Making a stronger case for comparative research to investigate the behavioral and neurological bases of three-dimensional navigation

The rich diversity of avian natural history provides exciting possibilities for comparative research aimed at understanding three-dimensional navigation. We propose some hypotheses relating differences in natural history to potential behavioral and neurological adaptations possessed by contrasting bird species. This comparative approach may offer unique insights into some of the important questions raised by Jeffery et al

Making a stronger case for comparative research to investigate the behavioral and neurological bases of three-dimensional navigation

The rich diversity of avian natural history provides exciting possibilities for comparative research aimed at understanding three-dimensional navigation. We propose some hypotheses relating differences in natural history to potential behavioral and neurological adaptations possessed by contrasting bird species. This comparative approach may offer unique insights into some of the important questions raised by Jeffery et al

Slope-Driven Goal Location Behavior in Pigeons

A basic tenet of principles of associative learning applicable to models of spatial learning is that a cue should be assigned greater weight if it is a better predictor of the goal location. Pigeons were trained to locate a goal in an acute corner of an isosceles trapezoid arena, presented on a slanted floor with 3 (Experiment 1) or 2 (Experiment 2) orientations. The goal could be consistently determined by the geometric shape of the arena; however, its position with respect to the slope gradient varied, such that slope position was not a good predictor of the goal. Pigeons learned to solve the task, and testing on a flat surface revealed successful encoding of the goal relative to the geometric shape of the arena. However, when tested in the arena placed in a novel orientation on the slope, pigeons surprisingly made systematic errors to the other acute—but geometrically incorrect—mirror image corner. The results indicate that, for each arena orientation, pigeons encoded the goal location with respect to the slope. Then, in the novel orientation, they chose the corner that matched the goal’s position on the slope plus local cue (corner angle). Although geometry was 2 times (Experiment 2) or even 3 times (Experiment 1) as predictive as slope, it failed to control behavior during novel test trials. Instead, searching was driven by the less predictive slope cues. The reliance on slope and the unresponsiveness to geometry are explained by the greater salience of slope despite its lower predictive value

Development of site fidelity in the nocturnal amblypygid, \u3ci\u3ePhrynus marginemaculatus\u3c/i\u3e

Amblypygids are capable of navigation in the complex terrain of rainforests in near complete darkness. Path integration is unnecessary for successful homing, and the alternative mechanisms by which they navigate have yet to be elucidated. Here, our aims were to determine whether the amblypygid Phrynus marginemaculatus could be trained to reliably return to a target shelter in a laboratory arena—indicating goal recognition—and to document changes in behavior associated with the development of fidelity. We recorded nocturnal movements and space use by individuals over five nights in an arena in which subjects were provided with two shelters that differed in quality. The target shelter, unlike the alternative shelter, shielded subjects from light in daylight hours. Individuals consistently exited and returned to a shelter each night and from the third night onward chose the target shelter more often than the alternative shelter. Indeed, on the fifth night, every subject chose the target shelter. This transition was associated with changes in movement and space use in the arena. Notably, the movement features of outbound and inbound paths differed but did not change across nights. Individuals were also characterized by distinct behavioral strategies reflecting candidate homing mechanisms

Development of site fidelity in the nocturnal amblypygid, \u3ci\u3ePhrynus marginemaculatus\u3c/i\u3e

Amblypygids are capable of navigation in the complex terrain of rainforests in near complete darkness. Path integration is unnecessary for successful homing, and the alternative mechanisms by which they navigate have yet to be elucidated. Here, our aims were to determine whether the amblypygid Phrynus marginemaculatus could be trained to reliably return to a target shelter in a laboratory arena—indicating goal recognition—and to document changes in behavior associated with the development of fidelity. We recorded nocturnal movements and space use by individuals over five nights in an arena in which subjects were provided with two shelters that differed in quality. The target shelter, unlike the alternative shelter, shielded subjects from light in daylight hours. Individuals consistently exited and returned to a shelter each night and from the third night onward chose the target shelter more often than the alternative shelter. Indeed, on the fifth night, every subject chose the target shelter. This transition was associated with changes in movement and space use in the arena. Notably, the movement features of outbound and inbound paths differed but did not change across nights. Individuals were also characterized by distinct behavioral strategies reflecting candidate homing mechanisms

Importance of the antenniform legs, but not vision, for homing by the neotropical whip spider \u3ci\u3eParaphrynus laevifrons\u3c/i\u3e

Amblypygids, or whip spiders, are nocturnal, predatory arthropods that display a robust ability to navigate to their home refuge. Prior field observations and displacement studies in amblypygids demonstrated an ability to home from distances as far away as 10 m. In the current study, micro-transmitters were used to take morning position fixes of individual Paraphrynus laevifrons following an experimental displacement of 10 m from their home refuge. The intention was to assess the relative importance of vision compared with sensory input acquired from the antenniform legs for navigation as well as other aspects of their spatial behavior. Displaced individuals were randomly assigned to three treatment groups: (i) control individuals; (ii) visiondeprived individuals, VD; and (iii) individuals with sensory input from the tips of their antenniform legs compromised, AD. Control and VD subjects were generally successful in returning home, and the direction of their movement on the first night following displacement was homeward oriented. By contrast, AD subjects experienced a complete loss of navigational ability, and movement on the first night indicated no hint of homeward orientation. The data strongly support the hypothesis that sensory input from the tips of the antenniform legs is necessary for successful homing in amblypygids following displacement to an unfamiliar location, and we hypothesize an essential role of olfaction for this navigational ability

On the Paleontology of Animal Cognition: Using the Brain Dimensions of Modern Birds to Characterize Maniraptor Cognition

Drawing inferences on the characteristics, including behavior, of extinct species using comparisons with extant species has a long tradition in paleontology. Departing from the observation that extinct maniraptors possessed brains with a relatively long and narrow telencephalon, we used digital endocasts taken from 11 species of modern birds to determine if any of the sampled modern bird species displayed a similar telencephalic shape, and by inference, similar cognitive ability. The analysis revealed that the telencephalon of the double-crested cormorant (Phalacrocorax auritus) is extraordinarily narrow (large length-to-width ratio) and strikingly similar to Archaeopteryx and even some non-avian, maniraptoran dinosaurs. The relatively narrow brain in turn suggests a relatively small nidopallium subdivision of the telencephalon and associated impoverished general cognitive ability. This first-order brain-anatomical observation, together with the relatively ancient origins of a cormorant fossil record, suggest that cormorants could be used as a model for the general cognitive abilities of extinct maniraptors

Sensitivity Analysis for Optimal Parameters for Marine Radar Data Processing

A bird and bat monitoring system has been developed that uses marine radar, IR camera and acoustic recorders for wind farm applications. IR video recording is used to monitor birds and bats activity which will be useful for wildlife biologists in developing mit igation techniques to minimize impact of wind turbines on birds and bats. The goal is to quantify birds and bats activity near wind turbines. Radar will provide z-coordinate (alt itude) and IR camera will provide (x, y) coordinates of birds/bats. Acous tic monitoring is used to identify birds and bats at their species level. This paper deals with the use of marine radar for determining altitudes, direction and quantity (passage rates) of birds/bats. Data from the marine radar is digitized and processed with open source radR software. Since the data is unknown tracking and quantification can be very challenging. This paper deals with the sensitivity analysis and effects of various parameters used in the tracking algorithm so resulting data can be meaningful