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The shape of birds' eggs has fascinated scientists for many years. It is now possible mathematically to describe shape accurately, allowing exploration of the physical and ecological factors driving the evolution of egg shape. However, there has been relatively little consideration of how egg shape is established in the oviduct or, given that even without an external calcitic layer eggs retain their shape, how shape is fixed in the isthmus. This paper proposes a hypothesis that attempts to explain how egg shape is established and fixed in the oviduct. The hypothesis suggests that as the egg mass (i.e. yolk and albumen) moves from the magnum into the isthmus, it is squeezed by the physical restriction imposed by the isthmus lumen and cannot easily move into the isthmus. As the leading edge of the egg mass enters the isthmus, the egg mass in the distal magnum is forced to bulge outwards, resulting in an asymmetrical shape. The various egg shapes observed in birds are, hence, produced by the interaction between the size of the egg mass relative to female body mass, and the degree of the restriction of the isthmus. Thus, a large egg mass, i.e. relative to female body mass, entering a narrow isthmus will produce a pointed egg shape. If the egg mass is relatively small, and the isthmus lumen wide, more of the egg mass could enter the isthmus and the degree of asymmetry would be reduced. It is further proposed that egg shape is fixed during the formation of the shell membranes in the isthmus because the constituent protein fibres permanently stick together as they are deposited. For the first time this hypothesis helps explain the pattern of deposition and characteristics of the calcitic egg in relation to the diversity of egg shapes in birds and reptiles. [ABSTRACT FROM AUTHOR]

Bird nests can be complex bio-engineered structures constructed from a range of materials to provide a site for incubation, and in many species chick rearing. Reports of the materials used in nest walls and cup linings are typically qualitative and do not assist in understanding the functional properties of the structure as a whole. This paper provides size and composition data for nests from four species of the Motacillidae family: the meadow pipit (Anthus pratensis), pied wagtail (Motacilla alba), grey wagtail (Motacilla cinerea), and the yellow wagtail (Motacilla flava), three species of the Sylviidae family: willow warbler (Phylloscopus trochilus), Eurasian reed warbler (Acrocephalus scirpaceus) and Eurasian blackcap (Sylvia atricapilla), and the dunnock (Prunella modularis) of the Prunellidae family. Three hypotheses were tested: do nest dimensions correlate with body mass? Is it possible to distinguish among species based on their nest composition; and for individual species? Is it possible to distinguish between the cup lining and outer nest wall based on the materials used in construction? Nest composition and size varied among species although the degree of intra-specific variation was different. Size of a nest was unrelated to average female adult body mass. Composition relied on similar types of materials but in differing quantities between species. It was possible to distinguish among species in terms of nest construction, and between the cup lining and the outer nest, on the basis of at least one of the component materials. By providing quantitative data on composition, it may be possible in the future to understand better the structural, insulative and hydrological properties of the nest. Such information will be invaluable as we begin to develop an understanding of the factors that have driven evolution of nest architecture. [ABSTRACT FROM AUTHOR]

Incubation and rearing of nestlings are energetically demanding activities that can be affected by insulation conferred by the nest wall. Although thermal properties of nests are widely studied, no reports to date have dealt with the relative effects of the various structural parts of the nest wall. This experimental study investigated the effects of air movement, and for the first time, the effects of wall structure, on nest insulation for the Common Blackbird Turdus merula and Song Thrush Turdus philomelos of the Turdidae. Insulatory values, i.e. difference in cooling rate measured simultaneously inside and outside a nest, and internal cooling rates within the nest cup, were determined using temperature loggers under still-air and moving-air conditions. Moving-air increased insulatory values and internal cooling rates in both species. Insulatory values were positively correlated with the nest base thickness, but not nest side wall thickness. Removal of the outer nest wall and cup lining to reveal the internal mud cup of thrush nests reduced the insulatory value compared to the whole nest, the effect of which was exacerbated under moving-air conditions. These results may reflect that the nest wall confers huge insulatory advantages and especially so during periods of air movement. However, it is unclear whether this is related to the presence of particular nest materials that confer insulation, or to the amount of air trapped in the nest wall. Alternatively, the thermal conductivity of the materials lining the cup wall may be important. [ABSTRACT FROM AUTHOR]

For many bird species in captivity the best practice for incubation procedures have not been yet developed. This is hampered by a lack of cooperation between bird breeders or by reluctance to experiment on valuable eggs. The last two problems may be solved by observation of natural incubation, which technology has made a lot easier. Many studies document incubation behavior: daily time spend in the nest, preferred hours of making absences, egg turning rate and incubation temperature. Such data is scientifically interesting but also allows for betteij protection of endangered species through development of captive breeding programmes. The Capercaillie (Tetrao urogallus) is a threatened species over much of its European range and various conservation actions are being taken to save populations from global or local extinction. Our study took place in Capercaillie Breeding Centre in Wisla Forestry District and describes nesting and incubation behaviour of Capercaillie females kept in captivity. Our aim was to better document the nesting behaviour by recording egg turning rate, and the time and length of incubation recesses. Time of day and day of incubation had no significant influence on recess length, but the number of recesses was related with time of day with two peaks at 06:00 h and 18:00 h. Egg turning activity was the greatest during the first and last two days of incubation but generally consistent throughout the rest of incubation. Captive hens spent less time outside of the nest than wild ones, their absences were shorter, rarer and took place mostly in the evening. However, differences in the preferred absence hours were not as clearly marked as in the case of wild birds. We hope that this information will help improve management practises to maximise the reproductive output of captive Capercaillie. [ABSTRACT FROM AUTHOR]

The article presents a study on population size estimation for smooth newts (Lissotriton vulgaris) breeding in Lincolnshire, England pond. It says that the population size of newts were monitored in an artificial pond during the spring and summer of 2007 using bottle and netting traps. It states that individual animals were distinguished from digital photographs and Schnable method was used. It adds that trapping demonstrated a clumped pattern because newts seemed to be leaving the pond only to return later in the season.