Effect of light intensity in the nest site on eggshell pigmentation in a hole-nesting passerine.

Daylight is an important factor necessary for the proper embryonic development of birds, which raises the question, what happens when birds nest in relatively dim sites? The study experimentally tested whether there is a relationship between light conditions at the nesting site and the protoporphyrin-based pigmentation in the eggshell of the Great Tit (Parus major). We hypothesised that at lower light levels, eggs are less pigmented to increase the amount of light reaching the embryo. Our study system consisted of two types of nest boxes: "dark", in which the only source of light was the entrance hole, and "bright", which had two additional side windows.

The use of trail cameras to monitor species inhabiting artificial nest boxes.

Artificial boxes are commonly used in studies of cavity-dwelling animals of various taxa. One advantage of nest boxes is that cameras can be used to monitor animals inside the cavity, however, most cameras used today have to be built de novo or modified or are expensive.Here, we describe a method for monitoring nest boxes using off-the-shelf models of trail cameras that can record photographs and videos in daylight and darkness (TCM; Trail Camera Method).

Cryoconite - From minerals and organic matter to bioengineered sediments on glacier's surfaces.

Cryoconite is a mixture of mineral and organic material covering glacial ice, playing important roles in biogeochemical cycles and lowering the albedo of a glacier surface. Understanding the differences in structure of cryoconite across the globe can be important in recognizing past and future changes in supraglacial environments and ice-organisms-minerals interactions. Despite the worldwide distribution and over a century of studies, the basic characteristics of cryoconite, including its forms and geochemistry, remain poorly studied.

A nocturnal rail with a simple territorial call eavesdrops on interactions between rivals.

The behaviour of most animals has evolved in a communication network environment, in which signals produced by senders are perceived by many intended and unintended receivers. In this study, we tested whether the corncrake (Crex crex), a nocturnal rail species with innate (non-learned) calls, is able to eavesdrop on the interactions of conspecific males and how this eavesdropping affects subsequent responses by the eavesdropper to territorial intrusion. In the first step, simulated aggressive or neutral interactions between male dyads were presented to a focal male.

The importance of illumination in nest site choice and nest characteristics of cavity nesting birds.

Light has a significant impact on many aspects of avian biology, physiology and behaviour. An increasing number of studies show that illumination may positively influences birds' offspring fitness by e.g.

How to reduce the costs of ornaments without reducing their effectiveness? An example of a mechanism from carotenoid-based plumage.

Abstract: Carotenoid-based ornaments are often considered to be honest indicators of individual quality assessed by potential mates. However, males can use a variety of strategies that minimize the amount of costly carotenoids used while retaining the effectiveness of color signaling. Birds could do this by altering pigment intake, metabolism, or its presentation to a potential signal receiver.