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Listening comprehension serves as a basic means for communication and participation in society. Unfortunately, especially low-performing students have difficulties understanding informational content presented in a listening format, even more so than with the comprehension of printed texts. Based on empirical findings that text features, such as global text cohesion, have proven to be effective for promoting reading comprehension, and cognitive processes of reading and listening to academic texts share commonalities, the question arises as to how much global cohesion can support students' listening comprehension. 140 ninth-grade students in German secondary schools listened to one of two informational listening texts which differed in their degree of global text cohesion (low vs. high in cohesion). Listening comprehension was assessed with a written test after listening. Regression analyses show that global text cohesion promotes listening comprehension and that the effect of cohesion remains significant and stable when controlling for topic-related prior knowledge and language-related background variables. Low-performing students profited more from the highly cohesive text than high-performing students. Thus, cohesion contributes to the comprehensibility of informational listening texts which can have implications for the construction of listening texts and listening comprehension instruction at school. [ABSTRACT FROM AUTHOR]

This study raises the question what makes school texts comprehensible by analyzing whether students' genre expectations about literary or expository texts moderate the impact of different forms of text cohesion on reading comprehension, even when the texts are similar regarding their genre. 754 students (Grade 9) from comprehensive schools read one of four text versions with similar content, but different degrees of local and global text cohesion. The four more or less cohesive texts were introduced as literary texts (part of a story) or as expository texts (newspaper article), although the different genres were only purported and the texts contained both literary and expository passages. Reading comprehension was assessed with multiple-choice-items, semi-open, and open-ended questions. Results demonstrate that global cohesion was profitable for reading comprehension with expository expectations, but not with literary ones. Local text cohesion and both forms of cohesion in combination did not interact with students' genre expectations and had no main effect on comprehension. When students reading skills and prior knowledge were considered, the interaction was still apparent. Moreover, students with lower levels of reading skills tended to profit especially from texts with global cohesion, whereas the readers with higher reading skills achieved equal means in reading comprehension irrespective of the degree of global text cohesion. The findings are discussed with respect to theoretical aspects of text--reader-interactions, cognitive and emotional components of genre expectations, and the composition and instruction of comprehensible school texts.

Eine kleine Gruppe von Insekten wird von Waldbränden angelockt. Sofort nachdem die Feuerwalze über ein Waldgebiet hinweg-Wärmegegangen ist, besiedeln diese Insekten, die regisals pyrophil bezeichnet werden, die frische Brandfäche (Abbildung 1) und beginnen mit der Fortpfanzung. Vertreter von drei Käfer- und einer Wanzengattung haben als Spezialanpassung an die pyrophile Lebens- empfndweise Infrarotrezeptoren entwickelt. Diese sind jedoch bei den vier Gattungen ganz unterschiedlich gebaut und daher offen- sichtlich unabhängig voneinander entstan- den. Zudem sind zwei verschiedene Funk- tionsprinzipien realisiert: ein sogenanntes photomechanisches und ein thermisches. [ABSTRACT FROM AUTHOR]

Copyright of Beiträge zur Lehrerinnen - und Lehrerbildung is the property of Schweizerische Gesellschaft fur Lehrerinnen- und Lehrerbildung (SGL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Both the gradual rise in atmospheric oxygen over the Proterozoic Eon as well as episodic fluctuations in oxygen over several million-year time spans during the Phanerozoic Era, have arguably exerted strong selective forces on cellular and organismic respiratory specialization and evolution. The rise in atmospheric oxygen, some 2 billion years after the origin of life, dramatically altered cell biology and set the stage for the appearance of multicelluar life forms in the Vendian (Ediacaran) Period of the Neoproterozoic Era. Over much of the Paleozoic, the level of oxygen in the atmosphere was near the present atmospheric level (21%). In the Late Paleozoic, however, there were extended times during which the level of atmospheric oxygen was either markedly lower or markedly higher than 21%. That these Paleozoic shifts in atmospheric oxygen affected the biota is suggested by the correlations between: (1) Reduced oxygen and the occurrences of extinctions, a lowered biodiversity and shifts in phyletic succession, and (2) During hyperoxia, the corresponding occurrence of phenomena such as arthropod gigantism, the origin of insect flight, and the evolution of vertebrate terrestriality. Basic similarities in features of adaptation to hyopoxia, manifest in living organisms at levels ranging from genetic and cellular to physiological and behavioral, suggest the common and early origin of a suite of adaptive mechanisms responsive to fluctuations in ambient oxygen. Comparative integrative approaches addressing the molecular bases of phenotypic adjustments to cyclic oxygen fluctuation provide broad insight into the incremental steps leading to the early evolution of homeostatic respiratory mechanisms and to the specialization of organismic respiratory function.

Infrared (IR) receptors are rare in insects and have only been found in the small group of so-called pyrophilous insects, which approach forest fires. In previous work the morphology of the IR receptors and the physiology of the inherent sensory cells have been investigated. It was shown that receptors are located on the thorax and the abdomen respectively and show an astounding diversity with respect to structure and the presumed transduction mechanism. What is completely missing, however, is any behavioral evidence for the function of the IR receptors in pyrophilous insects. Here we describe the responses of the Australian “firebeetle”, Merimna atrata to IR radiation. Beetles in a restrained flight were laterally stimulated with IR radiation of an intensity 20% above a previously determined electrophysiological threshold of the IR organs (40 mW/cm2). After exposure, beetles always showed an avoidance response away from the IR source. Reversible ablation experiments showed that the abdominal IR receptors are essential for the observed behavior. Tests with weaker IR radiation (11.4 mW/cm2) also induced avoidance reactions in some beetles pointing to a lower threshold. In contrast, beetles were never attracted by the IR source. Our results suggest that the IR receptors in Merimna atrata serve as an early warning system preventing an accidental landing on a hot surface. We also tested if another fire specific stimulus, the view of a large smoke plume, influenced the flight. However, due to an unexpected insensitivity of the flying beetles to most visual stimuli results were ambiguous. [ABSTRACT FROM AUTHOR]

Copyright of Unterrichtswissenschaft (Julius Beltz GmbH & Co. KG Beltz Juventa) is the property of Julius Beltz GmbH & Co. KG Beltz Juventa and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Every year forest fires cause severe financial losses in many countries of the world. Additionally, lives of humans as well as of countless animals are often lost. Due to global warming, the problem of wildfires is getting out of control; hence, the burning of thousands of hectares is obviously increasing. Most important, therefore, is the early detection of an emerging fire before its intensity becomes too high. More than ever, a need for early warning systems capable of detecting small fires from distances as large as possible exists. A look to nature shows that pyrophilous "fire beetles" of the genus Melanophila can be regarded as natural airborne fire detection systems because their larvae can only develop in the wood of fire-killed trees. There is evidence that Melanophila beetles can detect large fires from distances of more than 100 km by visual and infrared cues. In a biomimetic approach, a concept has been developed to use the surveying strategy of the "fire beetles" for the reliable detection of a smoke plume of a fire from large distances by means of a basal infrared emission zone. Future infrared sensors necessary for this ability are also inspired by the natural infrared receptors of Melanophila beetles. [ABSTRACT FROM AUTHOR]

The Australian 'fire-beetle' Merimna atrata can be found in large numbers directly after a fire in eucalyptus forests in the smoky burnt area. The main reasons for this so-called pyrophilous behaviour are reproduction and foraging. Beetles of both sexes are most probably attracted by the smell of burning eucalyptus trees and invade a freshly burnt area as early as possible. Nearly the entire cycle of reproduction, including mate finding, copulation and oviposition takes place, and the beetles are most likely protected from predators by heat and smoke. This is possible because M. atrata has developed special infrared receptors on the abdomen which serve for the detection of hot spots. As the burnt area gets cooler and the smell of burning declines, beetles disappear within about 3 days. Observations on burnt areas over a period of 12 years also have revealed that M. atrata is a diurnal sun-loving beetle which prefers high body temperatures above 40°C. [ABSTRACT FROM AUTHOR]

This study investigates the aerodynamics of the falcon Falco peregrinus while diving. During a dive peregrines can reach velocities of more than 320 km h−1. Unfortunately, in freely roaming falcons, these high velocities prohibit a precise determination of flight parameters such as velocity and acceleration as well as body shape and wing contour. Therefore, individual F. peregrinus were trained to dive in front of a vertical dam with a height of 60 m. The presence of a well-defined background allowed us to reconstruct the flight path and the body shape of the falcon during certain flight phases. Flight trajectories were obtained with a stereo high-speed camera system. In addition, body images of the falcon were taken from two perspectives with a high-resolution digital camera. The dam allowed us to match the high-resolution images obtained from the digital camera with the corresponding images taken with the high-speed cameras. Using these data we built a life-size model of F. peregrinus and used it to measure the drag and lift forces in a wind-tunnel. We compared these forces acting on the model with the data obtained from the 3-D flight path trajectory of the diving F. peregrinus. Visualizations of the flow in the wind-tunnel uncovered details of the flow structure around the falcon’s body, which suggests local regions with separation of flow. High-resolution pictures of the diving peregrine indicate that feathers pop-up in the equivalent regions, where flow separation in the model falcon occurred. [ABSTRACT FROM AUTHOR]

This study investigates the aerodynamics of the falcon Falco peregrinus while diving. During a dive peregrines can reach velocities of more than 320 km h−1. Unfortunately, in freely roaming falcons, these high velocities prohibit a precise determination of flight parameters such as velocity and acceleration as well as body shape and wing contour. Therefore, individual F. peregrinus were trained to dive in front of a vertical dam with a height of 60 m. The presence of a well-defined background allowed us to reconstruct the flight path and the body shape of the falcon during certain flight phases. Flight trajectories were obtained with a stereo high-speed camera system. In addition, body images of the falcon were taken from two perspectives with a high-resolution digital camera. The dam allowed us to match the high-resolution images obtained from the digital camera with the corresponding images taken with the high-speed cameras. Using these data we built a life-size model of F. peregrinus and used it to measure the drag and lift forces in a wind-tunnel. We compared these forces acting on the model with the data obtained from the 3-D flight path trajectory of the diving F. peregrinus. Visualizations of the flow in the wind-tunnel uncovered details of the flow structure around the falcon’s body, which suggests local regions with separation of flow. High-resolution pictures of the diving peregrine indicate that feathers pop-up in the equivalent regions, where flow separation in the model falcon occurred. [ABSTRACT FROM AUTHOR]

This paper gives the first detailed data on the number and body part related distribution of superficial neuromasts in twelve common European Cypriniform species and examines whether such anatomical variables can be related to rough scale habitat occurrence. The fishes Barbatula barbatula, Barbus barbus, Chondrostoma nasus, Cobitis taenia, Leuciscus cephalus, Leuciscus leuciscus, Phoxinus phoxinus, Rutilus rutilus, Rhodeus sericeus, Scardinius erythrophthalmus, Tinca tinca, Vimba vimba were classified in two generalized ‘ecological guilds’, 1 rheophilic and 2 limnophilic or indifferent, based on literature data. The total number of superficial neuromasts was consistent within each species, but differed considerably between species. Lowest numbers of superficial neuromasts were found in Barbatula barbatula21 ± 4.9 superficial neuromasts per cm body length mean ± SD, highest numbers in Vimba vimba233 ± 36.1. Both species can be classified as rheophilic. Over all no relationship was found between the total number of superficial neuromasts and large scale habitat occurrence. © 2010 WILEYVCH Verlag GmbH & Co. KGaA, Weinheim [ABSTRACT FROM AUTHOR]

Abstract: Globally the flat bug genus Aradus comprises about 200 species. About half a dozen Aradus species can be primarily found on burnt areas and, therefore, have been called pyrophilous. Bugs and their offspring feed on fungi growing on burnt wood. Recently, prothoracic infrared (IR) receptors have been described in the pyrophilous Australian species Aradus albicornis. In our study we investigated 10 Aradus species, once again including A. albicornis, and found prothoracic as well as hitherto unknown mesothoracic IR sensilla in A. albicornis, Aradus lugubris and Aradus fuscicornis. In Aradus flavicornis only prothoracic IR receptors were found. Currently the latter two species are not known as pyrophilous. However, there is considerable evidence that these flat bugs also approach forest fires. In all four species where IR receptors were identified, the dome-shaped IR sensilla look very similar. An IR sensillum consists of an internal exocuticular sphere reinforced by consecutive layers of chitin fibres. In the center of the sphere, a microfluidic core is located which consists of a cup-shaped plug of cuticle and an underlying fluid filled annular channel surrounding the tip of the dendrite of a mechanosensitive neuron. Like the IR receptors of buprestid beetles of the genus Melanophila, the IR sensilla found in Aradus species can be classified as photomechanic IR receptors. [Copyright &y& Elsevier]

Abstract: The thoracic infrared (IR) sensilla of the pyrophilous jewel beetle Melanophila acuminata most likely have evolved from hair mechanoreceptors (sensilla trichodea). To further elucidate the sensory transduction mechanism, the morphology of IR sensilla and of neighbouring hair mechanoreceptors was investigated by using conventional electron microscopical techniques (SEM, TEM) in combination with focused ion beam milling (FIB). It was assumed that any deviation from the bauplan of a sensillum trichodeum is of particular concern for the transduction of IR radiation into a mechanical stimulus. Thus, the structures supposed to be relevant for stimulus uptake and transduction were homologized. Compared to a hair mechanoreceptor, an IR sensillum shows the following special features: (i) the formation of a complex cuticular sphere instead of the bristle; the sphere consists of an outer exocuticular shell as well as of an inner porous mesocuticular part. (ii) The enclosure of the dendritic tip of the mechanosensitive neuron inside the sphere in a fluid-filled inner pressure chamber which is connected with a system of microcavities and nanocanals in the mesocuticular part. Hence we propose that an IR sensillum most probably acts as a microfluidic converter of infrared radiation into an increase in internal pressure inside the sphere which is measured by the mechanosensitive neuron. [Copyright &y& Elsevier]

Abstract: The Australian ‘little ash beetle’Acanthocnemus nigricans (Coleoptera, Cleroidea, Acanthocnemidae) is attracted by forest fires. A. nigricans has one pair of unique prothoracic sensory organs and it has been speculated that these organs may play a role in fire detection. Each organ consists of a cuticular disc, which is fixed over an air-filled cavity. On the outer surface of the disc, about 90 tiny cuticular sensilla are situated. The poreless outer peg of a sensillum is 3–5μm long and is surrounded by a cuticular wall. One ciliary sensory cell innervates the peg. As a special feature, the outer dendritic segment is very short already terminating below the cuticle. A massive electron-dense cylindrical rod, which most probably represents the hypertrophied dendritic sheath, extends through the cuticular canal connecting the tip of the outer dendritic segment to the peg. The dendritic inner segment and the soma are fused indistinguishably. Thin, leaflike extensions of glial cells deeply extend into that conjoint and considerably enlarged compartment which also contains large numbers of mitochondria. In summary, the sensilla of the sensory disc of A. nigricans represent a new type of insect sensillum of hitherto unknown function. The possible role of the prothoracic sensory organ in fire detection is discussed. [Copyright &y& Elsevier]

The CO2 release of the well-tracheated jumping spider, Marpissa muscosa, and the poorly tracheated, Pardosa lugubris, was tested while animals were running on a treadmill at three different speeds and under a selective elimination of lungs or tracheae. Thus, the influence of a well-developed tracheal system on the metabolism during physical exercise was examined. The CO2 release in intact animals increased with the running speed in both species. The costs of transport (COT) running at the maximal sustainable speed were nearly twice as big in M. muscosa as in P. lugubris. Elimination of one lung by sealing resulted in reduced COT and running times, and increasing anaerobic proportions in metabolism. Effects were greater in P. lugubris than in M. muscosa, indicating that tracheae compensate partly for the lacking lung capacity. Sealing of the tracheae in M. muscosa reduced the COT and the running times only at the highest speed. Results indicate that tracheae in M. muscosa support the aerobic metabolism only at the most intense physical exercise. At low and medium activity, tracheae may play their main role in the local supply of organs that are not involved in running activity. [ABSTRACT FROM AUTHOR]

Metabolic rates of adultLophopilio palpinalis(Herbst, 1799) (Arachnida, Opiliones, Phalangioidea) andParanemastoma quadripunctatum(Perty, 1833) (Arachnida, Opiliones, Troguloidea) are measured during rest and activity. Carbon dioxide release during rest is continuous in both species. Mean values at 20 °C are 4.2 µL min−1 g−1 for the males ofP. quadripunctatum, 4.1 µL min−1 g−1 for the males ofL. palpinalisand 4.7 µL min−1 g−1 for the females ofL. palpinalis, thus being significantly higher in the egg-producing females. InL. palpinalis,respiratory quotient at rest is 0.84. Spontaneous walking activity with speeds of 15–30 cm min−1 raises the metabolic rate by up to three-fold in both species.Lophopilio palpinalisis made to undertake constant running on a treadmill with speeds of 60, 72 and 96 cm min−1. Enforced activity causes the animals to raise their metabolic rates by up to five-fold above resting rates. Animals reach a steady state of CO2 release on the treadmill and show a fastt1/2 on-response, indicating aerobic exercise. The minimum cost of locomotion is determined to be 2.5 × 10−3 J cm−1 g−1, thus fitting the predicted values for terrestrial locomotion. [ABSTRACT FROM AUTHOR]

Most individuals of the Australian ‘fire-beetle’ Merimna atrata have two pairs of IR receptors which are located ventrolaterally on the second and third abdominal sternite. An IR receptor consists of a specialized IR absorbing area, which is innervated by a neural complex. This complex contains one thermoreceptive multipolar neuron with a unique terminal dendritic mass (TDM) and two scolopidia and was termed ‘sensory complex’. However, also individuals with one pair of IR receptors on the second sternite and beetles with three pairs on the second, third, and fourth sternites were found. Additionally, beetles having one or two pairs of IR receptors may have preliminary stages of IR receptors on the third and fourth sternite, respectively. We found two kinds of preliminary stages, both of which are characterized by a much less pronounced absorbing area. In all five abdominal sternites segmental nerves are attached to the cuticle with a neural complex. Investigation of complexes of non-IR sternites suggests that the sensory cells inside the sensory complex of an IR receptor have developed from common internal stretch receptors. From our results it can be hypothesized that the IR sensory system in Merimna atrata has not yet reached a stage, which can be regarded as evolutionary stable. [Copyright &y& Elsevier]

With flow-through respirometry under video tracking, the CO2 release of adult male and femalePardosa lugubris(wolf spider) andMarpissa muscosa(jumping spider) was measured during rest and activity. Activity metabolism was measured in phases in which the animals were spontaneously active and during forced exercise. Standard metabolic rates (VCO2/t) were 1.43 nmol s-1 g-1 inM. muscosaand 1.7-1.8 nmol s-1 g-1 inP. lugubris. Egg production caused higher resting rates in females compared with the males inP. lugubris. Maximum mass-specific CO2 release, the additional amount of CO2released after activity and the factorial aerobic scope were higher inM. muscosa. Additionally, half-time recovery and the lag between end of activity and maximum CO2 release were lower in the jumping spider. The results are consistent with the hypothesis that the well-developed tracheal system in jumping spiders increases the efficiency of the respiratory system in comparison with wolf spiders, which possess similarly developed lungs but only a simple tracheal system that is restricted to the opisthosoma. [ABSTRACT FROM AUTHOR]

The respiratory system of the wolf spider Pardosa lugubris consists of a pair of well-developed lungs and four unbranched tube tracheae. We used stereological morphometric methods to investigate the morphological diffusing capacity of the lungs and of the walls of the tracheae (‘lateral diffusing capacity’). We examined three groups of female P. lugubris with different mean body masses. The barrier thickness of the gas-exchange epithelium of the lungs was 0.17 μm for the total diffusion barrier and the calculated oxygen diffusing capacity (DO2) for the lungs was between 12.9 and 13.4 μl min−1 g−1 kPa−1. Measured metabolic rates compared with the DO2 of the lungs result in necessary oxygen partial pressure differences of 0.2 kPa during rest and 2.1 kPa during maximum measured activity. The diffusion barrier of the entire tracheal walls was 0.31–0.50 μm and the calculated lateral DO2 was 0.05–0.2 μl min−1 g−1 kPa−1. Therefore, tracheae are of no importance for the overall oxygen exchange. However, they might be of some importance in local oxygen supply or in overall carbon dioxide release. The comparison with the respiratory system of the jumping spider Salticus scenicus reveals that the lungs have very similar mass-specific DO2 in both species, and that, in addition, jumping spiders possess a much better developed tracheal system. [Copyright &y& Elsevier]

The Australian beetle Acanthocnemus nigricans is attracted by forest fires and has a pair of complex infrared (IR) receptor organs on the first thoracic segment. Each organ consists of a tiny sensory disc (diameter 120–130 µm) which serves as an absorbing structure for IR radiation. The disc is arranged above an air-filled cavity which is located just anteriorly to the coxae of the prothoracic legs. Inside the disc, about 30 multipolar thermoreceptors (warmth receptors) are tightly attached to the cuticle which is directed to the outside. The many dendrites of each multipolar neuron are tightly wrapped around the soma and contain a large number of mitochondria. Absorption of IR radiation by the disc causes an increase in temperature which is measured by the warmth receptors. Therefore, the IR receptors of A. nigricans can be classified as microbolometers with reduced thermal mass and in principle can be compared to the IR organs of pit vipers. [ABSTRACT FROM AUTHOR]

The tracheal system of harvestmen consists of two stem tracheae, which give rise to higher order tracheae that supply the extremities and internal organs. In this study, we used stereological morphometric methods to investigate diffusing capacities of the walls (‘lateral diffusing capacity’) of the tracheae of adult males and females of Nemastoma lugubre. Diffusing barriers of the tracheal walls tend to be thinnest (0.17–0.19 μm) for the smallest tracheae (inner diameter 0.5–2 μm). In other tracheal classes the diffusing barriers increase with increasing diameters. Calculation of the mass-specific diffusing capacity for oxygen (DO2) of the walls of all higher order tracheae revealed 10.57 μl min−1 g−1 kPa−1 for the females (mean body mass 3.8 mg) and 25.23 μl min−1 g−1 kPa−1 for the males (mean body mass 1.4 mg). In both animal groups, the main DO2 (58–67%) lies in the tracheae with an inner diameter of 0.5–2 μm, but also tracheae up to an inner diameter of 20 μm allow gas exchange via the tracheal walls. Stem tracheae are of no importance for lateral diffusion.Our results are consistent with the hypothesis that the functional morphology of the tracheal system of harvestmen represents an ‘intermediate state’ between the tracheal system of insects in which gas exchange is focused on the distal portions and that of spiders, in which the walls of all tracheae serve in gas exchange. [Copyright &y& Elsevier]

Investigates the morphological diffusing capacity of the lungs and the secondary trachea of jumping spiders. Role of the tracheal system in gas exchange in jumping spiders; Percentage of the total tracheal diffusing capacity; Function of the secondary tube trachea as tracheal lungs.

Evaluates the anatomical diffusing factors (ADF) of respiratory surfaces of adult Branchiostoma lanceolatum. Level of ADF in the lining of the atrium and for skin covering segmental muscles; Diffusing capacity of surfaces lying over coelomic cavities; Diffusing capacity of blood vessels.

The article discusses reports on papers presented at the First International Congress of Respiratory Biology held in Bonn, Germany from August 14 to 16, 2006.

In technical systems, static pressure and pressure changes are usually measured with piezoelectric materials or solid membranes. In this paper, we suggest a new biomimetic principle based on thin air layers that can be used to measure underwater pressure changes. Submerged backswimmers ( Notonecta sp. ) are well known for their ability to retain air layers on the surface of their forewings (hemelytra). While analyzing the hemelytra of Notonecta , we found that the air layer on the hemelytra, in combination with various types of mechanosensitive hairs (clubs and pins), most likely serve a sensory function. We suggest that this predatory aquatic insect can detect pressure changes and water movements by sensing volume changes of the air layer under water. In the present study, we used a variety of microscopy techniques to investigate the fine structure of the hemelytra. Furthermore, we provide a biomimetic proof of principle to validate our hypothesis. The suggested sensory principle has never been documented before and is not only of interest for sensory biologists but can also be used for the development of highly sensitive underwater acoustic or seismographic sensory systems.

Jewel beetles of the genus Melanophila possess a pair of metathoracic infrared (IR) organs. These organs are used for forest fire detection because Melanophila larvae can only develop in fire killed trees. Several reports in the literature and a modeling of a historic oil tank fire suggest that beetles may be able to detect large fires by means of their IR organs from distances of more than 100 km. In contrast, the highest sensitivity of the IR organs, so far determined by behavioral and physiological experiments, allows a detection of large fires from distances up to 12 km only. Sensitivity thresholds, however, have always been determined in non-flying beetles. Therefore, the complete micromechanical environment of the IR organs in flying beetles has not been taken into consideration. Because the so-called photomechanic sensilla housed in the IR organs respond bimodally to mechanical as well as to IR stimuli, it is proposed that flying beetles make use of muscular energy coupled out of the flight motor to considerably increase the sensitivity of their IR sensilla during intermittent search flight sequences. In a search flight the beetle performs signal scanning with wing beat frequency while the inputs of the IR organs on both body sides are compared. By this procedure the detection of weak IR signals could be possible even if the signals are hidden in the thermal noise. If this proposed mechanism really exists in Melanophila beetles, their IR organs could even compete with cooled IR quantum detectors. The theoretical concept of an active amplification mechanism in a photon receptor innervated by highly sensitive mechanoreceptors is presented in this article.

We investigated the mechanical properties (Young's modulus, bending stiffness, barb separation forces) of the tenth primary of the wings, of the alulae and of the middle tail feathers of Falco peregrinus. For comparison, we also investigated the corresponding feathers in pigeons (Columba livia), kestrels (Falco tinnunculus), and sparrowhawks (Accipiter nisus). In all four species, the Young's moduli of the feathers ranged from 5.9 to 8.4 GPa. The feather shafts of F. peregrinus had the largest cross-sections and the highest specific bending stiffness. When normalized with respect to body mass, the specific bending stiffness of primary number 10 was highest in F. tinnunculus, while that of the alula was highest in A. nisus. In comparison, the specific bending stiffness, measured at the base of the tail feathers and in dorso-ventral bending direction, was much higher in F. peregrinus than in the other three species. This seems to correlate with the flight styles of the birds: F. tinnunculus hovers and its primaries might therefore withstand large mechanical forces. A. nisus has often to change its flight directions during hunting and perhaps needs its alulae for this maneuvers, and in F. peregrinus, the base of the tail feathers might need a high stiffness during breaking after diving., (© 2014 Wiley Periodicals, Inc.)

This study investigates the aerodynamics of the falcon Falco peregrinus while diving. During a dive peregrines can reach velocities of more than 320 km h⁻¹. Unfortunately, in freely roaming falcons, these high velocities prohibit a precise determination of flight parameters such as velocity and acceleration as well as body shape and wing contour. Therefore, individual F. peregrinus were trained to dive in front of a vertical dam with a height of 60 m. The presence of a well-defined background allowed us to reconstruct the flight path and the body shape of the falcon during certain flight phases. Flight trajectories were obtained with a stereo high-speed camera system. In addition, body images of the falcon were taken from two perspectives with a high-resolution digital camera. The dam allowed us to match the high-resolution images obtained from the digital camera with the corresponding images taken with the high-speed cameras. Using these data we built a life-size model of F. peregrinus and used it to measure the drag and lift forces in a wind-tunnel. We compared these forces acting on the model with the data obtained from the 3-D flight path trajectory of the diving F. peregrinus. Visualizations of the flow in the wind-tunnel uncovered details of the flow structure around the falcon's body, which suggests local regions with separation of flow. High-resolution pictures of the diving peregrine indicate that feathers pop-up in the equivalent regions, where flow separation in the model falcon occurred.