmukh 1984). Post et al (2003) also reported clear synchronization of the timing of parturition by caribou to plant phenology, regardless of predation pressure, suggesting that food sufficiency also governs the timing and spread of births in northern ungulates.…”