Iterative Recognition of Bird's Nest in Aerial Photograph of High Voltage Transmission Tower

Background: Unmanned aerial vehicle automatic fault identification of high voltage transmission equipment has entered the stage of product development, in which image recognition technology is one of the key technologies. There are often bird nests on the high voltage transmission tower, which have an impact on the transmission, so they needs to be automatically detected. Methods: For bird's nest recognition, a novel algorithm is proposed. Firstly, the template image and auxiliary function are used to construct the system, and the iterative point trajectory set, called feature set, is obtained by iteration; Then, the target image is searched by blocks, and the image blocks are iterated with the same auxiliary function to construct the iterative system, and the set of iterative point tracks to be identified is obtained. The correlation coefficient is calculated by comparing the feature set with those to be recognized. And we can confirm whether the image block is a bird's nest according to the size of correlation coefficient. Results: Different from the general image recognition method, the iterative algorithm obtains the iterative trajectory by iterating the image and the auxiliary function, and takes the iterative trajectory as the image feature, then the feature comparison is carried out, so as to achieve the goal of bird's nest recognition. The effectiveness of the method is proved by experiments. The recognition accuracy is 99% by experiment on the self-built data set. Conclusion: This paper proposes a new feature extraction algorithm for bird's nest recognition. The algorithm based on iteration is very simple and effective for bird's nest identification. As a new method, it needs further development and improvement.

Odour-based natal nest recognition in the zebra finch ( Taeniopygia guttata ), a colony-breeding songbird

Passerine birds have an extensive repertoire of olfactory receptor genes. However, the circumstances in which passerine birds use olfactory signals are poorly understood. The aim of this study is to investigate whether olfactory cues play a role in natal nest recognition in fledged juvenile passerines. The natal nest provides fledglings with a safe place for sleeping and parental food provisioning. There is a particular demand in colony-breeding birds for fledglings to be able to identify their nests because many pairs breed close to each other. Olfactory orientation might thus be of special importance for the fledglings, because they do not have a visual representation of the nest site and its position in the colony when leaving the nest for the first time. We investigated the role of olfaction in nest recognition in zebra finches, which breed in dense colonies of up to 50 pairs. We performed odour preference tests, in which we offered zebra finch fledglings their own natal nest odour versus foreign nest odour. Zebra finch fledglings significantly preferred their own natal nest odour, indicating that fledglings of a colony breeding songbird may use olfactory cues for nest recognition.