Adam Felton

Orangutan population density, forest structure and fruit availability in hand-logged and unlogged peat swamp forests in West Kalimantan, Indonesia

We investigated the population density of Bornean orangutans Pongo pygmaeus pygmaeus and aspects of habitat quality in a selectively hand-logged peat swamp forest in West Kalimantan, Indonesia, and in a comparable unlogged forest nearby. We conducted orangutan nest surveys, measured different parameters of forest structure, recorded monthly changes in fruit availability, and noted the sex and the stage of maturity of orangutans encountered. Nest density, an index of orangutan population density, was 21% lower in the logged area. The forest, logged 2 years previously, had fewer large food trees and a greater number of canopy gaps. We discuss these differences in relation to the lower orangutan nest density in the logged forest. Significantly fewer adult orangutans were observed in the logged study area. We hypothesize that fully adult orangutans, particularly females, are the most severely affected by hand-logging.

Nutritional Ecology of Ateles chamek in lowland Bolivia: How Macronutrient Balancing Influences Food Choices

All free-living animals must make choices regarding which foods to eat, with the choices influencing their health and fitness. An important goal in nutritional ecology is therefore to understand what governs animals’ diet selection. Despite large variation in the availability of different food items, Peruvian spider monkeys (Ateles chamek) maintain a relatively stable daily protein intake, but allow total energy intake to vary as a function of the composition of available food items. This is referred to as protein-dominated macronutrient balancing. Here we assess the influence of this nutritional strategy on daily and seasonal nutritional intakes, estimate the nutritional value of different foods, and interpret unusual food choices. We conducted continuous all-day observations of focal spider monkeys inhabiting a semideciduous forest in Bolivia. We recorded feeding events, collected foods, and analyzed their nutrient content. By using the Geometric Framework for nutrition, we show that individuals reached their daily end-point in nutrient space —balance between protein and nonprotein energy intake— by consuming nutritionally balanced foods or by alternating between nutritionally complementary foods. The macronutritionally balanced figs of Ficus boliviana were their primary staple food and therefore dominated their overall nutritional intake. Our results also demonstrate that spider monkeys consumed a diverse array of ripe fruits to overcome periods of fig scarcity rather than vice versa; they could obtain sufficient protein on a diet of pure fruit; and unripe figs constituted a nutritionally rewarding and reliable food resource. We hope that the approaches taken and the conclusions reached in this study will catalyze further inquiries into the nutritional ecology of frugivorous primates.

Climate change, conservation and management: an assessment of the peer-reviewed scientific journal literature

Recent reviews of the conservation literature indicate that significant biases exist in the published literature regarding the regions, ecosystems and species that have been examined by researchers. Despite the global threat of climatic change, similar biases may be occurring within the sub-discipline of climate-change ecology. Here we hope to foster critical thought and discussion by considering the directions taken by conservation researchers when addressing climate change. To form a quantitative basis for our perspective, we assessed 248 papers from the climate change literature that considered the conservation management of biodiversity and ecosystems. We found that roughly half of the studies considered climate change in isolation from other threatening processes. We also found that the majority of surveyed scientific publications were conducted in the temperate forests of Europe and North America. Regions such as Latin America that are rich in biodiversity but may have low adaptive capacity to climate change were not well represented. We caution that such biases in research effort may be distracting our attention away from vulnerable regions, ecosystems and species. Specifically we suggest that the under-representation of research from regions low in adaptive capacity and rich in biodiversity requires international collaboration by those experienced in climate-change research, with researchers from less wealthy nations who are familiar with local issues, ecosystems and species. Furthermore, we caution that the propensity of ecologists to work in essentially unmodified ecosystems may fundamentally hamper our ability to make useful recommendations in a world that is experiencing significant global change.

Functional Richness and Relative Resilience of Bird Communities in Regions with Different Land Use Intensities

A bstractEmpirical estimates of the function and resilience of communities under different management regimes can provide valuable information for sustainable natural resource management, but such estimates are scarce to date. We quantified the functional richness and relative resilience of bird communities inhabiting five regions in southeastern Australia that represented different management regimes. First, we show that functional richness and relative resilience were reduced at species-poor sites in all regions. Second, we show that bird communities in agricultural regions had fewer body mass groups and fewer functional groups than expected by chance. This suggests that both the function and the resilience of bird communities in agricultural regions were reduced. The likely mechanisms for the observed loss of function and relative resilience are: (1) the simplification of landscape texture resulting in selective extinction of certain body mass groups; and (2) the selective extinction of certain functional groups that are particularly sensitive to intensive land use.

TEMPORAL CHANGES IN VERTEBRATES DURING LANDSCAPE TRANSFORMATION : A LARGE-SCALE NATURAL EXPERIMENT

Plantation development is a significant form of landscape change worldwide. We report findings from a large-scale longitudinal natural experiment that quantified changes in Australian vertebrates as a former grazing landscape was transformed to one dominated by a radiata pine (Pinus radiata) plantation. The study included four main “treatments”: woodland remnants surrounded by emerging radiata pine (52 sites, termed “woodland treatments”), stands of radiata pine (10 sites, “pine controls”), woodland remnants where the surrounding landscape remained unchanged (56 sites, “woodland controls”), and paddocks with scattered woodland trees that surrounded the 56 woodland remnants (10 sites, “paddock controls”). In our study region, woodland is distinguished from forest by differences in tree height, tree spacing, bole length, and canopy development. Between 1998 and 2006, occupancy rates of “woodland treatments” by most mammals and reptiles increased linearly. Similar trends occurred in the “woodland controls,” suggesting that species had increased landscape-wide, rather than displaying year × treatment interaction effects. We cross-classified birds according to the statistical significance and nature of time trajectories. Groups included those that: (1) declined in woodland treatments in comparison with woodland controls, (2) decreased within woodland treatments but increased in woodland controls, (3) declined across the entire study area, (4) increased within woodland treatments in comparison with woodland controls, (5) increased within woodland treatments but declined in woodland controls, and (6) increased across the entire study area. Attributes of woodland treatments significantly associated with temporal changes in bird occupancy included: (1) age of surrounding pine stands; (2) number of boundaries with surrounding pines; (3) size of the woodland patches; (4) dominant vegetation type of woodland patches; and (5) temporal changes in vegetation structure in the woodland treatments. Bird species associated with open country and woodland environments were disadvantaged by landscape transformation, whereas those that benefited were forest taxa and/or habitat generalists capable of inhabiting pine stands and adjacent woodland patches. Beyond this generalization, an unanticipated finding was a lack of association between life history attributes and landscape transformation. We suggest that several key processes are likely drivers of change at multiple spatial scales. Recognition of such processes is important for conservation in landscapes transformed by plantation expansion.

Diet and Feeding Ecology of Ateles chamek in a Bolivian Semihumid Forest: The Importance of Ficus as a Staple Food Resource

We describe temporal patterns of food consumption by Peruvian spider monkeys (Ateles chamek) in a semihumid forest in lowland Bolivia. We assessed dietary composition in relation to temporal variation in abundance, duration, and synchrony of different food items in their home range. We collected data from September 2003 to September 2004, in the forestry concession La Chonta, Department of Santa Cruz. Throughout the period of detailed feeding data collection (February-September 2004), Ateles chamek used Ficus as a staple food resource. Figs constituted almost 50% of their diet in terms of total time spent feeding, and subjects consumed them to a great extent even during times of high overall food availability. This is contrary to the general expectation that for Neotropical frugivores, Ficus is a fallback food in times of fruit scarcity, rather than a staple food resource. Surprisingly, despite being considered ripe fruit specialists, Ateles chamek spent 18% of their feeding times eating unripe figs. Ateles chamek consumed unripe figs all through the year, including periods when ripe figs and other ripe fruit were abundant. We identify other important fallback foods for Ateles chamek in the forest, in particular the ripe fruit of Myrciaria sp.

Applying resilience thinking to production ecosystems

Production ecosystems typically have a high dependence on supporting and regulating ecosystem services and while they have thus far managed to sustain production, this has often been at the cost of ...

The distribution and host range of the pandemic disease chytridiomycosis in Australia, spanning surveys from 1956–2007

Chytridiomycosis is the worst disease to affect vertebrate biodiversity on record. In Australia, it is thought to have caused the extinction of four frog species, and it threatens the survival of at least 10 more. We report the current distribution and host range of this invasive disease in Australia, which is essential knowledge for conservation management. We envisage that the data be used in a global and national context for predictive modeling, meta-analyses, and risk assessment. Our continent-wide data set comprises 821 sites in Australia and includes 10 183 records from >80 contributors spanning collection dates from 1956 to 2007. Sick and dead frogs from the field and apparently healthy frogs from museum collections were tested opportunistically for the presence of Batrachochytrium dendrobatidis, the fungal pathogen causing chytridiomycosis, and apparently healthy frogs and tadpoles found during surveys were tested purposively. The diagnostic tests used were histology of skin samples and quantitative PCR of skin swabs. Chytridiomycosis was found in all Australian states and the Australian Capital Territory, but not in the Northern Territory. Currently it appears to be confined to the relatively cool and wet areas of Australia, such as along the Great Dividing Range and adjacent coastal areas in the eastern mainland states of Queensland, New South Wales, and Victoria, eastern and central Tasmania, southern South Australia, and southwestern Western Australia. Batrachochytrium dendrobatidis may have been introduced into Australia via the port of Brisbane around 1978 and spread northward and southward. It did not appear to arrive in Western Australia until 1985. The earliest records from South Australia and Tasmania are from 1995 and 2004, respectively, although archival studies from these states are lacking. We also report negative findings showing that the disease does not currently occur in some areas that appear to be environmentally suitable, including Cape York Peninsula in Queensland and most of the World Heritage Area in western Tasmania. Infection with B. dendrobatidis has been recorded from 63 frog species in Australia to date, all belonging to the Hylidae, Limnodynastidae, and Myobatrachidae, with the exception of one individual of a species from the Microhylidae and the introduced cane toad of the family Bufonidae.

Multiple mate choice criteria and the importance of age for male mating success in the microhylid frog, Cophixalus ornatus

We examined multiple mate choice criteria in Cophixalus ornatus, a terrestrial breeding, microhylid frog. Mate choice consisted of three stages: mate attraction (male calling), courtship (male behavior between the call site and the nest), and nest site selection by the female. For male C. ornatus, the possession of a call with low dominant frequency relative to calling neighbors increased the probability that they would attract females. Dominant frequency was negatively correlated with age independent of male mass and snout vent length. When escorting the female from the call site to their nest, males traveled along more convoluted paths than when returning to the nest alone. The convolution of the path was, therefore, considered an aspect of courtship. Females released eggs into nests with structural characteristics typical of nests constructed by older males. Thus, females increased their chances of locating an acceptable nest by preferentially approaching males with lower dominant frequencies. This study is the first to demonstrate that age, independent of mass or snout-vent length, can influence call characteristics in anurans, and it is also the first to demonstrate the importance of male age to female mate choice in an amphibian.

A New Paradigm for Adaptive Management

Uncertainty is a pervasive feature in natural resource management. Adaptive management, an approach that focuses on identifying critical uncertainties to be reduced via diagnostic management experiments, is one favored approach for tackling this reality. While adaptive management is identified as a key method in the environmental management toolbox, there remains a lack of clarity over when its use is appropriate or feasible. Its implementation is often viewed as suitable only in a limited set of circumstances. Here we restructure some of the ideas supporting this view, and show why much of the pessimism around AM may be unwarranted. We present a new framework for deciding when AM is appropriate, feasible, and subsequently successful. We thus present a new paradigm for adaptive management that shows that there are no categorical limitations to its appropriate use, the boundaries of application being defined by problem conception and the resources available to managers. In doing so we also separate adaptive management as a management tool, from the burden of failures that result from the complex policy, social, and institutional environment within which management occurs.