Knowledge of mammalian diversity is still surprisingly disparate, both regionally and taxonomically. Here, we present a comprehensive assessment of the conservation status and distribution of the world's mammals. Data, compiled by 1700+ experts, cover all 5487 species, including marine mammals. Global macroecological patterns are very different for land and marine species but suggest common mechanisms driving diversity and endemism across systems. Compared with land species, threat levels are higher among marine mammals, driven by different processes (accidental mortality and pollution, rather than habitat loss), and are spatially distinct (peaking in northern oceans, rather than in Southeast Asia). Marine mammals are also disproportionately poorly known. These data are made freely available to support further scientific developments and conservation action.

International conservation planning at the end of the twentieth century is dominated by coarse-filter, supra-organismal approaches to conservation that may be insufficient to conserve certain species such as the jaguar ( Panthera onca ). If we are to retain broadly distributed species into the next century, we need to plan explicitly for their survival across their entire geographic range and through political boundaries while recognizing the variety of ecological roles the species plays in different habitats. In March 1999 the Wildlife Conservation Society sponsored a priority-setting and planning exercise for the jaguar across its range, from northern Mexico to northern Argentina. Field scientists from 18 countries reached consensus on four types of information: (1) the spatial extent of their jaguar knowledge, (2) the known, currently occupied range of jaguars, (3) areas with substantial jaguar populations, adequate habitat, and a stable and diverse prey base, and (4) point localities where jaguars have been observed during the last 10 years. During the exercise, these experts also conducted a range-wide assessment of the long-term survival prospects of the jaguar and developed an algorithm for prioritizing jaguar conservation units occurring in major habitat types. From this work, we learned that the known, occupied range of the jaguar has contracted to approximately 46% of estimates of its 1900 range. Jaguar status and distribution is unknown in another 12% of the jaguar's former range, including large areas in Mexico, Colombia, and Brazil. But over 70% of the area where jaguars are thought to still occur was rated as having a high probability of supporting their long-term survival. Fifty-one jaguar conservation units representing 30 different jaguar geographic regions were prioritized as the basis for a comprehensive jaguar conservation program. Planeación para Salvar una Especie: El Jaguar como ModeloResumen: La planeación de la conservación internacional al final del siglo veinte esta dominada por enfoques de grano grueso, supra-organísmicas que pueden ser insuficientes para conservar ciertas especies como el jaguar ( Panthera onca ). Si hemos de mantener especies ampliamente distribuidas en el próximo siglo, necesitamos planificar su supervivencia explícitamente en todo su rango geográfico a través de límites políticos al mismo tiempo que se reconozca la variedad de funciones ecológicas de las especies en diferentes hábitats. En marzo de 1999 la Sociedad de Conservación de Vida Silvestre promovió un ejercicio de definición de prioridades y de planeación para el jaguar en todo su rango de distribución, desde el norte de México hasta el norte de Argentina. Científicos de 18 países llegaron a consensos en cuatro tipos de información: (1) la extensión espacial de su conocimiento del jaguar, (2) el rango conocido, actualmente ocupado por el jaguar, (3) áreas con poblaciones importantes, hábitat adecuado y una base de presas estable y diversa y (4) localidades en las que se han observado jaguares durante los ú...

Threatened species lists are designed primarily to provide an easily understood qualitative estimate of risk of extinction. Although these estimates of risk can be accurate, the lists have inevitably become linked to several decision-making processes. There are four ways in which such lists are commonly used: to set priorities for resource allocation for species recovery; to inform reserve system design; to constrain development and exploitation; and to report on the state of the environment. The lists were not designed for any one of these purposes, and consequently perform some of them poorly. We discuss why, if and how they should be used to achieve these purposes.Governments and nongovernmental organizations produce threatened species lists for three main reasons: (1) to assess potentially adverse impacts on species; (2) to help inform conservation priorities, including reserve system design; or (3) as a component of State of the Environment Reports [1]. Moreover, in many countries there is a direct connection between threatened species lists and legislation (e.g. the Convention on International Trade in Endangered Species [2] and the US Endangered Species Act), leading to political and social considerations in the listing protocol. The ideal characteristics of these lists, and the protocols for generating them, will depend on the specific objectives. Regardless of who generated the list, there are three classes of user group: the public, governments and conservation organizations. All protocols result in an assessment of threat, couched in words that reflect the probability of decline or loss of a taxon at different regional scales [3]. Some are designed to apply within a local region or state [4][5][6], whereas others have national [7][8][9], or international status [10,11], or are used at multiple political scales [12][13][14]. Some have also been developed for specific taxonomic groups [15][16][17]. These protocols share many attributes and use similar information, such as population size, extent, number of populations and trends in at least some of these variables.Because of the variety of objectives and users, the interpretation of lists is variable, and most are used for more than one purpose, regardless of their original intent. Here, we critically assess four ways in which threatened species lists are commonly used. We argue that they are used for purposes beyond their original intent; furthermore, they perform some of these uses poorly. The protocols used to generate lists differ in the extent to which they consider management variables, taxonomic status, recoverability and assessments of past or future trends. In addition, they employ different logical systems to interpret data, treat missing data differently, and apply different weights to the variables. As a result, the level of correspondence among classifications resulting from different methods can be low, even when using the same data [18]. Given the widespread use of such lists to allocate scarce conservation resources, before app...

Brazilian free‐tailed bats (Tadarida brasiliensis) form enormous summer breeding colonies, mostly in caves and under bridges, in south‐central Texas and northern Mexico. Their prey includes several species of adult insects whose larvae are known to be important agricultural pests, including the corn earworm or cotton bollworm (Helicoverpa zea). We estimate the bats' value as pest control for cotton production in an eight‐county region in south‐central Texas. Our calculations show an annual value of $741 000 per year, with a range of $121 000–$1 725 000, compared to a $4.6–$6.4 million per year annual cotton harvest.

Evaluating the degree of disturbance of any region to determine its relative importance for conservation purposes requires procedures that are relatively inexpensive and that yield accurate results fast. Because bats are abundant, diverse, and easy to sample, especially in the Neotropical rainforest, they fulfill several of the requirements of indicator species as identified in the literature. For 10 months we sampled bat communities in the Selva Lacandona in Chiapas, Mexico, at 15 sites representing five habitats. We also measured 10 variables representing vegetation structure and diversity at each site. With fuzzy-set techniques we produced a gradient classification of disturbance for the 15 sites based on the vegetation data. We explored the relationship between vegetation conditions, described as the membership degrees in the construct "fuzzy forest set" (the complementary fuzzy set of "disturbance"), and four bat community variables. Bat species richness, number of rare bat species, and the bat diversity index were positively correlated with the vegetation scores, and relative abundance of the most abundant bat species was negatively correlated with vegetation scores. A high number of phyllostomine species in a community is a good indicator of low levels of disturbance. Although a single indicator group will probably not be sufficient for decision-making processes in conservation, evaluating bat populations may be a good first step in assessing an area's conservation value, especially in rainforest regions. Diversidad y Abundancia de Murciélagos como Indicadores de Perturbaciones en Selvas Húmedas NeotropicalesResumen: La evaluación del grado de perturbación de una región particular para determinar su importancia relativa para propósitos de conservación requiere que los procesos de toma de decisiones utilicen tecnologías relativamente baratas y que proporcionen resultados precisos pronto. Puesto que los murciélagos son abundantes, diversos y fáciles de muestrear, particularmente en las selvas húmedas del Neotrópico, llenan varios de los requerimientos de las especies indicadoras. Muestreamos por 10 meses comunidades de murciélagos en la Selva Lacandona de Chiapas, México, en 15 sitios representantes de cinco hábitats. También medimos 10 variables representantes de la estructura y diversidad de la vegetación en cada sitio. Mediante el uso de técnicas de conjuntos difusos produjimos una clasificación gradual de la perturbación de la vegetación para los 15 sitios. Exploramos las relaciones entre las condiciones de la vegetación, descritos como los grados de membresía en la construcción de los conjuntos difusos del bosque (el conjunto difuso complementario de la perturbación) y cuatro variables de la comunidad de murciélagos. La riqueza de especies de murciélagos, el número de especies de murciélagos raros, y el índice de diversidad de murciélagos estuvieron positivamente correlacionados con los valores de la vegetación y la abundancia relativa de la especie más abundante estuvo negativamente correlacionado con ...

Evaluating the degree of disturbance of any region to determine its relative importance for conservation purposes requires procedures that are relatively inexpensive and that yield accurate results fast. Because bats are abundant, diverse, and easy to sample, especially in the Neotropical rainforest, they fulfill several of the requirements of indicator species as identified in the literature. For 10 months we sampled bat communities in the Selva Lacandona in Chiapas, Mexico, at 15 sites representing five habitats. We also measured 10 variables representing vegetation structure and diversity at each site. With fuzzy-set techniques we produced a gradient classification of disturbance for the 15 sites based on the vegetation data. We explored the relationship between vegetation conditions, described as the membership degrees in the construct "fuzzy forest set" (the complementary fuzzy set of "disturbance"), and four bat community variables. Bat species richness, number of rare bat species, and the bat diversity index were positively correlated with the vegetation scores, and relative abundance of the most abundant bat species was negatively correlated with vegetation scores. A high number of phyllostomine species in a community is a good indicator of low levels of disturbance. Although a single indicator group will probably not be sufficient for decision-making processes in conservation, evaluating bat populations may be a good first step in assessing an area's conservation value, especially in rainforest regions. Diversidad y Abundancia de Murciélagos como Indicadores de Perturbaciones en Selvas Húmedas NeotropicalesResumen: La evaluación del grado de perturbación de una región particular para determinar su importancia relativa para propósitos de conservación requiere que los procesos de toma de decisiones utilicen tecnologías relativamente baratas y que proporcionen resultados precisos pronto. Puesto que los murciélagos son abundantes, diversos y fáciles de muestrear, particularmente en las selvas húmedas del Neotrópico, llenan varios de los requerimientos de las especies indicadoras. Muestreamos por 10 meses comunidades de murciélagos en la Selva Lacandona de Chiapas, México, en 15 sitios representantes de cinco hábitats. También medimos 10 variables representantes de la estructura y diversidad de la vegetación en cada sitio. Mediante el uso de técnicas de conjuntos difusos produjimos una clasificación gradual de la perturbación de la vegetación para los 15 sitios. Exploramos las relaciones entre las condiciones de la vegetación, descritos como los grados de membresía en la construcción de los conjuntos difusos del bosque (el conjunto difuso complementario de la perturbación) y cuatro variables de la comunidad de murciélagos. La riqueza de especies de murciélagos, el número de especies de murciélagos raros, y el índice de diversidad de murciélagos estuvieron positivamente correlacionados con los valores de la vegetación y la abundancia relativa de la especie más abundante estuvo negativamente correlacionado con ...

No abstract

We examined seed dispersal by bats and birds in four habitats of the Selva Lacandona tropical rain forest region, Cliiapas, Mexico. The four habitats represented a disturbance gradient: active cornfield, ten-year-old abandoned cornfield, cacao plantation, and forest. Using seed traps examined before sunrise (0400 h) and before sunset (1800 h), we compared volant vertebrate seed dispersal, assuming that seeds found at the end of the night were dispersed by bats and those found at the end of the day were dispersed by birds. We did not find seeds from other frugivores such as monkeys or opossums. In all habitats bats dispersed more seeds than birds. In most months bats also dispersed more seeds than birds, except in December when no seeds were found in the traps. Bats also consistently dispersed more species of seeds than birds, although a x2 comparison showed differences not to be significant. Fifty percent of the spccies represented in the dispersed seeds in all habitats were pioneer species. Cecropia seeds represented a high percentage (up to 87% of those dispersed by bats and up to 83% by birds) of dispersed seeds that fcll in our traps. 'I'hc influence of bars and birds on sccondary successional processes is likely to be fundamental for the establishment of vcgetation. Since bats dispersed more seeds than birds (primarily to disturbed areas and consisting primarily of pioneer species), they are likely to play an important role in successional and restoration processes among habitats as structurally and vegetationally different as cornfields, old fields, cacao plantations, and forest.