Impacts of salvage logging on biodiversity: A meta-analysis

Logging to "salvage" economic returns from forests affected by natural disturbances has become increasingly prevalent globally. Despite potential negative effects on biodiversity, salvage logging is often conducted, even in areas otherwise excluded from logging and reserved for nature conservation, inter alia because strategic priorities for post-disturbance management are widely lacking. A review of the existing literature revealed that most studies investigating the effects of salvage logging on biodiversity have been conducted less than 5 years following natural disturbances, and focused on non-saproxylic organisms. A meta-analysis across 24 species groups revealed that salvage logging significantly decreases numbers of species of eight taxonomic groups. Richness of dead wood dependent taxa (i.e. saproxylic organisms) decreased more strongly than richness of non-saproxylic taxa. In contrast, taxonomic groups typically associated with open habitats increased in the number of species after salvage logging. By analysing 134 original species abundance matrices, we demonstrate that salvage logging significantly alters community composition in 7 of 17 species groups, particularly affecting saproxylic assemblages. Synthesis and applications. Our results suggest that salvage logging is not consistent with the management objectives of protected areas. Substantial changes, such as the retention of dead wood in naturally disturbed forests, are needed to support biodiversity. Future research should investigate the amount and spatio-temporal distribution of retained dead wood needed to maintain all components of biodiversity

Defensive behaviors in wild and laboratory (Swiss) mice: The mouse defense test battery.

The development of laboratory rodent models for elicitation and measurement of a range of defensive behaviors raises the question of the relationship between defense in these animals and those of their wild congeners. To evaluate this relationship for mice, defensive responses to an anesthetized rat were compared for fourth-generation laboratory-bred wild mice and Swiss CD-1 (Swiss-Webster derived) laboratory mice in a Mouse Defense Test Battery. Wild mice showed enhanced levels of both freezing and flight, fleeing from distant approach of the predator in several situations and fleeing more quickly than the Swiss mice. However, Swiss mice did flee upon contact with the rat and also showed levels of several other defensive behaviors (risk assessment, defensive threat, and attack) that were often reliably higher than those of the wild mice. However, when wild mice were prevented from fleeing, their levels of defensive threat and attack were as high as, or at very short prey-predator distances higher than, those of the Swiss mice. These findings suggest that flight and freezing are the major defensive behaviors reduced in Swiss mice and that these reductions allow the appearance of higher levels of additional defensive behaviors in the laboratory animals. However, although Swiss mice do show lower levels of flight and freezing, their patterns of defensive behavior are sufficiently similar to those of wild mice that they provide adequate subjects for research on the biologic bases of defensive behavior. A final experiment indicated that when wild mice are familiarized with a chamber providing a place of concealment, they flee directly to this chamber on presentation of a rat, indicating that flight is a targeted response and not simply an abrupt increase in forward locomotion. Over 10 rat presentation trials with a blocked chamber entrance, however, this response declines

Metals and polycyclic aromatic hydrocarbons in colonial waterbird eggs from Lake Athabasca and the Peace-Athabasca Delta, Canada

In 2009, aquatic bird eggs from a variety of species were collected from three sites in northern Alberta, Canada. Two sites were located in receiving waters of the Athabasca River, which drains the oil sands industrial region north of Fort McMurray, Alberta. The third site, located on the Peace River, was remote from the influence of the Athabasca River. Levels of mercury, arsenic, and polycyclic aromatic hydrocarbons (PAHs) were measured in the eggs along with nitrogen stable isotopes (δ15N) as an indicator of bird trophic position. Levels of As and PAHs in eggs were low, whereas Hg was measureable in all samples. Egg Hg levels increased with δ15N values (a proxy of food web trophic position); however, some eggs exhibited Hg levels greater than expected based on trophic position. These eggs were from sites in receiving waters of the Athabasca River, namely, Mamawi Lake and Egg Island. Levels of Hg in egg pools were correlated with naphthalene levels, perhaps indicating a common source of contamination. Temporal comparison of Hg levels in California gull (Larus californicus) eggs from the Lake Athabasca colony indicated that egg Hg burdens increased 40% from 1977 to 2009. More research is required to evaluate temporal trends in levels of environmental contaminants and to identify sources

Larvae of the Costa Rican Hetaerina (Odonata: Calopterygidae) with comments on distribution

The larvae of seven of the nine Costa Rican species of Hetaerina (H.capitalis, H.cruentata, H. fuscogutfata, H. majuscula, H. miniata, H. occisa and H. titia) were identified by matching their Cellulose Acetate Gel Electrophoresis (CAGE) patterns with those of adults. CAGE allows larval descriptions to be processed at a much faster rate than through traditional rearing techniques and, provided that refrigeration and a power supply are available, is relatively portable and robust. Adults of H.capitalis, H.cruentata and H. miniata were also reared from final instar larvae. Larvae of H.caja and H.sempronia were identified by site association with adults and unique suites of morphological characters. Characters on the head, antennae, labium, pronotum, legs, abdomen, and caudal appendages are described and illustrated, and a key to final instar larvae of all nine species is presented. The distribution of Hetaerina in Costa Rica is influenced primarily by the Cordillera.Las larvas de siete de las nueve especies costarricenses de Hetaerina (H.capitalis, H.cruentata, H. fuscogutfata, H. majuscula, H. miniata, H. occisa y H. titia) fueron identificadas mediante el emparejamiento de sus electroforesis en gel de acetato de celulosa. (CAGE) con los de los adultos. CAGE permite que las descripciones de las larvas se procesen a un ritmo mucho más rápido que a través de las técnicas tradicionales de crianza y, siempre que se disponga de refrigeración y suministro eléctrico, es relativamente portátil y resistente. También se criaron adultos de H. capitalis, H. cruentata y H. miniata a partir de larvas en estadio final. Las larvas de H.caja y H.sempronia fueron identificadas por asociación de sitio con adultos y conjuntos únicos de caracteres morfológicos. Se describen e ilustran los caracteres de la cabeza, las antenas, los labios, el pronoto, las piernas, el abdomen y los apéndices caudales, y se presenta una clave para el estadio final de las larvas de las nueve especies. La distribución de Hetaerina en Costa Rica está influenciada principalmente por la Cordillera.Universidad Nacional, Costa RicaEscuela de Ciencias Biológica