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Owing to extensive overexploitation and continuous habitat loss in recent decades, Dalbergia stevensonii has become endangered in Central America and its place of origin. Genetic diversity is essential for ensuring the long-term survival of the species and is vital in breeding programs. However, knowledge of the genetic diversity ofD. stevensonii is limited, as no study has been conducted to estimate the population variability in Guatemala. This study is the first to determine the genetic diversity and structure of wild populations of D. stevensonii in Guatemala using molecular markers. The genetic diversity of 90 wild D. stevensonii trees from six populations located in their natural range is currently being evaluated. Genetic diversity was moderate, with an average of 5.83 alleles per locus, a mean Shannon index value of 1.42, and observed and expected heterozygosity of 0.32 and 0.37, respectively. AMOVA indicated that only 6 % of the genetic variation was between populations, and genetic distance values (pairwise FST) suggested moderate differentiation between populations. STRUCTURE and DAPC analyses revealed the existence of three clusters for the 90 samples, while the genetic differentiation among populations is attributed more to genetics than to geographic distance. Conservation of the genetic diversity of D. stevensonii is critical to ensure its long-term survival, and the success of breeding programs focused on improving the traits and characteristics of the species, such as growth rate, wood quality, and resistance to pests and diseases. These findings provide a crucial genetic basis for conservation, management, and restoration of this endemic species. [ABSTRACT FROM AUTHOR]

Severely fragmented habitats increase the risk of extirpation of native mammal populations through isolation, increased edge effects, and predation. Therefore, monitoring the movement of mammal populations through anthropogenically altered landscapes can inform conservation. We used metabarcoding of invertebrate‐derived DNA (iDNA) from carrion flies (Calliphoridae and Sarcophagidae) to track mammal populations in the wheat belt of southwestern Australia, where widespread clearing for agriculture has removed most of the native perennial vegetation and replaced it with an agricultural system. We investigated whether the localization of the iDNA signal reflected the predicted distribution of 4 native species—echidna (Tachyglossus aculeatus), numbat (Myrmecobius fasciatus), woylie (Bettongia penicillata), and chuditch (Dasyurus geoffroii)—and 2 non‐native, invasive mammal species—fox (Vulpes vulpes) and feral cat (Felis catus). We collected bulk iDNA samples (n = 150 samples from 3428 carrion flies) at 3 time points from 3 conservation reserves and 35 road edges between them. We detected 14 of the 40 mammal species known from the region, including our target species. Most detections of target taxa were in conservation reserves. There were a few detections from road edges. We detected foxes and feral cats throughout the study area, including all conservation reserves. There was a significant difference between the diversity (F3, 98 = 5.91, p < 0.001) and composition (F3, 43 = 1.72, p < 0.01) of taxa detections on road edges and conservation reserves. Conservation reserves hosted more native biodiversity than road edges. Our results suggest that the signals from iDNA reflect the known distribution of target mammals in this region. The development of iDNA methods shows promise for future noninvasive monitoring of mammals. With further development, iDNA metabarcoding could inform decision‐making related to conservation of endangered taxa, invasive species management, and impacts of habitat fragmentation. [ABSTRACT FROM AUTHOR]

Minimum patch size criteria for habitat protection reflect the conservation principle that a single large (SL) patch of habitat has higher biodiversity than several small (SS) patches of the same total area (SL > SS). Nonetheless, this principle is often incorrect, and biodiversity conservation requires placing more emphasis on protection of large numbers of small patches (SS > SL). We used a global database reporting the abundances of species across hundreds of patches to assess the SL > SS principle in systems where small patches are much smaller than the typical minimum patch size criteria applied for biodiversity conservation (i.e., ∼85% of patches <100 ha). The 76 metacommunities we examined included 4401 species in 1190 patches. From each metacommunity, we resampled species–area accumulation curves to evaluate how biodiversity responded to habitat existing as a few large patches or as many small patches. Counter to the SL > SS principle and consistent with previous syntheses, species richness accumulated more rapidly when adding several small patches (45.2% SS > SL vs. 19.9% SL > SS) to reach the same cumulative area, even for the very small patches in our data set. Responses of taxa to habitat fragmentation differed, which suggests that when a given total area of habitat is to be protected, overall biodiversity conservation will be most effective if that habitat is composed of as many small patches as possible, plus a few large ones. Because minimum patch size criteria often require larger patches than the small patches we examined, our results suggest that such criteria hinder efforts to protect biodiversity. [ABSTRACT FROM AUTHOR]

Los fenómenos meteorológicos extremos afectan a la reproducción de una población occidental aislada del sapo de espuela, Pelobates cultripes (Cuvier, 1829), en su límite de distribución más meridional Pelobates cultripes (Cuvier, 1829) se puede considerar como uno de los anfibios más afectados por el cambio climático en España. Su largo periodo larvario y la reducción prevista de la duración de las charcas temporales donde se reproduce podrían reducir en última instancia el reclutamiento demográfico de sus poblaciones. Realizamos estudios durante su período de reproducción (2021–2022) para analizar una de las últimas poblaciones urbanas en el límite más meridional de su distribución (la costa de la provincia de Málaga). Detectamos una disminución de las precipitaciones y un aumento de la temperatura en comparación con años anteriores. Aunque el periodo larvario de la especie fue más corto que el determinado en estudios anteriores, no se observaron juveniles posmetamórficos. Esta interrupción de la reproducción pone de relieve la necesidad de mejorar el seguimiento de estas poblaciones aisladas de anfibios, ya que podría ser una alerta temprana de cambios globales en la región del Mediterráneo.

Copyright of Acta Universitaria is the property of Universidad de Guanajuato/Acta Universitaria and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of SHILAP Revista de Lepidopterologia is the property of Sociedad Hispano-Luso-Americana de Lepidopterologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

La alteración antrópica modifica el tipo de mamíferos que consumen frutos de Attalea butyracea en una selva neotropical y la intensidad con que lo hacen La pérdida del hábitat y la caza son dos de las principales causas de la disminución de mamíferos, que no solo afecta a la presencia de especies, sino también a sus funciones ecológicas. La frugivoría es una interacción clave en las zonas tropicales debido a que se halla muy extendida entre los mamíferos y los efectos que ejerce en la dinámica de la selva. Mediante la comparación de las visitas realizadas por mamíferos a la palma Attalea butyracea en dos sitios con grados bien diferenciados de alteración antrópica (con alteración y sin alteración) de la selva Lacandona, en el sureste de México, evaluamos cómo afecta la alteración antrópica a la interacción entre los mamíferos frugívoros y los frutos que se acumulan en el suelo de la selva. Usando cámaras trampa, registramos a los mamíferos que interactuaron con los frutos y estimamos la intensidad de la interacción. Registramos una mayor riqueza de especies de mamíferos frugívoros en el sitio sin alteración antrópica (nueve especies) que en el sitio con alteración (cuatro especies), donde no se registraron los mamíferos de mayor tamaño. Los mamíferos de talla grande mostraron una interacción más intensa con los frutos en cuanto a la frecuencia y la duración de sus visitas. Nuestro estudio hace hincapié en la necesidad de adoptar medidas de conservación que permitan asegurar la presencia de las especies en los sitios con alteración antrópica, así como sus interacciones bióticas.

Introduction: The effects of habitat transformation have been widely studied and the effects are well-known at different levels of biological organization. However, few studies have focused on responses to this process at the level of multiple taxa in diverse taxonomic and functional groups. Objective: Determine the variations in taxonomic and functional diversity of ants, butterflies, and dung beetles, at a spatial and temporal level in a landscape mosaic of the ecoregion of the Colombian foothills. Methods: We assessed amount of natural habitat and landscape composition in four types of vegetation, during the highest and lowest rain periods. We collected butterflies with hand nets and used baited pitfall traps for dung beetles and ants. Results: Habitat loss positively affected ant and butterfly species richness, and negatively affected dung beetles. The abundance of ants and butterflies had a positive effect on the dominance of species in the transformed vegetation, for dung beetles the abundance was negatively affected by the absence of canopy cover. Habitat loss had no negative effect on functional diversity as there is no difference between natural and transformed vegetation. Conclusions: The amount of habitat, habitat connectivity and different types of vegetation cover were important factors in the maintenance of insect diversity in the modified ecosystems of foothills of the Colombian Orinoquia. The lack of a common spatial and temporal pattern shows that studies of multiple insect taxa should be carried out for biodiversity monitoring and conservation processes. [ABSTRACT FROM AUTHOR]

Antecedentes: La distribución de plantas depende de dispersores que transportan semillas a hábitats adecuados y de plantas que faciliten o inhiban germinación y establecimiento. Es importante conocer cómo estos factores influyen en la distribución de la vegetación y contemplar esta información en planes de manejo. Hipótesis: Las semillas y plántulas de las especies estudiadas diferirán en abundancia bajo diferentes especies de árboles y posición respecto al borde de la vegetación. Se espera una mayor densidad de semillas y plántulas bajo especies de árboles dispersos por animales y en los bordes de los fragmentos. Método. Se realizó conteo directo de semillas y plántulas de Zanthoxylum fagara (L.) Sarg. en México y Zanthoxylum coco Gillies ex Hook.f. & Arn. en Argentina, en fragmentos de vegetación remanente bajo copas de árboles, en borde e interior de vegetación. Resultados: Para ambas especies, la densidad de semillas fue similar en borde y en interior. La densidad de plántulas de Z. fagara fue mayor en el borde que 40 m al interior, así como bajo las copas de árboles dispersados por fauna. Para Z. coco no se encontraron diferencias. Conclusiones: Para ambas especies los dispersores de semillas no parecen importantes, se presenta similar densidad de semillas en borde e interior. Quizá tengan efecto en regeneración de Z. fagara, con mayor densidad de plántulas en borde que al interior. Es probable que mayor disponibilidad de luz en borde promueva regeneración de esta especie. Para Z. coco no parece existir un efecto de los dispersores en la regeneración.

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Oscine passerine birds learn their songs principally through cultural transmission. However, habitat fragmentation might induce cultural variation in song, leading to restrictions in the transmission of cultural information. In this study, we aim to evaluate individual responsiveness to conspecific vocalisations within and between two nearby bird populations to assess within-species behavioural changes with distance. To do so, we used song playbacks of'Elepaio Chasiempis sandwichensis in a fragmented landscape on the north-east slope of Mauna Loa Volcano (Hawaii Island, USA). We evaluated the response of'Elepaio males to songs recorded in their own populations and to those recorded in another population. We also compared vocalisations between both populations to assess acoustic differentiation. Our results indicate behavioural divergence in song responsiveness over a small spatial scale for this species as well as significant differences in acoustic traits. However, contrary to what was expected,'Elepaio individuals from both populations did not vary in their response pattern to songs depending on their origin. This suggests that acoustic differentiation may not be strong enough to drive behavioural divergence in response of'Elepaio individuals despite the existence of differences in the acoustic traits between both populations.—Oñate-Casado, J., Sebastián-González, E. & Hart, P.J. (2020). Response of male Hawaii Elepaio Chasiempis sandwichensis to conspecific songs: a small-scale playback study. Ardeola, 67: 387-400. [ABSTRACT FROM AUTHOR]

The importance of large reserves has been long maintained in the scientific literature, often leading to dismissal of the conservation potential of small reserves. However, over half the global protected‐area inventory is composed of protected areas that are <100 ha, and the median size of added protected area is decreasing. Studies of the conservation value of small reserves and fragments of natural area are relatively uncommon in the literature. We reviewed SCOPUS and WOK for studies on small reserve and fragment contributions to biodiversity conservation and ecosystem services, and fifty‐eight taxon‐specific studies were included in the review. Small reserves harbored substantial portions (upward of 50%) of regional species diversity for many taxa (birds, plants, amphibians, and small mammals) and even some endemic, specialist bird species. Unfortunately, small reserves and fragments almost always harbored more generalist and exotic species than large reserves. Community composition depended on habitat quality, surrounding land use (agricultural vs. urban), and reserve and fragment size, which presents opportunities for management and improvement. Small reserves also provided ecosystem services, such as pollination and biological pest control, and cultural services, such as recreation and improved human health. Limitations associated with small reserves, such as extinction debt and support of area‐sensitive species, necessitate a complement of larger reserves. However, we argue that small reserves can make viable and significant contributions to conservation goals directly as habitat and indirectly by increasing landscape connectivity and quality to the benefit of large reserves. To effectively conserve biodiversity for future generations in landscapes fragmented by human development, small reserves and fragments must be included in conservation planning. Article impact statement: Small reserves make meaningful contributions to biodiversity conservation and provisioning of ecosystem services. [ABSTRACT FROM AUTHOR]

This article aims to contribute to an identification of the ecological network for the municipality of Felgueiras, considering as broadleaf forest patches. Given that connectivity is a fundamental issue in planning and management for the conservation of species that occupy very small and increasingly altered habitat patches, we seek to analyse the landscape connectivity to locate potential corridors between the core areas that allow restoration or enhance conservation of species. Following this analysis, we used the analysis of the total cost of dispersion of species, taking as reference the permeability of the land uses and the maximum distance for a dispersion. Thus, several paths have been identified that enhance ecological connectivity and ease the effects of habitat fragmentation. [ABSTRACT FROM AUTHOR]

In Brazil, the Atlantic forest remnants have high biological diversity and a high level of endemism, but very little is known about the reproductive success of native species. Cabralea canjerana is a common tree in the Montane Atlantic forest, and its reproduction is highly dependent on pollinators. In order to contribute with the particular knowledge on this species, we collected data in three fragmented and three continuous forest sites, where the effects of fragmentation on both mutualistic (pollination) and antagonistic (seed predation) interactions were analysed. We determined fruit production and weight of 25 trees per site. The number of seeds and the percentage of predated and aborted seeds were also accessed for seven fruits of 10 trees per site. Pollinator visitation frequencies to flowers were recorded in two forest fragments and in two sites of the continuous forest. Our data showed that plants of C. canjerana produced more fruits (z-value=-8.24; p

The impacts of forest fragmentation on both reproductive biology and genetic diversity of native plant species is hardly understood, despite some studies have analyzed this current worldwide problem. Since this constitutes one of the main threats to seasonal semi-deciduous forests in Southeastern Brazil, we investigated the reproductive success and the genetic diversity of a distylous, understory shrub (Psychotria hastisepala) within this context of forest fragmentation. For this study, a set of seven forest fragments of sizes ranging from 4.1 to 168.7 hectares were chosen. The intervenient matrix comprised pastures (25-50%), monocultures (33-50%) and rural roads and buildings (14-28.5%). Overall, 91 plants (54 for the short-styled morph and 37 for the long-styled morph; mean of 6.5 plants per fragment) were investigated. To evaluate reproductive success, we quantified fruit and seed production under natural pollination; to evaluate genetic diversity and population structure, we employed ISSR markers on genomic DNA. Plants with the short-styled morph exhibited a significantly higher reproductive success than those with the long-styled morph; there was no association between seed production and size of the forest fragment. Levels of genetic diversity were positively associated with the number of plants per fragment; but they were not related to flower morph. AMOVA showed that about 65% of the overall genetic variation was attributed to the differences between plants within fragments. The results suggested that populations of P. hastisepala were susceptible to decline owing to forest fragmentation. Rev. Biol. Trop. 62 (1): 309-319. Epub 2014 March 01.

Copyright of Animal Biodiversity & Conservation is the property of Museu de Ciencies Naturals de Barcelona and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

En el año 2007 se efectuó un censo de los territorios de nidificación de carricero tordal Acrocephalus arundinaceus (Linnaeus, 1758) y de carricero común Acrocephalus scirpaceus (Hermann, 1804) en la Comunidad Autónoma del País Vasco, con la intención de evaluar el estado de conservación de sus poblaciones. Se contabilizaron 108 territorios de la primera especie y 243 de la segunda. En el caso del carricero tordal, mediante la comparación con los resultados de un estudio anterior (1996), se apreció una disminución en el número de cuadrículas UTM de 100 km2 con presencia (-90%), de localidades ocupadas (-86%) y de territorios (-91%) en la vertiente cantábrica del área de estudio, y estabilidad en esas mismas variables en la mediterránea. La fragmentación de los hábitats podría ser uno de los factores asociados a la regresión de la población de carricero tordal

We analyzed the genetic structure of the tropical tree Dendropanax arboreus (Araliaceae) in relation to habitat fragmentation. Genetic variation, structure, and genetic differentiation among populations from Los Tuxtlas tropical rainforest were estimated using ISSRs as molecular markers. DNA from 219 individuals belonging to 9 populations was amplified with 4 primers yielding a total of 75 loci. Adults and juveniles from each population were analyzed to assess the genetic diversity and structure pre and post-fragmentation, respectively. Dendropanax arboreus showed high levels of genetic diversity (h = 0.253) and significant but low genetic differentiation among populations ( or = 0.062). A hierarchical analysis of the gvenetic structure showed that 91.5% of the genetic variation is attributable to individual differences within populations. The average Nei's genetic distance among populations was low (D = 0.034) and genetic distance among pairs of populations increased with geographic distance separating them. Because genetic diversity is similar between adult and juvenile trees at all but 2 populations, we suggest that seed dispersal prevented genetic differentiation and maintains genetic connectivity among fragments and continuous forest populations. Juvenile populations showed a higher genetic differentiation ( or = 0.15) than adult trees, indicating a role of genetic drift via reduced population size.Se analizó la estructura genética del árbol tropical Dendropanax arboreus (Araliaceae) en relación con la fragmentación del hábitat en la selva tropical de Los Tuxtlas, Veracruz, México. La variación, estructura y diferenciación genética entre poblaciones del bosque continuo y de fragmentos se estimó usando ISSR como marcador molecular. El ADN de 219 individuos de 9 poblaciones se amplificó para 4 primers (75 loci). Se analizaron las poblaciones de árboles adultos y juveniles en cada sitio, representando la diversidad y estructura genética pre y postfragmentación, respectivamente. Dendropanax arboreus mostró altos niveles de variación genética (h = 0.253) y un nivel bajo de diferenciación entre poblaciones (= 0.062). Un análisis jerárquico de la estructura genética mostró que el 91.5% de la variación genética es atribuible a diferencias individuales dentro de las poblaciones. El promedio de las distancias genéticas de Nei entre las poblaciones fue bajo (D = 0.034), mientras que la distancia genética entre pares de poblaciones se incrementó con la distancia geográfica. En nivel poblacional, el efecto de la fragmentación no es evidente aún, lo cual podría deberse a una alta y efectiva dispersión de semillas por aves. Se sugiere que la dispersión de semillas ha mantenido la conectividad entre las poblaciones de selva continua y fragmentos. Las poblaciones juveniles muestran una diferenciación genética mayor ( o = 0.15) que las poblaciones de adultos, sugiriendo un papel de la deriva génica vía reducción en el tamaño poblacional.

En el bosque maulino, la herbivoría sobre Aristotelia chilensis (maqui) es negativamente afectada por la fragmentación del bosque, siendo mayor en el bosque continuo que en los fragmentos, particularmente a inicios de la temporada de crecimiento. Este fenómeno puede deberse a cambios en la dinámica de las poblaciones de defoliadores, esencialmente insectos. En este trabajo se evaluó la abundancia, riqueza de especies y composición de insectos defoliadores de actividad nocturna presentes en A. chilensis en un bosque continuo (600 ha) y en ocho fragmentos remanentes (0,4-20 ha). Los muéstreos se realizaron mensualmente, entre agosto de 2005 y febrero de 2006, en 32 ejemplares adultos de A. chilensis en el bosque continuo y en 32 ejemplares en los fragmentos. Los insectos fueron muestreados durante las cinco primeras horas de la noche. Se recolectaron 890 insectos defoliadores, pertenecientes a 17 familias y 77 especies pertenecientes a los órdenes Coleóptera, Orthoptera y Lepidoptera, siendo todas nativas. La abundancia total no varió según el habitat. Sin embargo, la fragmentación incrementó o disminuyó la abundancia de algunas especies. La riqueza de especies por árbol tampoco fue afectada por la fragmentación del bosque, aunque el número total de especies fue considerablemente mayor en los fragmentos que en el bosque continuo. La similitud de especies fue mayor dentro del bosque continuo que entre el bosque continuo y los fragmentos o que entre los fragmentos. A principios de la temporada de crecimiento de A. chilensis (septiembre), la abundancia de Sericoides obesa fue significativamente mayor en el bosque continuo que en los fragmentos. Al avanzar en la temporada, Sericoides viridis se hizo más abundante en los fragmentos. Por el tamaño y la voracidad de los insectos del género Sericoides ellos serían los principales responsables de los patrones de defoliación de A. chilensis en el bosque maulino.At the Maulino forest, herbivory upon Aristotelia chilensis (maqui) is negatively affected by forest fragmentation, being higher in the continuous forest than in the small remnant fragments, particularly at the beginning of the growing season (spring). This phenomenon may be attributable to changes in the population dynamics of herbivores, mostly insects. In this work, the effect of the Maulino forest fragmentation on the abundance, species richness and composition of nocturnal defoliating insects associated with A. chilensis was evaluated. The insects associated with A. chilensis were sampled monthly, between August 2005 and February 2006, in 32 trees located in a continuous forest (600 ha) and in 32 trees located in eight forest fragments (0.4-20 ha). Insect sampling was carried out during the first five night hours. 890 folivorous insects from 17 families and 77 species of Coleóptera, Orthoptera and Lepidoptera were collected. All species were native. The total abundance did not vary with habitat fragmentation. Nevertheless, some species increased their abundance with fragmentation, while others were depressed. The species richness of folivorous insects per tree did not vary with forest fragmentation, though the total number of species was considerably higher in the forest fragments. The species similarity was higher within the continuous forest than between the continuous forest and fragments or among fragments. At the beginning of the season (September), the abundance of Sericoides obesa was significantly higher in the continuous forest than in the forest fragments. Later in the season, Sericoides viridis became more abundant in the forest fragments. Because of the body size and the voracity of Sericoides sp., these insects seem to be responsible of the herbivory patterns of A. chilensis at the Maulino forest.

We present an inventory of the amphibians and reptiles of the San Vito de Coto Brus region, including the Las Cruces Biological Station, in southern Costa Rica, which is the result of a survey of the herpetofauna occurring in mountain forest fragments, pastures, coffee plantations, and other disturbed areas. We found 67 species, included 26 species of amphibians and of 41of reptiles. We describe the distribution patterns of the community on the basis of the life zones, elevation, fragmentation, and degree of anthropogenic impact. We also provide some nouvelle data on the systematics of some select taxa, their geographical ranges, microhabitats, activity, and other relevant ecological and natural history features. Finally, we comment on the present conservation status of the herpetofauna in the region. Previous literature and collection records indicate a higher number of species occurring in this area, which suggests that some declines have occurred, especially of amphibians, in last decades. Rev. Biol. Trop. 56 (2): 755-778. Epub 2008 June 30.En este artículo se presenta un inventario de los anfibios y reptiles de la región de San Vito de Coto Brus incluyendo la Estación de Biología Las Cruces, en el sur de Costa Rica. Se llevó a cabo una evaluación de las poblaciones de anfibios y reptiles presentes en los parches de bosque, potreros, cafetales y otras áreas perturbadas de la región. Como resultado de esta evaluación se registraron 26 especies de anfibios y 41 de reptiles lo que suma un total de 67 especies. Asimismo se describen los patrones generales de distribución de las especies basándose en los tipos de vegetación así como en la altitud, fragmentación y grado de perturbación antrópica en el área. Se proporcionan algunos datos sobre la sistemática de las especies, su distribución geográfica, el microhábitat que ocupan, su actividad y otros datos ecológicos y biológicos relevantes. Finalmente, se presenta una breve discusión sobre la conservación de la herpetofauna en la región. Algunos registros de la literatura y de colecciones científicas muestran que el número de especies de la herpetofauna conocidos en esta región era probablemente mayor, lo que podría indicar que han ocurrido algunas declinaciones importantes de especies, especialmente de anfibios en las últimas décadas.

Orchid bees (Hymenoptera: Apidae: Euglossini) are abundant and important pollinators of Neotropical forests, but orchid bee diversity is still poorly known in much of Mesoamerica, particularly in cloud forests. This paper presents results of a 2012 to 2013 survey of orchid bee diversity in Cusuco National Park, a cloud forest environment in northwest Honduras. Orchid bees were collected using insect nets at bait stations with chemical attractants. Bait stations were located at 68 sample sites throughout the park. We collected 4,293 orchid bees representing 24 species and 4 genera. One species, Euglossa imperialis Cockerell, accounted for 67.6% of the total individuals collected. A substantial easterly range extension was established for Eufriesea pallida (Kimsey). Our study provides the first intensive inventory of cloud forest orchid bee diversity in the region. Furthermore, it provides baseline data for future studies of orchid bees in a key biodiversity area that is threatened by human population growth and associated land use changes. [ABSTRACT FROM AUTHOR]

Los humedales son ecosistemas altamente productivos que se caracterizan por cumplir múltiples funciones, manteniendo además una alta diversidad biológica. No obstante, casi la mitad de los humedales en el mundo ha desaparecido en el último siglo debido al proceso de desarrollo urbano. En Chile, la diversidad bioclimática genera una gran variedad de ambientes acuáticos. Estos ecosistemas también han sido expuestos a fuertes presiones antrópicas, debido al proceso de urbanización. En la intercomuna Concepción-Talcahuano-San Pedro (Región del Biobío) más del 23 % (1.734 ha) del área ocupada por humedales se ha perdido en las últimas tres décadas. Evaluamos la relación entre características del hábitat (morfométricas, limnológicas y vegetacionales) y la estructura del ensamble de insectos en siete humedales palustres de la intercomuna, con el fin de determinar los efectos de la urbanización sobre los patrones de diversidad en estos ecosistemas. Los análisis mostraron que la abundancia relativa y la diversidad de especies se relacionan positivamente con la naturalidad de la matriz y el contenido de oxígeno en el agua, esta última característica fue el predictor más importante para la estructura del ensamble de insectos. De las 24 morfoespecies de insectos analizadas, la abundancia de siete especies fue relacionada significativamente con las características del hábitat consideradas. La naturalidad de la matriz, el área del humedal, la heterogeneidad vegetacional y la concentración de oxígeno disuelto se relacionaron positivamente con la abundancia de estas especies, mientras que la conductividad y/o turbidez del agua mostró un efecto negativo sobre ella. La disminución de la diversidad de insectos determinada por características del hábitat asociadas con la pérdida, fragmentación, homogeneización, eutroficación y/o contaminación de los humedales indica que los insectos podrían ser utilizados como indicadores de los efectos de la urbanización sobre el funcionamiento de estos ecosistemas. Sin embargo, dada la falta de información biológica y taxonómica en especies de insectos asociados a humedales palustres, solo características del hábitat con efectos significativos a un nivel taxonómico alto podrían ser consideradas para establecer recomendaciones iniciales de planes de manejoWetlands are one of the most productive ecosystems which provide a number of ecosystem functions, maintaining also a high biodiversity. Nevertheless, almost half of the wetlands in the world have disappeared in the last century due to urban development process. Along the Chilean landscape a great variety of aquatic habitats exist. Due to urban expansion those ecosystems have been exposed to strong anthropogenic pressures. In the intercomunal area Concepción-Talcahuano- San Pedro (Biobío Region), more than 23 % (1,734 ha) of the wetland areas have been lost in the last three decades. We evaluated the relationship between habitat characteristics (morphometric, limnology and vegetation) and the insect assemblage's structure in seven freshwater marshes in this intercomunal area. Our aim was to assess the influence of urbanization on the diversity patterns of these ecosystems. Insect abundance and species diversity were positively correlated to matrix pristinness and oxygen concentration of the water, this last feature was the best predictor for the structure of the insect assemblage. Of the 24 insect morphospecies included in the analysis, the abundance of only seven species was significantly related to the quantified habitat characteristics. Matrix pristinness, wetland area, vegetation heterogeneity and water oxygen concentration were positively related to species abundance, however, conductivity and water density showed a negative effect on the abundance. The insect species diversity decrease determined by the habitat characteristics associated to habitat loss, habitat fragmentation, habitat homogeneity, and wetland contamination, show that insects could be used as indicators of the urban effects on the functioning of these ecosystem. However, due to the missing biological and taxonomical information on the insect species related to freshwater marshes, only habitat characteristics with a significant effect on a high taxonomical level could be considered to establish initial recommendations for management plans

Habitat loss and fragmentation are considered as the main causes of biodiversity depression. Habitat loss implies a reduction of suitable habitat for organisms, and habitat fragmentation is a change in the spatial configuration of the landscape, with the remaining fragments resulting more or less isolated. Recent theory indicates that the effects of habitat loss are more important than those of habitat fragmentation, however there are few experimental studies evaluating both processes separately. To test the effects of habitat fragmentation per se on the abundance, species richness and diversity of epigeal coleopterans, 15 (30 x 30 m) alfalfa micro-landscapes, distributed in three blocks, were created. On twelve of them, 84 % of the habitat was removed, leaving in each landscape four or 16 fragments separated by 2 or 6 m of bare ground. From December 2002 to April 2003, before and after fragmentation, coleopterans were sampled using pitfall traps. In total, 8,074 coleopterans of 75 species belonging to 16 families were captured. Neither habitat fragmentation nor habitat loss affected the total abundance of coleopterans, with the exception of Anthicidae that was more abundant in the micro-landscapes composed by four fragments separated for 2 m. This family was also more abundant in the matrix of fragmented micro-landscapes, while most other beetle families were more abundant in the fragments, significantly Carabidae and Lathridiidae. Species richness (per trap and per landscape) was higher in micro-landscapes with 16 fragments separated by 6 m. Contrary to what is described frequently in the literature, habitat fragmentation did not negatively affect the abundance or the species richness of epigeal coleopterans. Rather, smaller and more isolated alfalfa fragments seem to provide habitat to support greater biodiversity. These results agree with more recent findings where habitat fragmentation per se seems not to have deleterious effects on the fauna, instead, it could favor the biota, at least at short time scalesLa pérdida y fragmentación del hábitat han sido consideradas como las principales causas de la disminución de biodiversidad. La pérdida de hábitat es una disminución del hábitat utilizable por los organismos y la fragmentación es un cambio en la configuración espacial del paisaje, donde los fragmentos remanentes quedan relativamente aislados entre sí. Trabajos teóricos recientes indican que los efectos de la pérdida de hábitat son más importantes que los de la fragmentación, sin embargo existen pocos estudios experimentales que evalúen por separado ambos procesos. Para estudiar los efectos de la fragmentación per se sobre la abundancia y riqueza de especies de coleópteros epigeos, se crearon 15 micro-paisajes de alfalfa de 30 x 30 m distribuidos en tres bloques. Doce de ellos se fragmentaron removiendo el 84 % del hábitat, dejando cuatro ó 16 fragmentos separados por 2 ó 6 m. Entre diciembre del 2002 y abril del 2003, antes y después de la fragmentación, se muestrearon los coleópteros mediante trampas Barber. Se capturó un total de 8.074 coleópteros de 75 especies pertenecientes a 16 familias. El tipo de paisaje no afectó la abundancia de coleópteros, sólo Anthicidae fue más abundante en los paisajes de 4 fragmentos separados por 2 m y fue más abundante en la matriz. El resto de de las familias fue más abundante en los fragmentos, significativamente Carabidae y Lathridiidae. La riqueza de especies por trampa y por paisaje fue mayor en los paisajes con 16 fragmentos separados por 6 m, concentrándose en los fragmentos. Contrario a lo descrito en la mayor parte de la literatura, la fragmentación no afectó negativamente la abundancia y riqueza de especies de coleópteros epigeos asociados a alfalfa. Más bien, fragmentos de alfalfa más pequeños y aislados ofrecieron un refugio de hábitat para la biodiversidad de coleópteros epigeos. Estos resultados concuerdan con los postulados más recientes que indican que la fragmentación per se puede no tener efectos sobre la biota, o incluso puede favorecerla, al menos en el corto plazo

La fragmentación del hábitat tiene un efecto negativo sobre la adecuación biológica de las plantas por la reducción en la cantidad de semillas producidas. Sin embargo, la fragmentación del hábitat también podría disminuir la adecuación biológica de las plantas a través de la reducción en la calidad de las semillas producidas, al reducir atributos como la viabilidad, tamaño o su capacidad germinativa. Esto podría ocurrir porque la reducción en los tamaños poblacionales en fragmentos, junto con el aumento en el grado de aislamiento, podrían generar una reducción de la variabilidad genética de las poblaciones e inducir a la expresión de depresión por endocruza. En este trabajo muestro el efecto de la fragmentación del bosque maulino sobre la calidad de las semillas producidas en la especie Lapageria rosea. Calidad es definida aquí como viabilidad, tamaño y capacidad germinativa de las semillas. Colecté semillas desde fragmentos de bosque y desde un bosque continuo, en el bosque maulino de Chile central. En al laboratorio se estimaron los porcentajes de viabilidad, el tamaño y la capacidad germinativa de las semillas colectadas. Los resultados muestran que las semillas producidas en fragmentos de bosque presentan porcentajes de viabilidad similares a las semillas producidas en el bosque continuo, sin embargo la variabilidad en estos porcentajes es mayor en las semillas de los fragmentos. Además, las semillas de fragmentos son de menor tamaño y poseen menor capacidad germinativa que las semillas de bosque continuo. Estas características de las semillas podría determinar que en fragmentos de bosque exista una reducción en el establecimiento de nuevos individuos, pudiendo inducir a un efecto negativo sobre la sobrevivencia de las poblaciones a largo plazoHabitat fragmentation is commonly associated to a reduction in plant fitness, because the reduction in the number of seeds produced. However habitat fragmentation might also affect plant fitness through a reduction in the quality of the seeds produced, as for example in seed viability, seed size or in seed germination. These factors could be affected because small populations size and high degree in isolation, frequently found in fragments, could induce to the loss of genetic population variability and the expression of inbreeding depression. Here I show the effect of forest fragmentation on the quality of seeds produced in Lapageria rosea, quality being measured as seed viability, seed size and seed germination. I collected seeds from the Maulino forest in central Chile, specifically from plants living in forest fragments and continued forest. Seed viability, seed size and seed germination capacity was estimated under laboratory conditions. Results indicated that seeds from forest fragments and from continuous forest have similar percentages of viability, although these percentages are more variable among fruits from forest fragments. Moreover, seeds from forest fragments are smaller than seeds from continuous forest. Finally, seeds from fragments have less germination capacity than seeds from continued forest. These reductions could determinate a negative effect on seedling establishment in fragmented populations and possibly in the long term population survival

La población navarra de Rana dalmatina se encuentra fragmentada en 4 núcleos incomunicados, con baja disponibilidad de humedales para la reproducción (entre 2 y 15 por área). La población de hembras adultas fluctúa anualmente entre 1000 y 1500 individuos, sin considerar de la La Barranca, todavía no investigada. La conservación de la especie depende de la gestión de las zonas húmedas.

The steady growth of human population causes that the urban area extends its limits to ecological reserves reducing the size of these, generating significant edge effects that accentuate the landscape fragmentation and increase the loss of continuity from vegetation cover. Ecological reserves and the urban green areas (represented by parks and gardens) are relict habitats for many species that survive in the urban matrix. The Pedregal de San Angel Ecological Reserve at Ciudad Universitaria (PSAER-CU) is the most important in the southwest of Mexico City because it embodies 237.3 hectares and possesses 377 species of vascular plants, 180 species of native vertebrates and preserves at least 817 arthropod species, out of which 26 are orthopterans, the latter play an important role in the food chain and are determinants of ecosystem functioning. This study aimed to: 1. Elaborate a check list of the Orthoptera species that survive in the Southeastern Territorial Reserve from Ciudad Universitaria (SETR); 2. Compare the attributes (abundance, diversity and density) of the Orthoptera community that inhabit the SETR with respect to the Orthoptera species occurring at the Southeast Core Zone at PSAER; 3. Discuss the environmental value of the SETR as Environmental Buffer Zone for PSAER. The relative abundance of each species did not differ significantly between the SETR and the Core Zone. We found five Orthoptera species at SETR, the species with greatest abundance was Sphenarium purpurascens purpurascens Charpentier, 1842 Pyrgomorphidae, followed by Phoetaliotes nebrascensis (Thomas, 1872) Acrididae. The presence of Conocephalus (Xiphidion) ictus (Scudder, 1875) Tettigoniidae represents a new taxonomic record for the study area. We discuss that the SETR differs on orthopterological diversity from the Southeast Core Zone at PSAER and argue its importance for wildlife conservation; as well as the importance that the Orthoptera possess according to their position in the food chain and why they are determinants of ecosystem functioning. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The impacts of forest fragmentation on both reproductive biology and genetic diversity of native plant species is hardly understood, despite some studies have analyzed this current worldwide problem. Since this constitutes one of the main threats to seasonal semi-deciduous forests in Southeastern Brazil, we investigated the reproductive success and the genetic diversity of a distylous, understory shrub (Psychotria hastisepala) within this context of forest fragmentation. For this study, a set of seven forest fragments of sizes ranging from 4.1 to 168.7 hectares were chosen. The intervenient matrix comprised pastures (25-50%), monocultures (33-50%) and rural roads and buildings (14-28.5%). Overall, 91 plants (54 for the short-styled morph and 37 for the long-styled morph; mean of 6.5 plants per fragment) were investigated. To evaluate reproductive success, we quantified fruit and seed production under natural pollination; to evaluate genetic diversity and population structure, we employed iSSR markers on genomic DNA. Plants with the short-styled morph exhibited a significantly higher reproductive success than those with the long-styled morph; there was no association between seed production and size of the forest fragment. Levels of genetic diversity were positively associated with the number of plants per fragment; but they were not related to flower morph. AMOVA showed that about 65% of the overall genetic variation was attributed to the differences between plants within fragments. The results suggested that populations of P. hastisepala were susceptible to decline owing to forest fragmentation. [ABSTRACT FROM AUTHOR]

The article discusses the conservation strategies concerning the biodiversity of the Cerrado Biome in Brazil. It analyzes the fragmentation process of the habitats, but reveals that the developing projects lack collaboration and result in a waste of resources and ineffective public policies. The authors suggest to make the Cerrado an object of a specific conservation policy that integrates different sectors of society and public authorities.

Ecological edges are increasingly recognized as drivers of landscape patterns and ecosystem processes. In fragmented and patchy landscapes (e.g., a fragmented forest or a savanna with scattered termite mounds), edges can become so numerous that their effects pervade the entire landscape. Results of recent studies in such landscapes show that edge effects can be altered by the presence or proximity of other nearby edges. We considered the theoretical significance of edge-effect interactions, illustrated various landscape configurations that support them and reviewed existing research on this topic. Results of studies from a variety of locations and ecosystem types show that edge-effect interactions can have significant consequences for ecosystems and conservation, including higher tree mortality rates in tropical rainforest fragments, reduced bird densities in grassland fragments, and bush encroachment and reduced wildlife densities in a tropical savanna. To clarify this underappreciated concept and synthesize existing work, we devised a conceptual framework for edge-effect interactions. We first worked to reduce terminological confusion by clarifying differences among terms such as edge intersection and edge interaction . For cases in which nearby edge effects interact, we proposed three possible forms of interaction: strengthening (presence of a second edge causes stronger edge effects), weakening (presence of a second edge causes weaker edge effects), and emergent (edge effects change completely in the presence of a second edge). By clarifying terms and concepts, this framework enables more precise descriptions of edge-effect interactions and facilitates comparisons of results among disparate study systems and response variables. A better understanding of edge-effect interactions will pave the way for more appropriate modeling, conservation, and management in complex landscapes. Interacciones del Efecto de Borde en Paisajes Fragmentados [ABSTRACT FROM AUTHOR]

Animal-mediated seed dispersal is important for sustaining biological diversity in forest ecosystems, particularly in the tropics. Forest fragmentation, hunting, and selective logging modify forests in myriad ways and their effects on animal-mediated seed dispersal have been examined in many case studies. However, the overall effects of different types of human disturbance on animal-mediated seed dispersal are still unknown. We identified 35 articles that provided 83 comparisons of animal-mediated seed dispersal between disturbed and undisturbed forests; all comparisons except one were conducted in tropical or subtropical ecosystems. We assessed the effects of forest fragmentation, hunting, and selective logging on seed dispersal of fleshy-fruited tree species. We carried out a meta-analysis to test whether forest fragmentation, hunting, and selective logging affected 3 components of animal-mediated seed dispersal: frugivore visitation rate, number of seeds removed, and distance of seed dispersal. Forest fragmentation, hunting, and selective logging did not affect visitation rate and were marginally associated with a reduction in seed-dispersal distance. Hunting and selective logging, but not fragmentation, were associated with a large reduction in the number of seeds removed. Fewer seeds of large-seeded than of small-seeded tree species were removed in hunted or selectively logged forests. A plausible explanation for the consistently negative effects of hunting and selective logging on large-seeded plant species is that large frugivores, as the predominant seed dispersers for large-seeded plant species, are the first animals to be extirpated from hunted or logged forests. The reduction in forest area after fragmentation appeared to have weaker effects on frugivore communities and animal-mediated seed dispersal than hunting and selective logging. The differential effects of hunting and selective logging on large- and small-seeded tree species underpinned case studies that showed disrupted plant-frugivore interactions could trigger a homogenization of seed traits in tree communities in hunted or logged tropical forests. Meta Análisis de los Efectos de la Perturbación Humana sobre la Dispersión de Semillas por Animales [ABSTRACT FROM AUTHOR]

Despite extensive research on the effects of habitat fragmentation, the ecological mechanisms underlying colonization and extinction processes are poorly known, but knowledge of these mechanisms is essential to understanding the distribution and persistence of populations in fragmented habitats. We examined these mechanisms through multiseason occupancy models that elucidated patch-occupancy dynamics of Middle Spotted Woodpeckers (Dendrocopos medius) in northwestern Spain. The number of occupied patches was relatively stable from 2000 to 2010 (15-24% of 101 patches occupied every year) because extinction was balanced by recolonization. Larger and higher quality patches (i.e., higher density of oaks >37 cm dbh [diameter at breast height]) were more likely to be occupied. Habitat quality (i.e., density of large oaks) explained more variation in patch colonization and extinction than did patch size and connectivity, which were both weakly associated with probabilities of turnover. Patches of higher quality were more likely to be colonized than patches of lower quality. Populations in high-quality patches were less likely to become extinct. In addition, extinction in a patch was strongly associated with local population size but not with patch size, which means the latter may not be a good surrogate of population size in assessments of extinction probability. Our results suggest that habitat quality may be a primary driver of patch-occupancy dynamics and may increase the accuracy of models of population survival. We encourage comparisons of competing models that assess occupancy, colonization, and extinction probabilities in a single analytical framework (e.g., dynamic occupancy models) so as to shed light on the association of habitat quality and patch geometry with colonization and extinction processes in different settings and species. [ABSTRACT FROM AUTHOR]

Understanding the way in which habitat fragmentation disrupts animal dispersal is key to identifying effective and efficient conservation strategies. To differentiate the potential effectiveness of 2 frequently used strategies for increasing the connectivity of populations in fragmented landscapes-corridors and stepping stones-we combined 3 complimentary methods: behavioral studies at habitat edges, mark-recapture, and genetic analyses. Each of these methods addresses different steps in the dispersal process that a single intensive study could not address. We applied the 3 methods to the case study of Atrytonopsis new species 1, a rare butterfly endemic to a partially urbanized stretch of barrier islands in North Carolina (U.S.A.). Results of behavioral analyses showed the butterfly flew into urban and forested areas, but not over open beach; mark-recapture showed that the butterfly dispersed successfully through short stretches of urban areas (<500 m); and genetic studies showed that longer stretches of forest (>5 km) were a dispersal barrier, but shorter stretches of urban areas (≤5 km) were not. Although results from all 3 methods indicated natural features in the landscape, not urbanization, were barriers to dispersal, when we combined the results we could determine where barriers might arise: forests restricted dispersal for the butterfly only when there were long stretches with no habitat. Therefore, urban areas have the potential to become a dispersal barrier if their extent increases, a finding that may have gone unnoticed if we had used a single approach. Protection of stepping stones should be sufficient to maintain connectivity for Atrytonopsis new species 1 at current levels of urbanization. Our research highlights how the use of complementary approaches for studying animal dispersal in fragmented landscapes can help identify conservation strategies. [ABSTRACT FROM AUTHOR]

Copyright of SHILAP Revista de Lepidopterologia is the property of Sociedad Hispano-Luso-Americana de Lepidopterologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Studies of avian area sensitivity have been prolific over the last 3 decades, yet general conclusions about the phenomenon are lacking. We undertook a systematic literature review to determine how widespread area sensitivity is; whether published information is biased toward certain geographic regions, habitat types, or taxonomic groups; whether the nature of area effects varies with respect to these criteria; and whether tests of area effects for individual species produce consistent results. Analysis of over 2700 area sensitivity tests, from more than 870 species, indicated the phenomenon is widespread across regions, habitats, and taxonomic groups, but that significant biases in research focus exist. North American forest habitats and Passeriformes (especially Fringillidae, Regulidae, and Paridae) are disproportionately represented in the literature. Detection of area effects was more common in tests of occurrence (47%) than in those for abundance (25%) and varied significantly among regions, habitats, and taxonomic groups. Inconsistent results for species studied multiple times and between tests of occurrence and abundance were common. These results suggest a need for future research to focus more on why area sensitivity patterns differ among studies and less on simple pattern description. [ABSTRACT FROM AUTHOR]

Using corridors for conservation is increasing despite a lack of consensus on their efficacy. Specifically, whether corridors increase movement of plants and animals between habitat fragments has been addressed on a case-by-case basis with mixed results. Because of the growing number of well-designed experiments that have addressed this question, we conducted a meta-analysis to determine whether corridors increase movement; whether corridor effectiveness differs among taxa; how recent changes in experimental design have influenced findings; and whether corridor effectiveness differs between manipulative and natural experiments. To conduct our meta-analysis, we analyzed 78 experiments from 35 studies using a conservative hierarchical Bayesian model that accounts for hierarchical and sampling dependence. We found a highly significant result that corridors increase movement between habitat patches by approximately 50% compared to patches that are not connected with corridors. We found that corridors were more important for the movement of invertebrates, nonavian vertebrates, and plants than they were for birds. Recent methodological advances in corridor experiments, such as controlling for the area added by corridors, did not influence whether corridors increased movement, whereas controlling for the distance between source and connected or unconnected recipient patches decreased movement through corridors. After controlling for taxa differences and whether studies controlled for distance in experimental design, we found that natural corridors (those existing in landscapes prior to the study) showed more movement than manipulated corridors (those created and maintained for the study). Our results suggest that existing corridors increase species movement in fragmented landscapes and that efforts spent on maintaining and creating corridors are worthwhile. [ABSTRACT FROM AUTHOR]

Copyright of Tropical Conservation Science is the property of Sage Publications Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Anthropogenic disturbances such as fragmentation are rapidly altering biodiversity, yet a lack of attention to species traits and abundance patterns has made the results of most studies difficult to generalize. We determined traits of extinction-prone species and present a novel strategy for classifying species according to their population-level response to a gradient of disturbance intensity. We examined the effects of forest fragmentation on dung beetle communities in an archipelago of 33 islands recently created by flooding in Venezuela. Species richness, density, and biomass all declined sharply with decreasing island area and increasing island isolation. Species richness was highly nested, indicating that local extinctions occurred nonrandomly. The most sensitive dung beetle species appeared to require at least 85 ha of forest, more than many large vertebrates. Extinction-prone species were either large-bodied, forest specialists, or uncommon. These explanatory variables were unrelated, suggesting at least 3 underlying causes of extirpation. Large species showed high wing loading (body mass/wing area) and a distinct flight strategy that may increase their area requirements. Although forest specificity made most species sensitive to fragmentation, a few persistent habitat generalists dispersed across the matrix. Density functions classified species into 4 response groups on the basis of their change in density with decreasing species richness. Sensitive and persistent species both declined with increasing fragmentation intensity, but persistent species occurred on more islands, which may be due to their higher baseline densities. Compensatory species increased in abundance following the initial loss of sensitive species, but rapidly declined with increasing fragmentation. Supertramp species (widespread habitat generalists) may be poor competitors but strong dispersers; their abundance peaked following the decline of the other 3 groups. Nevertheless, even the least sensitive species were extirpated or rare on the smallest and most isolated islands. [ABSTRACT FROM AUTHOR]

We present an inventory of the amphibians and reptiles of the San Vito de Coto Brus region, including the Las Cruces Biological Station, in southern Costa Rica, which is the result of a survey of the herpetofauna occurring in mountain forest fragments, pastures, coffee plantations, and other disturbed areas. We found 67 species, included 26 species of amphibians and of 41 of reptiles. We describe the distribution patterns of the community on the basis of the life zones, elevation, fragmentation, and degree of anthropogenic impact. We also provide some nouvelle data on the systematics of some select taxa, their geographical ranges, microhabitats, activity, and other relevant ecological and natural history features. Finally, we comment on the present conservation status of the herpetofauna in the region. Previous literature and collection records indicate a higher number of species occurring in this area, which suggests that some declines have occurred, especially of amphibians, in last decades. [ABSTRACT FROM AUTHOR]

Habitat fragmentation causes extinction of local animal populations by decreasing the amount of viable “core” habitat area and increasing edge effects. It is widely accepted that larger fragments make better nature reserves because core-dwelling species have a larger amount of suitable habitat. Nevertheless, fragments in real landscapes have complex, irregular shapes. We modeled the population sizes of species that have a representative range of preferences for or aversions to habitat edges at five spatial scales (within 10, 32, 100, 320, and 1000 m of an edge) in a nation-wide analysis of forest remnants in New Zealand. We hypothesized that the irregular shapes of fragments in real landscapes should generate statistically significant correlations between population density and fragment area, purely as a “geometric” effect of varying species responses to the distribution of edge habitat. Irregularly shaped fragments consistently reduced the population size of core-dwelling species by 10–100%, depending on the scale over which species responded to habitat edges. Moreover, core populations within individual fragments were spatially discontinuous, containing multiple, disjunct populations that inhabited small spatial areas and had reduced population size. The geometric effect was highly nonlinear and depended on the range of fragment sizes sampled and the scale at which species responded to habitat edges. Fragment shape played a strong role in determining population size in fragmented landscapes; thus, habitat restoration efforts may be more effective if they focus on connecting disjunct cores rather than isolated fragments. [ABSTRACT FROM AUTHOR]

Scientific interest in the impact of habitat fragmentation on biodiversity is increasing, but our understanding of fragmentation is clouded by a lack of appreciation for fundamental similarities and differences across studies representing a wide range of taxa and landscape types. In an effort to synthesize data describing ecological responses of animals to fragmentation across two classes of independent variables (taxonomic group and landscape), we sampled 148 studies of five major faunal groups from the primary literature and analyzed data on 13 variables extracted from those studies. We focused our analyses on three classes of dependent variables (effects of area and isolation on species richness, z values, and nestedness and species composition). Area ranged over more orders of magnitude than isolation and tended to explain more variation in species richness than isolation. There were few matrix or taxon effects on the patterns we investigated, although we did find that sky islands tended to manifest isolation effects on both species richness and nestedness more frequently than other patch types. Sky islands may offer insight into the future of habitat patches fragmented by contemporary habitat loss, and because they show a stronger effect of isolation than other patch types, we suggest that isolation will play an increasing role in the biology of habitat fragments. We use multiple lines of evidence to suggest that our understanding of the role of isolation on community assembly in fragmented landscapes is inadequate. Finally, our observation that consistent taxonomic differences in community patterns were minimal suggests that conservation actions intended to mitigate the negative effects of extinction may have far-reaching effects across taxonomic groups. [ABSTRACT FROM AUTHOR]

The effects of climate change and habitat destruction and their interaction are likely to be the greatest challenge to animal and plant conservation in the twenty-first century. We used the world's smallest butterfly, the Sinai baton blue (Pseudophilotes sinaicus ), as an exemplar of how global warming and human population pressures may act together to cause species extinctions. We mapped the entire global range of this butterfly and obtained extensive data on the intensity of livestock grazing. As with an increasing number of species, it is confined to a network of small habitat patches and is threatened both by indirect human-induced factors (global warming) and by the direct activities of humans (in this case, livestock grazing and collection of medicinal plants). In the absence of global warming, grazing, and plant collection, our model suggested that the butterfly will persist for at least 200 years. Above a threshold intensity of global warming, the chance of extinction accelerated rapidly, implying that there may be an annual average temperature, specific to each endangered species, above which extinction becomes very much more likely. By contrast, there was no such threshold of grazing pressure—the chance of extinction increased steadily with increasing grazing. The impact of grazing, however, decreased with higher levels of year-to-year variation in habitat quality. The effect of global warming did not depend on the future level of grazing, suggesting that the impacts of global warming and grazing are additive. If the areas of habitat patches individually fall below certain prescribed levels, the butterfly is likely to go extinct. Two patches were very important for persistence: if either were lost the species would probably go extinct. Our results have implications for the conservation management of all species whose habitats are at risk because of the direct activities of humans and in the longer term because of climate change. [ABSTRACT FROM AUTHOR]