An official website of the United States government
Visual and auditory signals are well-established components of avian courtship, but the role of chemical signaling remains poorly understood, particularly in mating systems with elaborate courtship displays. To test how chemical cues influence mating behavior we conducted two experiments in the lance-tailed manakin (Chiroxiphia lanceolata). First, in a field experiment, we tested the response of free-living males and females to manipulation of chemical cues at male display perches by cleaning the perches with ethanol or a dry cloth (control) and quantified a potential chemical signaling behavior (bill-wiping) in response to experimental manipulation. During bouts of dance perch maintenance and displays with a female present (i.e., activity relevant to female mate choice) males increased bill-wiping behavior during initial ethanol treatment periods. We also detected carryover effects of the ethanol treatment; in later treatment periods males bill-wiped more when the prior treatment was ethanol. The likelihood of a female either revisiting a display area or copulating with a male was unrelated to experimental treatment. Next, in captive trials, we assessed female preference for olfactory cues from males that differed in their genetic diversity, a trait previously identified as relevant to female mate choice. In contrast to similar trials in other bird species, females showed no clear preference. Together, these results provide some evidence for chemical signaling by males at display perches, but it remains unclear what information chemical cues convey.
more »
« less
Rat behavior and dopamine release are modulated by conspecific distress
Rats exhibit ‘empathy’ making them a model to understand the neural underpinnings of such behavior. We show data consistent with these findings, but also that behavior and dopamine (DA) release reflects subjective rather than objective evaluation of appetitive and aversive events that occur to another. We recorded DA release in two paradigms: one that involved cues predictive of unavoidable shock to the conspecific and another that allowed the rat to refrain from reward when there were harmful consequences to the conspecific. Behavior and DA reflected pro-social interactions in that DA suppression was reduced during cues that predicted shock in the presence of the conspecific and that DA release observed on self-avoidance trials was present when the conspecific was spared. However, DA also increased when the conspecific was shocked instead of the recording rat and DA release during conspecific avoidance trials was lower than when the rat avoided shock for itself.
more »
« less
- Award ID(s):
- 1633516
- PAR ID:
- 10108762
- Date Published:
- Journal Name:
- eLife
- Volume:
- 7
- ISSN:
- 2050-084X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract Wild‐caught European starlings (Sturnus vulgaris) were exposed to a learning task to determine whether heart rate (HR) and behavior responses to the learning activated the sympathetic nervous system. Birds learned to discriminate between images of opposite convexity (concave and convex) based on shading cues in a closed economy (food only available through task completion). Once learned, the task was changed in three ways: (a) manipulating the angle and shape of the image; (b) altering the availability of the task; and (c) reversing the positive stimulus. HR, used as an index of catecholamine release, was measured during each change to determine whether having to alter previously established behaviors to learn new behaviors elicited a sympathetic response. Starlings decreased their HR during the initial discrimination training and did not alter their HR when presented with modified images or when the positive stimulus was reversed. However, HR increased when the task became unavailable and decreased upon its return, suggesting that preventing task performance was perceived as stressful. Birds also modified their behavior when tasks were changed. The number of trials per minute decreased during the reversal treatment, as did the success rate, suggesting that starlings may try to conserve energy when access to food diminishes. This is also supported by the decrease in perch hops per minute when the task was unavailable and the subsequent increase upon its return. Overall, these results suggest that learning per se does not activate the sympathetic nervous system and, therefore, is not a stressor for wild birds.more » « less
-
Synopsis This study extends recent research demonstrating that the veiled chameleon (Chamaeleo calyptratus) can produce and detect biotremors. Chameleons were paired in various social contexts: dominance (male–male; female–female C. calyptratus); courtship (male–female C. calyptratus); heterospecific (C. calyptratus + C. gracilis); and inter-size class dominance (adult + juvenile C. calyptratus). Simultaneous video and accelerometer recordings were used to monitor their behavior and record a total of 398 biotremors. Chamaeleo calyptratus produced biotremors primarily in conspecific dominance and courtship contexts, accounting for 84.7% of the total biotremors recorded, with biotremor production varying greatly between individuals. Biotremors were elicited by visual contact with another conspecific or heterospecific, and trials in which chameleons exhibited visual displays and aggressive behaviors were more likely to record biotremors. Three classes of biotremor were identified—hoots, mini-hoots, and rumbles, which differed significantly in fundamental frequency, duration, and relative intensity. Biotremor frequency decreased with increasing signal duration, and frequency modulation was evident, especially in hoots. Overall, the data show that C. calyptratus utilizes substrate-borne vibrational communication during conspecific and possibly heterospecific interactions.more » « less
-
null (Ed.)An important problem in designing human-robot systems is the integration of human intent and performance in the robotic control loop, especially in complex tasks. Bimanual coordination is a complex human behavior that is critical in many fine motor tasks, including robot-assisted surgery. To fully leverage the capabilities of the robot as an intelligent and assistive agent, online recognition of bimanual coordination could be important. Robotic assistance for a suturing task, for example, will be fundamentally different during phases when the suture is wrapped around the instrument (i.e., making a c- loop), than when the ends of the suture are pulled apart. In this study, we develop an online recognition method of bimanual coordination modes (i.e., the directions and symmetries of right and left hand movements) using geometric descriptors of hand motion. We (1) develop this framework based on ideal trajectories obtained during virtual 2D bimanual path following tasks performed by human subjects operating Geomagic Touch haptic devices, (2) test the offline recognition accuracy of bi- manual direction and symmetry from human subject movement trials, and (3) evalaute how the framework can be used to characterize 3D trajectories of the da Vinci Surgical System’s surgeon-side manipulators during bimanual surgical training tasks. In the human subject trials, our geometric bimanual movement classification accuracy was 92.3% for movement direction (i.e., hands moving together, parallel, or away) and 86.0% for symmetry (e.g., mirror or point symmetry). We also show that this approach can be used for online classification of different bimanual coordination modes during needle transfer, making a C loop, and suture pulling gestures on the da Vinci system, with results matching the expected modes. Finally, we discuss how these online estimates are sensitive to task environment factors and surgeon expertise, and thus inspire future work that could leverage adaptive control strategies to enhance user skill during robot-assisted surgery.more » « less
-
Abstract Movement behavior is central to understanding species distributions, population dynamics and coexistence with other species. Although the relationship between conspecific density and emigration has been well studied, little attention has been paid to how interspecific competitor density affects another species' movement behavior. We conducted releases of two species of competingTriboliumflour beetles at different densities, alone and together in homogeneous microcosms, and tested whether their recaptures‐with‐distance were well described by a random‐diffusion model. We also determined whether mean displacement distances varied with the release density of conspecific and heterospecific beetles. A diffusion model provided a good fit to the redistribution ofT. castaneumandT. confusumat all release densities, explaining an average of >60% of the variation in recaptures. For both species, mean displacement (directly proportional to the diffusion rate) exhibited a humped‐shaped relationship with conspecific density. Finally, we found that both species of beetle impacted the within‐patch movement rates of the other species, but the effect depended on density. ForT. castaneumin the highest density treatment, the addition of equal numbers ofT. castaneumorT. confusumhad the same effect, with mean displacements reduced by approximately one half. The same result occurred forT. confusumreleased at an intermediate density. In both cases, it was total beetle abundance, not species identity that mattered to mean displacement. We suggest that displacement or diffusion rates that exhibit a nonlinear relationship with density or depend on the presence or abundance of interacting species should be considered when attempting to predict the spatial spread of populations or scaling up to heterogeneous landscapes.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.7554/eLife.38090
