Designatable Units for Status Assessment of Endangered Species

Abstract:  Species status assessment and the conservation of biological diversity may require defining units below the species level to portray probabilities of extinction accurately and to help set priorities for conservation efforts. What those units should be has been debated in the scientific literature largely in terms of evolutionarily significant units (ESUs), but this discourse has had little impact on government policy with regard to status assessment. As with species concepts, the variously proposed ESU concepts have not been resolvable into a single approach. The need for a practicable procedure to identify infraspecific entities for status assignment is the motivation behind employing designatable units (DUs). In aid of a policy to prevent elements of biodiversity from becoming extinct or extirpated, DUs are determined during the process of resolving a species' conservation status according to broadly applicable guidelines. The procedure asks whether putative DUs are distinguishable based on a reliably established taxonomy or a well-corroborated phylogeny, compelling evidence of genetic distinction, range disjunction, and/or biogeographic distinction as long as extinction probabilities also differ. The language of the DU approach avoids wording that implies value judgments concerning evolutionary importance or significance. Because species conservation status assessment is not science but, rather, the use of science to further policy, DUs contribute to a precautionary approach to listing whereby status may be assessed even though knowledge of systematic relationships below the species level may be lacking or unresolved. The pragmatic approach of using DUs has been adopted by the Committee on the Status of Endangered Wildlife in Canada for status assessment of species under the Canadian Species at Risk Act.     

Inhibition of Amazon Deforestation and Fire by Parks and Indigenous Lands

Abstract:  Conservation scientists generally agree that many types of protected areas will be needed to protect tropical forests. But little is known of the comparative performance of inhabited and uninhabited reserves in slowing the most extreme form of forest disturbance: conversion to agriculture. We used satellite-based maps of land cover and fire occurrence in the Brazilian Amazon to compare the performance of large (>10,000 ha) uninhabited (parks) and inhabited (indigenous lands, extractive reserves, and national forests) reserves. Reserves significantly reduced both deforestation and fire. Deforestation was 1.7 (extractive reserves) to 20 (parks) times higher along the outside versus the inside of the reserve perimeters and fire occurrence was 4 (indigenous lands) to 9 (national forests) times higher. No strong difference in the inhibition of deforestation ( p = 0.11) or fire ( p = 0.34) was found between parks and indigenous lands. However, uninhabited reserves tended to be located away from areas of high deforestation and burning rates. In contrast, indigenous lands were often created in response to frontier expansion, and many prevented deforestation completely despite high rates of deforestation along their boundaries. The inhibitory effect of indigenous lands on deforestation was strong after centuries of contact with the national society and was not correlated with indigenous population density. Indigenous lands occupy one-fifth of the Brazilian Amazon—five times the area under protection in parks—and are currently the most important barrier to Amazon deforestation. As the protected-area network expands from 36% to 41% of the Brazilian Amazon over the coming years, the greatest challenge will be successful reserve implementation in high-risk areas of frontier expansion as indigenous lands are strengthened. This success will depend on a broad base of political support.     

MEANING AND FORM IN COMMUNITY PERCEPTION OF TOWN CHARACTER

This study explored the notion of ‘town character’ within the context of one Australian coastal town from the perspective of the community. Responses from a sample of residents to a set of local environmental features were collected using adjective rating scales. Data concerning the perceived character compatibility of features was also collected. Several multivariate statistical procedures, including multi-dimensional scaling, were used to explore the underlying structure in the response pattern and to determine the salience of meanings related to the community's conception of town character, as conveyed through local landscape features. Town character in the context of this study was found to be related to a variety of environmental features and associated meanings. Specifically, a positive character image was strongly supported by natural landscape features associated with their naturalness, beauty, pleasantness, distinctiveness, and interest, by certain built features, (specifically landmark features), associated with their distinctiveness, pleasantness, charm, familiarity, and interest, and by popular social settings associated with connotations of familiarity, friendliness, openness, liveliness, and safety. Features identified as incompatible with local character were associated with negative meanings that included boredom, ugliness, lack of charm, lack of stimulation, monotony, unpleasantness, and being ordinary.     

Patterns of Giving and Receiving Help During Severe Winter Conditions: A Research Note

Severe winter conditions and blizzards may cause persons to be stranded, unable to move from one place to another. Being stranded under such conditions can be life-threatening and often requires help. This is a study of giving and receiving help among people who were stranded during severe winter conditions and blizzards in Bowling Green, Ohio, USA and the surrounding countryside in 1976–1977. Mail questionnaire data were collected from the Bowling Green, Ohio telephone directory which included listings from both rural and urban areas. The family, followed by friends and neighbors, were most important in the giving and receiving of help. There was little difference between the responses of rural and urban residents. Propinquity was found to be an important intervening variable.     

Effects of Human Population Density and Proximity to Markets on Coral Reef Fishes Vulnerable to Extinction by Fishing

Coral reef fisheries are crucial to the livelihoods of tens of millions of people; yet, widespread habitat degradation and unsustainable fishing are causing severe depletion of stocks of reef fish. Understanding how social and economic factors, such as human population density, access to external markets, and modernization interact with fishing and habitat degradation to affect fish stocks is vital to sustainable management of coral reef fisheries. We used fish survey data, national social and economic data, and path analyses to assess whether these factors explain variation in biomass of coral reef fishes among 25 sites in Solomon Islands. We categorized fishes into 3 groups on the basis of life‐history characteristics associated with vulnerability to extinction by fishing (high, medium, and low vulnerability). The biomass of fish with low vulnerability was positively related to habitat condition. The biomass of fishes with high vulnerability was negatively related to fishing conducted with efficient gear. Use of efficient gear, in turn, was strongly and positively related to both population density and market proximity. This result suggests local population pressure and external markets have additive negative effects on vulnerable reef fish. Biomass of the fish of medium vulnerability was not explained by fishing intensity or habitat condition, which suggests these species may be relatively resilient to both habitat degradation and fishing. Efectos de la Densidad de Poblaciones Humanas y la Proximidad del Mercado sobre Peces de Arrecifes de Coral Vulnerables a la Extinción     

Effects of an Alien Ant Invasion on Abundance,Behavior, and Reproductive Success of Endemic Island Birds

Abstract: Biological invaders can reconfigure ecological networks in communities, which changes community structure, composition, and ecosystem function. We investigated whether impacts caused by the introduced yellow crazy ant (Anoplolepis gracilipes), a pantropical invader rapidly expanding its range, extend to higher‐order consumers by comparing counts, behaviors, and nesting success of endemic forest birds in ant‐invaded and uninvaded rainforest on Christmas Island (Indian Ocean). Point counts and direct behavioral observations showed that ant invasion altered abundances and behaviors of the bird species we examined: the Island Thrush (Turdus poliocephalus erythropleurus), Emerald Dove (Chalcophaps indica natalis), and Christmas Island White‐eye (Zosterops natalis). The thrush, which frequents the forest floor, altered its foraging and reproductive behaviors in ant‐invaded forest, where nest‐site location changed, and nest success and juvenile counts were lower. Counts of the dove, which forages exclusively on the forest floor, were 9–14 times lower in ant‐invaded forest. In contrast, counts and foraging success of the white‐eye, a generalist feeder in the understory and canopy, were higher in ant‐invaded forest, where mutualism between the ant and honeydew‐secreting scale insects increased the abundance of scale‐insect prey. These complex outcomes involved the interplay of direct interference by ants and altered resource availability and habitat structure caused indirectly by ant invasion. Ecological meltdown, rapidly unleashed by ant invasion, extended to these endemic forest birds and may affect key ecosystem processes, including seed dispersal.     

Metaphors for Reflecting on Research Practice: Researching with People

There are renewed demands for transparency and stakeholder participation in environmental planning and management. Research is a generic form of practice common to many professions. Appreciating the position of the researcher and reflecting on research practice can enhance its transparency. The case is presented for considering underlying metaphors as a way of making understandings explicit, transparent and structured, so as to enhance reflection on research practice. Metaphors can be explored, either individually or jointly, and learning opportunities can come from the exploration and awareness of alternative metaphors. Four metaphors have been chosen to reflect on research practice: research-as-action, research-as-narrative, research-as-facilitation and research-as-responsible. These metaphors define various roles relevant to researching with people and seem powerful ways of discussing what researching or planning with people might entail, and how to include the position of the researcher/planner in reflective practice. Whilst the primary concern is with research practice, the arguments might equally apply to other forms of practice such as planning, managing, advising or regulating.     

Long-Term Ecosystem Dynamics in the Serengeti: Lessons for Conservation

Abstract:  Data from long-term ecological studies further understanding of ecosystem dynamics and can guide evidence-based management. In a quasi-natural experiment we examined long-term monitoring data on different components of the Serengeti-Mara Ecosystem to trace the effects of disturbances and thus to elucidate cause-and-effect connections between them. The long-term data illustrated the role of food limitation in population regulation in mammals, particularly in migratory wildebeest and nonmigratory buffalo. Predation limited populations of smaller resident ungulates and small carnivores. Abiotic events, such as droughts and floods, created disturbances that affected survivorship of ungulates and birds. Such disturbances showed feedbacks between biotic and abiotic realms. Interactions between elephants and their food allowed savanna and grassland communities to co-occur. With increased woodland vegetation, predators' capture of prey increased. Anthropogenic disturbances had direct (hunting) and indirect (transfer of disease to wildlife) effects. Slow and rapid changes and multiple ecosystem states became apparent only over several decades and involved events at different spatial scales. Conservation efforts should accommodate both infrequent and unpredictable events and long-term trends. Management should plan on the time scale of those events and should not aim to maintain the status quo. Systems can be self-regulating through food availability and predator-prey interactions; thus, culling may not be required. Ecosystems can occur in multiple states; thus, there may be no a priori need to maintain one natural state. Finally, conservation efforts outside protected areas must distinguish between natural change and direct human-induced change. Protected areas can act as ecological baselines in which human-induced change is kept to a minimum     

Using Changes in Agricultural Utility to Quantify Future Climate‐Induced Risk to Conservation

Much of the biodiversity‐related climate change impacts research has focused on the direct effects to species and ecosystems. Far less attention has been paid to the potential ecological consequences of human efforts to address the effects of climate change, which may equal or exceed the direct effects of climate change on biodiversity. One of the most significant human responses is likely to be mediated through changes in the agricultural utility of land. As farmers adapt their practices to changing climates, they may increase pressure on some areas that are important to conserve (conservation lands) whereas lessening it on others. We quantified how the agricultural utility of South African conservation lands may be altered by climate change. We assumed that the probability of an area being farmed is linked to the economic benefits of doing so, using land productivity values to represent production benefit and topographic ruggedness as a proxy for costs associated with mechanical workability. We computed current and future values of maize and wheat production in key conservation lands using the DSSAT4.5 model and 36 crop‐climate response scenarios. Most conservation lands had, and were predicted to continue to have, low agricultural utility because of their location in rugged terrain. However, several areas were predicted to maintain or gain high agricultural utility and may therefore be at risk of near‐term or future conversion to cropland. Conversely, some areas were predicted to decrease in agricultural utility and may therefore prove easier to protect from conversion. Our study provides an approximate but readily transferable method for incorporating potential human responses to climate change into conservation planning. Uso de Cambios en la Utilidad Agrícola para Cuantificar Riesgos Futuros para la Conservación Inducidos por el Clima     

Effects of an Invasive Plant on Population Dynamics in Toads

When populations decline in response to unfavorable environmental change, the dynamics of their population growth shift. In populations that normally exhibit high levels of variation in recruitment and abundance, as do many amphibians, declines may be difficult to identify from natural fluctuations in abundance. However, the onset of declines may be evident from changes in population growth rate in sufficiently long time series of population data. With data from 23 years of study of a population of Fowler's toad (Anaxyrus [ = Bufo] fowleri) at Long Point, Ontario (1989–2011), we sought to identify such a shift in dynamics. We tested for trends in abundance to detect a change point in population dynamics and then tested among competing population models to identify associated intrinsic and extrinsic factors. The most informative models of population growth included terms for toad abundance and the extent of an invasive marsh plant, the common reed (Phragmites australis), throughout the toads’ marshland breeding areas. Our results showed density‐dependent growth in the toad population from 1989 through 2002. After 2002, however, we found progressive population decline in the toads associated with the spread of common reeds and consequent loss of toad breeding habitat. This resulted in reduced recruitment and population growth despite the lack of significant loss of adult habitat. Our results underscore the value of using long‐term time series to identify shifts in population dynamics coincident with the advent of population decline. Efectos de una Planta Invasora sobre las Dinámica Poblacional de Sapos