Effects of elevated nest box temperature on incubation behaviour and offspring fitness-related traits in the Collared Flycatcher Ficedula albicollis

Ambient temperature experienced by an animal during development or subsequently as an adult can affect many aspects of its behaviour and life-history traits. In birds, egg incubation is a vital component of reproduction and parental care. Several studies have suggested that environmental factors (such as nest microclimate) can influence the ability of incubating parents to maintain suitable conditions for embryo development. Here, we manipulated the developmental conditions of embryos through a modification of nest box thermal microclimate to investigate female incubation behaviour and its impact on offspring fitness-related traits in a wild population of the Collared Flycatcher (Ficedula albicollis). The temperature in experimental nests was increased using a heat-pack placed under the roof of a nest box, resulting in an average temperature increase of 2.5 ºC, which corresponds to projected climate change scenarios. We demonstrated that females from nests with elevated temperature spent less time in the nest box during egg incubation and had more off-bouts than females from control nests. Moreover, we found that offspring from the experimentally heated nests had larger body mass at fledging in comparison to the control ones. Our study indicates that nest microclimate during the incubation period affects female incubation behaviour and offspring quality, indicating that environmental variation in nest temperature early in ontogeny can have important and long-lasting fitness consequences.

Head and body orientation of the White Stork Ciconia ciconia during incubation: effect of wind, apex predators and power lines

Incubation behaviour is essential for understanding the reproductive success in birds. For example, the orientation of the bird is important for reducing incubation costs associated with wind or sun, but on the other hand can be modified by the perceived risk of predation. We studied the body position of incubating White Stork Ciconia ciconia in eastern Poland using a small unmanned aerial vehicle (drone). The head and body orientation of the incubating storks was non-random and modified by natural factors, mainly wind direction and speed, but also by the presence of an apex predator, the White-tailed Eagle Haliaeetus albicilla. However, head orientation during incubation in nests located on electricity poles was also modified by the presence of the power lines, probably due to disturbance in the magnetic field detected by birds. Surprisingly, although the positioning of incubating birds (mainly females) is very important for the detection of predators and for reducing energy costs, these have not previously been studied. New technologies, such as drones, make it possible to collect new, extensive information on the incubation behaviour of birds.

Identification of 24bp indel(s) Polymorphism in the Promoter Region of prolactin Gene and its Association with Broodiness in Tellicherry Native Chicken

Background: Broodiness is a sex linked behavioural trait observed in most of the domestic fowls and it’s also known as incubation behaviour. Prolactin (PRL) is the principal gene which plays a crucial role to the onset and maintenance of broodiness in birds. The present study was aimed at identification of 24bp (insertion-deletion) indel polymorphism at the promoter region of prolactin gene and its association with broodiness in Telllicherry native chicken population. Methods: A total number of 200 birds of Tellicherry native chicken were randomly selected from All India Co-ordinated Research Project (AICRP) on poultry improvement, Mannuthy, Thrissur, Kerala. Blood samples were collected from the wing vein under aseptic condition and isolation of Genomic DNA was done. Isolated DNA samples were subjected to polymerase chain reaction (PCR) using specific set of forward and reverse primer to detect a 24bp indel polymorphism in the prolactin gene. PCR amplicons were subjected to further molecular analysis. Result: According to the polymorphic patterns birds were categorized to three different genotypes viz., II (insertion-insertion), ID (insertion-deletion) and DD (deletion-deletion). The genotype and allele frequency was calculated and the frequency of I allele (0.6975) was found to be higher than D allele (0.3025). Results of this study suggest that the incubation behaviour could be eliminated in Tellicherry native chicken population by increasing the frequency of I allele upon selective breeding which may enhance the egg production. Therefore, this 24bp indel polymorphism could be used as a molecular marker in poultry breeding.