Download or read book Olfactory Navigation of Pigeons Represented by Aerosol Dispersion Modeling written by Miriam Leah Handler and published by . This book was released on 2018 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt: The influence of anosmia on pigeon (Columba livia) navigation has been proven significant by biological and physical experiments conducted over decades. Although contested by competing hypotheses, navigation by olfaction has become the most modern and accepted hypothesis explaining homing behavior in pigeons. Pigeons possess the ability to store olfactory information in their memory for later recollection when displaced from home. Exactly how pigeons employ this remarkable skill has been cause for investigation. To understand how this mechanism works, a virtual olfactory map was generated by tracing air parcel trajectories 24 hours back in time to model their origin. This was repeated over the entire free-flying period of inexperienced pigeons kept at a field station in Arnino within Pisa, Italy until controlled release at some point later in time. Given the relationship between wind direction and the movement of air parcels, the origin locations of the virtual air-parcel trajectories were thus correlated with the wind direction blowing at the home loft at the time of the arrival of the air parcel. We hypothesize that by associating the wind direction with smell, it brings the pigeons to form a mental olfactory map. To quantify the strength of the olfactory map, we experimentally released birds under two treatments. Pigeons were either untreated (control group - C) or made anosmic, i.e., unable to smell (treatment group - ZnPA). Trajectories back toward the loft were recorded using GPS trackers mounted on the birds. Three indices quantified the density of different aspects of the mental olfactory map: Representation (RI), Uniqueness (UI), and Orientation Consistency (OCI), were created and compared to pigeon homing indices: Homing Efficiency Index (HEI) and Homing Component (HC), and to quantitative characteristics of the pigeon movement behaviors. A significant and positively-sloping relationship was found between C-group pigeons’ HEI and RI, whereas no significant relationship was found between any of the olfactory map and homing indices for ZnPA pigeons. Additional track characteristics were related to multiple olfactory map indices for both C and ZnPA pigeons. In addition to navigation via olfaction, the utilization of land cover class was explored by annotating the tracks of C and ZnPA pigeons with remote sensing data of land cover. The distributions of land cover classes among the tracks of C and ZnPA birds were compared to one another in addition to comparing their annotated tracks to the distribution of land cover classes in the available background. All comparisons displayed significantly different distributions, indicating that the pigeons had some preference with respect to land cover, helping to explain some of the unexpected relationships between ZnPA pigeon track behaviors and olfactory map indices that necessarily pass through land cover types with associated odors. Overall, the significant relationships between olfactory map indices and homing efficiency in untreated birds and the lack of such relationships in treated birds indicate that an olfactory map is created by relating wind directions with smells during the free-flying period. Our findings help shed light on the method by which pigeons apply smells to find their way.