Theodore Pavlic

Weaver ants regulate the rate of prey delivery during collective vertical transport

Publisher: The Company of Biologists

Date: 10-2023

DOI: 10.1242/JEB.245634

Habitat features and performance interact to determine the outcomes of terrestrial predator–prey pursuits

Publisher: Wiley

Date: 12-10-2020

DOI: 10.1111/1365-2656.13353

Weaver ants regulate the rate of prey delivery during collective vertical transport

Publisher: Cold Spring Harbor Laboratory

Date: 26-06-2022

DOI: 10.1101/2022.06.22.497253

Abstract: The collective transport of massive food items by ant teams is a striking ex le of biological cooperation, but it remains unclear how these decentralized teams coordinate to overcome the various challenges associated with transport. Previous research has focused on transport across horizontal surfaces and very shallow inclines, disregarding the complexity of natural foraging environments. In the ant Oecophylla smaragdina , prey are routinely carried up tree trunks to arboreal nests. Using this species, we induce collective transport over a variety of angled surfaces with varying prey masses to investigate how ants respond to inclines. We found that weight and incline pose qualitatively different challenges during transport. Prey were carried over vertical inclines faster than across horizontal surfaces even though inclines were associated with longer routes and a higher probability of dropping the load. This additional speed is associated with more transporters being allocated to vertical loads and not from the persistence of in idual ants. Ant teams also regulated a stable “prey delivery rate” (rate of return per transporter) across all treatments. Our proposed constrained optimization model explains these results: prey intake rate at the colony level is maximized when the allocation of transporters yields a similar prey delivery rate across loads.

Modeling the two-dimensional accuracy of soccer kicks

Publisher: Elsevier BV

Date: 04-2018

DOI: 10.1016/J.JBIOMECH.2018.03.003

Abstract: In many sports, athletes perform motor tasks that simultaneously require both speed and accuracy for success, such as kicking a ball. Because of the biomechanical trade-off between speed and accuracy, athletes must balance these competing demands. Modelling the optimal compromise between speed and accuracy requires one to quantifyhow task speed affects the dispersion around a target, a level of experimental detail not previously addressed. Using soccer penalties as a system, we measured two-dimensional kicking error over a range of speeds, target heights, and kicking techniques. Twenty experienced soccer players executed a total of 8466 kicks at two targets (high and low). Players kicked with the side of their foot or the instep at ball speeds ranging from 40% to 100% of their maximum. The inaccuracy of kicks was measured in horizontal and vertical dimensions. For both horizontal and vertical inaccuracy, variance increased as a power function of speed, whose parameter values depended on the combination of kicking technique and target height. Kicking precision was greater when aiming at a low target compared to a high target. Side-foot kicks were more accurate than instep kicks. The centre of the dispersion of shots shifted as a function of speed. An analysis of the covariance between horizontal and vertical error revealed right-footed kickers tended to miss below and to the left of the target or above and to the right, while left-footed kickers tended along the reflected axis. Our analysis provides relationships needed to model the optimal strategy for penalty kickers.

Modelling escape success in terrestrial predator-prey interactions

Publisher: Oxford University Press (OUP)

Date: 22-06-2020

DOI: 10.1093/ICB/ICAA070

Abstract: Prey species often modify their foraging and reproductive behaviors to avoid encounters with predators yet once they are detected, survival depends on out-running, out-maneuvering, or fighting off the predator. Though predation attempts involve at least two in iduals—namely, a predator and its prey—studies of escape performance typically measure a single trait (e.g., sprint speed) in the prey species only. Here, we develop a theoretical model in which the likelihood of escape is determined by the prey animal’s tactics (i.e., path trajectory) and its acceleration, top speed, agility, and deceleration relative to the performance capabilities of a predator. The model shows that acceleration, top speed, and agility are all important determinants of escape performance, and because speed and agility are biomechanically related to size, smaller prey with higher agility should force larger predators to run along curved paths that do not allow them to use their superior speeds. Our simulations provide clear predictions for the path and speed a prey animal should choose when escaping from predators of different sizes (thus, biomechanical constraints) and could be used to explore the dynamics between predators and prey.

The Ohio State University

Location: United States of America

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Arizona State University

Location: United States of America

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Using Performance To Predict The Survival Of Threatened Mammals

Start Date: 2018

End Date: 2020

Funder: Australian Research Council

Discovery Projects - Grant ID: DP180103134

Start Date: 02-2018

End Date: 12-2021

Amount: $344,192.00

Funder: Australian Research Council