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1.
Twenty-two components of the odour of the anal-gland secretions of a male and a female yellow mongoose Cynictis penicillata were identified by dynamic solvent effect sampling, gas-liquid chromatography and mass spectrometry. The odour volatiles were considerably more diverse than those reported from the anal gland secretions of Herpestes auropunctatus and H. ichneumon. 相似文献
2.
A.C. Marsh 《African Zoology》2013,48(2):130-136
Forager abundance, activity, dispersion and diet of Messor denticomis and Tetramorium rufescens was studied on a monthly basis for 17 months. There were large fluctuations in forager abundance with both species exhibiting similar patterns; the first peak in abundance occurring five months after a peak in food availability and the second peak in abundance coinciding with a second, smaller pulse of food. Food supplementation experiments demonstrated that availability of food partially regulated the absolute numbers of ants foraging. Both species shared similar activity patterns with the majority of activity occurring at night. Foragers were randomly dispersed within the 16 ha study plot. Most of the food collected by both species was Enneapogon brachystachyus seeds. These seeds were collected during the first half of the study when seeds were apparently superabundant. With declining seed availability both species took more non-seed plant matter and arthropods. In both species, diet range fluctuated widely, reflecting opportunistic responses to food availability. Opportunism was particularly apparent when seeds were relatively scarce. Despite large interspecific differences In body size, the majority of food utilized was the same size for both species. The above patterns suggest that interspecific competition for food is not an important factor in the ecology of these ant species. 相似文献
3.
Chafika Mouhoub-Sayah Hafsa Djoudad-Kadji Florian Kletty André Malan Jean-Patrice Robin Michel Saboureau 《African Zoology》2018,53(1):1-10
The Algerian hedgehog Atelerix algirus is an insectivorous species. However, the exact composition of its natural diet remains largely undetermined, especially in relation to seasonal variations in food availability. From March to November, we simultaneously analysed the composition of 180 hedgehog faecal samples and food availability in the Soumman Valley, Algeria to assess food selection in this species. The faeces contained 196 different prey species, of which 92% belonged to the class Insecta. The highest prey species diversity was found in the Coleoptera order (100 species recorded) and the highest species occurrence was found in Hymenoptera (65% of the prey items, mainly represented by the harvester ant Messor barbarus, a crop-ravaging species). This study shows that the Algerian hedgehog is mainly a generalist species with a diet that is strongly linked to food availability. However, seasonal variations were observed in prey selection, and a notable shift in food preference was observed during autumn. The exact nature of these changes in feeding behaviour remains to be investigated, notably in relation to changes in energy requirements of this species before hibernation, in terms of quantity and/or quality. 相似文献
4.
《African Zoology》2013,48(2):261-268
Seasonal changes in the diet of Cape clawless otters Aonyx capensis feeding in the surf zone in False Bay, Western Cape Province, South Africa, were investigated by spraint (faecal) analysis. The most common prey species, during all seasons, was the Cape rock crab, Plagusia chabrus. The next most important prey species was the Cape rock lobster, Jasus lalandii, with the fish species Clinus superciliosus being equally important in winter. Other prey were fresh-water crabs, Potamonautes perlatus, octopus, Octopus granulatus, and 17 other species of fish, frogs and mammals. In winter and autumn the most important prey category was fish while in spring and summer, crustaceans were the most important. Diversity of prey was lowest in winter, increasing through the seasons from spring to autumn. 相似文献
5.
N. Owen‐Smith 《African Journal of Range and Forage Science》2013,30(3):7-10
Abstract This paper considers the choice of a browsing ungulate to supplement cattle in savanna regions susceptible to problems of bush encroachment, and evaluates the kudu in particular. Relevant aspects of its ecology considered include (i) the vegetation components utilized at different seasons and in different areas, with regard to principal food species, reserve dry season species, rejected plant species and potential food limitations; (ii) social grouping patterns and home range extent; (iii) population densities, reproductive parameters, survival rates and population dynamics in relation to rainfall; (iv) impact on the vegetation of browsing and branch breakage. Features of the kudu are compared with those of other browsing ungulates, including giraffe, eland, impala and goats. It is concluded that the kudu is a prime candidate for inclusion alongside cattle in mixed species ranching enterprises in most regions of savanna vegetation. 相似文献
6.
An examination of 18 Crocuta crocuta dens in the Kruger National Park, showed that this species can be responsible for bone assemblages at dens, more so at permanent sites such as granite or calcrete caves than at temporarily occupied aardvark holes or road culverts. Because of the facultative nature of food-transporting behaviour, the rate at which bones are accumulated at dens varies, ranging from no bones collected to nine food items collected per month. The relative abundance of ungulate species represented in the large assemblages resembles that of ungulates living in the region surrounding a den. 相似文献
7.
D.J. Coetzee 《African Zoology》2013,48(2):59-66
Over the period October 1978 to April 1979 a total of 180 specimens of the estuarine round-herring Gilchristella aestuarius and 218 specimens of the Cape silverside Hepsetia breviceps were collected for stomach content analysis in the Swartvlei system and Groenvlei on the southern Cape coast. The diets of these two species were found to be fairly similar, with crustaceans forming their main food source in both water bodies. 6. aestuarius appears to filter feed throughout most of its length range, although the bigger food items are probably actively caught. Young H. breviceps also filter feeds, but it seems to catch most of its food actively as it grows older. Some H. breviceps consumed adult polychaetes and tube-dwelling amphipods covered by sand particles, indicating that these were probably removed from the substrate. 相似文献
8.
《African Zoology》2013,48(3):227-231
The land snail Theba pisana is a coastal species native to the Mediterranean but has been introduced to regions all over the world, including South Africa and Australia, where it is considered a pest. This study examines the diet of T. pisana and its preference for certain dune plants in the Cape Recife Nature Reserve of Algoa Bay in the Eastern Cape, South Africa. Field observations identified plants being fed on by T. pisana, accounting for almost half of the dune plant species present in the study area. Five plant species, on which snails were found frequently and in high abundance, were selected for feeding preference experiments. Laboratory experiments and field observations indicate that T. pisana feed preferentially on Tetragonia decumbens over Osteospermum moniliferum, Osyris compressa and Cynanchum obtusifolium. It is clear that while T. pisana is reported to have a generalist diet, consuming a range of plant species commonly found in South African dune vegetation, it also exhibits a definite preference for T. decumbens. The reasons for this preference need to be investigated further. 相似文献
9.
Magnus MAGNUSSON Gustaf SAMELIUS Birger H
RNFELDT Frauke ECKE 《Integrative zoology》2019,14(4):376-382
Grey‐sided voles (Myodes rufocanus) and bank voles (Myodes glareolus) co‐exist in boreal forests in northern Scandinavia. Previous studies suggest that the 2 species interact interspecifically, the grey‐sided vole being the dominant species. We tested the hypothesis that bank voles shift their diet due to competition with the dominant grey‐sided vole by studying stable isotope ratios in both species. Muscle samples were taken from voles in patches of old forest occupied by only bank voles and patches of old forest occupied by both grey‐sided voles and bank voles. We found that: (i) stable isotope ratios of bank voles differed in areas with and without grey‐sided voles; and that (ii) the stable isotope ratios of bank voles were more similar to those of grey‐sided voles in areas where grey‐sided voles were absent. Our data suggests that grey‐sided voles forced bank voles to change their diet due to interspecific competition. 相似文献
10.
《African Zoology》2013,48(1):114-115
This paper reports a previously undescribed form of predation upon the angulate tortoise, Chersina angulata, in the West Coast National Park, South Africa. Twelve recently killed C. angulata were found, within an area of 4–5 hectares, during April 2000. The head and neck were missing from all individuals, while the rest of the body was undamaged. Spoor of the large grey mongoose, Herpestes ichneumon, was observed at a freshly killed tortoise and it is argued that this was the predator responsible. 相似文献
11.
Abstract Fire intensity is an important component of the fire regime and its effect on the grass sward and bush were investigated in the Eastern Cape thornveld. Research indicated that fire intensity had no effect on the recovery of grass after a burn. Conversely it had a marked effect on the topkill of bush to a height of 2 m. The results provide valuable guidelines for the use of fire in controlling bush encroachment. 相似文献
12.
《African Zoology》2013,48(1):125-130
Climate has been proposed as an explanation for the present-day distribution of closely-related melanistic and non-melanistic cordylid species in the southwestern Cape of South Africa. However, diet may also contribute towards shaping geographic distributions. We present preliminary data on diet composition based on analyses of faecal pellets of Cordylus cordylus (non-melanistic), C. niger (melanistic) and C. oelofseni (melanistic). Coleoptera were the most common prey ingested both in summer and early spring for all species, followed by Hymenoptera for all species in summer. The overlap in other arthropod taxa ingested was low across species and seasons, suggesting an opportunistic component to their foraging behaviour.We distinguished plant matter in faecal samples of all species in all seasons, reflecting either voluntary or accidental ingestion. The results of this study suggest that the generalist diets of these cordylid species should not constrain their distributions despite the common preference for coleopterans. 相似文献
13.
A. Moore J.P. Van Niekerk I.W. Knight H. Wessels 《African Journal of Range and Forage Science》2013,30(4):7-10
Abstract Two formulations of tebuthiuron i.e. Graslan 20P and Graslan 40P are currently being evaluated in the Molopo area. Tebuthiuron was applied aerially at ten application rates, in combination with two application dates. After only two seasons, the chemical has already shown a reasonable selectivity for the woody species. Of these, Acacia mellifera, A. reficiens and Grewia flava are very sensitive while A. erioloba and Dichrostachys cinérea are less sensitive and Boscia albitrunca seems almost resistant to the lower application rates (<1,0 kg a.i./ha). The standing crop of grass on the treated plots increased by between 220 and 740 per cent. Changes in the total grass density and botanical composition can be ascribed to an increased density of Eragrostis lehmanniana. At this stage of the trial, its selectivity in favour of the more desirable woody species, suggests that tebuthiuron shows great promise for controlling bush encroachment in the Northern Cape, although a final conclusion would only be possible 5 years after its application. 相似文献
14.
Mammalian parental investment (i.e. care of descendant offspring) is largely biased towards maternal contributions due to the specific feeding needs of mammalian offspring; however, varying degrees of paternal investment have been reported in about 10% of all mammalian species. Within the order Carnivora, paternal contribution to rearing offspring is particularly high: an estimated 32% of all studied carnivore species exhibit direct paternal care. Despite the prominence of paternal investment in carnivores, the endocrine basis of this behaviour is not well understood. This review examines the current – highly constrained – state of knowledge about the endocrine basis of carnivore paternal investment. We attempt to link changes in androgen and glucocorticoid levels with variation in direct and indirect paternal care behaviour making specific predictions regarding the way forward. Well-studied species, such as bat-eared foxes (Otocyon megalotis), dwarf mongoose (Helogale parvula) and meerkats (Suricata suricatta), where social dynamics are relatively well understood, can act as ideal model systems through which we may further investigate the endocrine basis of paternal investment in carnivores. 相似文献
15.
Comparison of Cape Town and Skirrow's protocols used in isolation of Campylobacter in humans and broilers was carried out in a cross-sectional study in Morogoro, Tanzania. A total of 176 and 158 human stool
and broiler intestinal samples were collected, respectively. While human stool samples were collected from selected health
centers, broiler intestinal samples were obtained from selected farms and chicken markets. Samples were inoculated and cultured
in duplicate using two protocols and prevalence of Campylobacter were established. In humans, the prevalence of Campylobacter isolates was significantly higher (P < 0.001) (21.6%) with Cape Town protocol than Skirrow's method (9.1%). Similarly, a higher prevalence (P < 0.05) in broilers was recorded in Cape Town protocol (77.8%) than Skirrow's method (66.5%). There was a moderate (0.53)
Kappa test of agreement between Skirrow's and Cape Town protocols for human samples and substantial agreement (0.72) for broiler
samples. This demonstrates that Cape Town protocol is superior over the Skirrow's protocol in Campylobacter isolation. Campylobacter jejuni, Campylobacter coli and Campylobacter lari were the Campylobacter spp. isolated. In humans, C. jejuni accounted for 92.1% and 87.5% of all positive samples with Cape Town and Skirrow's protocols, respectively. In broilers,
C. jejuni was isolated at 91.1% and 92.5% of all species obtained with Cape Town and Skirrow's protocols, respectively. This shows
that C. jejuni is the common species that may be circulating from either broilers to humans or other animals and vice versa. The present
study has introduced Cape Town protocol in Tanzania for Campylobacter isolation from human and animal samples, which is expected to improve the isolation of Campylobacter species. Cape Town protocol may also be a good alternative for use in routine isolation of Campylobacter. 相似文献
16.
I G Horak F Chaparro J C Beaucournu J P Louw 《The Onderstepoort journal of veterinary research》1999,66(1):33-38
Eighty yellow mongooses, Cynictis penicillata, from five localities in South Africa were examined for arthropod parasites. Ten ixodid tick species, of which Haemaphysalis zumpti was the most abundant, prevalent and widely distributed, were collected. The mongooses were also infested with two mite species. Echidnophaga gallinacea was the most abundant of the eight flea species collected. It and Ctenocephalides connatus were present at every locality. A single biting louse species, Felicola cynictis, was recovered and it was the most prevalent ectoparasite on the mongooses. 相似文献
17.
《African Zoology》2013,48(2):387-392
Differences in the ecological niche requirements among rodent species competing in the same habitat may result from differences in the use of one to three resources: space, time and food or some combination of these. Alternatively, differences in resource use utilization among animal species may simply reflect availability of food, and when food is limited, different animal species compete. In this study, the diet of two rodent pest species, Mastomys natalensis and Gerbilliscus vicinus, coexisting in fallow land in central Tanzania were studied to assess the degree of diet differentiation among them. Dietary niche breadth of G. vicinus was greater than that of M. natalensis in all stages of the maize cropping seasons. The rodent species studied overlapped considerably in the food items consumed ranging from niche overlap (Ojk) of 0.77–0.89. Grains/seeds featured high in the diet of M. natalensis while plant material occurrence was high in G. vicinus. These two food categories may have contributed to differences in diet partitioning, which may, in turn, facilitate their coexistence in fallow land. 相似文献
18.
The influence of tree density on the grass layer of three semi-arid savanna types of southern Africa
《African Journal of Range and Forage Science》2013,30(2-3):103-109
The influence of bush density on the grass component of the herbaceous layer was investigated for three savanna veld types (Molopo Thornveld, Mixed Vaalbos Thornveld, and the Eastern Grass and Bushveld) in the Northern Cape and North-West Province of South Africa. Relationships between bush density and the density, species composition and phytomass production of the grass component were determined over a four-year period. Bush encroachment had an adverse influence on the density and production of the grass component, but not on the species composition. Fluctuations in seasonal rainfall appeared to be the most important factor governing changes in the species composition of the grass component. Bush enchroachment (2 500 tree equivalents ha?l) decreased the potential grazing capacity by as much as 331%, 149% and 58% in the Molopo Thornveld, the Mixed Vaalbos Thornveld and the Eastern Grass Bushveld, respectively, In comparison to sites with tree densities of less than 400 tree equivalents ha?1. In the encroached condition grazing capacities of 15, 13 and 10 ha LSU?1 are recommended for the Molopo Thornveld, the Mixed Vaalbos Thornveld and the Eastern Grass and Bushveld, respectively. The implementation of bush control measures in all problem areas is proposed in order to restore the productivity of these areas in the long term. 相似文献
19.
Differences and overlap in the diets of two sympatric, herbivorous rodents Otomys unisulcatus and Parotomys brantsii were investigated. Frequency of occurrence of plant species in the diets were compared with availability of the plants in the rodents' habitats. Both rodents are generalist herbivores, eating plants species in proportion to the availability in their habitats. Dietary patterns, diversity of diet and degree of overlap between rodent's diets are a function of food availability in the different habitats. It is suggested that these rodents separate niches on a spatial rather than trophic basis. Differences in dietary patterns are therefore not critical for niche separation but are the result of habitat segregation. 相似文献
20.
In this article we examine the gut morphology of the only three arid-occurring otomyine rodents; Brants’ whistling rat, Parotomys brantsii, Littledale’s whistling rat, Parotomys littledalei and the Karoo bush rat, Otomys unisulcatus and relate this to the semi-arid environment in which they are endemic. All three otomyine rodents display a gastro-intestinal system well suited to a wholly herbivorous diet, with a well-developed caecum and relatively long large intestine. Despite the broad similarity in the gross gastro-intestinal anatomy between the species examined in this study and their mesic-occurring otomyine counterparts, the results suggest an elongation of the large intestine, with a concurrent reduction in the size of the small intestine In the arid-occurring species. We argue that this trend may be related to water conservation and is supported by the distribution of the three species, with P. littledalei, which occurs in the most arid areas of the three, having the longest large intestine. 相似文献