Seasonal changes in nutrient content under three defoliation treatments in two coastal grassland communities of Transkei

Shackleton, Charlie M.; Mentis, M.T.

doi:10.1080/02566702.1992.9648296

Cited by 13 publications

(13 citation statements)

References 24 publications

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“…There are a number of possible explanations for this summarized by Crawley (1983), all of which may apply at MGR. The high proportion of principal but non-preferred species in the diet of herbivores at MGR is probably indicative of the low abundance of palatable species and the generally poor quality grazing afforded by Pondoland Sourveld (Shackleton & Mentis, 1992).…”

Section: Generalmentioning

confidence: 99%

Area and species selection by wild ungulates in coastal sour grasslands of Mkambati Game Reserve, Transkei, southern Africa

Shackleton¹

1992

African Journal of Ecology

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Summary Selection for particular areas and species by wild ungulates was assessed using ground survey and visual estimates of herbage removal through grazing. In general, the levels of herbivory were low (< 5%), except in grazing lawns. The Cymbopogon validus‐Digitaria natalensis Community experienced the greatest intensities of herbivory. There were marked seasonal changes in the intensity and pattern of herbivory, with the inclusion of more species and necromass material during the dry winter months. This was influenced by fire. Species were grouped into response classes according to hypothetical changes in herbivore preference ratios with maturation of the sward following a fire. Résumé On a estimé la sélection par des ongulés sauvages de zones et d'espèces végétales particulières en exerçant une observation au sol et en faisant des estimations visuelles de la quantité d'herbe broutée. En général, les taux d'herbivorie sont bas (5%), sauf dans les gazons pâturés. La communautéCymbopogon validus‐Digitaria natalensis subissait l'intensité d'herbivorie la plus élevée. Il y avait des différences saisonniéres marquées dans l'intensité et le type d'herbivorie, y compris la consommation d'un plus grand nombre d'espèces et de plus de matière sèche pendant les mois secs de l'hiver. Ceci était influencé par le feu. On a regroupé les espèces en différentes classes en fonction de changements hypothétiques des taux de préférence tout au long de la repousse du gazon après le feu.

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Section: Generalmentioning

confidence: 99%

Area and species selection by wild ungulates in coastal sour grasslands of Mkambati Game Reserve, Transkei, southern Africa

Shackleton¹

1992

African Journal of Ecology

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“…In the Mojave Desert, under conditions similar to those of the Karoo, the calcium content of plants changes seasonally and the jackrabbit (Lepu,r californicus) shows seasonal changes in the assimilation of calcium from plant material (Nagy et al, 1976). In the Transkei (now part of the Eastern Cape Region of South Africa), the calcium content of grass is slightly higher in summer than in winter (Shackleton & Mentis, 1992), and we suggest that the assimilation, by the elephant shrew, of calcium from fresh green foliage is more efficient than from mature foliage.…”

Section: Discussionmentioning

confidence: 59%

Reproduction in the round‐eared elephant shrew (Macroscelides proboscideus) in the southern Karoo, South Africa

Bernard

Kerley²,

Doubell

et al. 1996

Journal of Zoology

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With 4 figures in the text)Reproduction in round-eared elephant shrews occurred throughout the year. Male round-eared elephant shrews were sperniatogenically active, with spermatozoa stored in the cauda epididymes, throughout the year. Pregnant females occurred in all months except March and May and there was a decline in the occurrence of pregnancies during early winter (March-July). This tendency towards seasonality of pregnancies was mirrored by the appearance of juveniles, with 77% of all young animals caught between September and February. Bone calcium concentra-Lions were significantly lower during the dry winter than during summer. From October onwards (the beginning of the wet season), bone calcium concentrations increased, reaching high levels in December which were maintained until April. This increase in bone calcium concentrations coincided with the rainy season and with an increase in the intake of herbage, and during this period 60% of all pregnancies occurred. We conclude that the ability of the round-eared elephant shrew to vary its diet may allow some individuals to breed throughout the year. The reduction in the occurrence of pregnancies in early winter probably ensures that few births occur when bone calcium concentrations are low.

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“…Forage quality was better in recently burnt (<6 months post fire) grassland, see Shackleton & Mentis (1992), compared to older grassland. All step lengths <6 m were excluded during analysis in order to remove non-movements, as well as false movements due to GPS-error.…”

Section: Methodsmentioning

confidence: 96%

Ungulates rely less on visual cues, but more on adapting movement behaviour, when searching for forage

Venter

Prins

Mashanova

et al. 2017

PeerJ

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Finding suitable forage patches in a heterogeneous landscape, where patches change dynamically both spatially and temporally could be challenging to large herbivores, especially if they have no a priori knowledge of the location of the patches. We tested whether three large grazing herbivores with a variety of different traits improve their efficiency when foraging at a heterogeneous habitat patch scale by using visual cues to gain a priori knowledge about potential higher value foraging patches. For each species (zebra (Equus burchelli), red hartebeest (Alcelaphus buselaphus subspecies camaa) and eland (Tragelaphus oryx)), we used step lengths and directionality of movement to infer whether they were using visual cues to find suitable forage patches at a habitat patch scale. Step lengths were significantly longer for all species when moving to non-visible patches than to visible patches, but all movements showed little directionality. Of the three species, zebra movements were the most directional. Red hartebeest had the shortest step lengths and zebra the longest. We conclude that these large grazing herbivores may not exclusively use visual cues when foraging at a habitat patch scale, but would rather adapt their movement behaviour, mainly step length, to the heterogeneity of the specific landscape.

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Seasonal changes in nutrient content under three defoliation treatments in two coastal grassland communities of Transkei

Cited by 13 publications

References 24 publications

Area and species selection by wild ungulates in coastal sour grasslands of Mkambati Game Reserve, Transkei, southern Africa

Area and species selection by wild ungulates in coastal sour grasslands of Mkambati Game Reserve, Transkei, southern Africa

Reproduction in the round‐eared elephant shrew (Macroscelides proboscideus) in the southern Karoo, South Africa

Ungulates rely less on visual cues, but more on adapting movement behaviour, when searching for forage

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