Breeding ecology of Kori Bustard Ardeotis kori strunthiunculus in the Serengeti National Park

The breeding ecology of the Kori Bustard Ardeotis kori strunthiunculus was studied in the plains of the Serengeti National Park, Tanzania in 2014 and 2015. Random transects were used to search for male courtship displays, nests, chicks and subadults. GPS satellite collars were used to locate nesting females. Linear regression analyses and post hoc tests were used to determine the predictors that contributed most to the variation of the dependent variables (courtship display, nest, chicks and subadults). The results indicate that courtship behaviour peaks during the short dry and short rainy season before the peaks in nests and chicks. The highest nest frequency was found in short grass habitats. Female Kori Bustard may undergo repeated nestings within a single breeding season. The adult sex ratio was female skewed during the breeding season. The Kori Bustard breeding season in the Serengeti plains is relatively long, lasting for almost nine months, and taking place during all seasons except for the long dry season. We recommend that management authorities conduct assessments of Kori Bustard recruitment as well as habitat suitability in the Serengeti ecosystem to develop future conservation strategies.     

Wildlife–water quality interactions in the Serengeti National Park, Tanzania

Surveys of water quality in the surface waters in the Serengeti National Park were undertaken in both the wet and dry seasons of 1996. Most rivers were ponded, with ponds having a flushing time of 1 month in the wet season and zero flushing in the dry season. pH values varied spatially from extremely alkaline conditions (pH>10) in the southern plains to acidic conditions in the northern region (pH=5·9). In the southern plains at the end of the dry season the salinity of surface waters was high (5–17‰) while there was abundant surface water and the zebras and wildebeest had started to migrate away, a finding suggesting excessive salinity may be the trigger initiating the annual migration. Most surface waters were heavily eutrophicated as a result of animal dung. As a result, the dissolved oxygen concentration near the surface fluctuated widely between 1 and 200% of saturation, smaller values occurring deeper in the water column. Stirring and mechanical aeration by hippos, crocodiles and mammals crossing the rivers prevented the formation of anoxic conditions. The oxygen stress was measurably lessened in wetland‐fringed water bodies as a result of filtering. Light penetration was high (≥10 cm) in saline waters as a result of flocculation enhanced by bacteria and vegetation detritus, elsewhere the euphotic zone was less than 1 cm thick and the waters generally inhospitable to aquatic life. The discontinuity between wooded savanna and grassland coincides with the occurrence of alkaline, high salinity waters in the dry season.     

Differences in Fecal Androgen Patterns of Breeding and Nonbreeding Kori Bustards (Ardeotis kori)

To better understand breeding conditions to promote reproduction in captive kori bustards, fundamental endocrine studies measuring fecal androgen metabolites in male and female kori bustards were conducted. Feces collected weekly from males and females were analyzed for testosterone using enzyme‐linked immunoassay. Results from adult males (n = 5), adult females (n = 10), immature males (n = 10), and immature females (n = 10) revealed seasonally elevated testosterone concentrations in fertile, but not nonfertile adult males and females (P > 0.05). Adult females that were not maintained in a breeding group, or that did not produce eggs, did not demonstrate increases in testosterone compared to egg laying counterparts. In males, but not females, seasonal testosterone increases were accompanied by weight gain. Peaks in male fecal androgen metabolites ranged from 10‐ to 22‐fold higher than nonbreeding season (181.5 ± 19.1 vs. 17.0 ± 0.94 ng/g; P < 0.05). Mean breeding season values for adult males were 83.6 ± 6.1 ng/g vs. nonbreeding season values of 12.3 ± 0.73 ng/g (P < 0.05). In females, average breeding season testosterone concentrations were approximately 4‐fold higher than nonbreeding season (55.9 ± 6.0 vs. 14.5 ± 1.8 ng/g), with peaks 10‐ to 30‐fold higher. Results show that noninvasive fecal androgen metabolite analysis can provide a means of predicting fertility potential of male and female kori bustards and might be utilized to assess effects of modifying captive environments to promote reproduction in this species. Zoo Biol. 32:54‐62, 2013. © 2012 Wiley Periodicals, Inc.     

The influence of wetlands in regulating water quality in the Seronera River,Serengeti National Park,Tanzania

The distribution of temperature, salinity, visibility and dissolved oxygen was sampled from 1996 to 2002 at sites along the Seronera River. The minimum temperature decreased with distance upstream. The salinity increased up-river where occasionally hypersaline conditions prevailed. Dissolved oxygen was highly variable spatially and temporally, depending on both the level of eutrophication by animal dung and the presence of wetlands that help filter the excess nutrients. During the study period, fringing, freshwater wetlands have generally been degraded and in some cases destroyed, and this has been accompanied by significantly decreased oxygen levels, sometimes nearing anoxic conditions. Also during this period, saltwater wetlands have increased, and since wildlife impacted these wetlands little, dissolved oxygen levels remained high throughout. Visibility was highest in areas fringed by wetlands.This revised version wa published online in March 2005 with corrections to the issue cover date.     

Factors influencing conservation attitudes of local people in Western Serengeti,Tanzania

Attitudinal studies are increasingly being adopted as tools for evaluating public understanding, acceptance and the impact of conservation interventions. The findings of these studies have been useful in guiding the policy interventions. Many factors affect conservation attitudes positively or negatively. The factors inspiring positive attitudes are likely to enhance the conservation objectives while those inducing negative attitudes may detrimentally undermine these objectives. The magnitude of the resultant effects of each particular factor is determined by the historical, political, ecological, socio-cultural and economic conditions and this may call for different management interventions. In this study we examined how conservation attitudes in western Serengeti are shaped by the following factors: level of conflicts with protected areas; wildlife imposed constraints (inadequate pasture, water, diseases, loss of livestock during migration, theft and depredation); participation in the community based project; and socio-demographic factors (age, education level, wealth, immigration, gender and household size). The results indicated that the level of conflicts, participation in the community based project, inadequate pasture, lack of water, diseases, wealth and education were important in shaping peoples’ attitudes. However, in a stepwise linear regression analysis, 59% of the variation in peoples’ attitudes was explained by three variables i.e., conflict level with protected areas, lack of water and participation in the community based project. In addition to these variables, level of education also contributed in explaining 51% of the variation in people’s attitude regarding the status of the game reserves. Five variables (lack of water, level of education, inadequate pasture, participation in the community based project and diseases) explained 12% of the variation in people’s attitude towards Serengeti National Park. The paper discusses the implications for conservation of these results and recommends some measures to realise effective conservation of wildlife resources.     

Breeding biology of ostriches (Struthio camelus) in the Serengeti ecosystem, Tanzania

Ostrich breeding behaviour in the Serengeti ecosystem, Tanzania was investigated for differences in laying dates between low altitude western area (WA) and high altitude eastern area (EA) populations. Ostriches in WA laid eggs significantly earlier than in EA. The differences could be attributed to topography and rainfall pattern. Reliable rains in lower altitudes ensure availability of food that in turn influences the whole process of the reproductive cycle. Clutches were contributed by several females with a nest having up to 38 eggs. We also compared the frequency of observation of predators, ostriches, nests, 'singletons' (single eggs laid randomly) and broods between the two areas. There was no significant difference between WA and EA in 1) ostrich/nest ratio, indicating similar breeding densities; 2) ostrich/predator and predator/nest ratios, indicating that predation pressure was equally high; 3) nest/singleton and predator/singleton ratios, indicating that loss of nests did not vary between areas. However, there were significantly more predators, nests and ostriches compared to broods in EA than in WA, indicating a significantly lower reproductive success in EA. Using metapopulation terminology, ostriches in EA could be regarded as a 'sink' population and those in WA as a 'source' population, but investigations over longer time-periods are needed to further resolve if this is the case.     

Revegetation of natural and human-caused disturbances in the Serengeti National Park,Tanzania

Patterns of revegetation on natural and human-caused disturbances in grasslands and savannas of the Serengeti National Park, Tanzania, were investigated by recording species compositions on all disturbances, in the undisturbed vegetation, and in unique microhabitats in 51 sites along a north-to-south transect through the park. The 487 resulting samples were ordinated by detrended correspondence analysis (DCA) and classified by two-way indicator species analysis (TWINSPAN). Natural disturbances were, in most cases, ordinated near or classified together with the climax sample from the same site but human-caused disturbances were classified separately. Human disturbances from all regions of the park were classified together in one group, while natural disturbances were divided into communities associated with different rainfall regimes. Natural disturbances were revegetated by species growing in the surrounding undisturbed communities while human-caused disturbances were revegetated by a set of ruderal species not found in the undisturbed communities nor in natural disturbances.Plant nomenclature follows Clayton a.o. (1970–1982) Flora of Tropical East Africa: Gramineae Parts 1–3, Nairobi for grasses and Agnew (1974), Upland Kenya Wildflowers, London for herbs and shrubs.This research was funded by a grant from the U.S. National Science Foundation (DEB-81-14306) and is Serengeti Research Institute Contribution #335.     

Rodent species diversity in relation to altitudinal gradient in Northern Serengeti,Tanzania

Rodents are among the successful small mammals in the world. In species richness, rodents outnumber other mammalian orders owing partly to their capability to exploit many different habitats. Their diversities have been influenced by many factors including the altitude. This study assessed rodent diversity across the two altitudinal zones, that is, lowland western zone and highland eastern zone, in the Serengeti ecosystem, Tanzania. Capture‐Mark‐Recapture studies were undertaken in November 2009 and April 2010 using live traps in the ecosystem to compare variations in species diversity of rodents in the two zones of the ecosystem. Eight (8) rodent species were recorded in each zone area. However, species richness was higher in crop land and woodland areas than in grasslands in each zone. The two zones comprised of different species diversities for which Rényi Diversity profiles indicated the higher diversity in the eastern zone than the western zone although the difference was not significant (P > 0.05). Differences between the eastern and western zones could be attributed to the altitudinal gradient whereby the east was at a higher elevation than the west. Maintenance and management of wildlife corridors will assist migration of rodents between the two zones and enhance continuous gene flow.     

Small-scale pattern in grassland communities in the Serengeti National Park,Tanzania

Small-scale community gradients and patterns in four grassland communities in the Serengeti National Park, Tanzania, were analyzed by detrended correspondence analysis (DCA) and percentage distance ordination (PD). The main goals of the study were (1) to describe the vegetation patterns in the communities, (2) to identify the potential underlying causes of the patterns, and (3) to rank the communities by their relative levels of patchiness. Species cover in a small number (16–32) of discontinuous plots was estimated and soils were collected. DCA successfully identified community gradients and phases of discrete mosaics, and PD identified the relative heterogeneity of the sites. Results suggested that the two most arid sites were composed of weakly or strongly differentiated vegetational mosaics and the two most mesic sites were essentially homogeneous. Termite modification of water infiltration properties of the soils and clonal growth of dominant species were identified as two factors possibly causing the mosaic vegetation patterns.     

Co-existence between the traditional societies and wildlife in western Serengeti, Tanzania: its relevancy in contemporary wildlife conservation efforts

This paper seeks to show how the traditional societies in western Serengeti have coexisted and continue to coexist with wildlife. It also recognizes the relevancy of this coexistence in furthering contemporary conservation efforts although there are practical constraints to putting this into practice. The following questions are examined: (1) How did/do traditional societies in Serengeti interact with their nature? (2) Which traditional management institutions governed/govern interaction between people and wildlife species, resources and ecosystems and, how do they operate? (3) Which factors were (or are) responsible for erosion of traditional management institutions? (4) What can the traditional practices offer to contemporary conservation efforts and what are the limitations? The paper identifies four ways in which traditional institutions and practices can contribute to current conservation efforts: regulating the overexploitation of resources; complementing the current incentives aiming at diffusing prevailing conflicts between conservation authorities and communities; minimising the costs of law enforcement and; complementing the modern scientific knowledge in monitoring and responding to ecosystem processes and functions. The practical constraints likely to limit adoption of these practices are presented as: methodological complications of acquiring indigenous knowledge; prevailing historical conflicts; human population growth; poverty and lack of appreciation among the conservation planners and managers. In conclusion the need to address the current constraints in order to achieve effective taping of the existing potentials is emphasized.     

Forb diversity and community similarity of kopjes in the Serengeti National Park, Tanzania

The forb communities of kopjes (rock outcrops) in the Simba, Maasai and Loliondo areas of the Serengeti National Park were examined to determine differences in species composition from surrounding grassland communities, and among sites within kopje and grassland communities. Species diversity measures and multivariate ordination techniques were used to examine the community similarity and species turnover between sites. All measures of forb species diversity were higher on the kopje sites with the exception of one grassland site, and the community composition significantly differed between these two habitat types, with more species and families exclusive to the kopje habitat. Species turnover was very high in grassland habitats, with two of the three areas (Simba and Loliondo) exhibiting a complete change in species composition. Kopjes, on the other hand, had remarkably similar forb communities, suggesting that the populations of the species present on these rock outcrops form patch structures. The distinct flora and higher diversity of kopje forbs raise interesting questions regarding distribution, dispersal and patch dynamics.     

The influence of fire frequency on the abundance of Maerua subcordata in the Serengeti National Park,Tanzania

Aims Invasive species alter the composition and function of communities, threatening the conservation of important ecosystems worldwide. In savanna ecosystems, fire plays a key role by modifying biogeochemical cycles and shaping the composition and structure of vegetation communities. Although many studies have examined the long-term effects of fire frequency on grassland communities, few studies have examined the relationship between fire regime and woody species invasions.Methods The Serengeti ecosystem is an ecologically and economically valuable natural resource in East Africa whose conservation is currently threatened by a variety of factors, including invasive species. We determined the abundance of Maerua subcordata, a noxious woody shrub, in three different regions of the Serengeti National Park, Tanzania. We then examined the influence of fire frequency, developed through the use of 7 years of Moderate Resolution Imaging Spectroradiometer (MODIS) imagery, on M. subcordata abundance.Important findings In all regions, burned transects had significantly greater abundances of M. subcordata compared to unburned transects. Furthermore, the number of times each transect burned from 2000 to 2006 had a significant positive effect on the abundance of M. subcordata and the number of years since a transect last burned had a significant negative relationship with abundance. These results are particularly important as this species provides little forage value and is potentially toxic to wildlife and cattle. Additional studies are needed to determine the ecological consequences of increasing M. subcordata abundance, as the potential expansion of noxious shrubs into protected areas of important conservation status is of serious concern.     

Abundance and diversity of rodents at the human–wildlife interface in Western Serengeti, Tanzania

Rodent species abundance and diversity in Western Serengeti are evaluated and discussed in relation to different levels of conservation status [Unprotected Area (UA), Game Reserve (GR) and National Park (NP)] and broad site differences in human livelihood activities. A total of 2170 individuals, spread over 16 rodent species, were caught in a capture‐mark‐recapture study which covered both the dry and wet seasons. The more humid site (Tabora B) in the northern part of Serengeti had the highest diversity of rodents followed by the Mihale site at the western extension. The driest site at Robanda had the lowest overall species diversity. Diversity also varied between the three levels of conservation status whereby the UA had the least diversity while the NP, which enjoyed the highest level of conservation status, had the highest diversity of rodents. Unprotected Area and NP plots at Tabora B showed a rodent species similarity index of 40%; all the other paired plots scored over 50% similarity indices, suggesting that, within a site, species composition did not vary significantly between the three levels of conservation status. The Robanda site had the highest (56%) overall abundance of rodents; Mihale and Tabora B sites had about the same level of rodent abundance (20 and 24% respectively). For the Mihale site, Mastomys natalensis ranked first followed by Arvicanthis niloticus and Tatera robusta, each of which contained 40, 38 and 16%, respectively, of all individuals caught at the site. For the Robanda site, the figures were 66%A. niloticus, 22%M. natalensis and 9%T. robusta; while for the Tabora B site the scores were 37%M. natalensis, 18%T. robusta and 11%Lemniscomys barbarus. The differences in diversity, species composition and population abundance appear to result largely from physiognomic vegetation types, and habitat perturbations caused by livelihood activities in Western Serengeti.     

The poultry thief: Subsistence farmers' perceptions of depredation outside the Serengeti National Park,Tanzania

Improving the understanding of human–carnivore conflicts is fundamental for the effective management of interventions. However, earlier research has largely focused on conflicts caused by top carnivores, and there is a general lack of knowledge about the drivers behind conflicts caused by smaller carnivores. Here, we investigated the characteristics and spatial patterns of perceived predators that caused losses of poultry. We used a structured interview of 481 households across seven villages outside Serengeti National Park, Tanzania. Most households kept poultry and livestock, and 48.4% of all households perceived to have lost poultry to predators, but it was unrelated to perceived livestock depredation. On average, predators killed almost one‐third of the poultry kept by each household, which is equivalent to an average annual economic loss of US $14.5 ± 18.6, or 10.4% of the cash income. Economic dependency did not influence the likelihood of perceiving depredation. The most parsimonious linear mixed‐effects model showed that the probability of claiming losses to predators increased with increasing flock sizes and distance to the nearest protected area. We discuss our findings in relation to the current interest in rural poultry production shown by conservation programmes in Africa.     

Microsatellite loci for the plains topminnow (Fundulus sciadicus,Fundulidae)

The plains topminnow (Fundulus sciadicus) is a killifish endemic to the Great Plains region. Recent field surveys indicate that populations may be declining in northerly portions of its range and perhaps throughout. Here, we describe the isolation and characterization of 11 microsatellite loci developed for population genetic studies in the species. We also conducted cross‐species amplifications to test primer efficacy in five additional taxa, including four killifishes.     

Disturbance,species loss and compensation: Wildfire and grazing effects on the avian community and its food supply in the Serengeti Ecosystem,Tanzania

An important question in biodiversity studies is whether disturbances in ecosystems will cause a net loss of species or whether such losses can be compensated by replacement of other species. We use two natural disturbances, fire and grazing, to examine the response of bird and arthropod communities in grasslands of Serengeti, Tanzania. Both burning and grazing by migrant ungulates take place at the end of the rains in June–July. We documented the communities before disturbance, then 1, 4 and 20 weeks after disturbance on three replicate plots and compared them with three undisturbed plots. Birds were recorded by observation, arthropods from pitfall, tray trap and sweepnet samples. We expected that as the grass biomass was reduced by either disturbance, bird communities would change with concomitant change in arthropod food abundance. Alternatively, bird communities would change not with the absolute amount of food but with the greater accessibility of food as the grass structure changed from long to short grass. Results showed first that both bird species richness and abundance increased after both types of disturbance, but burnt sites showed a greater increase than that for grazed sites. Second, there was a change in bird species composition with disturbance. The functionally equivalent athi short‐toed lark (Calandrella athensis) was replaced by the red‐capped lark (Calandrella cinerea). Third, the abundance of most groups of arthropods was lower on disturbed sites than those on undisturbed sites, and the reduction of arthropod numbers was greatest on burnt sites. These results imply that bird abundance did not occur through an increase in arthropod abundance but rather through a change in the grass structure making food more accessible; and the higher predation could have caused the lower arthropod abundance. In addition, some bird species replaced others thus functionally compensating for their loss.     

新疆木垒波斑鸨的繁殖成功率

作者于 1998～ 2 0 0 0年 4～ 7月 ,采用野外直接观察、栖息地植被样方调查和无线电跟踪等方法对分布于新疆木垒的波斑鸨 (Chlamydotiundulatamacqueenii)种群的繁殖生态进行了初步观察与研究。考察中共发现45个巢、 84窝幼雏。研究结果表明 ,木垒波斑鸨有两个产卵高峰期 ,表明雌鸟第一次繁殖失败后可能再次产卵。雌鸟营巢成功率平均为 0 5 0 5。波斑鸨的窝卵数在 2～ 6枚之间 ,出现 4枚卵的频率最高。第一产卵期内的平均窝卵数 ( 4 0± 0 8枚 /窝 )大于第二产卵期内的平均窝卵数 ( 3 3± 0 8枚 /窝 )。木垒波斑鸨种群三年间卵孵化率分别为 0 84、 0 80和 1,繁殖成功率为 0 45 6。种群在繁殖期几乎不受人类活动干扰 ,巢卵及幼雏损失主要来自天敌捕食 ,如沙狐、大和棕尾等.     

湘北烟区烟青虫发生情况研究

烟青虫在湘北烟区1年发生5代,第一至四代危害烟草,第五代在其他作物上取食。自然条件下,世代重叠比较明显,幼虫发生与危害最大的是第一代,危害时期是5月下旬至6月下旬,同时,还得出了烟青虫各代的发生期、历期及其发育起点温度和有效积温。