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Petr Kočárek - One of the best experts on this subject based on the ideXlab platform.
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Effect of substrate on the risk of being washed away by floods for the Groundhoppers Tetrix subulata and Tetrix tenuicornis (Orthoptera: Tetrigidae)
River Research and Applications, 2017Co-Authors: David Musiolek, Petr KočárekAbstract:Inundation zones of rivers are risky environments for terrestrial animals because of the regular or irregular occurrence of floods. Although animals in these zones have evolved several strategies to survive floods, behavioural anti-flooding strategies have seldom been studied but could play an important role in their life history strategies. We previously reported that the groundhopper Tetrix tenuicornis moves to dense vegetation in response to low atmospheric pressure (which may signal rain and flooding) but prefers mossy microhabitats and bare ground under high atmospheric pressure. In the current study, we found that the ability of the semi-aquatic groundhoppers T. tenuicornis and Tetrix subulata to withstand direct water flow was greater in patches of dense vegetation than in patches of moss or on bare ground. Even a relatively low water velocity led to water transport (presumably passive) of both species, perhaps because they lack arolia or other adhesive devices on their tarsi. This morphological limitation precludes vertical migration on vegetation, which is a common anti-flooding strategy in insects. Our results suggest that, by moving to dense vegetation in response to drops in atmospheric pressure, groundhoppers may reduce their risk of being washed away by floods.
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Biology of Tetrix bolivari (Orthoptera: Tetrigidae)
Open Life Sciences, 2011Co-Authors: Petr Kočárek, Jaroslav Holuša, Šárka Grucmanová, David MusiolekAbstract:The ecological requirements and biology of the Tetrigidae are almost unknown. The aim of the present work is to contribute to the knowledge of Tetrix bolivari, one of the least studied species of European Tetrigidae, by investigating its seasonal and daily activity, food biology, and vibratory communication. Adults of T. bolivari were found from March to September, with the greatest number of detections occurring between May and August. Based on the study of the daily activity patterns, most activities were positively correlated with temperature and negatively correlated with relative humidity. Detritus and mosses were the main components of the diet, with the most frequently consumed mosses being Bryum caespiticium and Bryum argenteum. Substrate-borne vibrational signals used in communication of T. bolivari are described here in detail for the first time. We distinguished four structural types of vibrational signals produced by males, including the signal produced by wing tremulation.
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Substrate-borne Vibrations as a Component of Intraspecific Communication in the Groundhopper Tetrix ceperoi
Journal of Insect Behavior, 2010Co-Authors: Petr KočárekAbstract:Substrate-borne vibrational signals used in communication of Tetrix ceperoi (Orthoptera: Tetrigidae) are described for the first time. Among all studied Tetrix species, T. ceperoi use the richest repertoire of vibrational signals. These signals consist of isolated pulses or pulses united into rhythmically repeated or irregularly repeated groups and are used in rivalry, pre-copulation, and copulation behaviour (1st, 3rd, and 4th structural types of signals), and are also used by single males or females (2nd type of signal). A 5th type of vibrational signal is produced by wing tremulation, which was unknown Tetrigidae. Based on the results of this study, the vibrational signalisation seems to play an important role in species-specific mate recognition of T. ceperoi . The significance of individual signals is discussed based on results of manipulative contact experiments.
David Musiolek - One of the best experts on this subject based on the ideXlab platform.
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Effect of substrate on the risk of being washed away by floods for the Groundhoppers Tetrix subulata and Tetrix tenuicornis (Orthoptera: Tetrigidae)
River Research and Applications, 2017Co-Authors: David Musiolek, Petr KočárekAbstract:Inundation zones of rivers are risky environments for terrestrial animals because of the regular or irregular occurrence of floods. Although animals in these zones have evolved several strategies to survive floods, behavioural anti-flooding strategies have seldom been studied but could play an important role in their life history strategies. We previously reported that the groundhopper Tetrix tenuicornis moves to dense vegetation in response to low atmospheric pressure (which may signal rain and flooding) but prefers mossy microhabitats and bare ground under high atmospheric pressure. In the current study, we found that the ability of the semi-aquatic groundhoppers T. tenuicornis and Tetrix subulata to withstand direct water flow was greater in patches of dense vegetation than in patches of moss or on bare ground. Even a relatively low water velocity led to water transport (presumably passive) of both species, perhaps because they lack arolia or other adhesive devices on their tarsi. This morphological limitation precludes vertical migration on vegetation, which is a common anti-flooding strategy in insects. Our results suggest that, by moving to dense vegetation in response to drops in atmospheric pressure, groundhoppers may reduce their risk of being washed away by floods.
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Biology of Tetrix bolivari (Orthoptera: Tetrigidae)
Open Life Sciences, 2011Co-Authors: Petr Kočárek, Jaroslav Holuša, Šárka Grucmanová, David MusiolekAbstract:The ecological requirements and biology of the Tetrigidae are almost unknown. The aim of the present work is to contribute to the knowledge of Tetrix bolivari, one of the least studied species of European Tetrigidae, by investigating its seasonal and daily activity, food biology, and vibratory communication. Adults of T. bolivari were found from March to September, with the greatest number of detections occurring between May and August. Based on the study of the daily activity patterns, most activities were positively correlated with temperature and negatively correlated with relative humidity. Detritus and mosses were the main components of the diet, with the most frequently consumed mosses being Bryum caespiticium and Bryum argenteum. Substrate-borne vibrational signals used in communication of T. bolivari are described here in detail for the first time. We distinguished four structural types of vibrational signals produced by males, including the signal produced by wing tremulation.
Axel Hochkirch - One of the best experts on this subject based on the ideXlab platform.
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The importance of validated alpha taxonomy for phylogenetic and DNA barcoding studies: a comment on species identification of pygmy grasshoppers (Orthoptera, Tetrigidae)
Pensoft Publishers, 2017Co-Authors: Arne Lehmann, Josip Skejo, Hendrik Devriese, Josef Tumbrinck, Gerlind U.c. Lehmann, Axel HochkirchAbstract:In a recently published paper on colour polymorphism in a Pygmy grasshopper from China (Zhao et al 2016) an unidentified Paratettix sp. was misidentified as Tetrix bolivari. This case highlights the need for correct species identification and provides an opportunity to recommend some aspects of Good Taxonomic Practice (GTP) in Tetrigidae to reduce the number of erroneous identifications
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Reproductive Interference between the Common Ground-hopper Tetrix undulata and the Slender Ground-hopper Tetrix subulata (Orthoptera, Tetrigidae)
Bulletin of entomological research, 2008Co-Authors: Axel Hochkirch, Amelie Bücker, Julia GröningAbstract:The coexistence of closely related species is often hampered by resource competition or reproductive interference (interspecific sexual interactions). Species utilising similar signal channels might face substantial problems when they cooccur. It has, therefore, been suggested that reinforcement might drive signal evolution in narrow suture zones of secondary contact. However, species with large overlapping ranges are usually not believed to interact sexually. The Slender Ground-hopper, Tetrix subulata, and the Common Ground-hopper, Tetrix undulata (Orthoptera: Tetrigidae) are sister species, which occur sympatrically in large parts of western and Central Europe, but rarely share the same habitat. It has been hypothesized that reproductive interference might account for their missing coexistence. Here, we test experimentally whether these two species interact sexually. Our results suggest an incomplete premating isolation of these groundhoppers, as we recorded heterospecific courtship, mating attempts and mating. The number of conspecific copulations and mating attempts of T. subulata decreased substantially in the presence of T. undulata, whereas the latter species was not negatively affected. Males of both species preferred to approach females of T. undulata, whereas females of both species did not discriminate against heterospecific males. Further studies on the reproductive success are needed to clarify whether reproductive interference might influence habitat partitioning between these species.
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Specialized diet and feeding habits as key factors for the habitat requirements of the grasshopper species Tetrix subulata (Orthoptera: Tetrigidae)
Entomologia Generalis, 2000Co-Authors: Axel Hochkirch, Julia Gröning, Tamara Loos, Corinna Metzing, Maren ReicheltAbstract:On four days in spring 1999, the behaviour of Tetrix subulata (Linnaeus 1758) was observed at a sand pit near Bremen (Germany) with main emphasis on the feeding behaviour. Males were exclusively feeding on algae and mosses, while females also included grasses and forbs in their diet. The % of feeding specimens was 12.8%. A clear correlation between temperature and feeding was found. On a cool day only 1% of the specimens were feeding, while on the warmest day it were 24.7%. The same correlation was found for foraging, but not for any other behaviour. Feeding occurred more often during sunny conditions at locations with high insolation and temperature. Tetrix subulata sat more often on open soil and grass litter than it was present in the habitat, but less common on grasses and forbs. The feeding locations differed significantly from the locations of non-feeding specimens. Feeding took place on open soil, mosses and leaf litter. In conclusion it can be said that damp, open patches, exposed to sun are important structural features (probably key factors) of the habitat of Tetrix subulata. This stresses the need of disturbances in wet meadows and flat, open shores at lakes, rivers, ditches and streams.
Julia Gröning - One of the best experts on this subject based on the ideXlab platform.
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Reproductive Interference between the Common Ground-hopper Tetrix undulata and the Slender Ground-hopper Tetrix subulata (Orthoptera, Tetrigidae)
Bulletin of entomological research, 2008Co-Authors: Axel Hochkirch, Amelie Bücker, Julia GröningAbstract:The coexistence of closely related species is often hampered by resource competition or reproductive interference (interspecific sexual interactions). Species utilising similar signal channels might face substantial problems when they cooccur. It has, therefore, been suggested that reinforcement might drive signal evolution in narrow suture zones of secondary contact. However, species with large overlapping ranges are usually not believed to interact sexually. The Slender Ground-hopper, Tetrix subulata, and the Common Ground-hopper, Tetrix undulata (Orthoptera: Tetrigidae) are sister species, which occur sympatrically in large parts of western and Central Europe, but rarely share the same habitat. It has been hypothesized that reproductive interference might account for their missing coexistence. Here, we test experimentally whether these two species interact sexually. Our results suggest an incomplete premating isolation of these groundhoppers, as we recorded heterospecific courtship, mating attempts and mating. The number of conspecific copulations and mating attempts of T. subulata decreased substantially in the presence of T. undulata, whereas the latter species was not negatively affected. Males of both species preferred to approach females of T. undulata, whereas females of both species did not discriminate against heterospecific males. Further studies on the reproductive success are needed to clarify whether reproductive interference might influence habitat partitioning between these species.
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Specialized diet and feeding habits as key factors for the habitat requirements of the grasshopper species Tetrix subulata (Orthoptera: Tetrigidae)
Entomologia Generalis, 2000Co-Authors: Axel Hochkirch, Julia Gröning, Tamara Loos, Corinna Metzing, Maren ReicheltAbstract:On four days in spring 1999, the behaviour of Tetrix subulata (Linnaeus 1758) was observed at a sand pit near Bremen (Germany) with main emphasis on the feeding behaviour. Males were exclusively feeding on algae and mosses, while females also included grasses and forbs in their diet. The % of feeding specimens was 12.8%. A clear correlation between temperature and feeding was found. On a cool day only 1% of the specimens were feeding, while on the warmest day it were 24.7%. The same correlation was found for foraging, but not for any other behaviour. Feeding occurred more often during sunny conditions at locations with high insolation and temperature. Tetrix subulata sat more often on open soil and grass litter than it was present in the habitat, but less common on grasses and forbs. The feeding locations differed significantly from the locations of non-feeding specimens. Feeding took place on open soil, mosses and leaf litter. In conclusion it can be said that damp, open patches, exposed to sun are important structural features (probably key factors) of the habitat of Tetrix subulata. This stresses the need of disturbances in wet meadows and flat, open shores at lakes, rivers, ditches and streams.
Jacob Höglund - One of the best experts on this subject based on the ideXlab platform.
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Phylogeography and subspecies status of Black Grouse
Journal of Ornithology, 2014Co-Authors: Carolina Corrales, Mariia Pavlovska, Jacob HöglundAbstract:Phylogeographie und Status der Birkhühner-Unterarten Die kalten Perioden im Pleistozän hatten einen starken Einfluss auf die Ausbreitung der meisten Organismen in den gemäßigten Breiten. Für die Birkhühner sind die phylogeographischen Muster und die Ausbreitung nach der Eiszeit noch überwiegend unbekannt. Die Art ist in Eurasien weit verbreitet und wurde aufgrund morphologischer Unterschiede und geographischer Isolationen in mehrere Unterarten eingeteilt. Zur Untersuchung der Entwicklungsgeschichte der Spezies wurden für 143 Proben aus unterschiedlichen Gegenden die Fragmente der mtDNA Kontrollregionen untersucht. Generell unterstützten die mtDNA-Analysen die Unterscheidung zwischen Tetrao Tetrix Tetrix , T. t. ussuriensis und T. t. mongolicus . Die Analysen verdeutlichten die Auswirkungen der Ausbreitung aus den eiszeitlichen Rückzugsgebieten heraus auf die genetische Vielfalt und die genetische Struktur der Birkhühner. Die phylogeographischen Ergebnisse passen zu einer demographischen Populations-Ausbreitung entsprechend einer glockenförmig ungleich verteilten Verbreitung, einer sternförmigen Stammesentwicklung und einer geringen Nukleotid-Vielfalt. Die Muster der postglazialen Ausbreitung legen nahe, dass die südeuropäischen Birkhühner auf diese Gebiete beschränkt blieben und nicht zur genetischen Vielfalt der nordeuropäischen beitrugen. Stattdessen breiteten sich die Birkhühner aus einem Zufluchtsgebiet in Ost- und möglicherweise auch einem in Westeuropa nach Nordeuropa aus und folgten so dem Rückzug der Eismassen, wobei allerdings die genaue Lage beider Zufluchtsgebiete noch unklar ist. Wir schlagen vor, daß T. t. britannicus und T. t. viridanus der nördlichen T. t. Tetrix entsprechen und sich diese Linie von der anderen Unterart abgespalten hat. Diese Einteilung muss wegen der begrenzten Stichprobengröße noch als vorläufig gelten, wird aber die Arbeit mit den unterschiedlichen entwicklungsbiologisch signifikanten Einheiten dieser Spezies erleichtern. The cold periods of the Pleistocene have had a striking impact on the diversification of most organisms in temperate regions. Phylogeographic patterns and postglacial expansion are poorly understood in the Black Grouse ( Tetrao Tetrix ). This species is widely distributed across Eurasia, and has been divided into a number of subspecies on the basis of morphological differences and geographic isolation. To investigate the evolutionary history of the species, 143 samples from different regions were examined for a mtDNA control region fragment. Overall, analyses of mtDNA gave support for the divergence between Tetrao Tetrix Tetrix , T. t. ussuriensis and T. t. mongolicus . The analyses reveal the effects of colonisation out of glacial refugia on the genetic diversity and genetic structure of Black Grouse. The phylogeographical results are consistent with a demographic population expansion following a bell-shaped mismatch distribution, a star-shaped phylogeny and low nucleotide diversity. Patterns of postglacial dispersal imply that Black Grouse from southern Europe have been restricted to this area, and did not contribute to the genetic diversity of northern Europe. Instead, Black Grouse spread out to northern Europe from a refugium in the east and a possible one in western Europe, following the retreat of glacial ice sheets, although both refugia remain unidentified. We suggest that T. t. britannicus and T. t. viridanus correspond to northern T. t. Tetrix , and that this lineage has diverged from the other subspecies. This division is tentative due to limited sampling, but it will facilitate the management of different evolutionary significant units of the species.
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Fine scale genetic structure in the lek-breeding black grouse Tetrao Tetrix
2011Co-Authors: Carolina Corrales, Jacob HöglundAbstract:Black grouse (Tetrao Tetrix) is a bird species with a lek mating system found in the Palearctic boreal taiga. It is assumed that it has a continuous distribution along Scandinavia and Siberia, whereas in Central Europe it has declined during the last decades. The primary objective of this thesis was to obtain a deeper understanding of the history, systematic classification and the genetic structure of black grouse on different geographical scales using microsatellites and control region mtDNA sequences (CR). I determined how much the mating system, habitat fragmentation and historical population processes have influenced the partitioning of genetic diversity in this species. Phylogeographical results are consistent with a demographic population expansion, and the patterns of postglacial dispersal suggest that a glacial refugium was located somewhere in central Asia, and from there black grouse spread out to Europe following the retreat of glacial ice sheets. I suggest that the two European black grouse subspecies, T. t. Tetrix and T. t. britannicus correspond to only one subspecies: T. t. Tetrix, and that this lineage has diverged from T.t. viridanus, a subspecies found in Kazakhstan. The British population is significantly divergent from the remaining Eurasian samples for microsatellites but it is not for mtDNA. Therefore, they should regard as a separate Management Unit and not as a subspecies. Furthermore, British black grouse occur in three independent genetic units, corresponding to Wales, northern England/southern Scotland and northern Scotland. There was also genetic structure within Sweden. Habitat fragmentation is the main cause of population genetic structure in southern Swedish black grouse. In contrast, low levels of genetic differentiation and high connectivity were found in northern Sweden due to female-biased dispersal. On a finer geographical scale, I found genetic differences between leks due to a mixture of related and unrelated individuals within leks. However, mean relatedness values hardly differed from zero. Some leks were similar to one another and I interpret this as a result of variation in local reproductive success and philopatry. These factors would cause genetic structuring but this by itself would not reveal that kin selection is operating within black grouse leks.
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Genetic impoverishment of the last Black grouse (Tetrao Tetrix) population in the Netherlands
Molecular ecology, 2008Co-Authors: Jobs Karl Larsson, Gernot Segelbacher, Jacob Höglund, Hugh Jansman, F.j.j. Niewold, H.p. KoelewijnAbstract:We have studied a small isolated population of black grouse (Tetrao Tetrix) in the Netherlands to examine the impact of isolation and reduction in numbers on genetic diversity. We compared the ge ...
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Genetic variability in European black grouse (Tetrao Tetrix)
Conservation Genetics, 2006Co-Authors: Jacob Höglund, Jobs Karl Larsson, Hugh Jansman, Gernot SegelbacherAbstract:We studied microsatellite genetic variation in 14 different geographic populations of black grouse (Tetrao Tetrix) across the European range. Populations were grouped in three different fragmentati ...
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Genetic variation within and structure among Black grouse (Tetrao Tetrix) populations in Great Britain
2005Co-Authors: Jobs Karl Larsson, David Baines, Gernot Segelbacher, Jacob HöglundAbstract:Genetic variation within and structure among Black grouse (Tetrao Tetrix) populations in Great Britain
