a-new-approach-that-eliminates-handling-for-studying-aggression-loser

A New Approach that Eliminates Handling for Studying Aggression and the "Loser" Effect in <em>Drosophila melanogaster</em>

Aggressive behavior in Drosophila melanogaster is composed of the sequential expression of stereotypical behavioral patterns (for analysis see 1). This ...

Harvard Medical School

Considerable efforts have been made to investigate how homing pigeons (Columba livia f. domestica) are able to return to their loft from distant, unfamiliar sites while the mechanisms underlying navigation in familiar territory have received less attention. With the recent advent of global positioning system (GPS) data loggers small enough to be carried by pigeons, the role of visual environmental features in guiding navigation over familiar areas is beginning to be understood, yet, surprisingly, we still know very little about whether homing pigeons can rely on discrete, visual landmarks to guide navigation. To assess a possible role of discrete, visual landmarks in navigation, homing pigeons were first trained to home from a site with four wind turbines as salient landmarks as well as from a control site without any distinctive, discrete landmark features. The GPS-recorded flight paths of the pigeons on the last training release were straighter and more similar among birds from the turbine site compared with those from the control site. The pigeons were then released from both sites following a clock-shift manipulation. Vanishing bearings from the turbine site continued to be homeward oriented as 13 of 14 pigeons returned home. By contrast, at the control site the vanishing bearings were deflected in the expected clock-shift direction and only 5 of 13 pigeons returned home. Taken together, our results offer the first strong evidence that discrete, visual landmarks are one source of spatial information homing pigeons can utilize to navigate when flying over a familiar area.

Evidence for discrete landmark use by pigeons during homing.

In Drosophila, prior fighting experience influences the outcome of later contests: losing a fight increases the probability of losing second contests, thereby revealing "loser" effects that involve learning and memory. In these experiments, to generate and quantify the behavioral changes observed as consequences of losing fights, we developed a new behavioral arena that eliminates handling. We compared two commonly used fly handling procedures with this new chamber and demonstrated that handling influences aggressive behavior and prevents "loser" effect formation. In addition, we induced and observed novel aspects of learning associated with aggression such as the formation of robust winner effects.

Article	Year
Evidence for discrete landmark use by pigeons during homing. The Journal of experimental biology\| PubMed ID: 22735350	2012
Handling alters aggression and "loser" effect formation in Drosophila melanogaster. Learning & memory (Cold Spring Harbor, N.Y.)\| PubMed ID: 25593291	2015

Budhaditya Chowdhury

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