A population study of the Rook Corvus frugilegus in Leon Province, northwest Spain

A resident population of Kooks Corvus frugilegus in Leon, Spain, decreased by 247; from 197679. Migrant Rooks appear not to enter the range of this population which is unique in the Iberian Peninsula. During the breeding seasons colonies are attacked by man: 17–19% of birds failed to breed and only 0.5-0.7 young per nest survived to fly. The trees chosen for nesting are in plantations subject to regular cropping, after which colonies are scattered. Adult mortality was 16–26% annually. Young formed 17.6–23% of the population in June; 11–15.6% of birds in March were in their first year and many of these bred successfully. Communal roosts were used only from mid-July to mid-October.     

Seasonal variations in feeding range and flock structure of the Rook Corvus frugilegus in eastern Ireland

The feeding range and flock structure of Rooks showed temporal variations caused mainly by the dispersion of food and reproductive behaviour.
Feeding range was restricted in spring, autumn and early winter when food availability was high and Rooks were reproductively active. A large feeding range occurred in late summer and late winter, when food availability was either generally low or locally distributed and when Rooks were reproductively inactive. The occurrence of flocks common to several rookeries mirrored variations in feeding range; mixed rookery flocks were more common in late summer and late winter. Similarly, the size of the rookery (as measured by the number of nests) was related to feeding range only when Rooks were reproductively inactive and at such times larger rookeries had greater feeding ranges.
Flock structure showed similar seasonal variations; small widely spaced flocks predominated in summer, autumn, early winter and spring, whereas large dense flocks occurred in late winter. Diurnal variations in flock structure occurred within any one season. Both seasonal and diurnal variations in flock structure may be determined by the dispersion of the prey and the feeding strategy used to obtain it, reproductive behaviour and the risk of predation.     

Nest-Building by Chimpanzees (Pan troglodytes verus) at Seringbara, Nimba Mountains: Antipredation, Thermoregulation, and Antivector Hypotheses

The construction of nests (or beds) for sleeping is a chimpanzee universal, yet little is known about the adaptive function of nest-building. We present an in-depth study of nest-building by unhabituated chimpanzees at the Seringbara study site in the Nimba Mountains, Guinea, West Africa. We recorded 1520 chimpanzee nests over 28 mo during three study periods between 2003 and 2008. We investigated where chimpanzees built their nests, both across the home range and in nest trees, and assessed how altitude and habitat type affected nest site selectivity. We examined whether or not chimpanzees were selective in nest tree choice regarding physical tree characteristics and tree species and assessed plant species preference for both tree- and ground-nesting. We tested three, nonmutually exclusive, hypotheses for the function of arboreal nest-building. We assessed whether selectivity for nest tree characteristics reflected an antipredator strategy, examined whether nesting patterns (both arboreal and terrestrial) and nesting height were influenced by variation in climatic conditions (temperature, humidity, wind), and measured mosquito densities at ground level and in trees at 10 m and related mosquito densities to nesting patterns. Chimpanzees preferred to nest above 1000 m and nested mainly in primary forest. They preferred relatively large trees with a low first branch, dense canopy, and small leaves and showed preference for particular tree species, which was stable across years, whereas plant choice for ground-nesting was largely based on plant availability. We found no support for the antipredation hypothesis, nor did mosquito densities explain arboreal nest-building. The thermoregulation hypothesis was supported, as both nesting patterns and nest-height variation across seasons reflected a humidity-avoidance strategy. Chimpanzees nested higher in trees and at higher altitudes in the wet season. In sum, chimpanzees were selective in their choice of nest sites, locations, and materials, and tree-nesting patterns at Seringbara were best explained by a thermoregulation strategy of humidity avoidance.     

Late Embolectomy

Embolectomy with a balloon catheter even up to two months after embolism may be successful. Late embolectomy, meaning operation more than 48 hours after embolism, should be undertaken in a hospital where all facilities for arterial reconstruction are available.     

Modern Distribution and Biology of the Rook (<Emphasis Type="Italic">Corvus frugilegus</Emphasis>) in Yakutia

This paper presents modern information on the distribution of the rook (Corvus frugilegus L.) in Yakutia, at the northeastern limit of its range. The history of the spreading of this species is traced over the past 30 years. Data on the breeding biology and feeding of the rook are given.     

Fungal remains from the Late Riphean

The paper describes organic remains of one billion years old from the Lakhanda microbiota of the Uchur-Maya Region of southeastern Siberia. The microfossils were discovered on organic sapropelic films. The preserved morphological characters and some developmental stages of the ancient organisms, which are fixed in fossil state, suggest that some of them resembled zygomycetes. Other microfossils under consideration are comparable to reproductive structures of myxomycetes in the type of fusion of spheroid cells and formation of various types of aggregation (sori). Colonies of unicellular microfossils that are arranged in a branching pseudomycelium superficially resemble yeasts. The presence in the same biota of fungal remains belonging to the Myxomycota and Mycota, as well as members of xanthophyte vaucherian algae, indicates that various branches of eukaryotes might have developed in parallel even earlier than the Late Riphean.