Impact of busy roads on breeding success in pied flycatchers Ficedula hypoleuca

The impact of dense traffic on the breeding success in pied flycatchers (Ficedula hypoleuca) was studied using roadside nest-boxes. Nest site selection and breeding success of flycatchers were observed in relation to the distance from the road. The number of occupied territories was no higher closer to the road than it was deeper inside the forest. The distance to the road had no effect on the laying date, clutch size, or brood size. However, nests closer to the road were more likely to fail at the chick stage. The number of broods that were closer to roads and were lost completely was significantly higher than those further away. As a consequence, the number of fledglings per breeding attempt decreased closer to roads. The nestlings typically died as older chicks when the parent birds were providing them with maximum quantities of food. A possible reason for the declining reproductive success was the traffic-related mortality of parent birds, as weather conditions were not especially adverse for raising healthy offspring.     

Population Persistence and Offspring Fitness in the Rare Bellflower Campanula cervicaria in Relation to Population Size and Habitat Quality

Abstract: Data from several animal species and a few plant species indicate that small populations face an elevated risk of extinction. Plants are still underrepresented in these studies concerning the relation between population size and persistence. We studied the effect of population size on persistence among natural populations of the rare bellflower Campanula cervicaria in Finland. We monitored 52 bellflower populations for 8 years and found that the mean population size decreased from 24 to 14 during this period. Small populations with ≤5 individuals were more prone to losing all fertile plants than were larger ones. Reduction in population size was nevertheless unrelated to the degree of population isolation, measured as the distance to the nearest known population. To test the hypothesis that offspring fitness is lower in small populations, we germinated bellflower seeds from different-sized populations in a laboratory and found that seed germination ability was independent of population size. The seedlings raised from seeds of small populations grew faster than those taken from larger populations. Population size was negatively related to the amount of shade in the habitats. In conclusion, decreasing population sizes of C. cervicaria seemed not to be caused by lowered germination ability or growth rate in small populations; rather, population size reductions appeared to be due to closing of vegetation in the habitats.     

Urbanisation Without Development: Environmental and Health Implications in African Cities

Sustainable development advocates for a balance between socio-economic development and the environment in the pursuit of human advancement. In Africa, high population growth and inadequate infrastructure in urban areas exert pressure on the environment and this threatens the health and wellbeing of urban residents. The population of the African continent until the 1960s was predominantly rural. This scenario has taken a swift turn and some of the major shifts in the global urbanisation process are taking place on the continent. Factors including natural increase in the population, rural–urban migration, strife and hunger leading to the internal displacement of populations have exacerbated the urbanisation process in Africa. The situation has been worsened by the imposition of Western development policies, including structural adjustment programmes on African nations, which has eroded the subsistence base of rural agricultural communities and further ignited rural urban migration. The failure of industry to absorb the increasing labour force has created massive unemployment and deepening poverty crisis in urban centres. Inadequate provision of infrastructure and services to meet the growth in urban populations has resulted in inefficient spatial development of urban centres, the proliferation of squatter settlements, inadequate basic amenities including potable water, sanitation and waste disposal. Poor environmental sanitation has resulted in the upsurge of infectious diseases and deteriorating urban health. Urban populations in Africa are also the worst affected by newly emerging diseases, particularly HIV/AIDS. The poor bear a disproportionately large share of the problems due to their particular vulnerability to environmental and health risks. Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Testing the Use of a Land Cover Map for Habitat Ranking in Boreal Forests

Habitat loss and modification is one of the major threats to biodiversity and the preservation of conservation values. We use the term conservation value to mean the benefit of nature or habitats for species. The importance of identifying and preserving conservation values has increased with the decline in biodiversity and the adoption of more stringent environmental legislation. In this study, conservation values were considered in the context of land-use planning and the rapidly increasing demand for more accurate methods of predicting and identifying these values. We used a k-nearest neighbor interpreted satellite (Landsat TM) image classified in 61 classes to assess sites with potential conservation values at the regional and landscape planning scale. Classification was made at the National Land Survey of Finland for main tree species, timber volume, land-use type, and soil on the basis of spectral reflectance in satellite image together with broad numerical reference data. We used the number and rarity of vascular plant species observed in the field as indicators for potential conservation values. We assumed that significant differences in the species richness, rarity, or composition of flora among the classes interpreted in the satellite image would also mean a difference in conservation values among these classes. We found significant differences in species richness among the original satellite image classes. Many of the classes examined could be distinguished by the number of plant species. Species composition also differed correspondingly. Rare species were most abundant in old spruce forests (>200 m³/ha), raising the position of such forests in the ranking of categories according to conservation values. The original satellite image classification was correct for 70% of the sites studied. We concluded that interpreted satellite data can serve as a useful source for evaluating habitat categories on the basis of plant species richness and rarity. Recategorization of original satellite image classification into such new conservation value categories is challenging because of the variation in species composition among the new categories. However, it does not represent a major problem for the purposes of early-stage land-use planning. Benefits of interpreted satellite image recategorization as a rapid conservation value assessment tool for land-use planners would be great.     

Urban Waste Pollution in the Korle Lagoon, Accra, Ghana

The Korle Lagoon in Accra, Ghana, has become one of the most polluted water bodies on earth. It is the principal outlet through which all major drainage channels in the city empty their wastes into the sea. Large amounts of untreated industrial waste emptied into surface drains has led to severe pollution in the lagoon and disrupted its natural ecology. The increased levels of industrial activity and consumption by the urban population lead to the generation of copious quantities of waste. Managing the volume of wastes poses a major challenge for the city authorities, particularly, ensuring that all the waste generated is collected for disposal. In Accra, the Waste Management Department is currently capable of collecting only 60 percent of the waste generated daily. The rest is dumped in open spaces, in surface drains, and into water bodies which end up in the Korle Lagoon. High eutrophication levels have developed in the shallow water body. The net effect is that, at the slightest downpour, the lagoon overflows its banks causing regular flooding in parts of the city.The Government of Ghana, having realized the adverse impacts of pollution in the lagoon on the physical and economic environment of Accra, with the support of donor agencies, is implementing measures to restore the lagoon to its natural ecology. Attempts are also being made to get the communities in the catchment area to become involved in managing their environment through environmental education and awareness programes.     

Effects of Land Use Changes on the Landscape Composition: A Comparison Between Finnish and Russian Karelia

During the last 50 years the practising and intensity of agriculture and forestry have differed considerably between Finnish and Russian Karelia. We studied the effects of different land use practices on the landscape composition in the two countries using the road transect sampling along four study routes (99-121 km) between 1997 and 1999. Effective environmental management in Finland has resulted in more distinct agricultural land types, more even distribution of the different age classes of forests, and the higher abundance of coniferous forests. Fields (mean percentage of the landscape: Finland 28%, Russia 13%), clearcuts and sapling stands (15%, 6%), and young forests (23%, 9%) were more typical elements of the Finnish landscape, whereas settlements (9%, 13%), semi-natural grasslands (3%, 7%), and mature forests (20%, 49%) were more characteristic of the Russian landscape. Landscape-level differences between the two countries may have various effects on the diversity of fauna and flora inhabiting Finnish and Russian Karelia.     

Effects of male removal on female foraging behavior in the Eurasian treecreeper

In old, spruce-dominated forests of central Finland, Eurasian treecreepers Certhia familiaris divide their territories spatially during the breeding season. Females forage primarily on the upper parts of the tree trunks, while males use the lower parts of the tree trunks. In this study we removed males from eight territories in the early nestling period to see if the mate's absence would change the foraging patterns of the resident female. Widowed females foraged at lower heights, thus behaving more like paired males. These females also spent less time on each tree and on each foraging bout than did paired females. We conclude that male removal facilitated the change in a female's foraging niche and foraging time at the trees. Females may re-optimize their foraging site selection owing to the absence of dominant males and a consequent need to increase their parental care. Behavioral plasticity may be the mechanism of niche partitioning between the sexes in this species. Received: 28 June 1996 / Accepted after revision: 27 March 1997     

Municipal Solid Waste Management in the Accra Metropolitan Area, Ghana

Municipal solid waste management in Accra, Ghana, is at present delivered in an unsustainable manner. Due to uncontrolled urbanisation, large quantities of waste are generated daily in Accra, and this exerts much pressure on an over strained solid waste management system. Coupled with weak institutional capacity, and lack of resources, both human and capital, the city authorities face difficulties in ensuring that all the waste generated in the city is collected for disposal. Home collection of waste is limited to high and, some middle income areas while the poor are left to contend with the problem on their own. This leads to indiscriminate disposal of waste in surface drains, canals and streams, creating unsanitary, and unsightly environments in many parts of the city.     

Do Highways Influence Density of Land Birds?

Phylloscopus trochilus ), crossbills (Loxia spp.), and tree pipit (Anthus trivialis). The composition of the bird community did not vary significantly between the compared transects. Some species appeared to favour road–forest edges but this could not be confirmed with our data. These species were not the same as have been reported to favor clear-fellings–mature forest edges. Therefore, the edge effect does not seem to be the most important factor controlling relative bird densities immediately adjacent and further away from highways. The likelihood of avoiding the problems the highways are causing for bird density are been discussed.