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It is commonly argued that cities face unprecedented pressures and therefore must transform. To guide transformations, it is important to develop guiding visions. This paper reports on a futures thinking exercise in the context of cities. It employs a methodology based on a series of community workshops with a diverse mix of experts using a “strategic conversation”. The conversation was framed around the question: ‘How might your city build and maintain resilience in a range of plausible futures?’ Results of the process help to identify risks and opportunities, as well as urban transformation archetypes. Furthermore, these narratives are interpreted as city reorganization patterns similar to those theorized in resilience thinking through the notion of adaptive cycles. Finally, the possibility of developing a more functional transformation narrative for cities is outlined, which would enable the development of a collective vision for a desired urban future and how to avoid the adverse consequences of drivers of change in cities.

Integrated assessment of natural and human systems is regarded as a way to facilitate effective governance of complex environmental issues, and engagement of stakeholders is recognised as a key requirement of such an assessment. Place-based ecosystem service analysis is one framework for integrative research on understanding citizen values. By using the lens of place, participants can articulate values and perceptions. Advantages of this framework are particularly relevant in the urban setting, given that the population and functioning of cities create especially high pressure on ecosystems and biodiversity of the surrounding areas. This study reports on a place-based ecosystem service analysis study in Bogota, Colombia. It aimed to identify how urban citizens conceptualise the socio-ecological value of a nearby protected natural area, the Eastern Hills Protected Forest Area. The objective was to generate an integrated understanding of the services the Hills provide to Bogota. The study found that the services of fresh water and habitat provision, biodiversity, carbon sequestration, erosion control and climate and air quality were highly prioritised ecosystem services due to their fundamental importance for the maintenance of human life. The Hills also hold cultural value for Bogotans, such as a sense of belonging and identity, being the natural symbol of Bogota and inspiration for escapism. There is enthusiasm for greater stewardship and conservation of the Hills, and demand for a greater role in decision making. The place-based ecosystem service approach can be developed as a tool for developing an integrated understanding of citizen values for landscape management.

This chapter attempts to distil key messages and guidelines from the literature on futures-thinking in order to help researchers, policymakers and land managers decide when and how to apply futures-thinking when considering ecosystem services. Futures-thinking draws on a range of disciplines to acknowledge and address the psychological and other barriers to thinking openly and creatively about future possibilities and their implications for planning over multiple timeframes. The methods associated with futures-thinking explore how external forces have interacted with human thinking, values and behaviours to shape the past and present and how such interactions might shape the future. The chapter explores a large body of literature on futures-thinking and shows how it can contribute to ecosystem assessments. Like ecosystem assessments, critical and integral futures approaches aim to improve societies' ability to think more deeply about social as well as bio-physical futures. The Millennium Ecosystem Assessment sought to make explicit the relationships between ecosystem services and human needs.

© 2015, The Author(s). Published by Taylor & Francis. A new approach was developed for Australia's 2011 national State of the Environment (SoE) report to integrate the assessment of biophysical and human elements of the environment. A Common Assessment and Reporting Framework (CARF) guided design and implementation, responding to jurisdictional complexity, outstanding natural diversity and ecosystem values, high levels of cultural and heritage diversity, and a paucity of national-scale data. The CARF provided a transparent response to the need for an independent, robust and evidence-based national SoE report. We conclude that this framework will be effective for subsequent national SoE assessments and other integrated national-scale assessments in data-poor regions.

Fruit bodies of hypogeous fungi are an important food source for many small mammals and are consumed by larger mammals as well. A controversial hypothesis that prescribed burning increases fruiting of certain hypogeous fungi based on observations in Tasmania was tested in the Australian Capital Territory to determine if it applied in a quite different habitat. Ten pairs of plots, burnt and nonburnt, were established at each of two sites prescribe-burnt in May 1999. When sampled in early July, after autumn rains had initiated the fungal fruiting season, species richness and numbers of fruit bodies on the burnt plots were extremely low: most plots produced none at all. Both species richness and fruit body numbers were simultaneously high on nonburnt plots. One of the sites was resampled a year after the initial sampling. At that time species richness and fruit body abundance were still significantly less on burnt plots than on nonburnt, but a strong trend towards fungal recovery on the burnt plots was evident. This was particularly so when numbers of fruit bodies of one species, the hypogeous agaric Dermocybe globuliformis, were removed from the analysis. This species strongly dominated the nonburnt plots but was absent from burnt plots in both years. The trend towards recovery of fruit body abundance in the burnt plots one year after the burn was much more pronounced with exclusion of the Dermocybe data. The Tasmanian-based hypothesis was based mostly on the fruiting of two fire-adapted species in the Mesophelliaceae. Neither species occurred on our plots. Accordingly, the results and conclusions of the Tasmanian study cannot be extrapolated to other habitats without extensive additional study. Implications for management of habitat for fungi and the animals that rely on the fungi as a food source are discussed.

Models of what makes good koala habitat are a key to developing effective conservation policy and practices. Koala habitat models are based on (1) ecological studies of high-density koala populations in limited areas, (2) physiological studies of koala nutrition and characteristics of food plants, and (3) surveys of koala geographic distribution and biophysical features of forests and woodlands. The role of models in koala conservation varies because legislators, decisionmakers, land managers, and citizens have different expectations and uses for models. Although current habitat models address many of these needs, overall they lack sufficient certainty and authority to resolve disputes and develop policy. Unpublished and inadequately peer-reviewed data and models add to misinterpretation and argument. Improvements are needed in the decision-making process to increase the constructive involvement of all interest groups and to focus on the koala conservation problem, thereby reducing use of the popular media and courts of law to achieve objectives. Resumen: Los modelos de lo que constituiria un buen habitat para koalas son clave para desarrollar politicas y practicas efectivas de conservacion. Los modelos de habitat del koala se basan en (1) estudios ecologicos de poblaciones de koala con alta densidad en areas limitadas (2) estudios fisiologicos de la nutricion del koala y caracteristicas de las plantas usadas como alimento, y (3) reconocimientos de la distribucion geografica del koala y las caracteristicas biologicas y fisicas de los bosques. La funcion de modelos para la conservacion de koalas varia segun las expectativas y los usos asignados a estos modelos por los legisladores, las personas responsables de adoptar decisiones, los manejadores de tierras y los ciudadanos. Si bien los modelos de habitat actuales abordan muchas de estas necesidades, en general carecen de suficiente certeza y autoridad para resolver disputas y desarrollar politicas. Los datos y modelos no publicados e inadecuadamente revisados contribuyen a su interpretacion equivocada y argumentacion. Se necesita mejorar el proceso de toma de decisiones para incrementar la participacion constructiva de todos los grupos de interes y para enfocar en el problema de conservacion del koala, y asi reducir el uso de medios de comunicacion masiva y juzgados para alcanzar los objetivos.

Adequacy of the ongoing koala policy process and whether it can conserve koalas is currently in dispute. To address this issue, interdisciplinary guidelines are available to improve koala policy and management and to find consensus. These guidelines focus attention on five policy elements. The first three are rational, political, and moral perspectives on koala policy; the fourth the standpoint of a participant, and the fifth is knowledge integration for practical action. We discuss and illustrate these elements with koala case material. Rationality in policy is addressed through problem orientation, which requires participants to clarify goals, identify problems, and create alternatives in an iterative way. We examined the political dynamics—value clashes—in decision processes. A decision process ideally clarifies and secures common interests. We provide standards for each decision function, such as reliability, comprehensiveness, timeliness. Morality rests on basic premises that are used to justify policy positions. Clarification of the participant's standpoint addresses differing personalities, epistemologies, disciplines, and organizational and parochial biases. Integrating knowledge for practical policy action requires a conceptual framework that is up to the demands of the task. Together the five policy elements make up a logically comprehensive set of interrelated concepts for koala policy development, implementation, and appraisal. Many opportunities exist to use these guidelines skillfully in on-the-ground koala conservation efforts to improve koala policy outcomes. Resumen: En la actualidad se cuestiona si el proceso existente usado para fijar politicas sobre koalas es adecuado y si puede resultar en su conservacion. Para tratar este tema, existen directrices interdisciplinarias dirigidas a mejorar las politicas y el manejo de los koalas y a lograr un consenso. Estas directrices analizan cinco “elementos” relacionados con la fijacion de politicas. Los primeros tres abarcan las perspectivas racionales, politicas y morales de las politicas sobre koalas; el cuarto se refiere al punto de vista del participante; y el quinto a la integracion del conocimiento para una accion practica. Discutimos e ilustramos estos elementos con ejemplos de casos para koalas. La racionalidad en la politica es atendida mediante la orientacion del problema, lo cual requiere que los participantes clarifiquen metas, identifiquen problemas y creen alternativas de manera iterativa. Examinamos la dinamica politica ( por ejemplo el choque de valores) en el proceso de decision. En el caso ideal, el proceso de decision aclara y asegura los intereses en comun. Proveemos normas para cada funcion de decision (es decir, confiabilidad, comprension, oportunidad). La moralidad descansa sobre premisas basicas que se usan para justificar las posiciones politicas. La aclaracion del punto de vista del participante atiende las diferencias entre personalidades, epistemologias, disciplinas y sesgos locales y de organizacion. La integracion del conocimiento para fijar politicas de accion practica requiere de un marco conceptual que se basa en las demandas del trabajo. Juntos, estos cinco aspectos del desarrollo de politicas integran un juego logico e integrado de conceptos relacionados para el desarrollo, la implementacion y la evaluacion de politicas sobre koalas. Existen muchas oportunidades para usar estas directrices de manera experimentada en los esfuerzos de conservacion del koala sobre el terreno y mejorar los resultados de las politicas sobre koalas.

Australia's koalas are a global treasure, yet there is growing concern that present policy may not adequately conserve viable, wild populations in abundant habitats. Problems in the content and particularly the process of policy making for koala conservation include integrating reliable knowledge and diverse perspectives. We reviewed the overall decision process involved in developing Koala conservation policy, including the functions of intelligence, promotion, prescription, invocation, application, appraisal, and termination. To date, intelligence ( planning ) has lacked social science data, and promotion (open debate) has been confrontational. Koala policy has been unclear about prescription (setting rules) and lacks specificity about needed standards, penalties for violating standards, and making resources available. Invocation and application (implementation) have been differentially successful. Appraisal has been adversarial and incomplete, and termination of weak practices has been difficult. We suggest implementation of procedural standards such as timeliness, comprehensiveness, and rationality for a better koala decision process. The 1998 National Koala Conservation Strategy and various state policies can be upgraded to meet these standards. Opportunities exist to improve koala management policy in all seven functions. We recommend a three-part strategy: (1) identify, describe, and appraise successful conservation efforts to find the best practices, (2) disseminate success stories, and (3) open up new opportunities for improvement in all aspects of koala conservation. Resumen: Los koalas australianos son un tesoro universal, sin embrago existe una creciente preocupacion de que las politicas actuales podrian no estar conservando adecuadamente poblaciones viables y silvestres en habitats abundantes. Los problemas en el contenido y, particularmente, en el proceso de elaboracion de politicas para la conservacion de koalas incluyen aquellos relacionados con la integracion de conocimiento confiable y de diversas perspectivas. Revisamos el proceso general de toma de decisiones usado en el desarrollo de las politicas de conservacion de koalas (inteligencia, promocion, prescripcion, invocacion, aplicacion, evaluacion, terminacion). A la fecha, la inteligencia ( la planificacion) ha carecido de datos provenientes de las ciencias sociales, y la promocion (el debate abierto) ha sido de confrontacion. En cuanto a la prescripcion (el establecimiento de reglas) la politica sobre koalas no es clara y carece de especificidad en cuanto a las normas necesarias, las condenas impuestas por violar las normas y la disponibilidad de recursos. La invocacion y la aplicacion (implementacion) han sido exitosas de manera diferencial. La evaluacion ha sido confrontativa e incompleta y la terminacion de practicas debiles ha sido dificil. Sugerimos que las normas de procedimiento (oportunidad, comprension, racionalidad) sean implementadas para mejorar el proceso de decision para los koalas. La Estrategia Nacional de Conservacion del Koala de 1998 y las politicas estatales pueden ser actualizadas para alcanzar estos estandares. Existen oportunidades para mejorar las politicas de manejo del koala en todas las siete funciones. Recomendamos una estrategia de tres partes: (1) identificar, describir y evaluar los esfuerzos exitosos de conservacion para determinar las mejores practicas (2) diseminar informacion sobre experiencias exitosas, y (3) abrir nuevas oportunidades para mejorar todos los aspectos de la conservacion del koala.

Hypogeous fungi are a large yet unknown component of biodiversity in forests of south-eastern mainland Australia. To better define their diversity and habitat relationships, we identified and counted fruit-bodies at 136 study sites sampling the climatic, geological and topographic features of the region. In one year 7451 fruit-bodies representing 209 species were collected in an autumn and spring sampling period. Only 57 of these species were previously described. Within genera, the number of species ranged from 1 to 21. Sites sampled in autumn averaged higher diversity of species and greater number of fruit-bodies than the same sites sampled in spring. Most major taxa occurred at more sites in autumn than in spring, whereas a few occurred more frequently in spring than in autumn. These patterns are consistent with those identified in previous smaller studies and likely reflect seasonal changes in soil moisture and temperature levels. Subsequent papers will explore factors influencing the occurrence, relative abundance and numbers of species of hypogeous fungi at the study sites and their community structure and possible host–plant relationships.

Fruit-bodies of hypogeous fungi were sampled over two seasons across 136 forested study sites representing a stratified sample of the climatic, geological and topographic features of far south-eastern mainland Australia. Two hundred and nine species, over three-quarters being undescribed, were recorded. Statistical models based on various environmental attributes measured for each site were developed for the occurrence of several common taxa. At a landscape scale, climatic factors such as mean minimum temperature of the coldest month and annual mean moisture index were important explanatory variables for most taxa examined, but the type of response varied. More locally, topographic position, soil fertility, time since last fire and micro-habitat structures such as the leaf litter layer and number of large fallen trees also influenced the distribution of taxa in different ways. A model was then developed for the number of fungal species occurring at each site. Important explanatory variables were type of substrate, topography and diversity of potential host eucalypt species. The utility of each model constructed needs evaluation by further sampling of hypogeous fungi. Possible implications of our findings for forest management are discussed. Further analyses of our existing data are also identified.

We evaluated the nutritional value of sporocarps of Rhizopogon vinicolor, a common hypogeous fungus in the coniferous forests of North America, for two small mammal species: the Californian red-backed vole (Clethrionomys californicus) and the northern flying squirrel (Glaucomys sabrinus). Although the nitrogen concentration of sporocarps was high, much of it was in non-protein form or associated with cell walls, suggesting that it may be of low nutritional value or protected from mammalian digestive enzymes. Sporocarps also had high concentrations of cell wall constituents, indicating low availability of digestible energy. When fed a diet of this fungus alone in a controlled feeding experiment both mammal species lost a small amount of body mass. Digestibilities of dry matter, nitrogen, cell wall constituents and energy from sporocarps by both species were lower than the digestibilities of other food types by other similarly sized small mammals. Red-backed voles digested the various components of sporocarps at least as well as the flying squirrels, even though they were almost six-fold smaller in body mass. This observation supports the notion that red-backed voles, like other microtine rodents, have morphological and physiological adaptations of the digestive system that are postulated to permit greater digestion of fibrous diets than predicted on the basis of body size. Despite this, our results re-affirm previous conclusions that hypogeous fungi are only of moderate nutritional value for most small, hindgut-fermenting mammals. Future studies should focus on the importance of mixed-species of fungi in the diet of small mammalian mycophagists.

Theory predicts that mammalian herbivores detoxify different classes of plant secondary compounds via separate metabolic pathways and that generalist herbivores maintain broad diet breadth to avoid overloading individual detoxification pathways. We tested the hypothesis that a generalist marsupial herbivore, the common brushtail possum, Trichosurus vulpecula, can maintain a higher intake of food when allowed to select from two diets containing different profiles of secondary compounds (phenolics and terpenes) than when given access to the diets individually. Diets consisted of a fruit and vegetable mash to which was added ground leaves of either Eucalyptus melliodora or E. radiata. E. melliodora and E. radiata differ in their concentrations and types of secondary compounds. Brushtail possums include these eucalypt species as part of their natural diet. We measured food consumption and detoxification metabolites of possums on these diets. Consistent with the hypothesis, animals presented with a choice of both diets consumed more food than animals given diets singly. One of the two indicators of detoxification, acid load in urine, differed significantly between diets while the other, glucuronic acid, did not. These results provide partial support for the hypothesis that diet breadth is governed by detoxification abilities.

Seedlings of Eucalyptus tereticornis (Smith) were grown under two levels of availability each of CO2 (352 and 793 µmol mol−1), soil nutrients (1/24 and 1/4 Hoagland’s solution) and light (full and 30% sunlight). Low soil nutrient availability or high light increased the C:N ratio of leaves, leading to lower leaf nitrogen concentrations, higher leaf specific weights and higher levels of both total phenolics and condensed tannins. These results were consistent with other studies of the effect of environmental resource availability on foliage composition. Similar results were observed when the C:N ratio of leaves was increased under elevated CO2. The changes in leaf chemistry induced by the treatments affected the performance of 4th-instar larvae of Chrysophtharta flaveola (Chapuis) fed on the leaves. Increased C:N ratios of leaves reduced digestive efficiencies and pupal body sizes and increased mortality. Below a threshold nitrogen concentration of approximately 1% dry mass, severe reductions in the performance of larvae were recorded. Such changes may have significant consequences for herbivores of Eucalyptus, particularly in view of projected increases in atmospheric CO2.

The eucalypt forests of temperate eastern Australia contrast with many forests in tropical Australia, Asia, Africa and Central America in terms of degrees of sclerophylly, concentrations of nutrients in foliage, types and amounts of chemical challenges posed for herbivores, and the range of alternatives to foliage as food. Comparisons between digestive strategies employed by arboreal herbivorous marsupials and primates inhabiting these forests reveal several trends : (i) foregut-fermenters occur only in tropical and sub-tropical forests, whereas caecum and caecum-colon fermenters occur in both temperate eucalypt and the tropical forests ; (ii) the arboreal marsupials and primates (koalas, greater gliders, ringtail possums and sportive lemurs) that are the most folivorous are caecum or caecum-colon fermenters with colonic specializations for selective retention of small particles of digesta ; (iii) no caecum or caecum- colon fermenters lacking colonic separation mechanisms achieve consistently high degrees of folivory ; (iv) even the most folivorous foregut-fermenting arboreal marsupials (tree kangaroos) or primates (colobus monkeys) include a substantial proportion of high-quality components (fruits or seeds) in their diet. Caecum or caecum-colon fermentation with colonic separation is postulated to be essential for a high degree of folivory in small mammals because it offsets potential limits on intake of high-fibre food and minimizes losses of faecal nitrogen that otherwise would be prohibitive. This digestive strategy is common among folivores in eucalypt forests because the low abundance of large seeds and fleshy fruits limits folivory-frugivory and folivory-granivory. Foregut fermentation employing a sacciform/tubiform forestomach (as in tree kangaroos and colobus monkeys) is postulated to be optimal for mixed leaf/fruit and leaf/seed diets that are available in many tropical forests, assuming it allows high-fibre meals to be retained for microbial fermentation while permitting low-fibre meals to pass rapidly to the hindstomach for acid/enzymic digestion. However, foregut fermentation appears innappropriate for either primary frugivory or exclusive folivory due to the inefficiency of microbial digestion of simple sugars and constraints on microbial fermentation as a primary energy source for small mammals.

We tested predictions of a chemical reactor model of digestion of glucose solutions by rainbow lorikeets (Trichoglossus haematodus, 125 g). The optimization criterion was the maximization of net energy gain. The predictions were that residence time in the small intestine would be inversely related to sugar concentration, and extraction efficiency would be inversely related to sugar concentration and generally below 90%. Residence time in the small intestine was indexed by the transit time (TT) of the nonabsorbed marker polyethylene glycol (molecular weight = 4, 000), and extraction efficiency was measured by the inert indicator ratio technique. Birds were tested when ingesting 0.4 or 1.2 M D-glucose. All predictions were rejected: TT was independent of concentration (average = 37 ± 4 min, n = 7 birds), and extraction efficiency was uniformly very high (98.0% ± 0.4%) and also not influenced by glucose concentration. At low and high sugar concentration the rates of glucose absorption were similar (average =...

Regulation of acid-base homeostasis is essential for mammals and birds. Biotransformation and metabolism of absorbed plant secondary metabolites (PSMs) results in the production of organic acids that threaten acid-base homeostasis. Consequently these acids must be buffered and excreted from the body. The production of an acid load from detoxified PSMs should occur in herbivorous mammals and birds and with most PSMs and so may provide a unifying theme to explain many effects of PSMs on animal metabolism. Since the organic acids will be largely ionized at physiological pH, disposal of the hydrogen ion and the organic anion may proceed independently. Most hydrogen ions (H(+)) from organic acids are eliminated by one or more of three ways: (1) when they react with bicarbonate in the extracellular fluid to form carbon dioxide and the carbon dioxide is exhaled, (2) when they bind to dibasic phosphate and are excreted by the kidney as monobasic phosphate, and (3) when they are buffered and retained in the skeletal system. The secretion of phosphate ions and ammonium excretion are two ways in which the kidney replaces bicarbonate ions that have been eliminated as carbon dioxide. Secretion in the kidney tubule is an important means of excreting excessive organic anions rapidly. This process is saturable and may be subject to competition from a variety of different metabolites. Lagomorphs have limited capacity to form new bicarbonate from ammonium excretion and may therefore be obliged to excrete other cations such as sodium to balance the excretion of organic anions from PSMs. Acidemia has wide-ranging impacts on animals but browsing mammals and birds may have to break down muscle tissues to provide for urinary ammonium in order to generate bicarbonate for buffering. Acidemia also can affect the extent of urea recycling. Animals consuming browse diets may have to regulate feeding so that the rate of formation of hydrogen ions does not exceed the rate of disposal. The mechanisms by which this could occur are unknown.

The metabolic pathways involved in degradation of tannin-protein complex (T-PC) were investigated in various facultatively anaerobic bacteria, with specific reference to fecal isolates from the koala including T-PC-degrading enterobacteria (T-PCDE),Streptococcus bovis, Klebsiella pneumoniae, andK. oxytoca. It was demonstrated that T-PCDE andS. bovis biotype I were capable of degrading protein complexed with gallotannin (a hydrolyzable tannin), but not that complexed with quebracho (a condensed tannin). Subsequent studies showed that these strains metabolized gallic acid to pyrogallol. Strains ofKlebsiella pneumoniae andK. oxytoca, which did not degrade T-PC, also metabolized gallic acid into pyrogallol. Pyrogallol was not degraded by any strains studied, but it was not detected in fresh feces of the koalas. The majority of strains isolated from feces could degrade phloroglucinol. Based on these findings, we propose that members of the gut microflora of the koala cooperate in the degradation of T-PC.

The long-nosed potoroo (Potorous tridactylus), a medium-sized, ground-dwelling marsupial, inhabits the foothills and coastal forests of southeastern mainland Australia. Faecal analysis confirmed the mycophagous habit of P. tridactylus at a eucalypt forest site in East Gippsland, Victoria; in one month, the spores of 33 different fungi were identified. The majority of species (27) were hypogeal or subhypogeal gasteromycetes that form ectomycorrhizae with forest trees and shrubs, and included the widespread and common Mesophellia pachytrix. The possible role of mycophagy in establishment of eucalypt-fungal mycorrhizae was investigated in several ways. Fungal spores were viable after passage through the gut of P. tridactylus; application of spore-bearing faeces to seedlings of Eucalyptus sieberi and Eucalyptus globoidea grown in sterile soil produced ectomycorrhizae. Spores of M. pachythrix were among the most common spores in these faeces and some of the resulting ectomycorrhizae were of the type expected from M. pachythrix. In contrast, direct application of M. pachythrix spores from sporocarp tissue to seedlings produced no ectomycorrhizae. Ectomycorrhizae also were established on seedlings grown in unsterilized forest soil, indicating that soil-borne spores had been conditioned, either by passage through the gut of a mammal or some other means, for reaction with the roots of eucalypts. Addition of faeces improved root and shoot growth of seedlings, although we could not determine whether this was primarily due to the formation of ectomycorrhizae, the addition of nutrients in the faeces, or a combination of both. Potorous tridactylus may enhance the re-establishment of mycorrhizal colonies in logged and/or burned forest sites by dispersing in its faeces, the spores of mycorrhizal fungi from sporocarps consumed within the disturbed area, as well as spores from sporocarps eaten in adjacent undisturbed habitat. In performing this function, P. tridactylus may also aid in the recovery of regenerating silvertop ash-stringybark forests.

Allometric considerations suggest that small mammals should be unable to eat highly fibrous diets. A combination of the selective and more rapid passage of fibrous material through the gut, together with changes in gut capacity when energy requirements increase, may allow small mammals to escape these allometric constraints. Recent evidence that birds can absorb essential amino acids from the caecum (which has hitherto been considered insignificant in mammals) suggests that birds and mammals have evolved very different ways to be a herbivore.

Optimal conditions for extraction of tannins and other phenolics from tree foliage and their subsequent storage rarely have been investigated. We investigated methods of drying leaves, optimal solvents, and the effects of light and temperature on the extractability and stability of condensed tannins (proanthocyanidins) and total phenolics from leaves ofEucalyptus trees. Aqueous acetone was a better solvent than aqueous methanol for condensed tannins and total phenolics, but condensed tannins were less stable in aqueous acetone than aqueous methanol. Stability of condensed tannins also was decreased substantially by room temperature versus 4°C and by exposure to indirect sunlight, although the assay for total phenolics was unaffected. For quantitative estimation of condensed tannins, extraction with 50% acetone was better than methods of direct analysis of leaf tissue. The highest estimates of total condensed tannins were obtained by exhaustive extraction with 50% acetone followed by direct analysis of the residue. Lyophilization of fresh leaf increased yield of condensed tannin (although usually by less than 10%). Lyophilization and subsequent storage of extracts had little effect on assays for condensed tannins or total phenolics.

We investigated the utility of near-infrared reflectance spectroscopy (NIRS) as a means of rapidly assaying chemical constituents of Eucalyptus leaves and of directly predicting the intake of foliage from individual trees by greater gliders (Petauroides volans) and common ringtail possums (Pseudocheirus peregrinus). The concentrations of total nitrogen, neutral detergent fiber, condensed tannins and total phenolics could be predicted accurately by partial least squares regression models relating the near-infrared reflectance spectra of foliage samples to analyses performed using standard laboratory procedures. Coefficients of determination (r2) for all four constituents ranged between 0.88 and 0.98, and standard errors of prediction between 0.80 mg g–1 dry matter (DM) for total nitrogen and 5.14 quebracho equivalents g–1 DM for condensed tannins. Near-infrared spectral- based models of food intake had r2 values of 0.90 and 0.95 with a standard error of prediction of 3.4 and 8.3 g DM kg–0.75 day–1 for greater gliders and common ringtail possums respectively. We used the predictive model of food intake for greater gliders to examine the relationship between leaf palatability and documented food preferences of animals in the wild. Ranked differences in leaf palatability across four Eucalyptus species were consistent with documented food preferences of greater gliders in the wild. We conclude that NIRS provides a powerful tool to predict foraging behaviour of herbivores where forage choices are determined by compositional attributes of food.

The production of milk by lactating females, and energy expenditure and foliage intake of their dependent young, were investigated in free-ranging koalas. Koalas had the lowest mass-specific daily milk-energy production at peak lactation so far recorded in a mammal, but the duration of reproduction was 58% longer than the combined marsupial and eutherian average. As a consequence, the total energy input to reproduction in koalas was similar to that in other mammals. We propose that the prolonged lactation and low daily rate of energy transfer to the young by female koalas is an adaptation to the low energy availability from their diet of Eucalyptus foliage. Energy requirements (field metabolic rates) of young koalas were lower than those expected for typical marsupials (only 60% at permanent pouch exit), which may be a necessary preadaptation that allows the low rate of maternal energy transfer. However, the energy requirements of the adult females were no lower than expected for marsupials. This pattern of energy requirements and age resulted in a linear relationship between field metabolic rate and mass for the koalas in this population. Differences in milk production between the years of the study coincided with fluctuations in the availability of preferred young foliage, which suggests that lactational output by koalas may be flexible and affected by diet quality. Despite the interannual differences in milk production, growth of the young was similar in the two years.

We tested the hypothesis that most sugar absorption across the small intestine's brush border is normally by a mediated pathway, i.e., the Na(+)-glucose cotransporter. In nectar-eating rainbow lorikeets (Trichoglossus haematodus, 120 g), we measured mediated D-glucose uptake in vitro using the everted-sleeve technique. The apparent Michaelis constant (7.7 mM) was similar to that observed in hummingbirds and other birds in general. Maximal mediated D-glucose uptake summed along the entire length of intestine (48 cm) was not notably high (5.34 mumol/min) when compared with other avian species and was an order of magnitude too low to explain observed rates of glucose absorption in vivo (54.5 mumol/min). This implied that nonmediated glucose absorption predominated, and independent verification of that was sought. We applied a pharmacokinetic technique to measure in vivo absorption of L-glucose, the stereoisomer that does not interact with the Na(+)-glucose cotransporter. Eighty percent of L-glucose that was ingested was absorbed, confirming that nonmediated absorption can be substantial. We discuss how equating L-glucose absorption with passive D-glucose absorption depends on certain assumptions regarding the relative importance of diffusive and convective passive flux. In either case, the conclusion about the relative importance of passive absorption should still hold.

Trees of the genus Eucalyptus dominate the temperate forests of Australia. Eucalypts are known for high production of a wide range of polyphenols, many of which affect acid-base balance and retention of energy and nitrogen in the few marsupials (pouched mammals) that eat Eucalyptus foliage (i.e., koalas and possums). Koalas and leafeating possums are abundant in a small proportion of present eucalypt forests and appear to be restricted to eucalypt communities growing on the best soils. I have investigated two hypotheses: (1) The concentration of polyphenols in foliage increases as nutrient availability for growth decreases; (2) the nutritional quality of foliage is higher in eucalypt communities favorable for arboreal, folivorous marsupials than in unfavorable communities, largely due to the influence of polyphenols. Both hypotheses appear to hold when total polyphenols are considered, although the same trends are not evident for all components of the polyphenolic fraction. The challenge now is to understand the rules determining allocation of carbon to individual polyphenols in eucalypts and the significance of between-species differences for the ecology of leaf-eating marsupials.

The passage of particulate and solute digesta through the alimentary tract of koalas fed the mature foliage ofEucalyptus punctata was investigated using radioisotopic markers. The solute marker was retained for longer than the particulate marker, the mean retention times of both markers (213 h and 99 h respectively) being longer than has been reported in most other mammals. Both the pattern of excretion in faeces of orally administered markers and data from a slaughter experiment indicated that the principal site of marker retention was the highly developed caecum/proximal colon which appeared to function as a single mixing compartment. An undettermined physiological mechanism caused solutes and fine particles of digesta to be selectively retained in the caecum/proximal colon. It is suggested that this caused the particulate marker to distribute in two pools situated in parallel producing a marker excretion curve different from any reported in other mammals. It is postulated that the rate of clearance of dietary fibre from the hindgut would be maximized by this mechanism and that this in turn would elevate the upper limit to intake of food, and hence digestible nutrient, by koalas. Such an adaptation would partially compensate for the physiological constraints on nutrient acquisition from fibrous diets imposed by small body size and thus may be important in enabling the koala to utilize a diet avoided by most other small herbivores.

The pattern and rate of microbial fermentation were studied in captive and wild-shot greater gliders (Petauroides volans) and captive brushtail possums (Trichosurus vulpecula) fed Eucalyptus foliage. The cecum and the cecum/proximal colon were the principal sites of microbial activity in the greater glider and brushtail possum, respectively. Total short-chain fatty acid (SCFA) concentrations were 36 mM and 70 mM in captive and wild-shot greater gliders, respectively, and 75 mM in the brushtail possums. SCFA production rates in the hindgut were similar in vitro in the two species (19-20 mmol/L/h) but slower than in the hindgut of most herbi-vores, although this was of set by the large volume of digesta contained in the hindgut. The pattern and rate of fermentation were similar in captive and wild-shot greater gliders. The difference between the initial molar proportions of acetate, propionate, and butyrate and their proportional contributions to total SCFA production in both species suggested that SCFAs we...

Digestion and energy metabolism in an arboreal marsupial, the koalaPhascolarctos cinereus, fed mature foliage from a common food tree, the grey gumEucalyptus punctata, were investigated. Six feeding (balance) experiments, at various times of year, and one slaughter experiment were performed and average daily oxygen consumption was measured. The average apparent digestibilities of dietary constituents were: dry matter 54%; total cell-contents 69%; available carbohydrate 92%; crude lipid 43%; total nitrogen 45%; total phenolics 91%; total cell walls 25%; hemicellulose 24%; acid-detergent fibre 25%; cellulose 31%; lignin 19%. Average digestible and metabolizable energy intakes were 0.50 and 0.43 MJ kg−0.75 d−1 respectively of which only 0.28 MJ kg−0.75 d−1 was expended in oxidative metabolism. The digestible energy intake required for maintenance was estimated to be 0.33 MJ kg−0.75 d−1, which is lower than that of eutherian and of other marsupial herbivores. The principal sources of metabolizable energy were non-structural carbohydrate and lipid. It is postulated that the ability of koalas to utilizeEucalyptus foliage as a sole source of nutrients is facilitated by their low requirement for energy and their ability to maximize intake of non cell-wall constituents.E. punctata foliage has a high digestible energy content compared with the foliage of many other trees and this may be a factor in its selection by koalas.

Hypogeous fungi often contain high concentrations of nitrogenous compounds, vitamins, and minerals and are major dietary items for many rodents and other small mammals in North American forests. For these reasons ecologists have presumed hypogeous fungi to be of high nutritional value for small mammals. In a series of feeding experiments we investigated the nutritional quality of sporocarps (fruiting bodies) of the hypogeous fungus Elaphomeyces granulatus in the diet of the golden—mantled ground squirrel Spermophilus saturates, which is highly mycophagogus throughout its season of activity. We compared the digestive utilization of the fungus by this small mammal with digestibility of a range of plant foods available in nature. The sporocarps of E. granulatus had a high concentration of nitrogen, but 80% of this nitrogen was in the totally indigestible spores and the relatively indigestible cell walls of the peridium, and only half of the remaining 20% was protein nitrogen. Even though the squirrels ate the peridium in preference to the spore—laden core, the digestibility of the ingested nitrogen was only °50%, which is much lower than the digestibility of most plants. The digestible energy content of the fungus was low compared with that of conifer seeds and similar to that of grasses and legumes that are naturally eaten by the ground squirrels in small amounts. The overall (dry—matter) digestibility of E. granulatus sporocarps (60%) appears to be near the minimum digestibililty on which golden—mantled ground squirrels are able to maintain themselves. Therefore, sporocarps of E. granulatus cannot be regarded as a high—quality dietary items in terms of the availability of nutrients. We suggest that this is true for hypogeous fungi in general and that their value as a food resource derives mainly from their great abundance during the active season of small mammals such as ground squirrels and from their emission of strong odors, which makes mature sporocarps highly detectable. These features should maximize the yield of energy and nutrients to small mammalian mycophagists in relation to foraging effort.

The rate of volatile fatty acid (VFA) production in the hindgut of three koalas (Phascolarctos cinereus) maintained onEucalyptus punctata foliage was measured by in vitro incubation.