Causes and consequences of bird extinctions

Journal ArticleIncreased human domination of the planet has caused the declines and extinctions of countless species. Each species has not only intrinsic value, but ecological functions of organisms are also essential for the integrity of ecosystems that allow people to benefit from essential free ecosystem services, such as carcass disposal, pest control, pollination and seed dispersal. In order to retain global biodiversity and ecosystem services, we must study the factors behind species' declines, understand their consequences, improve capacity of human-dominated landscapes to maintain biodiversity, and persuade local human communities to preserve their natural heritage. With birds as my focal group, I take various approaches to addressing these issues, including an analysis of the world's bird species, modeling bird extinctions in the 21st century, field research on effects of habitat degradation on tropical forest bird communities, a radio telemetry study of forest birds that persist in deforested landscapes, and a review of birdwatching tourism. My research sheds light on the ecological consequences of species' declines, the long-term impacts of tropical forest degradation, the role of mobility for persistence of birds in deforested tropical landscapes, the conservation significance of integrating human-dominated and native habitats, and the importance of local human communities for biodiversity preservation. Analyzing a database of all the world's bird species, I found that certain functional groups, such as frugivores, herbivores, piscivores and scavengers, are more extinction-prone than average, and some areas, such as oceanic islands and forested landscapes, have significantly more species that are at risk. These patterns are likely to deteriorate in the 21st century, signaling the potential loss of crucial ecosystem services such as pest control, pollination, and seed dispersal. In Uganda, I found that beyond a certain intensity, one-time forestry practices can have long-term negative impacts on forest birds through changes in vegetation structure, whereas low intensity forestry can be compatible with the preservation of local biodiversity. The largest simultaneous study of forest understory insectivorous birds, their diets and prey base in the premontane forest fragments of southern Costa Rica showed that these area-sensitive species disappear from small forest fragments not due to lack of food, but because their limited mobility prevents movements between small habitat patches, making them vulnerable to stochastic, local extinctions. On the other hand, three forest bird species that were able to persist in agricultural countryside dominated by coffee plantations were able to do so either by being pre-adapted to disturbed habitats (Catharus aurantiirostris) or by being highly mobile and making efficient use of 11% of the landscape still covered by trees (Tangara icterocephala and Turdus assimilis). Results from radio telemetry also underlined the importance of remnant trees, riparian strips, and small forest patches for native forest species. An analysis of birdwatching tourism revealed that, just as human-dominated landscapes are often excluded from conservation initiatives, most local people in less-developed areas are also excluded from the income generated by birdwatching that is overwhelmingly conducted by wealthy citizens of developed countries. If the combination of large scale habitat clearance, exclusion of human-dominated landscapes from conservation policies, and alienation of local communities from ecotourism initiatives continues, consequent disappearance of species is likely to cause collapses in ecosystems and their services that are crucial for humanity

Ibis quest

Journal ArticleThe day I arrived in Ethiopia, researcher Yilma Dellelegn Abebe of the Ethiopia Wildlife and Natural History Society (EWNHS) was just leaving the capital city, Addis Ababa, to search for three Northern Bald Ibises in a remote, roadless area of the country. These critically endangered birds had been satellite-tagged earlier in Syria by a team of researchers from Britain's Royal Society for the Protection of Birds (RSPB), BirdLife Middle East, and Cambridge University. According to the satellite signals, they had crossed into Ethiopia the previous month and were frequenting an area only some 80 kilometers to the northeast of us. Also known as the Walldrap, the Northern Bald Ibis (Geronticus eremita) was once common in the Mediterranean area, but the birds now stand in imminent danger of extinction, with fewer than 300 individuals existing in the wild. Until 2002, the only known populations were in Morocco and Turkey, and these birds were nonmigratory

Forest fragmentation hits insectivorous birds hard

Journal ArticleHabitats around the world, especially in the tropics, are being fragmented at a rapid rate, causing a tremendous loss of biodiversity[1]. For example, 12% of the approximately 10,000 bird species are threatened with extinction in the next 10 to 100 years, and another 8% are near-threatened[2]. This loss of species is likely to result in the collapse of significant ecosystem processes and free ecosystem services to people[3], such as pest control by insectivorous birds. Tropical forest insectivorous birds, such as antbirds, woodcreepers, and wrens, present a good example of an important, species-rich group of small, noncharismatic organisms who do not get much public attention, but whose demise may have significant negative ecological and financial consequences. They are among the species most likely to go extinct as a result of forest fragmentation[4] and their loss may result in insect pest outbreaks in tropical forests and surrounding agricultural areas. Finding out the causes of the disappearance of understory insectivores may help explain the disappearance of the other small, short-lived, and specialized bird species that comprise the majority (65%) of threatened bird species in the world[5]. In a recent study of the factors behind the disappearance of insectivorous birds in Costa Rican forest fragments reported in the Proceedings of the National Academy of Sciences[6], we provide evidence that interfragment dispersal, rather than food limitation, may be the most critical factor for the persistence of understory insectivorous birds in forest fragments. As in previous studies[4,7], small forest fragments had significantly lower insectivore species diversity and abundance than more extensive forest. However, our initial hypothesis - that the decline of insectivorous birds in forest fragments is caused by an impoverished invertebrate prey base - was not supported by invertebrate counts and examination of bird diet samples. Instead, the inability of understory insectivores to use the nonforest matrix surrounding the fragments seemed to be the main reason for their decline

Impacts of birdwatching on human and avian communities

Journal ArticleEcotourism can be a vehicle for community-based conservation if it is conducted with an emphasis on the well-being of local ecosystems and human communities. Birdwatchers form the largest group of ecotourists, and are, on average, well-educated, wealthy and committed. This makes them ideal ecotourists for community-based conservation. Therefore, there is a need for a comprehensive review of birdwatching from a conservation biology perspective. Specific objectives here are: (1) to review the economic potential of non-residential birdwatching for community-based conservation; (2) to outline the potential benefits and problems associated with this activity; and (3) to provide suggestions for improving the conservation value of birdwatching. Birdwatching tourism has a high potential to improve the financial and environmental well-being of local communities, educate locals about the value of biodiversity and create local and national incentives for successful protection and preservation of natural areas. However, there needs to be more research on the economical and environmental impacts of this hobby, birdwatchingrelated disturbance needs to be reduced, and much has to be done to increase the financial contribution of birdwatching to local communities

Bird surveys for REDD+: avian communities indicate forest degradation in a Peruvian coffee landscape

Shade coffee cultivation in the Peruvian Andes assists in reducing emissions from deforestation because it avoids conversion to non-forest land uses such as coca and sun grown coffee farming. REDD+ is a potential finance mechanism which may provide incentives for local coffee cooperatives to maintain high shade tree cover. REDD+ has potential multiple benefits other than carbon sequestration, including the conservation of biodiversity. When monitoring for REDD+, surveys of bird biodiversity may prove to be particularly valuable: apart from their high intrinsic value and their value as essential ecosystem service providers, birds inhabiting forest habitats are extremely sensitive to forest loss and forest degradation and are therefore potential useful indicators for the impact of habitat and climate disturbances on biodiversity and environmental health.
We analyzed the impact of coffee cultivation on the conservation of birds and assessed what can be learned from bird surveys when monitoring the Peruvian mountain forests for REDD+. Using twelve day-long transect walks, bird species were recorded in two sites in the buffer zone of the Bahuaja-Sonene National Park in SE Peru. The two sites had contrasting human pressure: one site an intimate mixture of shade coffee plantations, orchards, secondary forest patches and coca plantations and the other site secondary forest with patchily distributed shade coffee, fruit and coca plantations. An indirect gradient approach (non-metric multidimensional scaling and multi-response permutation procedure tests) was used to detect differences in forest degradation between sites.
In a two-dimensional ordination space, individual counts of the less disturbed site were separated from the other counts, but sites did not differ significantly at the community-level. Observed birds were indicative for one habitat type. The bird assemblage was dominated by species of forest edges and second growth habitat (78%). The majority of species (68%) had a wide range covering Amazonia and the east slopes of the Andes; only 25 species (29%) were more or less restricted to Andes and the outlying ridges.
The current state of the forest, in both sites with contrasting human influence, can be described as disturbed secondary montane evergreen forest of the transition zone between the Andes and the Amazon. Despite severe human impact, several forest specialists (22%) of both Andean montane and Amazonian forest persisted –including the enigmatic Andean cock-of-the-rock and Military macaw. For such species, REDD+ projects should not only focus on the sustainable management of the shade coffee stands but also aim to conserve the remaining old-growth secondary forest patches

Promoting community-based bird monitoring in the tropics: conservation, research, environmental education, capacity-building, and local incomes

ManuscriptLong-term, locally-based biodiversity monitoring programs are essential for understanding and mitigating the effects of global change on tropical biodiversity while providing capacity-building, environmental education, and public outreach. However, these programs are lacking in most tropical countries. Birds are the best-known major group of organism, comprise excellent environmental indicators, are relatively easy to monitor, and are met with enthusiasm and interest by people worldwide. Bird monitoring programs using mist nets and bird banding (ringing) are especially valuable, as these well-established techniques enable the use of capture-mark-recapture (CMR) models to measure population change and other demographic parameters. Equally important for conservation, the ability to capture and release birds makes it possible to provide hands-on ornithological training and educational activities to students, conservationists, villagers, decision-makers, journalists, and other local people. Bird banding programs provide local jobs for research assistants, who often go on to productive careers in conservation, education, research, or ecotourism. Long-term bird banding stations also provide the nuclei, infrastructure, and staff for monitoring, education, and conservation programs focused on other taxa. As successful examples from Costa Rica and Ethiopia show, bird monitoring programs that integrate conservation, ecological research, environmental education, capacity-building, and income generation are cost-effective tools to achieve the goals of community-based biodiversity conservation and poverty reduction in the developing world. Therefore, locally-based and long-term bird monitoring programs should be encouraged, established, and funded throughout the tropics

Ontario\u27s Small Non-Community Drinking Water Systems: How to Ensure Provision of Safe Drinking

Waterborne disease outbreaks associated with drinking water systems occur in Canada and elsewhere. Previous research has shown that the small non-community drinking water system (SDWS) users are at increased risk of becoming ill compared to the community drinking water system users. Although public awareness surrounding access to safe drinking water has been increased considerably since the Walkerton tragedy in 2000, the provision of safe drinking water in Ontario’s SDWSs is relatively understudied. Furthermore, a key initiative to safeguard drinking water sources in Ontario, the planning for source water protection, does not include SDWSs. Our research consists of three manuscripts addressing the following objectives: a) to examine contributing factors to adverse water quality incidents in SDWSs, b) to investigate risk awareness and perceptions of the SDWS owners in the provision of safe drinking water and protecting their water sources, c) to develop a sustainable operation model for Ontario’s SDWSs. We use a mixed methods approach by analyzing quantitative and qualitative data in different phases of the research. The study region, Wellington-Dufferin-Guelph, is situated in the heart of southern Ontario. Our research investigates the relationship between operational characteristics of SDWSs and adverse water quality incidents and concludes that the presence of operator training, an upstream behavioural determinant, significantly reduces the incidence of adverse water quality incidents in SDWSs. The interviews with SDWS owners reveal the need for low-cost and easily accessible training opportunities, and financial support for some SDWS owners. Although the current literature on Ontario’s SDWSs is limited, the review of the current water management strategies in Canada and across the world provides fruitful results to create of a unique model for Ontario’s SDWSs using the Multiple-Barrier Approach framework. Our sustainable operation model consists of five main components: Commitment to providing safe drinking water; assessment of the system and source water; system operation and operator training; management of incidents and emergencies; and communication and raising awareness. Our model addresses the areas that need more attention for today, and in the future, such as protecting source water, financial stability, enhanced communication, and increased awareness

People skills for the conservation professional

Journal ArticleConservation scientists are increasingly becoming aware of the importance of the human aspects of conservation, and in conservation circles, ‘‘social science'' is the word of the day. There is a rapidly growing social science working group in the Society for Conservation Biology and it is hard to imagine a conservation project that does not have a strong emphasis on the importance of working effectively with local people. In fact, most of the challenges in conservation biology are not scientific, but diplomatic-in persuading people to follow the advice of conservation science

Habitat use and movements of native forest birds in southern Costa Rican agricultural countryside

Journal ArticleWe used radio telemetry to study the habitat use, activity budgets, and movements of three bird species that are found in native forest and coffee plantations of southern Costa Rica. We obtained 7522 locations from Turdus assimilis (n=27), Tangara icterocephala (n=53), and Catharus aurantiirostris (n=42), the species ranked from most to least forest-dependent. We caught birds in coffee and radiotracked them to understand their dependence on remnant native vegetation patches. Home range size and frequency of long-distance movement was positively correlated with the species' forest dependence. T. assimilis and T. icterocephala preferred forest fragments, riparian strips and remnant forest trees, mostly avoided coffee plantations, and moved frequently between suitable habitat patches. Even though remnant forest trees and riparian strips covered 3.7% and 4.8% of the land area, respectively, they made up 9%-49% of T. assimilis and T. icterocephala home ranges, and were especially important in the dry season (25%-49%). C. aurantiirostris, an edge/second growth species, was highly sedentary, opportunistic in its habitat preference in the wet season, and preferred second growth in the dry season. Home range size for C. aurantiirostris and T. icterocephala decreased significantly in the dry season, concentrating around food resources in secondary growth and fruiting trees, respectively. Native habitat patches were cooler, more humid, had reduced microclimatic fluctuations, and increased in importance during the dry season. Remnant patches of native vegetation in Costa Rican agricultural countryside provide crucial resources for these bird species that evolved in forest, but now have to live in an increasingly deforested landscape. Active management of tropical humandominated ecosystems can significantly increase their capacity to support native bird species