Color-mediated foraging by pollinators: A comparative study of two passionflower butterflies at Lantana camara

Colorful floral signaling and resulting insect foraging behaviors have only been extensively examined in hymenopteran pollinators, especially bees, in comparison to flies, beetles, and butterflies regardless of their ecological importance. Therefore, my study provides novel information by focusing on foraging behaviors of adult passionflower butterflies, Heliconius melpomene and Dryas iulia, to the color changing flowers of Lantana camara. My dissertation which is divided into four chapters, aims to explore various aspects of color mediate foraging in passionflower butterflies by combining observations in the wild with controlled field and laboratory experiments. In the first chapter I reviewed flower color development and pollinators\u27 sensory mechanisms to detect color changes to first elucidate the evolution of communication tactics from the senders (plants), and the detection mechanisms used by receivers (pollinators). In the second chapter I examined the relationship between sexual and foraging color biases of butterflies. In my third chapter I determined how color change associated with reward differences affected pollinator-plant attraction; and for my final chapter I investigated foraging movement patterns as butterflies fed on L. camara plants in their natural habitat. Overall, I presented evidence that indicated the following: 1) L. camara evolved a generalized pollination visitation system based on honest signaling―of reward quantity and quality tied to color changing visual signals acting in consort to produce a billboard effect that was easily perceived and deciphered by both passionflower butterflies; 2) experienced butterflies fed at flowers and were attracted to inflorescences that were of similar color to their wings, however, newly emerged butterflies exhibited different but species specific behaviors; 3) foraging behaviors were subject to change based on light environment, with yellow flower color eliciting feeding responses under blue light (open sky), and red elicited foraging under green light conditions (under forest canopy); 4) butterflies partitioned food resources spatially and temporally from each other, and from aggressive territorial hummingbirds; and 5) butterfly species changed the number of visits to plants, number of plants visited, and time spent foraging in order to successfully coexist with heterospecific competitors that shared the same space and food resource

A Review of Floral Color Signals and Their Heliconiid Butterfly Receivers

Signals vary in type and function. However, regardless of the signal, effective transmission and receiver detection are needed to exist for communication. This chapter focuses on a review of visual color signals used by plants to attract pollinators. Signal detection work has intensely focused on epigamic signals; therefore, this review adds to the body of knowledge on nonsexual signal communication. In this review, we investigate visual signals as it relates to pollinators. We focus specifically on visual color signals used by Angiosperms flowers, both static and dynamic, and look at their Heliconiid pollinators as these butterflies provide a perfect organism for studies on floral signal use and pollinators’ behavior. We noted that many of these butterflies have three specifically distinct rhodopsins used to identify food and oviposition sites and some have more due to selective pressures of conspecific and mate identification as such they have served as the focal organisms of numerous genetic and ecological studies as they use color signaling in all aspects of their lives. This review further shows that although their color preferences related to feeding, ovipositing, and mate selection have been demonstrated in countless studies, there are gaps in invertebrate literature, as research on the relationships among signal use, evolution, dynamic signals, effects of signals changes on decision making and thus behavior have not been carried out to a large extent

Detecting Gold Mining Impacts on Insect Biodiversity in a Tropical Mining Frontier with SmallSat Imagery

Gold mining is a major driver of Amazonian forest loss and degradation. As mining activity encroaches on primary forest in remote and inaccessible areas, satellite imagery provides crucial data for monitoring mining-related deforestation. High-resolution imagery, in particular, has shown promise for detecting artisanal gold mining at the forest frontier. An important next step will be to establish relationships between satellite-derived land cover change and biodiversity impacts of gold mining. In this study, we set out to detect artisanal gold mining using high-resolution imagery and relate mining land cover to insects, a taxonomic group that accounts for the majority of faunal biodiversity in tropical forests. We applied an object-based image analysis (OBIA) to classify mined areas in an Indigenous territory in Guyana, using PlanetScope imagery with ~3.7 m resolution. We complemented our OBIA with field surveys of insect family presence or absence in field plots (n = 105) that captured a wide range of mining disturbances. Our OBIA was able to identify mined objects with high accuracy (\u3e90% balanced accuracy). Field plots with a higher proportion of OBIA-derived mine cover had significantly lower insect family richness. The effects of mine cover on individual insect taxa were highly variable. Insect groups that respond strongly to mining disturbance could potentially serve as bioindicators for monitoring ecosystem health during and after gold mining. With the advent of global partnerships that provide universal access to PlanetScope imagery for tropical forest monitoring, our approach represents a low-cost and rapid way to assess the biodiversity impacts of gold mining in remote landscapes

Use of logging roads by terrestrial mammals in a responsibly managed neotropical rainforest in Guyana

Selective logging is the most widespread use of tropical forests. Building logging roads facilitates access to previously remote rainforests, and so proper management is essential for ensuring biodiversity retention in logged landscapes. Terrestrial mammals often directly use logging roads (via movement corridors, hunting or foraging), making them vulnerable to poorly managed roads. Here we explore how the presence, arrangement and use of logging roads influence terrestrial mammal occupancy and detection within a Forest Stewardship Council (FSC) certified logged forest in Guyana. We compared camera trap data from20 natural ‘game’ trails in an unlogged area, with camera trap data from 23 sites set near to or on logging roads within the Iwokrama forest. Our findings showed high occupancy within logged areas with no statistically significant difference to unlogged areas. Higher detections were noted along secondary and feeder roads compared to skid trails and the natural trails in control areas. Additionally, our data showed a negative correlation between occupancy and distance to village for a scatter hoarding rodent, most likely driven by subsistence hunting by local communities. Our results indicate that proper road management geared towards the monitoring and guarded access of logging roads, can have a positive effect on terrestrial mammal occurrence within responsibly managed rainforests

Variable shifts in bird and bat assemblages as a result of reduced-impact logging revealed after 10 years

1. Selective logging is the most widespread driver of land-use change in biodiverse and carbon-rich tropical forests. However, the effects of selective logging on bio-diversity are less than those associated with other drivers of forest degradation. A suite of recent research has shown that reduced-impact logging (RIL) results in few or no changes to biological assemblages. But because this logging technique is relatively new, most studies have only considered short-term impacts. 2. We address this research gap by quantifying changes in biodiversity assemblage as a result of RIL over the longer term. We comprehensively sampled bird and bat assemblages pre-logged, 1 year after, and 10 years after RIL in Guyana, using a before-after control-impact (BACI) sampling design. We compared bird and bat assemblages in each timeframe, and additionally appraised the impact of time since logging, and the number of trees harvested across the suite of species which we further divided between different feeding guilds, disturbance sensitivity and vertical stratification of forest use. 3. We found that 1 year after logging only minor changes could be detected, but 10 years later richness had slightly declined in some groups, while others had shown complete recovery. Nectivorous and insectivorous birds, and carnivorous bats declined in richness, while carnivorous birds, showed a clear recovery to a state akin to pre-logging. This indicates that for some niches a subtle, but long-term relaxation effect may be occurring, whereby extinction debts are realized long after the initial disturbance, while other groups have either recovered or not changed after logging. 4. Assemblage changes were also predicted by vertical stratification of forest use, with avian species using the understorey and mid–upper levels of the forest being most affected. 5. Synthesis and applications: Our study demonstrates how best practice forestry and logging can maintain healthy vertebrate populations over the long term. Forestry concessions that adopt techniques of low-harvest RIL and are managed for their long-term timber provision through extension of regeneration times beyond 10 years after harvest, are likely to benefit from the ecosystem services provided by biodiversity, while also making a valuable contribution to the global conservation estate

Impacts of Large Classes on Student’s Performance: A Case Study from the University of Guyana

As more persons seek higher education, class sizes continue to increase. The impact of an increase in class size has sparked much debate among policymakers and the education community. While there is no agreed definition of what size constitutes a large class, it is a common view that it exceeds an average of 100 students. Many believe that larger classes will negatively affect the student's performance and lead to a decrease in interaction. This may deter the teaching and learning process resulting in decreased performance. Our study was conducted to determine biology students’ perception of the impact of large classes on their performance at the University of Guyana. Data was collected through an online survey and distributed to 1st -4th year students registered in the biology program. Nine-mark (grade) sheets from the department of biology with varying numbers of students were analyzed. We found that students believed that class size does have an impact on their performance. They indicated that their performance is poor in larger classes due to less interaction, limited feedback, and more disruptions. An analysis of courses in the biology department showed higher failure rates in larger classes, however, it cannot be concluded that this is a result of the class size. It is recommended that professional development training be provided to instructors on modes of teaching large classes. Keywords: class size, large class, performance, interaction DOI: 10.7176/JEP/13-13-04 Publication date:May 31st 202

Data of analyzed measures

This file contains choice data from an experiment testing the effects of color preference on sampling and tracking in bumble bees. There tabs for the subject data, the treatment data, and both the blocked and whole mean data for the series of measures in the paper

Data from: Influence of pre-existing preference for color on sampling and tracking behavior in bumblebees

Animals reduce uncertainty in their lifetime by using information to guide decision making. Information available can be inherited from the past or gathered from the present. Therefore, animals must balance inherited biases with new information that may be in conflict with those potential biases. In our study, we set up color pairings such that an arbitrarily chosen focal color, human-orange, would result in an inherent bias in comparison to three other colors tested resulting in equal, medium, and strong preference differences. We chose color pairings through a series of preferences tests across 8 colonies of bumblebees. We subsequently used these pairings with rewards that varied in quality (good or bad states) and consistency (steady and fluctuating) in order to investigate how inherited biases affect the foraging choices of bumblebees when new information is gathered. We found that the pre-existing color biases within our bees were only maintained when the reward associated with those colors was steady, even if paired with mediocre sugar concentrations. When maintained, we observed that other aspects of bee choice also reflected this bias, including increased sampling for the preferred color and an increased likelihood of choosing that color in a subsequent choice. Thus, environmental change and reward differences interact with the level of pre-existing bias to determine whether inherited information is more heavily weighted than newly gathered information, and even a strong pre-existing bias can be quickly erased with experience under some conditions

Appendix 1. from Systematic challenges and opportunities in insect monitoring: a Global South perspective

Publication record biased query and result