Variation of small mammal populations across different habitat types in the Serengeti ecosystem

This study investigated the abundance and diversity of small mammals in cultivated land (unprotected area) and wooded grassland in the Serengeti National Park (protected area) in the Serengeti ecosystem. Small mammal populations were sampled through capture-mark-recapture trapping techniques in March-April 2010. A total of 896 trap nights covering wet season, 9 species of rodents and 1 species of soricomorphs (shrew family) were captured. Overall, Multimammate rat Mastomys natalensis (Smith) was by far the most abundant rodent in cultivated land (28%) while inside the park, shrew Crocidura sp., was high in numbers (8%). A significantly higher abundance (trap success) of small mammals was obtained in the cultivated area compared to the national park (p < 0.01). There was also a significant difference in the two diversity indices between the cultivated areas (Hꞌ = 0.84) and national park (Hꞌ= 0.57) (p < 0.01).  The differences are probably habitat related i.e. types of crops cultivated in agricultural fields that might have attracted small mammals. There was moderately high similarity in the number of species caught in the two sites (Sørensen Coefficient (CCs) = 0.57), indicating that species composition did not vary significantly between the two sites with different conservation status. Overall high abundance and diversity in the cultivated areas may have resulted from the availability of food materials to granivorous small mammals which were majority.  This high abundance and diversity  outside the national park raises doubt as to whether the protected areas can still be considered as the most feasible approach of ensuring small mammals protection.Keywords: agriculture, habitat, small mammals, Serenget

Traditional medicinal uses of small mammal products: a case study of the African savannah hares, crested porcupines and rock hyraxes in Serengeti District, Tanzania

Traditional medicines, both plant and animal products, have been used to cure various diseases since time immemorial especially in rural areas worldwide. Many studies have focused on traditional plant products, but little research has been conducted on animal traditional medicines. This study investigated the use of small mammal products for medicinal purposes in three villages bordering Serengeti National Park in Serengeti District, Tanzania. A total of 71 respondents were interviewed in Kisangura, Nyamburi and Machochwe villages in November 2010, using questionnaires. Villagers hunted small mammals mainly by dogs for cultural and ornamental reasons. Products of African savannah hare (Lepus microtis), crested porcupine (Hystrix cristata) and rock hyrax (Procaviacapensis), were the most commonly used materials for believably curing nearly 11 different ailments including stomach pain, diarrhoea, convulsions and bleeding nose. Use of traditional medicines from these animals was significantly higher than other uses combined (p < 0.001), indicating that these small mammal products are important alternative medicinal products. However, although the small mammals utilised for medicinal purposes in the study area are categorised as Least Concerned (LC) presence and utilization of rare or threatened species in the same area cannot be ruled out. Therefore sustainable utilization of small mammals needs to be advocated.Keywords: Traditional medicine, small mammal, Serengeti Ecosystem, Tanzani

Group-size effect on scanning behaviour of Maasai Ostrich Struthio camelus massaicus

Scanning behaviour enables birds to collect information important for their survival, such as detecting predators (anti-predatory strategy) and searching for food. The scanning behaviour of the Common Ostrich Struthio camelus was investigated by determining the scanning duration (total seconds during 5-min periods that a bird’s head was raised) and scanning rate (number of times an individual raised its head per minute) among different group sizes in late 2006 in Serengeti National Park, Tanzania. A total of 14 males and 20 females were observed. Scanning duration was a function of group size where individuals in small groups scanned for longer times than individuals in large groups. However, increasing group size did not have a significant effect on the scanning rate among the groups. Individual vigilance among ostriches is influenced by group size, whereas individual scanning rate may be influenced by factors other than group size, such as body size and habitat type. Higher scanning duration in small groups is attributed to anti-predatory behaviour

The influence of agricultural activities on the diversity of rodents in Kindoroko forest reserve and surrounding areas, North Pare Mountains, Tanzania

The patterns of richness, diversity and similarity in rodent communities in agricultural areas and in adjacent Kindoroko Forest Reserve in the North Pare Mountains, Tanzania were assessed. By using a capture-mark-recapture method, 289 individuals of nine rodent species in March and May 2011 were captured. Seven species were recorded in agricultural area and 5 species in the Forest Reserve. Multimammate Rat (Mastomys natalensis) was abundant in agricultural area while soft-furred mouse (Praomys delectorum) was dominant in the Forest Reserve. Species diversity was greater outside than inside the forest, supporting results of earlier studies. Species similarity between the two habitats was high indicating that the species were generally evenly distributed across the landscape. The results showed the importance of agricultural land to the rodent community. Differences in rodent diversity between the two areas could be attributed to the availability of food and the heterogeneous environment in agricultural areas. While the factors causing lower diversity in the Forest Reserve are not yet understood, reduced food availability and competition with herbivores could be a contributing factor. Further work to understand the factors determining habitat preferences of species for conservation and ecosystem function is recommended.Keywords: Diversity, Kindoroko, North Pare Mountains, Rodents, Tanzani

Bird tolerance to humans in open tropical ecosystems

AbstractAnimal tolerance towards humans can be a key factor facilitating wildlife–human coexistence, yet traits predicting its direction and magnitude across tropical animals are poorly known. Using 10,249 observations for 842 bird species inhabiting open tropical ecosystems in Africa, South America, and Australia, we find that avian tolerance towards humans was lower (i.e., escape distance was longer) in rural rather than urban populations and in populations exposed to lower human disturbance (measured as human footprint index). In addition, larger species and species with larger clutches and enhanced flight ability are less tolerant to human approaches and escape distances increase when birds were approached during the wet season compared to the dry season and from longer starting distances. Identification of key factors affecting animal tolerance towards humans across large spatial and taxonomic scales may help us to better understand and predict the patterns of species distributions in the Anthropocene.</jats:p

Medicinal and commercial uses of ostrich products in Tanzania

Background Traditional communities have been utilizing animal products for numerous purposes and have for a long time contributed to the accumulation of world knowledge. Local people in Tanzania and elsewhere in Africa, have been using birds including ostriches as pets or their products such as meat, eggs as food; their body parts such as feathers, bones and hide for ornaments but more importantly have used such products in traditional medicine and rituals. Nevertheless, there is a general lack of information about the differences that exist between local people with different cultures, and the best use of such products to improve their livelihoods. This study aimed to determine the use of ostrich products among people residing around Serengeti National Park and explore the potential of improving livelihoods through game ranching. Methods Use of the products was compared between that of agriculturalists with long hunting traditions in the Serengeti District to the west of Serengeti National Park (SNP) and the largely pastoral community in the Ngorongoro District to the east by using semistructured questionnaires in June 2006. Results A total of 115 respondents were interviewed, and the majority (74.5%) in the Serengeti district admitted that ostriches were mainly hunted for their products by snares, while in the Ngorongoro district, 98.2% of the respondents said that villagers only gathered products such as feathers and eggs. Ostriches were hunted for food, ornamentation, medical and economic purposes, and eggs and oil, which are believed to have medicinal properties, were used for the treatment of various ailments, including asthma. This indigenous knowledge of the medicinal value of ostrich products must be integrated with scientific knowledge to prove the supposed medical efficacy of the products. Ostrich products also had market value and were thus sold to the villagers. Conclusion Since it has been found that ostrich products are commercially used, legal establishment of markets through game ranching, might improve local livelihood while simultaneously promoting the conservation of ostriches, whose populations are declining, by reducing hunting pressure. Ostrich farming and conservation education programs are recommended

Do Ostriches Struthio camelus reject parasitic eggs by making use of colour as a cue?

The Ostrich communal breeding system involves several females laying in a single nest. Only the ‘major’ female and the territorial male, however, provide parental care from incubation to fledging of chicks. Eggs are turned and displaced frequently upon the onset of incubation, and the major female evicts excess eggs out of the nest when the number of eggs is above a specific threshold level. A previous study indicated that the major female ostrich recognises her own eggs and selectively evicts eggs of minor females based on size, shape and shell texture. Our aim was to investigate if accepted and ejected eggs differ in colour characteristics. We quantified colour by measuring egg reflectance spectra, which were subsequently analysed using a visual model approach. Within clutches, there were no significant differences in colour between accepted and ejected eggs. These results suggest that female ostriches do not discriminate against foreign eggs based on deviations in colour.OSTRICH 2010, 81(3): 247–25

Responses of the Serengeti avifauna to long-term change in the environment

In this paper we examine how climate change interacts with other disturbances to alter the functioning of a tropical ecosystem, the Serengeti in Tanzania. Tropical Africa has increasing temperatures and changes in rainfall. Long-term data have shown how the avifauna responds to the interaction of environmental change with other disturbances: (1) habitat modification through agriculture by limiting endemic species and top trophic levels. Rare species are lost so this is a problem for conservation. Top trophic levels are lost and the lack of predators then releases pests. This is a problem for natural resource management. (2) Disease and hunting cause slow change in the species complex. This can alter community dynamics depending on which species enter or leave. (3) Habitat fragmentation or decay can cause slow change. When this reaches a threshold there may be rapid change in the species composition causing multiple states. One lesson is that present-day ecosystem states and trends can only be understood in the context of past historical events. Another is that all systems change so this requires a new approach to conservation. Within protected areas, new boundaries or new areas will be required. Outside rewilding is required to support more biodiversity.Keywords: agricultural disturbance, climate change, forest regeneration, fragile species, granivores, insectivores, raptors, resilient species, Serengeti avifaunaOSTRICH 2014, 85(1): 1–1

Bird community responses to changes in vegetation caused by increasing large mammal populations in the Serengeti woodlands

Context: The increase in density of large tree species, Vachellia robusta and V. tortilis, in the Serengeti Ecosystem of Tanzania has resulted in a decline of small tree species Senegalia senegal, V. hockii, Commiphora spp. This change has occurred since the late 1970s, a consequence of an increase in wildebeest following the extirpation of rinderpest, which reduced the dry grass fuel for fires, resulting in low fire frequencies. Change in tree species raises the question of whether there are indirect consequences for the avifauna that depend on the large trees for food and nesting. Aims: To determine how an increase in large mammals could influence diversity and distribution of avifauna communities in the Serengeti ecosystem woodlands. Methods: Data used to estimate changes in density of large and small trees were measured by Point Centre Quarter (PCQ). Bird species were recorded in 19 small-tree sites and 18 large-tree sites in the Serengeti National Park. Richness of bird guilds was calculated in the two habitat complexes (small and large trees), and the ‘rarefaction’ method was used to assess the difference in richness in habitats of the study area. Mean abundance for each species was calculated over the total number of sites for each habitat and compared using the Wilcoxon Rank Sum test to examine how the abundance of avifauna changes with each habitat type. Key results: There was an increase in the density of large trees in some areas in which they have replaced the original small trees. Such changes have resulted in greater richness of hole nesters and bark feeders, and a greater abundance of large-hole nesters and gleaner bird species. Conclusions: Because the increase in tree density was caused by an increase in large mammals, we conclude that this increasing mammal population is indirectly increasing richness and abundance of birds using the trees. Implications: Understanding the influence of large mammal populations on bird distributions has important conservation implications because the Serengeti ecosystem is classified as an important, endemic bird area