The hypothesis that small body size is correlated with preference for young leaves was tested in a community of leaf-chewing insect herbivores feeding on Ficus wassa in a humid tropical forest in Papua New Guinea. Feeding experiments on 48 species of herbivorous insects revealed a negative correlation between body size and a preference for feeding on young leaves. While small species preferred young leaves, large species showed no preferences, or preferred young leaves only slightly. This relationship was found for the entire leaf-chewing community, as well as for many of the constituent taxa on several taxonomic levels, from orders to genera. Taxonomic position of a species played little role in determining its preferences. It is proposed that higher toughness and lower nutrient content may act as complementary defences, which prevent small insects from feeding on mature foliage. While the low nutrient content of mature leaves may affect smaller herbivores due to their relatively higher metabolic rate and lower digestion efficiency, their toughness complicates feeding mechanically and may prevent the compensatory feeding necessary to offset the low nutritive value of mature leaves.
Another article describes a study entitled Return of the European Bison (Bison bonasus) to the Czech Republic published by the Czech Landscape in collaboration with scientists from the Biology Centre and the Institute of Vertebrate Biology, both of the ASCR and the University of South Bohemia. Research in the Czech Republic identified areas suitable for their return to the wild, mainly former military areas; surface areas of which range between 219-372 km2. In 2012, European bison was returned to the wild at Ralsko nature reserve, a former military training ground in Central Bohemia. and Miloslav jirků [et al.].
Alej podél cesty z jihomoravského městečka Valtice k Bořímu lesu patří mezi vyhlášené lokality brouků. Několik desítek stromů starých jírovců tu hostilo tak široké spektrum chráněných a ohrožených druhů hmyzu, že většina rezervací jen bledne závistí. Přesto se tento poklidný kout naší vlasti nedávno několikrát dostal do médií. Kauza Břeclavské aleje je totiž exemplární ukázkou selhání státní ochrany přírody i nekvalifikovanosti "ochrany přírody" nestátní. Aby bylo možno v budoucnosti podobným přehmatům předejít, je žádoucí s událostmi v Břeclavské aleji seznámit také čtenáře Živy a zároveň uvést několik pravidel, jimiž by se měla řídit péče o lokality obývané ohroženými organismy vázanými na staré stromy. and Liquidation of Endangered Species was Paid for through Funds for Nature Conservation. The article deals with the destruction of old horse chestnut trees growing along a rarely used old way from Valtice to Břeclav. The destruction of trees that hosted populations of numerous red-listed and protected species of saproxylic insect was sponsored by a grant from the Operational Programme Environment.