Bird communities, roads and development: prospects and constraints of applying empirical models

Our objectives were to explain the prospects and constraints of applying empirical models that relate bird community metrics to broad-scale characteristics of roads and development. We explored the practical value of regression models that were derived for a large protected area in the Chihuahuan Desert. These models related bird species richness, relative abundance, or probability of occurrence to total length of roads within each of two spatial extents (1- and 2-km radii), distance to the nearest road, distance to the nearest development, or the two-way interactions of these variables. Empirical models can be used to inform conservation decisions, to parameterise simulation models for conservation planning, to identify threshold levels of road and development variables, and to determine the focus of management experiments for confirmatory hypothesis testing and improvement of model realism.     

Correlates of extinction risk and hunting pressure in gamebirds (Galliformes)

The 284 species of Galliformes are a highly threatened group of birds subject to direct exploitation for food, sport and cultural practices. The impact of hunting is often assumed to contribute to the high percentage of species (26.4%) listed as threatened with extinction in the IUCN Red List. We take a macroecological approach to examine the anthropogenic and ecological correlates of extinction risk and hunting pressure using linear and stepwise regression. Independent contrasts are analysed, as well as raw species data, to control for the potential confounding influence of phylogenetic trends. Extinction risk is found to be predicted both by the ecological factors considered (e.g., latitudinal range, body mass, elevational range, habitat use) and secondarily by human factors (e.g., human population density, total calorie intake, composition of diet). Hunting pressure itself is also predicted well for the threatened species by several of the anthropogenic and ecological variables. The study demonstrates that human variables can be used successfully to predict extinction risk, and represent an improvement upon methods which examine ecological variables alone. Furthermore, we show that individual threats can be explored using similar techniques, providing a more detailed insight into the processes leading to extinction. As applied to the Galliformes, both approaches provide evidence supporting the hypothesis that hunting pressure has contributed to the high proportion of threatened species in this group, and thus reinforce the case for urgent measures to reduce the impacts of direct exploitation upon these birds.     

Geographic associations of breeding bird distribution in an urban open space

The Puente-Chino Hills, extending west into the highly urbanized Los Angeles Basin, represent one of the largest expanses of lowland habitats in the region. During spring and early summer of 1997 and 1998, birds and vegetation surveys were conducted to clarify the influence of geographical position in the distribution of birds in the hills. Using logistic regression, the inclusion of longitudinal position as a variable is shown to make a statistically significant contribution to bird species presence beyond that of habitat alone for 12 of the 49 most commonly detected species. Species more common than would be expected based on habitat in the east were typical of grassland and open habitats, whereas those more common in the west were characteristic of tall scrub or urban habitats. Thus, species’ distributions in the hills are likely influenced by landscape-scale vegetation patterns and by the aggregate amount of urbanized areas in the west. This emphasizes the importance of using geographical position as a variable when analyzing patterns in bird distribution and siting conservation areas.     

Effects of ground fires on understorey bird assemblages in Amazonian forests

Avifaunal responses to understorey fire disturbance and subsequent changes in habitat structure were examined within 20 burnt and unburnt forest plots of 0.25 ha (10×250 m), 10-15 months after an unprecedented understorey fire swept through the Tapajós-Arapiuns Extractive Reserve of central Brazilian Amazonia following the severe 1997-1998 El-Niño dry season. Although these surface fires in the previously undisturbed primary forest were relatively mild, they resulted in dramatic changes in forest structure consistent with those found elsewhere in Amazonia. Bird species negatively affected by these changes tended to be the least common, the most disturbance-sensitive, and habitat specialists. Considering different guilds, ant followers, dead-leaf gleaners, terrestrial gleaners, and arboreal sallying insectivores were the most negatively affected, whereas nectivores and arboreal granivores became more abundant in the burnt forest. The results highlight the severe consequences of even relatively mild surface fires in neotropical forests, and the importance of controlling haphazard frontier expansion for the conservation of susceptible species that are endemic to fire-prone regions.     

重庆市綦江地区秋季不同生境鸟类多样性研究

1999年9-10月,采用样方法对綦江地区森林生境、灌丛生境、农田生境的鸟类群落结构进行调查研究,结果表明：本次调查记录到鸟类79种,分属于9目25科,雀形目鸟类的种数最多,占总数的73．42％。国家Ⅱ级保护鸟类7种,占所观察到鸟类的8．86％。在调查研究的3种生境鸟类多样性从高到低的是农田生境、灌丛生境、森林生境。     

Prioritisation of Philippine Island avifaunas for conservation: a new combinatorial measure

Given the ubiquitous fact that resources for preserving whole faunas are limited, prioritisation of areas is called for. The popularity of the complementarity approach for setting priorities derives from their representing the maximum number of species of a taxon with a minimum number of areas, e.g. islands in an archipelago like the Philippines. While the logic of the approach is impeccable, it lacks dynamism. Here a new approach to prioritisation is exemplified with avifaunas in the Philippines. A combinatorial, linear model permits assigning to each island avifauna a priority index that allows ranking of islands in terms of prioritisation. The model is (1) dynamically proactive in that it takes into account the island-specific ongoing and future dieback of the avifaunas at stake; by applying the well-established species-area relationship to the remaining forests as the new islands; (2) it is accountable by operationalising the weighting of its parameters by introducing the new quantity ‘opportunity for choice’; (3) it is combinatorial, being thereby more realistic. The model's results for the six largest Philippine islands were reasonably well validated based on a ranking of island-specific number of endangered endemics. The results lead to assigning the Greater Negros faunal region (Negros, Panay) top priority, similar to more species-rich Greater Luzon and Greater Mindanao, thus substantially changing the ranking of islands derived from the rather static one-parameter complementarity approach.     

Differences in bird diversity between two swidden agricultural sites in mountainous terrain, Xishuangbanna, Yunnan, China

This study took a comparative look at the relationship between human-altered landscapes and bird diversity in two mountainous swidden (slash and burn) agricultural sites in Xishuangbanna, Yunnan, China. Over the course of 3 years (1998-2000) the authors used line-transect identification surveys in the two regions, Mengsong and Jinuo, where four different habitats were surveyed: 6-year fallow fields; traditional economic forests; monsoon evergreen broadleaf forests; and montane rain forests. Data were analyzed for species diversity, richness (family, genera, species), co-occurrence (family, genera, species), characterization of migratory status and feeding habits. Both of these study areas are inhabited by minority groups (Hani and Jinuo) that employ swidden agriculture as their main form of economic activity. The forest landscape in the Jinuo ethnic region is quickly transforming due to changing agricultural practices, and as a result bird diversity and richness are declining, while the Hani ethnic region (Mengsong), with a stable form of traditional swidden agriculture, is maintaining a high diversity and richness of birds. The greatest differences in bird diversity between the two sites occurred in the traditional economic forests and the 6-year fallow fields where the Hani region had a much greater richness and diversity. The two natural forest types (monsoon evergreen broadleaf forests and montane rain forests) were more similar in richness and diversity and also maintained the greatest richness and diversity of the four forest types analyzed. The transformation of healthy forests into degraded landscapes is one of the major impacts of human activity on the natural environment, which is posing a great threat to biodiversity. This study looks at the bird diversity of the two regions and tries to take into account how humans can extract economic benefits while preserving ecological benefits, such as a landscape that allows biodiversity to thrive.     

Disposition of marbofloxacin in vulture (Gyps fulvus) after intravenous administration of a single dose

The pharmacokinetics properties of marbofloxacin were studied in adult Eurassian Griffon vulture after single-dose intravenous (IV) administration of 2 mg/kg. Drug concentration in plasma was determined by high-performance liquid chromatography and the data obtained were subjected to compartmental and non-compartmental kinetic analysis. Marbofloxacin presented a volume of distribution at steady-state (Vdss) of 1.51 ± 0.22 L and total plasma clearance (Cl) of 0.109 ± 0.023 L/h kg. The permanence of this drug was long in vultures (T_1/2λ = 12.51 ± 2.52 h; MRT_∞ = 13.54 ± 2.29 h). The optimal dose of marbofloxacin estimated is 2.73 mg/kg per day for the treatment of infections in vultures with MIC₉₀ = 0.2 μg/mL.     

哈尔滨太平国际机场春季鸟类的群落结构

1999年和2000年3月-5月，对哈尔滨太平国际机场及附近的旱田，水田，树林，水域，草甸和村屯6种生境春季鸟类群落的相似性及鸟类群落结构进行了调查，共记录鸟类96种，分属12个目，34个科，其中树林生境中密度及种类最多，分别为227.27只/10hm^2，54种，旱田生境中的密度及种类最低，分别为64.91只/10hm^2。27种，水田和水域的相似性系数最高，为73.97%。水域与村屯最低，为10.69%，树林生境的多样性及均匀性最高，分别为0.9437,5.4312，水域均匀性最低，为0.3891。春季对飞机飞行安全可能造成较大威胁的鸟类有5种，即毛脚Kuan(Buteo lagopus)，金斑Heng（Charadrius Placidus)，扇尾沙锥（Gallinago gollinago)，长耳Hao（Asio otus)，小嘴乌鸦（Coruvs corone)。     

合肥市董铺水库及临近区域鸟类多样性研究

2012年12月-2013年11月,采用样线调查和样点观察相结合的方法对合肥市董铺水库及其临近区域不同生境的鸟类资源进行了调查。共记录到鸟类14目31科87种,其中国家Ⅱ级保护鸟类1种、安徽省地方重点保护鸟类25种;古北界鸟类45种（占51.7%）,东洋种25种（占28.7%）,广布种17种（占19.5%）;留鸟33种（占37.9%）,夏候鸟19种（占21.8%）,冬候鸟21种（占24.1%）,旅鸟14种（占16.1%）鸟类群落多样性指数最大生境为水库周围灌丛、树林;而指数最小者为大面积水域。