Research Repository :: Browsing by Author "John, J.R."

Browsing by Author "John, J.R."

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Avian Flight Heights across Power lines in Dar es Salaam.
(Tanzania Wildlife Research Institute (TAWIRI), 2015) John, J.R.
In recent years, Africa has experienced an increase in power generation projects. However, such development projects come with negative side effects on the environment. For example, electrocution and collision with power lines have become among the causes of mortality to populations of large terrestrial birds. Many species of birds are especially vulnerable to collision with high voltage transmission lines because of the height of these structures with respect to birds’ flight altitudes. Despite the increased power lines networks, there have been very little studies on the flight heights of birds in relation to power lines. From December to February 2015, we studied flight heights of local birds as they commuted across low (LVP, 33KV) and high (HVP, 132KV) voltage power lines in Dar es Salaam. In additional to avian flight heights, we also studied their behaviours as they approached the power lines. The two power lines had different heights from the ground (13 m versus 24 m) but we targeted birds that passed between 13 5 m and 24 5 m recording whether a bird passed below, between or above electric cables. Using the abundance of birds that crossed the power lines, we found no preferred flight heights at LVP and HVP although all egrets passed above the cables. Changing of flight heights as birds approached power lines was recorded only for egrets whereas collision was observed for Indian House Crow and House Sparrow. We recommend that before any installation or erection of power lines, investigation on birds’ routes to and from roosts and foraging sites must be conducted first. Use of underground connections and wire-marking or bird flight diverters at sensitive locations can help to reduce the risk of collision for both local and migratory flying animals especially birds.
Birds of Serengeti and Ngorongoro Conservation Area
(Ostrich: Journal of African Ornithology, 2016) John, J.R.
This is a book review article on the book titled "Birds of the Serengeti and Ngorongoro Conservation Area".
Checklist of Tanzanian Species, Version 1
(African Journal of Ecology, 2015) John, J.R.
This is a review article for the book titled "Checklist of Tanzanian Species, Version 1". The article provides the strong points in this book and suggestions for improving future version of the book. It also narrates the format and flow of the book.
A comparative Study of Species Diversity of Migrant Birds between Protected and Unprotected areas of the Hadejia-Nguru Wetlands, Nigeria
(Tanzania Journal of Sciences, 2017) Ringim, A.S.; Magige, F.J.; John, J.R.
Among the most complex and fascinating behaviour in birds is their long, non-stop migration. Despite Hadejia-Nguru Wetlands (Ramsar site) being an important wintering ground for migratory birds, little is known about the diversity while density is completely lacking. This study assessed the status of migratory birds in the wetland’s Protected Areas (PAs) and Unprotected Areas (UPAs). A total of 99 census points spaced 400 m apart with radius of 100 m were surveyed from 14 wetlands (48 point count stations in the PAs and 51 in the UPAs). A total of 54 migrant bird species belonging to 13 orders and 25 families were recorded. Of the 54 species, 20 were Intra-African migrants and 34 Palearctic winters including two globally threatened species; the European Turtle Dove Streptopelia turtur and Pallid Harrier Circus macrourus. Results showed that Protected wetlands had significantly higher species diversity (H' = 1.39) than Unprotected ones (H' = 1.28) (p = 0.0064), however, there was no significant difference in the density of birds between the two areas (p = 0.9246). The two areas were similar in species composition by 81%. Both Palearctic and Intra-Africa migrant birds were recorded in the wetland, thus revealing the importance of the Hadejia-Nguru as wintering sites for migratory birds. The Nigerian government has obligation to protect these migratory birds because it is a signatory to several international treaties aimed at conserving these birds.
Diversity and Density of Avifauna in Areas with Different Protection Status: A Case Study in Hadejia-Nguru Wetlands, North-eastern Nigeria.
(International Journal of Ecology and Environmental Sciences, 2018) Ringim, A.S.; Magige, F.J.; John, J.R.
The paper is about the diversity and density of waterbirds in Hadejia-Nguru Wetlands, in areas with different protection status. See the abstract on the attached full article.
Kihansi spray wetlands under mitigation measures and its implication to the biodiversity of the resultant ecosystems.
(Journal of Biodiversity and Environmental Science, 2014) Mutagwaba, S.J.; John, J.R.
Originally, the Kihansi River Falls produced sprays that created microhabitat with high humidity and low temperatures. These microhabitats were the only habitats for Kihansi Spray Toad (KST) Nectophyrinoides asperginis, while adjacent forest supported other endemic species. However, in 1999 the Kihansi Hydropower Project diverted over 90% of the water from Kihansi River to the reservoir resulting into population crash of some wetland dependent species due to dryness. In 2001, artificial sprinklers were installed in three spray wetlands within the Kihansi Gorge (KG) to mitigate effects especially for KST, which unfortunately were declared extinct in the wild in 2009. Wetlands and forest microclimate under these mitigation measures were examined from 2010 to 2012 using data loggers set and left in the study sites to record temperature and humidity. Data were then downloaded and analysed. Temperature and relative humidity (RH) showed variation according to location and time but remained within tolerable limits for KST survival (16-21°C;60-100%) with varying mean differences at -0.860°C (2010), -0.585°C (2011), and 0.274°C (2012) and RH (±9.576%) between 2010 and 2012. Temperatures were significantly higher in adjacent forest than in wetlands and vice versa for RH suggesting that species outside the artificially maintained wetlands currently experience considerable dryness. This indicates that, the collapse or terminating artificial sprinklers may cause immediate negative effects to the ecosystem, and especially the endemic species. Thus, a long-term monitoring program and expansion of the artificial sprinklers are recommended for the healthier KG ecosystem.
Responses of large wetland birds to human disturbances: results from experimental bird approaches in areas with different protection status in western Tanzania
(Journal of Biodiversity and Environmental Science, 2015) John, J.R.
Flight distances are quite often used to establish wildlife responses to humans. It is generally hypothesised that animals in protected areas are more sensitive to approaching humans than in areas where animals may coexist with humans at high densities. But this hypothesis may not hold true if animals are persecuted. A field experiment was designed on three large wetland birds, two ‘Vulnerable’ and CITES Appendix II; Shoebill Balaeniceps rex and Wattled Crane Bugeranus carunculatus and one ‘Least Concern’ Saddle-billed Stork Ephippiorhynchus senegalensis, in areas with different protection status to test the effect of protection gradient on flight distances. Because Shoebill and Wattled Crane are restricted in western Tanzania and all the three species in this study are trapped it was also expected they should respond to the hunting pressure. The study found that birds were more wary in heavily protected area with longer flight initiation distance (83.75 ± 18.84 m) than in unprotected (57.24 ± 23.53 m), conforming to the first hypothesis. However, flight distances for Saddle-billed Stork did not differ significantly among the sites. In addition, Shoebill formed tight flocks in heavily protected area when flushed suggesting that birds were responding to persecution familiarity. Allegations of illegal bird trapping in protected areas were also rampant and insufficient on-site law enforcement was noted. Given the small population of the Wattled Crane and Shoebill in Tanzania (< 500 individuals for each species), the study recommends suspension of trapping and trade of the two species, and improving on-site law enforcement.
Shoebill population estimates in Tanzania from 2,500 in 1990 to <200 birds in 2011: what went wrong?
(Tanzania Wildlife Research Institute (TAWIRI), 2013) John, J.R.
This paper is about a threatened bird species endemic to Africa. It is a wetland dependent large waterbird. Although it is found in many countries, its population in Tanzania has declined sharply in recent years. This article is a review of what happened for such unexpected decline.

Browsing by Author "John, J.R."

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