scholarly journals Compass Cue Integration and Its Relation to the Visual Ecology of Three Tribes of Ball-Rolling Dung Beetles

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 526
Author(s):  
Lana Khaldy ◽  
Claudia Tocco ◽  
Marcus Byrne ◽  
Marie Dacke
Keyword(s):  
Visual Cues ◽  
Relative Weight ◽  
Dung Beetles ◽  
Visual Ecology ◽  
Line Orientation ◽  
The Sun ◽  
Tall Grass ◽  
Directional Information ◽  
Ball Rolling ◽  
Straight Line

To guide their characteristic straight-line orientation away from the dung pile, ball-rolling dung beetles steer according to directional information provided by celestial cues, which, among the most relevant are the sun and polarised skylight. Most studies regarding the use of celestial cues and their influence on the orientation system of the diurnal ball-rolling beetle have been performed on beetles of the tribe Scarabaeini living in open habitats. These beetles steer primarily according to the directional information provided by the sun. In contrast, Sisyphus fasciculatus, a species from a different dung-beetle tribe (the Sisyphini) that lives in habitats with closely spaced trees and tall grass, relies predominantly on directional information from the celestial pattern of polarised light. To investigate the influence of visual ecology on the relative weight of these cues, we studied the orientation strategy of three different tribes of dung beetles (Scarabaeini, Sisyphini and Gymnopleurini) living within the same biome, but in different habitat types. We found that species within a tribe share the same orientation strategy, but that this strategy differs across the tribes; Scarabaeini, living in open habitats, attribute the greatest relative weight to the directional information from the sun; Sisyphini, living in closed habitats, mainly relies on directional information from polarised skylight; and Gymnopleurini, also living in open habitats, appear to weight both cues equally. We conclude that, despite exhibiting different body size, eye size and morphology, dung beetles nevertheless manage to solve the challenge of straight-line orientation by weighting visual cues that are particular to the habitat in which they are found. This system is however dynamic, allowing them to operate equally well even in the absence of the cue given the greatest relative weight by the particular species.

scholarly journals The effect of step size on straight-line orientation

2019 ◽  
Vol 16 (157) ◽  
pp. 20190181 ◽  
Author(s):  
Lana Khaldy ◽  
Orit Peleg ◽  
Claudia Tocco ◽  
L. Mahadevan ◽  
Marcus Byrne ◽  
...  
Keyword(s):  
Sensory Information ◽  
Dung Beetles ◽  
Line Orientation ◽  
Step Size ◽  
Directional Information ◽  
Straight Path ◽  
Directional Error ◽  
Straight Line ◽  
Motor Error ◽  
Orientation Cues

Moving along a straight path is a surprisingly difficult task. This is because, with each ensuing step, noise is generated in the motor and sensory systems, causing the animal to deviate from its intended route. When relying solely on internal sensory information to correct for this noise, the directional error generated with each stride accumulates, ultimately leading to a curved path. In contrast, external compass cues effectively allow the animal to correct for errors in its bearing. Here, we studied straight-line orientation in two different sized dung beetles. This allowed us to characterize and model the size of the directional error generated with each step, in the absence of external visual compass cues ( motor error ) as well as in the presence of these cues ( compass and motor errors ). In addition, we model how dung beetles balance the influence of internal and external orientation cues as they orient along straight paths under the open sky. We conclude that the directional error that unavoidably accumulates as the beetle travels is inversely proportional to the step size of the insect, and that both beetle species weigh the two sources of directional information in a similar fashion.

scholarly journals The role of the sun in the celestial compass of dung beetles

2014 ◽  
Vol 369 (1636) ◽  
pp. 20130036 ◽  
Author(s):  
M. Dacke ◽  
Basil el Jundi ◽  
Jochen Smolka ◽  
Marcus Byrne ◽  
Emily Baird
Keyword(s):  
Dung Beetle ◽  
Dung Beetles ◽  
Relative Influence ◽  
The Sun ◽  
Azimuthal Position ◽  
Ball Rolling ◽  
Straight Line ◽  
Celestial Compass ◽  
Compass System

Recent research has focused on the different types of compass cues available to ball-rolling beetles for orientation, but little is known about the relative precision of each of these cues and how they interact. In this study, we find that the absolute orientation error of the celestial compass of the day-active dung beetle Scarabaeus lamarcki doubles from 16° at solar elevations below 60° to an error of 29° at solar elevations above 75°. As ball-rolling dung beetles rely solely on celestial compass cues for their orientation, these insects experience a large decrease in orientation precision towards the middle of the day. We also find that in the compass system of dung beetles, the solar cues and the skylight cues are used together and share the control of orientation behaviour. Finally, we demonstrate that the relative influence of the azimuthal position of the sun for straight-line orientation decreases as the sun draws closer to the horizon. In conclusion, ball-rolling dung beetles possess a dynamic celestial compass system in which the orientation precision and the relative influence of the solar compass cues change over the course of the day.

scholarly journals Multimodal cue integration in the dung beetle compass

2019 ◽  
Vol 116 (28) ◽  
pp. 14248-14253 ◽  
Author(s):  
Marie Dacke ◽  
Adrian T. A. Bell ◽  
James J. Foster ◽  
Emily J. Baird ◽  
Martin F. Strube-Bloss ◽  
...  
Keyword(s):  
South African ◽  
Dung Beetle ◽  
The Sun ◽  
Behavioral Experiments ◽  
Compass Orientation ◽  
Directional Information ◽  
Ball Rolling ◽  
Straight Line ◽  
Memory Network ◽  
Line Path

South African ball-rolling dung beetles exhibit a unique orientation behavior to avoid competition for food: after forming a piece of dung into a ball, they efficiently escape with it from the dung pile along a straight-line path. To keep track of their heading, these animals use celestial cues, such as the sun, as an orientation reference. Here we show that wind can also be used as a guiding cue for the ball-rolling beetles. We demonstrate that this mechanosensory compass cue is only used when skylight cues are difficult to read, i.e., when the sun is close to the zenith. This raises the question of how the beetles combine multimodal orientation input to obtain a robust heading estimate. To study this, we performed behavioral experiments in a tightly controlled indoor arena. This revealed that the beetles register directional information provided by the sun and the wind and can use them in a weighted manner. Moreover, the directional information can be transferred between these 2 sensory modalities, suggesting that they are combined in the spatial memory network in the beetle’s brain. This flexible use of compass cue preferences relative to the prevailing visual and mechanosensory scenery provides a simple, yet effective, mechanism for enabling precise compass orientation at any time of the day.

The brain behind straight-line orientation in dung beetles

2019 ◽  
Vol 222 (Suppl 1) ◽  
pp. jeb192450 ◽  
Author(s):  
Basil el Jundi ◽  
Emily Baird ◽  
Marcus J. Byrne ◽  
Marie Dacke
Keyword(s):  
Dung Beetles ◽  
Line Orientation ◽  
Straight Line ◽  
The Brain

Dung beetles ignore landmarks for straight-line orientation

2012 ◽  
Vol 199 (1) ◽  
pp. 17-23 ◽  
Author(s):  
Marie Dacke ◽  
Marcus Byrne ◽  
Jochen Smolka ◽  
Eric Warrant ◽  
Emily Baird
Keyword(s):  
Dung Beetles ◽  
Line Orientation ◽  
Straight Line

How Dung Beetles Steer Straight

2021 ◽  
Vol 66 (1) ◽  
pp. 243-256
Author(s):  
Marie Dacke ◽  
Emily Baird ◽  
Basil el Jundi ◽  
Eric J. Warrant ◽  
Marcus Byrne
Keyword(s):  
Milky Way ◽  
Dung Beetles ◽  
The Sun ◽  
The Moon ◽  
Fixed Bearing ◽  
Polarization Pattern ◽  
Straight Path ◽  
Ball Rolling ◽  
Wide Range ◽  
Night Sky

Distant and predictable features in the environment make ideal compass cues to allow movement along a straight path. Ball-rolling dung beetles use a wide range of different signals in the day or night sky to steer themselves along a fixed bearing. These include the sun, the Milky Way, and the polarization pattern generated by the moon. Almost two decades of research into these remarkable creatures have shown that the dung beetle's compass is flexible and readily adapts to the cues available in its current surroundings. In the morning and afternoon, dung beetles use the sun to orient, but at midday, they prefer to use the wind, and at night or in a forest, they rely primarily on polarized skylight to maintain straight paths. We are just starting to understand the neuronal substrate underlying the dung beetle's compass and the mystery of why these beetles start each journey with a dance.

Visual cues used by ball-rolling dung beetles for orientation

2003 ◽  
Vol 189 (6) ◽  
pp. 411-418 ◽  
Author(s):  
Marcus Byrne ◽  
Marie Dacke ◽  
Peter Nordstr�m ◽  
Clarke Scholtz ◽  
Eric Warrant
Keyword(s):  
Visual Cues ◽  
Dung Beetles ◽  
Ball Rolling

scholarly journals How dim is dim? Precision of the celestial compass in moonlight and sunlight

2011 ◽  
Vol 366 (1565) ◽  
pp. 697-702 ◽  
Author(s):  
M. Dacke ◽  
M. J. Byrne ◽  
E. Baird ◽  
C. H. Scholtz ◽  
E. J. Warrant
Keyword(s):  
Dung Beetle ◽  
The Sun ◽  
The Moon ◽  
Polarization Pattern ◽  
Animal Group ◽  
Straight Line ◽  
Celestial Orientation ◽  
Polarization Compass ◽  
Celestial Compass ◽  
Diurnal Species

Prominent in the sky, but not visible to humans, is a pattern of polarized skylight formed around both the Sun and the Moon. Dung beetles are, at present, the only animal group known to use the much dimmer polarization pattern formed around the Moon as a compass cue for maintaining travel direction. However, the Moon is not visible every night and the intensity of the celestial polarization pattern gradually declines as the Moon wanes. Therefore, for nocturnal orientation on all moonlit nights, the absolute sensitivity of the dung beetle's polarization detector may limit the precision of this behaviour. To test this, we studied the straight-line foraging behaviour of the nocturnal ball-rolling dung beetle Scarabaeus satyrus to establish when the Moon is too dim—and the polarization pattern too weak—to provide a reliable cue for orientation. Our results show that celestial orientation is as accurate during crescent Moon as it is during full Moon. Moreover, this orientation accuracy is equal to that measured for diurnal species that orient under the 100 million times brighter polarization pattern formed around the Sun. This indicates that, in nocturnal species, the sensitivity of the optical polarization compass can be greatly increased without any loss of precision.

Endless skies and open seas – how birds and fish navigate

Neuroforum ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lisa Spiecker ◽  
Bo Leberecht ◽  
Corinna Langebrake ◽  
Malien Laurien ◽  
Shambhavi Rajendra Apte ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnetic Fields ◽  
Home Range ◽  
Environmental Conditions ◽  
Geomagnetic Field ◽  
Visual Cues ◽  
Quantum Mechanical ◽  
The Sun ◽  
Seasonal Migrations ◽  
Research Questions

Abstract Every year, billions of animals leave their home range and start seasonal migrations in order to find more favorable resources and to escape harsh environmental conditions. These round trips often span thousands of kilometers. To successfully navigate along their route, animals rely on various external references. While landmarks and celestial cues like stars or the sun are easy to imagine as guidance on these journeys, using the geomagnetic field for orientation is more elusive. The geomagnetic field is an omnipresent cue, which can be sensed and relied upon by many animals, even when visual cues are sparse. How magnetic fields can be perceived seems to vary between birds and fish. While birds seem to use a mechanism based on the quantum mechanical properties of electron spins, fish may have evolved a compass similar in its function to the technical devises developed by humans. How these mechanisms work precisely and how they are integrated are research questions addressed in SFB 1372.

scholarly journals Mathematical modeling shows that ball-rolling dung beetles can use dances to avoid competition

2021 ◽  
Author(s):  
Zhanyuan Yin ◽  
Leif Zinn-Brooks
Keyword(s):  
Mathematical Modeling ◽  
Optimal Strategy ◽  
Rolling Direction ◽  
Dung Beetles ◽  
Time Interval ◽  
Angular Deviation ◽  
Ball Rolling ◽  
Wide Range

Abstract Ball-rolling dung beetles shape a portion of dung into a ball and roll it away from the dung pile for later burial and consumption. These beetles perform dances (rotations and pauses) atop their dung balls in order to choose an initial rolling direction and to correct their rolling direction (reorient). Previous mathematical modeling showed that dung beetles can use reorientation to move away from the dung pile more efficiently. In this work, we study if reorientation can help beetles avoid competition (i.e., avoid having their dung balls captured), and if so, under what circumstances? This is investigated by implementing a model with two different type of beetles, a roller with a dung ball and a searcher which seeks to capture that dung ball. We show that reorientation can help rollers avoid searchers in a wide range of conditions, but that there are some circumstances in which rolling without reorienting can be a beetle's optimal strategy. We also show that rollers can minimize the probability that their dung ball is captured without making precise measurements of the time interval between dances or the angular deviation for dances.

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