Warning signals confer advantage to prey in competition with predators: bumblebees steal nests from insectivorous birds

Jablonski, Piotr G.,Cho, Hyun Jun,Song, Soo Rim,Kang, Chang Ku,Lee, Sang-im Springer Berlin Heidelberg 2013 Behavioral ecology and sociobiology Vol.67 No.8

<P>Aposematic (warning) signals of prey help predators to recognize the defended distasteful or poisonous prey that should be avoided. The evolution of aposematism in the context of predation has been in the center of modern ecology for a long time. But, the possible roles of aposematic signals in other ecological contexts have been largely ignored. Here we address the role of aposematic signals in competition between prey and predators. Bumblebees use visual and auditory aposematic signals to warn predators about their defenses. For 2 years, we observed competition for nestboxes between chemically defended insects, <I>Bombus ardens</I> (and possibly also <I>Bombus ignitus</I>), and cavity nesting birds (<I>Parus minor</I> and <I>Poecile varius</I>). Bumblebees settled in 16 and 9 % of nestboxes (in 2010 and 2011 breeding seasons, respectively) that contained bird nests at the advanced stage of nest building or at the stage of egg laying. Presence of bumblebees prevented the birds from continuing the breeding activities in the nestboxes, while insects took over the birds’ nests (a form of kleptoparasitism). Playback experiments showed that the warning buzz by bumblebees contributed to the success in ousting the birds from their nests. This demonstrates that aposematic signals may be beneficial also in the context of resource competition.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1007/s00265-013-1553-2) contains supplementary material, which is available to authorized users.</P>

Imitating flush-pursue foraging birds

Jablonski Piotr G,Lee Sang-im 한국조류학회II 2017 한국조류학회지 Vol.24 No.2

Avian flush-pursuers exploit escape behavior in insects by using displays of spread tails and wings to visually cause insects to escape, when they are pursued by birds in aerial chases. By using simple bird models that approach insects in the bird territories we studied reactions of flies, dragonflies, and two types of moths to the previously unstudied mode of foraging movements comprising displays of the visual patterns, pivoting / pirouetting body movements performed by birds during intermittent pauses between hops along branches or trunks. The results suggest that these pirouetting movements, conspicuously present in flush-pursuing birds, may substantially help the birds to increase the number of prey flushed and available for chase.

Criteria for Algebraic Operators to be Unitary

Zenon Jan Jablonski,Jan Stochel,정일봉 경북대학교 자연과학대학 수학과 2023 Kyungpook mathematical journal Vol.63 No.1

Criteria for an algebraic operator T on a complex Hilbert space H to be unitary are established. The main one is written in terms of the convergence of sequences of the form {∥Tnh∥}∞n=0 with h ∈ H. Related questions are also discussed.

Vigilance responding to number of conspecifics among mixed groups of cranes in demilitarized zone

Piotr Grzegorz Jablonski,이상돈,Elizabeth Ellwood 한국통합생물학회 2018 Animal cells and systems Vol.22 No.2

Numerous studies have addressed antipredatory benefits of mixed-species flocks of foragers, but studies on individual’s vigilance as a function of group size are limited. In the Cheolwon area of the Korean Demilitarized Zone, vigilance of the subordinate White-naped cranes (Grus vipio) in 11 groups composed of conspecifics and the dominant Red-crowned cranes (Grus japonensis) was examined. Vigilance correlated negatively with group size due to negative correlation with the number of conspecifics, but not the dominant heterospecifics. This is consistent with the hypothesis that a decrease in vigilance in larger groups is due to antipredatory benefits from increased predator detection in larger groups (associated with the presence of a larger number of conspecifics). This suggested that the mechanism leads to canceling out of the otherwise expected antipredatory benefits to the subordinate species from the increased predator detection by larger group size (associated with larger number of dominants). This is one of only a few behavioral studies of these endangered crane species in the relatively inaccessible wintering area of international importance in the areas of high conservation value.

How do animals “see” the colors of insect? Visual modelling of animal vision to study insect coloration

Changku Kang,Jongyeol Moon,Piotr G. Jablonski 한국응용곤충학회 2013 한국응용곤충학회 학술대회논문집 Vol.2013 No.10

The diverse color pattern of insects are products of natural/sexual selection and affect their survival and reproductive success. Therefore understanding the function of the color patterns is critical to understand their life-history traits such as defensive/territorial behavior or mating strategies. However how we (humans) see and perceive their colors does not reflect the true nature of the insect colors because the insect colors have evolved to work best for the appropriate receiver. For example, defensive coloration have evolved to deceive predators’ eyes, and sexual traits of males have evolved to attract the eyes of the conspecific females. The visual system (therefore the perception of color, too) substantially differ between species and it is important to consider the appropriate receiver’s point of view (visual system) to properly understand the functional aspect of insect color pattern. Here I introduce the concepts of visual modelling of animals’ point of view to study insect coloration and present a case study research on camouflage of moths.

Which sensory organ is used to find more cryptic positions and body orientations in moths?

Jongyeol Moon,Changku Kang,Piotr G. Jablonski 한국응용곤충학회 2013 한국응용곤충학회 학술대회논문집 Vol.2013 No.10

Geometrid moths are well known for their camouflage. Their wing color patterns resemble tree bark which is their preferential resting place. After landing on tree bark, many of them show the re-positioning behavior which makes the moths more cryptic effectively. Previous study revealed that moths perceive structural cues from tree bark to position their bodies. However, to date, it is not clear which sensory organ is used during re-positioning behavior. We performed a series of experiments to find out how (i.e. by using which sensory organs) moths seek out an appropriate position and body orientation. We used a geometrid moth, Jankowskia fuscaria, to test our hypothesis. We hypothesized that one of four sensory organs (eyes, antennae, front legs, and wings) may be responsible for their ability to find more cryptic position and body orientation. We amputated one of these organs and observed whether they are still able to find a cryptic position. The results indicates that visual cue is essential for their cryptic-positioning searching behavior, but antennae or front legs are not. Tactile cues from their wings seem to have a role in their behavior, but the evidence is flimsy. Therefore we cautiously conclude that moths mainly rely on visual cues (most likely through eyes) to orient their bodies on resting place, but additional tactile cues from their wings seem to play an additional role.

Three Species of Water Striders from Different Types of Habitats Exhibit Different Types of Anti-predator Strategies

Jae Hak Son,Sang-Im Lee,Piotr G. Jablonski 한국응용곤충학회 2013 한국응용곤충학회 학술대회논문집 Vol.2013 No.04

Prey species should avoid areas where predation risk is high. However, if this is impossible, prey should reduce activities that may make them conspicuous and attract predators, such as foraging or mating. Thus, predation risk should change behavioral pattern of prey species. Not all species have same anti-predator behavioral patterns because they have evolved in the presence of different types or number of predators in their habitat. In this study we measured microhabitat use and escape initiation distance to identify how sensitive each species is to approaching predators. We measured jumping performance and morphological characteristics to reveal the relationship between jumping and morphology and whether jumping is helpful for escaping from predators' attack. Finally, we compared the survival rate among three species to identify how survival rate is affected by anti-predator behavioral patterns. The survivorship was related to microhabitat use and to the escape initiation distance, rather than on the jumping ability. We predicted that a species with the best survival rate will have superior jumping ability in order to escape from predators at the moment when they were attacked by predators. The jumping ability, however, was probably limited by hydrodynamic and morphological constraints, so jumping appears to contribute little to successfully escaping from predators’ attacks.

A multiplicative property characterizes quasinormal composition operators in L²-spaces

Budzynski, P.,Jablonski, Z.J.,Jung, I.B.,Stochel, J. Academic Press 2014 Journal of mathematical analysis and applications Vol.409 No.1

A densely defined composition operator in an L<SUP>2</SUP>-space induced by a measurable transformation φ is shown to be quasinormal if and only if the Radon-Nikodym derivatives h<SUB>φ^n</SUB> attached to powers φ<SUP>n</SUP> of φ have the multiplicative property: h<SUB>φ^n</SUB>=h<SUB>φ</SUB><SUP>n</SUP> almost everywhere for n=0,1,2,....

Subnormality of unbounded composition operators over one-circuit directed graphs: Exotic examples

Budzynski, P.,Jablonski, Z.J.,Jung, I.B.,Stochel, J. Academic Press ; Elsevier Science B.V. Amsterdam 2017 Advances in mathematics Vol.310 No.-

<P>A recent example of a non-hyponormal injective composition operator in an L-2-space generating Stieltjes moment sequences, invented by three of the present authors, was built over a non-locally finite directed tree. The main goal of this paper is to solve the problem of whether there exists such an operator over a locally finite directed graph and, in the affirmative case, to find the simplest possible graph with these properties (simplicity refers to local valency). The problem is solved affirmatively for the locally finite directed graph g(2,0), which consists of two branches and one loop. The only simpler directed graph for which the problem remains unsolved consists of one branch and one loop. The consistency condition, the only efficient tool for verifying subnormality of unbounded composition operators, is intensively studied in the context of g(2),(0), which leads to a constructive method of solving the problem. The method itself is partly based on transforming the Krein and the Friedrichs measures coming either from shifted Al-Salam-Carlitz q-polynomials or from a quartic birth and death process. (C) 2017 Elsevier Inc. All rights reserved.</P>

Unbounded subnormal weighted shifts on directed trees. II

Budzynski, P.,Jablonski, Z.J.,Jung, I.B.,Stochel, J. Academic Press 2013 Journal of mathematical analysis and applications Vol.398 No.2

Criteria for subnormality of unbounded injective weighted shifts on leafless directed trees with one branching vertex are proposed. The case of classical weighted shifts is discussed. The relevance of an inductive limit approach to subnormality of weighted shifts on directed trees is revealed.