West Usambara Research Articles

Predicting small mammal and flea abundance using landform and soil properties in a plague endemic area in Lushoto District, Tanzania.

Small mammals particularly rodents, are considered the primary natural hosts of plague. Literature suggests that plague persistence in natural foci has a root cause in soils. The objective of this study was to investigate the relationship between on the one hand landforms and associated soil properties, and on the other hand small mammals and fleas in West Usambara Mountains in Tanzania, a plague endemic area. Standard field survey methods coupled with Geographical Information System (GIS) technique were used to examine landform and soils characteristics. Soil samples were analysed in the laboratory for physico-chemical properties. Small mammals were trapped on pre-established landform positions and identified to genus/species level. Fleas were removed from the trapped small mammals and counted. Exploration of landform and soil data was done using ArcGIS Toolbox functions and descriptive statistical analysis. The relationships between landforms, soils, small mammals and fleas were established by generalised linear regression model (GLM) operated in R statistics software. Results show that landforms and soils influence the abundance of small mammals and fleas and their spatial distribution. The abundance of small mammals and fleas increased with increase in elevation. Small mammal species richness also increases with elevation. A landform-soil model shows that available phosphorus, slope aspect and elevation were statistically significant predictors explaining richness and abundance of small mammals. Fleas' abundance and spatial distribution were influenced by hill-shade, available phosphorus and base saturation. The study suggests that landforms and soils have a strong influence on the richness and evenness of small mammals and their fleas' abundance hence could be used to explain plague dynamics in the area.

Vegetation Response to Climate Change and Human Impacts in the Usambara Mountains

East and West Usambara Mountain blocks are unique based on three characteristics. Firstly, they are connected blocks; secondly, they have an oceanic-influenced climate; and thirdly, the rain seasons are not easily discernible due to their close proximity to the Indian Ocean and Equator. Sediment cores were collected from peat bogs in Derema (DRM) and Mbomole (MBML) in East Usambara and from Madumu (DUMU) in West Usambara. The multiproxy record provides an understanding on climate and vegetation changes during the last 5000 years. DRM and MBML cores result in radiocarbon ages and age-depth curve which showed hiatus at 20 cm and 61 cm and huge inversion for DUMU core at 57 cm. Period 5000–4000 14C yr BP for DUMU core revealed increased Montane forest indicative of relatively moist conditions. Periods 3000–2000 and 2000–1000 14C yr BP, DUMU core demonstrated increased submontane and lowland forests. Period 1000–200 14C yr BP, DUMU core signified increased coprophilous fungi while DRM and MBML cores signified fluctuating herbaceous pollen spectra (wet-dry episodes). Period 200 14C yr BP to present, all cores demonstrated stable recovery of forest types especially dominance of submontane forests. Abundant coprophilous fungi indicated increased human impacts including forest fires, cultivation, and grazing.

Distribution and genetic diversity of the Endangered Abbott’s duiker Cephalophus spadix in the Udzungwa Mountains, Tanzania

Abbott's duiker Cephalophus spadix is a forest antelope endemic to a very few high- land forests in Tanzania. Apparently extinct over much of its historical range, the species is listed as Endangered by the International Union for Conservation of Nature based on its rarity and its known current distribution in only 5 isolated upland areas: Kilimanjaro, Southern Highlands, West Usambara, Rubeho and Udzungwa Mountains. In contrast to the situation in the rest of its range, Abbott's duiker is relatively well documented and locally abundant in parts of the Udzungwa Mountains, which may now be the only stronghold for the species. We review the distribution of Abbott's duiker within the Udzungwa Mountains and present new information based on the non- invasive genetic identification of dung piles collected from the majority of forest blocks between 2006 and 2010 (73 confirmed dung samples). Our results include new records from outlying forest blocks where the presence of Abbott's duiker was previously unknown. Moreover, we present the first population-level analysis of genetic structure and diversity in this endangered species based on nuclear microsatellites and mitochondrial sequence data. While these genetic results are lim- ited due to small sample sizes, they indicate differentiation from other Abbott's duiker popula- tions, as well as low genetic diversity relative to sympatric antelope species. Finally, we discuss threats to Abbott's duiker and identify broad trends within the differently managed Udzungwa Mountain forests, and elsewhere, that suggest potentially successful conservation strategies for this neglected species.

Ecological correlates of vulnerability to fragmentation among Afrotropical terrestrial small mammals in northeast Tanzania

Understanding ecological traits of species associated with vulnerability to habitat fragmentation is important for the development of effective conservation efforts. However, few studies have examined ecological correlates of vulnerability to fragmentation among tropical small mammals at fine spatial scales. Here we use random forests and regression tree models to identify ecological correlates of vulnerability to fragmentation among terrestrial small mammal species across 2 networks of forest fragments in the East and West Usambara Mountains, Tanzania. Small mammal species vary considerably in their vulnerability to fragmentation as assessed by species occupancy and change in abundance. Random forests models indicate that matrix use is the highest-ranked predictor of vulnerability to fragmentation with small mammal species that do not use or use few matrix habitat types, being more vulnerable to fragmentation than species that use all adjacent matrix habitat types. Our results emphasize the importance of local-scale approaches for designing conservation strategies for Afrotropical small mammal species.

Effectiveness of sustainable land management measures in West Usambara highlands, Tanzania

Soil erosion is a serious problem that affects food security and social livelihoods in the highlands of East Africa. Sustainable land management (SLM) measures have been widely promoted to reduce erosion and increase crop yield, but the adoption of SLM measures has remained low. In order to understand the contribution of biophysical factors on adoption, this study was carried out to (i) determine the biophysical conditions of fields with SLM measures; (ii) assess the impact of different SLM measures on soil degradation; and (iii) determine the effects of SLM measures on crop productivity. The study was conducted in Lushoto District, north-eastern Tanzania. Sixty fields with five different SLM categories were studied. The five SLM categories ranged from no intervention at all (SLM 5 — control plots), to excellent land and crop management, including well-constructed bench terraces and application of farmyard manure (SLM 1). SLM 2 also has terraces, but the management is not as good as for SLM 1. SLM 3 has some poorly maintained terraces or grass trips, while SLM 4 has only poorly maintained grass strips. The bio-physical properties of the fields were determined, and measurements of meteorology, soil properties, soil erosion and crop yield were carried out during the period October 2009–June 2011. The results showed that the better SLM categories (SLM 1 and SLM 2) are preferentially implemented on less steep slopes, and they do stabilize the slope and reduce soil losses by water erosion significantly. The use of high amounts of farmyard manure (>6.0tonha−1y−1) on the terraces of SLM 1 and SLM 2 category fields resulted in a 3 to 4 times higher yield of maize compared to the control plots (SLM 5), while yield of beans increased 6 to 7 times compared to the control plots. Despite the use of farmyard manure on better managed fields, no significant improvements of soil fertility were found. This is probably because the amounts applied are too small to allow build-up of soil nutrients.

Annotated list of Tettigoniidae (Orthoptera) from the East Usambara Mountains, Tanzania and new Tettigoniidae species from East Africa.

A list of the Tettigoniidae (Orthoptera) of the East Usambara Mountains is presented and 16 new species are described from East Africa. A total number of 29 Tettigoniidae species is recorded for the East Usambara Mountains. New species are described from the Shimba Hills in Kenya, coastal Tanzania from the Kazimzumbwi forest reserve, Mt Kilimanjaro, the East and West Usambara and Uluguru Mountains in Tanzania, namely in Conocephalinae Afroagraecia pwania n. sp., Afroagraecia shimbaensis n. sp., Afroanthracites discolor n. sp., Afroanthracites jagoi n. sp. and Afroanthracites viridis n. sp., in Meconematinae Afrophisis flagellata n. sp., Afrophisis kisarawe n. sp., Afrophisis mazumbaiensis n. sp. and Afrophisis pseudoflagellata n. sp., in Hexacentrinae Aerotegmina megaloptera n. sp., in Mecopodinae Apteroscirtus cristatus n. sp., and A. planidorsatus n. sp., in Phaneropterinae Gelotopoia amabilis n. sp., and in Pseudophyllinae Cymatomerella pardopunctata n. sp. and Cymatomera viridimaculata n. sp. Seven species are endemic to the East Usambara Mountains which are 25% of the recorded forest-bound bush crickets. The Tettigoniidae fauna is compared between the East Usambara Mountains and Mt Kilimanjaro and mechanisms of speciation discussed in Orthoptera for the area. New Tettigoniidae records are given for Mt Kilimanjaro (Oxyecous apertus Ragge, Tropidonotacris grandis Ragge and Eurycorypha conclusa Hemp).

A new species of Colosmittia Andersen et Sæther from Costa Rica (Chironomidae: Orthocladiinae)

Colosmittia anamariae sp. n. from Costa Rica is described and figured as male imago. The genus Colosmittia Andersen et Sæther, 1994 was described based on a single species, C. clavata Andersen et Sæther, 1994 from the West Usambara Mountains in Tanzania, East Africa. A second species, C. brasileira Mendes et Andersen, 2009 was recently described from Brazil. The discovery of a third species in Costa Rica indicates that the genus might be widespread in the Neotropical region.

Small Mammal Inventories in the East and West Usambara Mountains, Tanzania. 1. Study Areas, Methodologies, and General Results

The Eastern Arc Mountains of southeastern Kenya and Tanzania hold a rich and unique biodiversity. The most celebrated of these mountains are the East and West Usambaras. Although these massifs have been the subjects of biological study for over a century, little is known about the shrews, bats, and rodents occurring in the montane forests. Using pitfall buckets, small mammal traps, and mist-nets, between 1991 and 1993, we surveyed the small mammals in the Amani area in the East Usambara and Ambangulu area in the West Usambara to document the natural history of the local fauna. These surveys were conducted during the dry season annually between early July and early September.In this chapter, we outline the study sites, methodologies, capture rates, and other trapping details. A total of 18,563 sample-nights was accrued over the three-year study, and on these two massifs, we documented 12 crocidurine shrew, one macroscelidid elephant shrew, 19 bat, and 14 rodent species. Species accumulation curves suggest that additional trapping effort may be required in the East Usambara Mountains to have a more complete view of the local small mammal fauna. There was no significant difference in the number of individuals captured or measures of species diversity in the pitfall and trap lines that were installed in the same location during the course of this study, suggesting that repeated sampling did not negatively affect the small mammal fauna of the study areas.

Small Mammal Inventories in the East and West Usambara and South Pare Mountains, Tanzania. 3. Chiroptera

Whereas the terrestrial mammal fauna of the East and West Usambara Mountains have been the subject of numerous investigations, the local bat fauna remains poorly documented, as is the case for bats of the South Pare Mountains. During mammal surveys of these three massifs, we used mist nets to collect local bats, documenting 20 bat species in total.In the Usambara Mountains, 161 individual bats representing 19 species were documented during the three years of the survey between 1991 and 1993. In the East and West Usambara Mountains, 17 and 12 species, respectively, were recorded. Most animals were taken in net sets placed outside or at the edge of forested habitats. In the South Pare Mountains, 67 bats representing six species were collected during the two surveys, including 62 bats of six species at 1100 m (surveyed 17–29 July 1993) and five bats representing three species at 2000 m (surveyed 19–28 August 2004). Based on our morphological studies, no evidence of undescribed taxa in these collections exists.Species common across all three massifs include two pteropodids (Epomophorus wahlbergi and Lissonycteris angolensis), one rhinolophid (Rhinolophus clivosus), and one vespertilionid (Neoromicia capensis). Taxa only captured on a single massif include Rousettus lanosus and Rhinolophus simulator (South Pare, 10% of total captures), Myonycteris relicta and Nycteris thebaica (West Usambara, 10% of total captures), and Rousettus aegyptiacus, Rhinolophus deckenii, R. fumigatus, R. swinnyi, Nycteris grandis, Myotis bocagei, and Scotophilus viridis (East Usambara, 35% of total captures).Comparisons of capture rates and species richness between these three montane sites to more lowland forest sites indicate a notable reduction in species richness and density with increasing elevation. Our preliminary surveys are at best rough estimates of patterns of species diversity and richness in the montane portions of these massifs; more fieldwork and associated taxonomic work are clearly needed to have more in-depth knowledge of the local bat fauna.

Herpetofauna of Montane Areas of Tanzania. 3. Amphibian Diversity in the Northwestern Eastern Arc Mountains, with the Description of a New Species of Arthroleptis (Anura: Arthroleptidae)

Amphibians of the Eastern Arc Mountains are poorly known, apart from those of the East Usambara, Uluguru, and Udzungwa Mountains. Here, we detail specimens collected in the northwestern Eastern Arc Mountains (West Usambara, South Pare, and North Pare) over the past 100 years. Although not comprehensive, the list is compiled from specimens held at institutions in Europe and the United States and in personal collections; it includes most of the specimens known from this area. From these specimens, we describe one new species of the frog genus Arthroleptis and discuss other specimens that may represent new species. We add substantially to the known diversity in these areas. Using the compiled species list, we assess species diversity and relate the differences to sampling bias and possible biogeographic differences among the mountains. The future preservation of amphibians across this area is of concern given the increasing loss of forest.

Small Mammal Inventories in the East and West Usambara Mountains, Tanzania. 4. Rodentia

During three field seasons between 1991 and 1993, we carried out rodent inventories of the East and West Usambara Mountains, Tanzania. The general trapping protocol used involved both pitfall lines and trap lines (Sherman, Victor, and Museum Special traps), with a limited number of animals trapped within and outside of forest habitats by local people. A total of 885 individual rodents, representing 15 species, were collected during this study. For the East and West Usambara Mountains, 13 (12 native) and 12 (all native) rodent species were recorded, respectively. Most rodents were captured by trap lines (96.6%); a few individuals were captured in the pitfall devices or brought to us by local people. The major exception is that all individuals of Dendromus (n = 11) obtained during the survey were in pitfall buckets.A total of 18,563 sample-nights were accrued over the three years, including 11,339 sample-nights (3314 pitfall-nights and 8025 trap-nights) in the East Usambara and 7224 sample-nights (1924 pitfall-nights and 5300 trap-nights) in the West Usambara Mountains. Based on species accumulation curves, no previously unrecorded species was trapped after 11,064 sample-nights in the East Usambara and after 5213 sample-nights in the West Usambara. However, a previously untrapped rodent (Graphiurus kelleni) was captured in the East Usambara on the third-to-last of 59 sampling days, suggesting that other non-canopy–restricted rodent species may have been missed during this survey. In a series of species accounts, information regarding the natural history of the different taxa handled during these surveys, including distribution, ecology, and condition of sexual organs, a list of referable specimens, and the trap devices that collected them, are presented.Trap and bucket lines combine to effectively sample most small- to medium-sized rodents. However, larger scansorial and canopy-restricted (squirrel) and fossorial (mole rat) species were not captured with our trapping methods, and these tabulations should not be considered a complete list of the small mammals of the Usambaras.

Small Mammal Inventories in the East and West Usambara Mountains, Tanzania. 2. Families Soricidae (Shrews) and Macroscelididae (Elephant Shrews)

Abstract Field surveys conducted in the montane forests of the East and West Usambara Mountains between 1991 and 1993 provide data on the species of shrews (Family Soricidae, Subfamily Crocidurinae) and elephant shrews (Family Macroscelididae). In total, 11 species of crocidurine shrew and one elephant shrew were documented on the Usambara Mountains, which include 10 shrew and one elephant shrew species for the East Usambara, and six species of shrew and one elephant shrew in the West Usambara. Information is presented on the captured animals regarding their natural history, distribution, ecology, and reproduction, as well as external and cranio-dental measurements. Species richness and different levels of endemism between the insectivorous small mammal faunas of tropical Africa and Madagascar are compared.

Description of the tadpole of Amietophrynus brauni (Anura: Bufonidae) from the West Usambara Mountains, Tanzania

The tadpole of Amietophrynus brauni (Anura: Bufonidae), endemic to the forests of the Eastern Arc Mountains of Tanzania, is barcoded using 16S rRNA and described from the West Usambara Mountains. It differs from tadpoles of A. maculatus by its body proportions, A. garmani and A. xeros by its smaller size, and A. gutturalis by its colour pattern. Body proportions were examined across Gosner stages, revealing that most remain relatively constant across development; however, internarial distance/narial diameter fluctuates dramatically and should not be used in the identification of Amietophrynus tadpoles.

The agrarian question in Tanzania: using new evidence to reconcile an old debate

Rural poverty continues to be one of the most trenchant development problems in Tanzania, and yet no comprehensive solution has been found. In this paper it is argued that without a fundamental understanding of the agrarian question, any attempt to derive meaningful conclusions on rural development is doomed to be incomprehensive and incomplete. The paper traces back the roots of this important scholarly exchange of the late nineteenth and early twentieth century, as well as summarising the resulting debate mainly between the neo-populist school and Marxian political economy. It then goes on to outline how this original understanding of the agrarian question extended to and influenced the contemporary rural development discourse, which however widely misrepresented the original contributions and created an illustrious array of antagonistic and inconclusive approaches that culminated in the recent World Development Report 2008: Agriculture for development. This theoretical discussion is framed and exemplified by the case of rural development, labour market participation and poverty in the West Usambara Mountains, Tanzania. Primary survey data collected by the author in 2008 is employed to analyse the current state of the farmers, their engagement in labour markets as well as ongoing processes of class differentiation. Returning to the initial debate, an attempt to link these current realities with the overall outlook for Tanzanian development is provided.

Gender and socio-economic factors influencing domestication of indigenous medicinal plants in the West Usambara Mountains, northern Tanzania

The limited capacity of governments in developing countries to service primary health care has resulted in a rapid increase in use of indigenous medicinal plants. This increase, together with other biological and non-biological factors, has rendered these plants vulnerable to over-use and extirpation. Domestication is a conservation intervention that can relieve pressure on medicinal species. In order to ensure effectiveness and sustainability of an intervention, understanding the influencing factors is imperative. We examined the influence of gender and some socio-economic factors on domestication of medicinal plants in the West Usambara Mountains of northern Tanzania. Participatory wealth ranking, structured and semi-structured interviews, botanical surveys and participant observations were employed in data collection. Results showed that domestication has played a fundamental role in conservation of medicinal plants in the study area. Forty (89%) and twelve (27%) of forty-five indigenous plant species were domesticated on farms and around homesteads, respectively. A total of 89% of respondents (n = 173) had domesticated medicinal plants on their farms and around homesteads. Gender was the most important factor that influenced this practice, with more male-headed than female-headed households involved in the domestication effort. This can be attributed to social and cultural factors that, besides dispossessing women of tenure rights over resources and land, also subject them to heavy workloads and therefore diminish the time available for plant domestication. The number of domesticated medicinal plants also depended on age, affluence, farm size, household size and ethnicity. We recommend that agroforestry research should focus not only on integrating forest plants in farmlands, but also on cultural, socio-economic and institutional aspects affecting the whole system of domestication.

Availability, Preference, and Consumption of Indigenous Forest Foods in the Eastern Arc Mountains, Tanzania

We investigated the availability, preference, and consumption of indigenous forest foods in Uluguru North (UNM) and West Usambara Mountains (WUM) of Tanzania. Data collection techniques involved focus group discussion, structured questionnaires, and botanical identification. Results revealed (1) there were 114 indigenous forest food plant species representing 57 families used by communities living adjacent to the two mountains; (2) sixty-seven species supplied edible fruits, nuts and seeds: 24 and 14 species came from WUM and UNM, respectively, while 29 came from both study areas; (3) of the 57 identified vegetable species, 22 were found in WUM only, 13 in UNM only, and 12 in both areas; (4) there were three species of edible mushrooms and five species of roots and tubers; (5) unlike the indigenous roots and tubers, the preference and consumption of indigenous vegetables, nuts, and seeds/oils was higher than exotic species in both study areas; and (6) UNM had more indigenous fruits compared to WUM, although preference and consumption was higher in WUM. We recommend increased research attention on forest foods to quantify their contribution to household food security and ensure their sustainability.

Ranging behavior and habitat selection of terrestrial insectivorous birds in north‐east Tanzania: implications for corridor design in the Eastern Arc Mountains

AbstractUnderstanding the ranging behavior and habitat selection of understory tropical birds is important for corridor design and enhancing functional connectivity in fragmented tropical landscapes. Here we report on the ranging behavior and habitat selection of three terrestrial insectivorous bird species, the spot‐throat Modulatrix stictigula, Usambara thrush Turdus roehli and orange ground thrush Zoothera gurneyi, in the East (EUM) and West (WUM) Usambara Mountains in north‐east Tanzania. Based on 5945 locations and 3676 bird radio‐tracking hours conducted between 2001 and 2008 at four study sites in the EUM and WUM, we determined that the 95% kernel home range and 50% kernel core range for the spot‐throat, Usambara thrush, and orange ground thrush are similar yet large (aggregate mean home range=10.3±1.1 ha; aggregate mean core range 1.5±0.4 ha); that these species are adverse to crossing non‐forested openings – no bird was recorded over the course of the study to cross a non‐forested opening >15 m; and that the most extinction‐prone species in our study system, the spot‐throat and Usambara thrush, preferentially used slightly disturbed and primary forest, respectively. These results indicate that maintaining continuous forest cover and minimizing forest disturbance in corridors in the Eastern Arc Mountains is important for enhancing their habitat suitability for these species.

A new genus of African Karniellina (Orthoptera, Tettigoniidae, Conocephalinae, Conocephalini): integrating morphological, molecular and bioacoustical data

Melanoscirtes gen.n. is established within Karniellina. The members of this subtribe are small conocephaline bush crickets, confined to Africa. Melanoscirtes is erected on Phlesirtes kibonotensis, a species restricted to forest clearings and forest edge in the submontane and montane zones of Mt. Kilimanjaro. A subspecies, M. kibonotensis uguenoensis, is described from the North Pare mountains, a mountain range of the Eastern Arc adjacent to Mt. Kilimanjaro. Further species of Melanoscirtes occur on other mountain ranges of the northern branch of the Eastern Arc mountains of northern Tanzania and southern Kenya. The South Pare mountains harbour M. shengenae; the West Usambaras, M. usambarensis, and the Taita Hills, M. taitensis. All species and subspecies of Melanoscirtes exhibit a similar morphology and occupy analogous habitats on the respective mountains. The song patterns for all species found within this genus are very similar, and this, together with evidence from molecular data, suggests that allopatric speciation is the reason for the biogeographic pattern found in this genus. A key for the subspecies and species of Melanoscirtes is provided.

A Revision of Afrotropical Quasimodo Flies (Diptera: Curtonotidae: Schizophora). Part II — The East African Afromontane GenusTigrisomyiagen. n., with Descriptions of Four New Species

A new East Africa genus, Tigrisomyia Kirk-Spriggs gen. n., is described; being apparently restricted to high-elevation Afromontane forests associated with the Malawi Rift and Eastern Arc mountain group of Kenya and Tanzania. A diagnosis of the genus is provided and character states (synapomorphies) distinguishing the genus from other genera in the Curtonotidae are outlined. Four new species are described; and are illustrated using pen and ink drawings and light microscopy, namely T. amnoni Kirk-Spriggs, sp. n. (Malawi, Tanzania and Zambia), T. kinskii Kirk-Spriggs, sp. n. (Malawi), T. rhayaderi Kirk-Spriggs, sp. n. (Kenya and Malawi) and T. scoliosis Kirk-Spriggs, sp. n. (Tanzania); the first-named species being designated as type-species for the genus. An identification key to the four species is provided based on external characters. The distribution of the four species is mapped, indicating that T. rhayaderi sp. n. has a disjunct distribution on the Zomba Plateau (Malawi) and coastal forests of Kenya; T. kinskii sp. n. is apparently restricted to Ntchisi Forest (Malawi), and T. kinskii sp. n. to the Rebeho (Usagara) Mountains in the Eastern Arc group. Tigrisomyia amnoni sp. n. is more widely distributed occurring from the West Usambara Mountains in the north of Tanzania to the Zomba Plateau in the Shire District of southern Malawi (and some intervening relict forests). The historical biogeographical significance of the distribution of the four species is discussed in relation to historical pan-African forest cover in Africa.

First record of the genus Colosmittia Andersen & Sæther (Chironomidae: Orthocladiinae) from the Neotropical region

Colosmittia brasileira sp. n. from São Paulo state, Brazil, is described and illustrated based on a male imago. The genus Colosmittia Andersen & Saether was described based on a single species, C. clavata Andersen & Saether, from the West Usambara Mountains, Tanzania, East Africa. The discovery of the new species shows that Colosmittia has an Afro-Brazilian distribution pattern.