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Funder: The research was funded through a long‐term collaboration between Conservational International and Chevron., The mitigation hierarchy (MH) is a prominent tool to help businesses achieve no net loss or net gain outcomes for biodiversity. Technological innovations offer benefits for business biodiversity management, yet the range and continued evolution of technologies creates a complex landscape that can be difficult to navigate. Using literature review, online surveys, and semi‐structured interviews, we assess technologies that can improve application of the MH. We identify six categories (mobile survey, fixed survey, remote sensing, blockchain, data analysis, and enabling technologies) with high feasibility and/or relevance to (i) aid direct implementation of mitigation measures and (ii) enhance biodiversity surveys and monitoring, which feed into the design of interventions including avoidance and minimization measures. At the interface between development and biodiversity impacts, opportunities lie in businesses investing in technologies, capitalizing on synergies between technology groups, collaborating with conservation organizations to enhance institutional capacity, and developing practical solutions suited for widespread use.

International audience; The Convention on Biological Diversity’s post-2020 Global Biodiversity Framework will probably include a goal to stabilize and restore the status of species. Its delivery would be facilitated by making the actions required to halt and reverse species loss spatially explicit. Here, we develop a species threat abatement and restoration (STAR) metric that is scalable across species, threats and geographies. STAR quantifies the contributions that abating threats and restoring habitats in specific places offer towards reducing extinction risk. While every nation can contribute towards halting biodiversity loss, Indonesia, Colombia, Mexico, Madagascar and Brazil combined have stewardship over 31% of total STAR values for terrestrial amphibians, birds and mammals. Among actions, sustainable crop production and forestry dominate, contributing 41% of total STAR values for these taxonomic groups. Key Biodiversity Areas cover 9% of the terrestrial surface but capture 47% of STAR values. STAR could support governmental and non-state actors in quantifying their contributions to meeting science-based species targets within the framework.

SummaryImportant Bird and Biodiversity Areas (IBAs) are sites identified as being globally important for the conservation of bird populations on the basis of an internationally agreed set of criteria. We present the first review of the development and spread of the IBA concept since it was launched by BirdLife International (then ICBP) in 1979 and examine some of the characteristics of the resulting inventory. Over 13,000 global and regional IBAs have so far been identified and documented in terrestrial, freshwater and marine ecosystems in almost all of the world’s countries and territories, making this the largest global network of sites of significance for biodiversity. IBAs have been identified using standardised, data-driven criteria that have been developed and applied at global and regional levels. These criteria capture multiple dimensions of a site’s significance for avian biodiversity and relate to populations of globally threatened species (68.6% of the 10,746 IBAs that meet global criteria), restricted-range species (25.4%), biome-restricted species (27.5%) and congregatory species (50.3%); many global IBAs (52.7%) trigger two or more of these criteria. IBAs range in size from < 1 km2 to over 300,000 km2 and have an approximately log-normal size distribution (median = 125.0 km2, mean = 1,202.6 km2). They cover approximately 6.7% of the terrestrial, 1.6% of the marine and 3.1% of the total surface area of the Earth. The launch in 2016 of the KBA Global Standard, which aims to identify, document and conserve sites that contribute to the global persistence of wider biodiversity, and whose criteria for site identification build on those developed for IBAs, is a logical evolution of the IBA concept. The role of IBAs in conservation planning, policy and practice is reviewed elsewhere. Future technical priorities for the IBA initiative include completion of the global inventory, particularly in the marine environment, keeping the dataset up to date, and improving the systematic monitoring of these sites.

The target adopted by world leaders of significantly reducing the rate of biodiversity loss by 2010 was not met but this stimulated a new suite of biodiversity targets for 2020 adopted by the Parties to the Convention on Biological Diversity (CBD) in October 2010. Indicators will be essential for monitoring progress towards these targets and the CBD will be defining a suite of relevant indicators, building on those developed for the 2010 target. Here we argue that explicitly linked sets of indicators offer a more useful framework than do individual indicators because the former are easier to understand, communicate and interpret to guide policy. A Response-Pressure-State-Benefit framework for structuring and linking indicators facilitates an understanding of the relationships between policy actions, anthropogenic threats, the status of biodiversity and the benefits that people derive from it. Such an approach is appropriate at global, regional, national and local scales but for many systems it is easier to demonstrate causal linkages and use them to aid decision making at national and local scales. We outline examples of linked indicator sets for humid tropical forests and marine fisheries as illustrations of the concept and conclude that much work remains to be done in developing both the indicators and the causal links between them.

SummaryImportant Bird Areas (IBAs) form a network of priority sites that are critical for the conservation of birds and biodiversity. A standard framework for monitoring IBAs is being implemented by the BirdLife Partnership globally. Scores are assigned on a simple ranked scale for state (condition), pressure (threats) and response (conservation action) at each site, from which IBA indices can be calculated. In Kenya, this scoring system was applied retrospectively using information in the national IBA directory (1999) and subsequent status reports (2004 and 2005). IBA indices for 36 IBAs show that their average condition deteriorated between 1999 and 2005, with the mean state score being between ‘unfavourable’ and ‘near favourable’. Pressures on IBAs showed a slight decline in intensity, especially from 2004 to 2005, coincident with an improvement in management that was reflected in increasing response scores. Compared to unprotected IBAs, officially protected sites had substantially greater conservation responses underway, were subject to marginally lower pressures and tended to be in slightly better condition. Other disaggregations of the data allow comparisons to be made for sites in different habitats, of different size, and managed by different agencies. This national example for Kenya suggests that the BirdLife IBA monitoring framework provides a simple but effective way of tracking trends in the state of IBAs, the pressures upon them, and the responses in place. The system is sensitive enough to detect differences between sites and over time, but simple enough to be implemented with little training and without sophisticated technology. The results provide vital information for managers of individual protected areas, management agencies responsible for suites of sites, and national governments, and can be used to track progress in tackling the global biodiversity crisis.

Critical Habitat has become an increasingly important concept used by the finance sector and businesses to identify areas of high biodiversity value. The International Finance Corporation (IFC) defines Critical Habitat in their highly influential Performance Standard 6 (PS6), requiring projects in Critical Habitat to achieve a net gain of biodiversity. Here we present a global screening layer of Critical Habitat in the terrestrial realm, derived from global spatial datasets covering the distributions of 12 biodiversity features aligned with guidance provided by the IFC. Each biodiversity feature is categorised as ‘likely’ or ‘potential’ Critical Habitat based on: 1. Alignment between the biodiversity feature and the IFC Critical Habitat definition; and 2. Suitability of the spatial resolution for indicating a feature’s presence on the ground. Following the initial screening process, Critical Habitat must then be assessed in-situ by a qualified assessor. This analysis indicates that a total of 10% and 5% of the global terrestrial environment can be considered as likely and potential Critical Habitat, respectively, while the remaining 85% did not overlap with any of the biodiversity features assessed and was classified as ‘unknown’. Likely Critical Habitat was determined principally by the occurrence of Key Biodiversity Areas and Protected Areas. Potential Critical Habitat was predominantly characterised by data representing highly threatened and unique ecosystems such as ever-wet tropical forests and tropical dry forests. The areas we identified as likely or potential Critical Habitat are based on the best available global-scale data for the terrestrial realm that is aligned with IFC’s Critical Habitat definition. Our results can help businesses screen potential development sites at the early project stage based on a range of biodiversity features. However, the study also demonstrates several important data gaps and highlights the need to incorporate new and improved global spatial datasets as they become available.

Our study focused on the Taita White-eye Zosterops silvanus, one of three bird species endemic to the Taita Hill forests, south-east Kenya. Formerly considered Critically Endangered, Taita White-eye has been down-listed to Endangered following the findings of this study. Between November 1998 and September 1999 we counted this species along line transects to establish their current population status and distribution in its entire range. White-eye censuses were conducted in nine forest fragments of the Taita Hills and the virtually undisturbed Mt Kasigau forest. The total global population of Taita White-eyes was estimated to be c. 7,100 birds. Mt Kasigau was shown to be the species' main stronghold, maintaining a very high density (26 birds ha−1) and holding 80% (5,600 individuals) of the entire population. In the Taita Hills forests, densities were consistently higher in the small isolated fragments than in the large ones, though the former held only a small population (3% of total). At Mt Sagala, a large isolated block where indigenous trees have been largely replaced with exotic plantation, this species was not encountered. We found no evidence of interchange between the White-eye populations on Mt Kasigau and the Taita Hills forests, probably because of the separation by a low-altitude, dry woodland habitat barrier. While prioritization for conservation action should focus more on the Taita Hills forest fragments, Mt Kasigau should be treated as fragile ecosystem which holds a huge, apparently insular population of Taita White-eyes.

Montane grassland is a severely threatened habitat in Kenya. Despite a high level of faunal endemism, it has received very little conservation attention. We investigated habitat selection in a threatened grassland endemic bird species, Sharpe's longclaw (Macronyx sharpei) (family Motacillidae), in order to understand its likely response to land-use changes. Between November 1995 and May 1996, we studied 41 territories of this species on the Kinangop Plateau in central Kenya. With an overall density of 0.4 birds ha(-1), longclaws lived in permanent groups of two to seven individuals. They were sedentary and territorial, with a mean home range size of 0.5 ha. The species avoided non-grassland areas entirely, and within grassland showed a strong preference for short grass with tussocks. Territory sizes and foraging ranges were smaller, and rates of pecking for food higher, in this grassland type than in open short grass or long grass. Land use changes, in particular conversion to cultivation or woodlots and ploughing up of grassland to remove tussocks, pose a serious and immediate threat to this species. Dairy farming is potentially compatible with grassland conservation, and conservation-friendly livestock rearing needs to be promoted through economic incentives, awareness-raising and technical advice. (C) 2002 Elsevier Science Ltd. All rights reserved.

The highland grasslands of central Kenya hold a suite of restricted-range bird species, including several of global conservation concern. These grasslands occur almost entirely on private land with no formal protection, and have received little conservation attention. This paper describes land-use change on the Kinangop Plateau, Kenya, and considers the implications for grassland bird species, especially Sharpe's Longclaw Macronyx sharpei . The Kinangop Plateau is an area of montane grassland east of the Rift Valley, used primarily for dairy farming since human settlement in 1964. However, dairy farming (which retains grassland as pasture) has given way to other forms of land-use, especially cultivation of crops. In March 1996, a questionnaire was administered to 50 landowners to investigate community attitudes towards birds and their conser vation, the extent of present land-use changes and likely future land-use patterns. The mean acreage of landholding was decreasing, and more grassland was rapidly being converted into cultivated land, with 3.2% being ploughed up during the six months from November 1995 to May 1996. Farmers expressed a preference for crop farming (66%) over livestock farming (26%) or other land uses. Thirty-two per cent expressed a positive attitude, and 60% were indifferent, towards birds. Most (76%) were not aware of biodiversity values or conservation. Though 64% were aware of declining bird populations around them, 82% of this group did not realize that their activities might be contributing to this decline. Sixty-eight per cent of landowners planned to convert all or part of their grassland holdings. Although landowners' interests seemed generally incompatible with grassland conservation, a substantial proportion (44%) were prepared to consider opportunities to enhance the area's conservation value. An informal follow-up survey in March 1999 concluded that prospects for the dairy industry and for grassland habitats on Kinangop were not as bleak as the initial survey suggested, but confirmed the delicate conservation status of Sharpe's Longclaw and its habitat. We suggest a variety of actions that might help to secure the future of Sharpe's Longclaw while promoting sustainable agricultural development on Kinangop, and propose several topics where further research is needed. Species such as Sharpe's Longclaw will only survive if we can develop ways of managing their habitats in a manner that is consistent, rather than in conflict, with the needs of the agricultural community.

Waterbird populations were censused each January from 1991 to 1999 at Lakes Naivasha, Elmenteita and Nakuru and from 1992 at Lake Bogoria. These shallow lakes in the Kenyan Rift Valley fluctuate greatly in water level and alkalinity. All but Naivasha are usually saline; Nakuru and Elmenteita at times support fish, while Bogoria is fishless. A standardized logarithmic index of relative abundance (value 1.0 for the mean) was calculated for each major waterbird group at each lake, and for Naivasha, Elmenteita and Nakuru combined (‘combined lakes’). Its variance was used to compare levels of variation within and across lakes. For the combined lakes, there was high variance in large piscivores (whether combined or separated into groups), grebes, rallids and flamingos. There was low variance in Palaearctic waders (combined or separated into groups), ibises and spoonbills and birds of prey. However, the lakes generally showed idiosyncratic patterns of variation across the different groups. Variance in the indices for birds of prey and kingfishers were consistently low (max. 0.036 and 0.042, respectively), but no group had consistently high variance across all sites. The variance for all birds (other than flamingos) combined was low (0.018 – 0.085) and similar across all lakes and for combined lakes (0.018). For the combined lakes, the variance for flamingos was five times higher than for all other birds (p

Long-term monitoring of wetlands is an essential element of management for ‘wise use’. Indeed, the Ramsar Convention requires regular monitoring in order to detect changes in ecological character at listed sites. However, there are few examples of successful long-term monitoring in tropical wetlands. Monitoring schemes run into three kinds of difficulties: conceptual, logistical and political. To be effective, monitoring schemes must be carefully planned and designed. In practice, the questions to be addressed are rarely made explicit. Strictly defined, monitoring should assess deviations from a pre-set level so that appropriate corrective action can be taken. This assumes that good baseline information exists, and that we have sufficient knowledge of the system to set sensible signal levels. Neither is usually the case in tropical wetlands. This means that carefully focused surveillance (a time-series of systematic observations) is an essential first step. Providing resources and co-ordination for surveillance or monitoring is challenging over the long term, especially if the variables being measured require expensive analyses and highly trained staff. I suggest that surveillance or monitoring programmes should focus on likely threats, and ecological or economic concerns, should be as simple, robust and inexpensive as possible, should be sustained and consistent, and should involve local people and volunteers. If it is to be effective, monitoring must have a clear linkage to wetland management. Ideally, it should form part of each country's wetland policy. I suggest some variables that could be incorporated in sustainable long-term monitoring programmes. Two examples of successful surveillance work at Kenyan wetlands illustrate that the challenges involved in long-term programmes can, at least in part, be overcome.

This study investigated the distribution and habitat selection of the globally threatened East Coast Akalat Sheppardia gunningi sokokensis in Arabuko-Sokoke Forest, the Shimba Hills (both Kenya) and the lowland East Usambara Mountains (Tanzania). The species is more abundant than originally thought. In Arabuko-Sokoke Forest, akalats occur in two of the main vegetation types, and an estimated 7,500–9,000 territories represent one of the largest populations of this species in the world. Akalats occurred at similar densities to those in Arabuko-Sokoke (c. 0.5 pairs/ha) in parts of Shimba Hills and East Usambaras, but were more patchily distributed. This akalat prefers areas where the undergrowth is partially open with large amounts of dead wood. It forages on or near the ground. In Arabuko-Sokoke Forest, areas where akalats were present had a higher abundance of ground-dwelling arthropods than areas where they were not. The akalat inhabits both primary forest and regenerated areas that have been selectively logged probably more than 20 years ago. Despite its relatively high densities where it occurs, this species (like other threatened birds in the East African coastal forests) is very patchily distributed and dependent on a habitat that is now highly fragmented and under considerable human pressure. The conservation situation in Arabuko-Sokoke gives cause for concern, and the destructive effects of a large elephant population threaten the forests of the Shimba Hills. The conservation status of the lowland Usambara Mountains is probably better and more stable.

Njoroge, P. & Bennun, L. A. 2000. Status and conservation of Hinde's Babbler Turdoides hindei, a threatened species in an agricultural landscape. Ostrich 71 (1 & 2): 69–72. Hinde's Babbler is a restricted-range species endemic to Central Kenya. In recent years it appears to have suffered a marked reduction of population within its range. Using active searching and playback of vocalisations, we assessed the species' status in three study areas (Kianyaga, Mukurweini and Machakos) between July 1993 and May 1994. Distribution of the babbler was closely linked to river valleys and swamps, and to the presence of dense thicket vegetation. In Kianyaga and Mukurweini, clearance for intensive cultivation has removed most natural vegetation. Here the babblers rely on small (ranging from 5 m2 to 0.81 ha) patches of the exotic weed Lantana camara for shelter and nest sites. In Machakos (a lower altitude site with less rainfall) the birds occurred in riverine thicket that has not yet been cleared. Densities in Machakos...

Bennun, L. & Fishpool, L. 2000. The Important Bird Areas Programme in Africa: an outline. Ostrich 71 (1 & 2): 150–153. BirdLife International works to conserve the world's birds at the levels of species, sites and habitats. The Important Bird Areas (IBA) programme is a process of setting site-based priorities for birds based on information about species' distribution and numbers. The African IBA programme started in 1993, building on similar successful programmes in Europe and the Middle East. Important Bird Areas are selected according to internationally agreed criteria based upon the presence of globally threatened species, species of restricted range, biome-restricted species assemblages and concentrations of numbers. In Africa, a continental directory of sites is scheduled for publication in 2000, and work is underway to identify and document IBAs across the continent and its associated islands. In 18 countries so far, the process of compiling information is being combined at a national level with str...

Bennun, L. & Nasirwa, O. 2000. Trends in waterbird numbers in the southern Rift Valley of Kenya. Ostrich 71 (1 & 2): 220–226. Each January since 1991, volunteer teams have counted waterbirds at major wetlands in the southern Kenyan Rift Valley. There has been consistent coverage at Lakes Naivasha, Elmenteita, Nakuru and (since 1992) Bogoria. These lakes are shallow and, except for Bogoria, fluctuate greatly in extent; all but Naivasha are saline. Lake levels were moderately high in 1991–1993 but have been generally low since. Flamingo totals for the three saline lakes combined were more than one million from 1992–1994, but roughly halved each year since then. Greater Flamingos Phoenicopterus ruber made up between 0.7 and 4.1% of total flamingo numbers; other waterbirds made up between 2.7 and 10.2% of the overall total. Lakes Naivasha, Elmenteita and Nakuru together hold most of the non-flamingo waterbirds in the southern Rift; to compare trends for other species, we pooled totals for these sites. Signifi...

Waiyaki, E. & Bennun, L.A. 2000. The avifauna of coastal forests in southern Kenya: status and conservation. Ostrich 71 (1 & 2): 247–256. The biological importance and uniqueness of East African coastal forests is widely recognised; they form an Endemic Bird Area. Important remnants of this fragmented habitat OCCUT on the southern Kenyan coast, but their avifauna has been little studied. In October 1992, September 1993 and May-August 1994, we systematically assessed the avifauna of fifteen South Coast forest fragments (and the threats facing them) using mist-netting, timed species counts and direct observations. Sixty forest-dependent bird species were recorded, amongst them three that are globally threatened (Sokoke Pipit Anthus sokolcensis, Spotted Ground Thrush Turdus fischeri, East Coast Akalat Sheppardia gunningi) three that are near-threatened (Southern Banded Snake Eagle Circaetus fasciolatus, Fischer's Turaco Tauraco fischeri, Plain-backed Sunbird Anthrepres reichenowi) and four that are ‘restrict...

Bennun, L.A., Njoroge, P. & Pomeroy, D. 2000. Birds to watch: a Red Data List for East Africa. Ostrich 71 (1 & 2): 310–314. The value of Red Data books and lists is well established; there has been much recent work on improving the criteria for listing species of conservation concern. So far these have been applied mainly at the global level. Regional lists can be useful, however, in improving the resolution of conservation priorities and setting an agenda for research, monitoring and conservation, especially where data are collected by amateur naturalists. A Red Data list for East African birds has been drawn up following an eight-month process that involved wide consultation within the region, defined as Uganda, Rwanda, Tanzania, Kenya and Burundi. The criteria for listing were based on those defined by IUCN, and summarised in a single, simple table that could be used for screening large numbers of species. A criterion based on geographic range eliminated from consideration vagrant species or those on t...

Matiku, P.M., Bennun, L.A. & Nemeth, E. 2000. Distribution and population size of the threatened East Coast Akalat in Arabuko-Sokoke Forest, Kenya. Ostrich 71 (1 & 2): 282–285. The East Coast Akalat Sheppardia gunningi sokokensis is one of six globally threatened bird species that occur in the Arabuko-Sokoke Forest, the largest remnant of forest on the East African coast. The akalat has been little studied but appears to have a patchy distribution both between and within forests. From October 1995 to February 1996 we studied the akalat's status in Arabuko-Sokoke, carrying out transect counts and plot-based surveys to determine its distribution and population size. Playback of calls was used to stimulate the bird to reveal its presence. The akalat was present in two of the forest's main vegetation types, Cynometm woodland and Mixed forest. It was absent from the more open Brachystegia woodland, and from low-canopied intermediate Cynometra and Cynometra thicket. In Cynometra woodland, the akalats were evenl...

Patterns and environmental correlates of species distributions and richness are identified for Kenyan birds at a quarter degree-square scale. This information is used together with iterative complementarity analyses, which employ species richness, taxonomic dispersion and range-restrictedness, to identify priority areas for possible conservation attention. Bird species apparently not conserved by existing protected areas in Kenya are identified. Six avifaunal zones (and one transitional zone) are distinguished based on distributions of suites of bird species. Variation in biotope diversity (the number of forest and aquatic systems) accounts for 79% of the observed variation in Kenyan bird species richness. Although both rainfall and altitudinal range are significantly correlated with species richness, they only explain an additional 3% of the observed variation. The priority areas identified are situated mainly within highlands and coastal lowlands. Although few priority areas are identified in northern Kenya, this region also constitutes a priority, as it contains a suite of xeric species with habitats that are not represented elsewhere in Kenya. The papyrus yellow warbler, Chloropeta gracilirostris, William's bush lark, Mirafra williamsi, white-winged dove, Streptopelia reichenowi, and Jubaland weaver, Ploceus dichrocephalus, are identified as endemics or near-endemics that are probably not adequately conserved in Kenya at present.

Nasirwa, O. & Bennun, L. A. 2000. Co-ordinated waterbird counts: the Kenyan experience. Ostrich 71 (1 & 2): 99–101. In Kenya annual waterbird counts have been carried out consistently since 1991. The counts are a collaborative effort between the National Museums of Kenya, Kenya Wildlife Service and the Kenya Wetlands Working Group. Their aim has been to train and equip Kenyan volunteers to monitor the ecological status of wetlands. At the same time, data on waterbird numbers are collected in a standard way. Focal wetland sites are the major Rift Valley lakes. Increased volunteer response and experience in counting led to the expansion of the monitoring from an initial eight sites to 26 sites in 1996. Over 500 volunteers have so far been involved and around 100 have regularly taken part. Many counters who cannot participate regularly in the main counts remain in touch and provide information on waterbird numbers in other wetland sites. The high turn-over of volunteers has created difficulties but has also ...

SummaryKenya possesses one of the richest and most diverse avifaunas in Africa: this reflects the country's varied habitats and the fact that it lies at the intersection of several biogeographic zones. Some 1,070 species have been recorded; nine are national endemics and 14 can be considered globally threatened. A number of other species or groups are of particular national concern. Alteration and degradation of habitats is taking place rapidly, mainly due to human population growth combined with increased urbanization and industrialization. Overall, forests are the most threatened habitats; the coastal Arabuko-Sokoke Forest is particularly important in global terms. A number of wetlands are also under threat from a variety of causes. Habitat destruction is the key problem; direct threats such as hunting, trade and the use of pesticides and poisons are of relatively minor importance. Specific suggestions to be incorporated within a national bird conservation strategy include: better regulation and development of bird tourism as a means of generating revenue; increased efforts in particular areas of conservation education; provision of appropriate training to bird guides and researchers; and improved integration of research.

Robust and rapid ways of assessing and monitoring forest biodiversity are increasingly necessary. To this end, we present a classification of forest birds in Kenya and Uganda into three simple categories: forest-specialists (FF species), forest generalists (F species) and forest visitors (f species). FF and F species, but not f species, are dependent on forests. Out of 479 forest birds in the two countries, 214 are FF, 156 F and 109 f species. Forest-dependent birds, and particularly forest specialists, are less widespread than forest visitors. Uganda has 420 forest birds compared to Kenya's 335, and a higher proportion of forest specialists: this reflects differences in forest structure and biogeography, rather than the area of natural forest. Using this classification allows species lists and densities to be interpreted more meaningfully. The number of FF species is an initial measure of a forest's relative conservation importance, while the proportion of FF, F and f species and their relative abundance will shift according to changes in forest structure. Journal of East African Natural History Vol. 85 (1&2) 1996: pp. 23-48

We studied the presence of ‘floaters', i.e. non-territorial individuals roaming occupied territories awaiting future breeding opportunities, in two separate White-starred Robin ( Pogonocichla stellata ) populations at the Taita Hills, Kenya, using a removal experiment. Previous vegetation analyses at this site had showed that ‘population Ngangao' occupied a high-quality forest fragment, and ‘population Chawia' occupied a low-quality one. Using a combination of radio telemetry, dawn calls, visual observations and targetted playbacks in one 16ha plot per fragment, 52 individuals of different territorial status were identified. Ngangao hosted 14 resident and 13 floating males, while Chawia hosted eight residents and two floaters. Population Chawia (but not Ngangao) hosted unmated territorial males. Floating males in Ngangao took over three of seven (i. e. 43%) vacated territories within a few days of the residents' removal. In both populations, no resident neighbouring males expanded their territories or moved to take over the vacant territories following experimental removal of resident males. These results suggest that (1) territorial behaviour is an important factor limiting the number of breeders in Population Ngangao; (2) other factors such as poor habitat quality and female scarcity, most likely associated with the lower bird densities in Population Chawia, can limit numbers of breeders before territorial exclusion becomes a concern. Ostrich 2006, 77(1&2): 28–35

The rapid destruction of the planet's biodiversity has prompted the nations of the world to set a target of achieving a significant reduction in the rate of loss of biodiversity by 2010. However, we do not yet have an adequate way of monitoring progress towards achieving this target. Here we present a method for producing indices based on the IUCN Red List to chart the overall threat status (projected relative extinction risk) of all the world's bird species from 1988 to 2004. Red List Indices (RLIs) are based on the number of species in each Red List category, and on the number changing categories between assessments as a result of genuine improvement or deterioration in status. The RLI for all bird species shows that their overall threat status has continued to deteriorate since 1988. Disaggregated indices show that deteriorations have occurred worldwide and in all major ecosystems, but with particularly steep declines in the indices for Indo-Malayan birds (driven by intensifying deforestation of the Sundaic lowlands) and for albatrosses and petrels (driven by incidental mortality in commercial longline fisheries). RLIs complement indicators based on species population trends and habitat extent for quantifying global trends in the status of biodiversity. Their main weaknesses are that the resolution of status changes is fairly coarse and that delays may occur before some status changes are detected. Their greatest strength is that they are based on information from nearly all species in a taxonomic group worldwide, rather than a potentially biased subset. At present, suitable data are only available for birds, but indices for other taxonomic groups are in development, as is a sampled index based on a stratified sample from all major taxonomic groups., An index is developed from the IUCN Red List that measures the overall threat status of taxa and reveals that the status of the world's birds has deteriorated since 1988

Lens, L., Muchai, M., Bennun, L.A. & Duchateau, L. 2000. Conservation planning in an agricultural landscape: the case of Sharpe's Longclaw. Ostrich 71 (1 & 2): 300–303. We studied the distribution and habitat use of Sharpe's Longclaw, Macmnyx sharpei, a Kenyan montane grassland endemic, in a fragmented agricultural landscape at two spatial scales. Monthly counts in a fixed number of plots selected in contrasting habitat types provided insight in the species' distribution in relation to the available habitat. Simultaneously, focused ecological work in a smaller area provided information on its behaviour, movements and habitat choice, and allowed us to interpret the wider distribution patterns in a biologically meaningful way. Sharpe's Longclaw occurs only in grasslands, not in cultivated fields or plantations of exotic trees. It prefers short grassland with a well-developed tussock structure, apparently because tussocks provide good cover while foraging and nesting. However, as tussock grass is unpalatable...

Bennun, L. 2000. Assessing and monitoring bird populations in Africa: an overview. Ostrich 71 (1 & 2): 214–215. Access to reliable population data is crucial for effective conservation and management of birds. So far, relatively little attention has been paid to assessing and monitoring bird populations in Africa. This is beginning to change. Regional meetings, for example in East Africa, are discussing and defining standard methodologies, and making technical information more widely available. Researchers are using these methods to access the populations of threatened species, or those of economic value. Projects involving long-term monitoring, particularly of waterbirds, are beginning to yield results that are useful for management. Some challenges that remain include: securing institutional and financial support for long-term monitoring work; integrating monitoring efforts (especially of migratory species) across borders; understanding the ecological significance of population trends; finding robust an...

Coordinated waterbird counts have been carried out in major Kenyan wetlands annually over the last decade. The lakes of Naivasha, Elmenteita, Nakuru (counted since 1991) and Bogoria are close to each other in the southern Rift Valley and hold the bulk of both resident and migrant waterbirds counted each year. Levels of the four lakes fluctuate substantially and all but Naivasha are saline. By contrast, Dandora Ponds near Nairobi is a site with stable water levels. We compared trends in numbers of birds, categorized by family and by migratory status, with an earlier analysis in 1996 and between the fluctuating Rift Valley lakes and Dandora Ponds. Flamingo numbers remained highly variable at all sites, showing no long-term trends. In 1996, significant declines were found in many piscivorous waterbird groups, including grebes, pelicans, cormorants, storks, terns and gulls, mainly associated with falling lake levels at Lake Nakuru; by 2000, numbers had recovered. Consistent declines in rallids, birds...

typically live in family !Iroups that defend permanent terri- tories centred on an acorn store, and breed at a single nest. In central (California, groups usually include kletween one and four breeding riales and one or two breeding females, as well as up to ten non- t reeding helpers, who are group off- spring from previous seasons’ . In about one-fifth of the groups, there are two females nesting jointly: they l;~y their eggs in the same nest and cooperate to raise the young1)2. Joint nesting females each produce about 35% fewer young per year than ff!males that nest singly, partly because they destroy each other’ s e 3gs before incubation begins3. Why, then, does joint nesting take place? To answer this question, infor- mation on three aspects of acorn noodpecker demography is re- q Aired. First, the lifetime reproduc- ti /e success of birds adopting differ- ent strategies; second, the effect that tt-e strategy adopted has on the re- production of relatives; and third, knowledge of how the costs and benefits of joint nesting vary be- tween individuals. Recently Ronald Mumme, Walter Koenig and Frank Pitelka have considered the first two, calculating the mean lifetime repro- dLlctive success of females nesting jo ntly and those nesting singly”. 4fter analysing data gathered over 15 years, Mumme et