Vigilance during feeding and preening in coots Fulica atra

Während des Fressens als auch während des Putzens unterbrechen Blesshühner ihre jeweilige Aktivität um zu sichern (‘vigilance’). Je größer eine Gruppe ist, desto niedriger ist die Sicherungsrate des einzelnen Individuums. Dafür werden verschiedene Erklärungen geboten: 1) Vögel können von der Aufmerksamkeit ihrer Artgenossen profitieren, da viele Augen einen herannahenden Prädator eher entdecken, 2) der Verdünnungseffekt besagt, dass die Wahrscheinlichkeit, Opfer eines Beutegreifers zu werden, in größeren Gruppen geringer ist als in kleineren oder, 3) Vögel konkurrieren in größeren Gruppen stärker um begrenzte Nahrungsressourcen (Konkurrenzhypothese). Sollte die Konkurrenz um vorhandene Ressourcen tatsächlich zumindest teilweise für den Rückgang der individuellen Sicherungsrate mit zunehmender Gruppengröße verantwortlich sein, dann sollten putzende Blesshühner eine höhere Sicherungsrate zeigen. Daten zum Sicherungsverhalten wurden in drei Wintern erhoben. Gruppengröße und Nachbardistanz besaßen einen signifikanten Einfluss auf die Sicherungsrate. Dabei korrelierte die Gruppengröße negativ und die Nachbardistanz positiv mit der Sicherungsrate. Um diese Effekte unter Kontrolle zu halten, wurden jeweils die standardisierten Residuen der Sicherungsrate berechnet. Der Unterschied in der Sicherungsrate zwischen Fressen und Putzen war signifikant. Dies bedeutet, dass Blesshühner während des Putzens tatsächlich häufiger sichern als beim Fressen. Dies könnte ein Beleg für die Konkurrenzhypothese sein. Allerdings können diese Ergebnisse durch verschiedene Aspekte überlagert werden, wie z.B. die Distanz zum Ufer, eine eingeschränkte Sicht während des Putzens oder die Gruppengeometrie.During both feeding and preening, coots Fulica atra regularly interrupt their activities to visually scan their environment. This behaviour is considered to be used for detecting predators. Animals in groups lower their individual vigilance since they benefit from other animals’ vigilance (‘many-eyes-hypothesis’), from the adilution-effect, or because they compete for a limited amount of scarce resources. When competition for scarce resources should at least partially contribute to the decline in vigilance during an increase in group size, then preening coots should show a higher vigilance, given a constant flock size and a constant nearest neighbour distance. Data were collected during three winter seasons. I recorded the number of scans during one minute of foraging on land and during preening. Scans were defined every time when the focal bird interrupted its actual activity to look up. I regressed nearest neighbour distance and flock size either within a 10 m or 20 m radius against vigilance. Afterwards, I found a higher vigilance rate in preening coots supporting the competition hypothesis. However, other effects may have contributed to these result, e.g. different body postures or a reduced visibility during preening

Tail flicking in birds

Schwanzwippen ist bei einer Reihe von Vogelarten ein sehr auffälliges Verhalten, dennoch ist die Funktion dieses Verhaltens bislang wenig geklärt. In dieser Arbeit werden verschiedene Hypothesen vorgestellt und diskutiert. Dabei erscheinen Hypothesen am überzeugendsten, die dieses Verhalten in einem Räuber-Beute-Kontext platzieren. Wippen signalisiert die Wachsamkeit eines Individuums an einen potenziellen Beutegreifer. Mögliche weitere Interpretationen sind Alarmsignale oder Kommunikation innerhalb eines Paares, sowie eine lokomotorische Funktion. Die letzten drei Hypothesen wurden bislang allerdings noch nicht experimentell getestet oder durch Beobachtungen bestätigt.Tail movements such as wagging, flicking or pumping are reported from many bird species but their adaptive functions remain poorly understood. Different hypothesis have been explicated, e.g. signalling quality to sexual partners, quality advertisement, serving as an alarm signal, as a signal of submission, signalling to a predator that it has been spotted, signaling quality to a predator or signaling inpalatability. Further it may serve to flush prey and it may support the vocal communication especially in habitats with much noise. Locomotory functions have also been proposed. However, most of these suggestion remain poorly tested. Here, I present some evidence that tail flicking serves as a signal to a potential ambushing predator, rather than an alarm signal to conspecifics or as a signal of submission, but further studies should be encouraged to examine this behaviour in detail. Especially, hypotheses dealing with communication within a pair and locomotory functions of tail movements seem promising

Differences in flight initiation distances in two Carrion/Hooded crow populations

Da Vögel in der Regel vor einem sich annähernden Menschen fliehen bzw. auffliegen, kann die Fluchtdistanz als ein Maß genommen werden, mit dem sich einerseits die „Ängstlichkeit”, andererseits auch der Konflikt zwischen Bleiben und Auffliegen quantifizieren lässt. Hier untersuchte ich die Fluchtdistanz zweier Aaskrähenpopulationen, einer in Sachsen und einer in Schwaben. Mithilfe statistischer Methoden wurde eine Vielzahl von Einflussvariablen kontrolliert. Die Fluchtdistanz sank, je mehr Menschen sich in der Nähe aufhielten. Je weiter entfernt von einem sicheren Platz und je weiter entfernt von der nächsten Siedlung, auf desto größere Distanz flogen die Krähen auf. Sächsische Aaskrähen (im Raum Leipzig) flogen bereits bei einer Distanz von 86,8 m auf, schwäbische im Raum Stuttgart dagegen erst bei 67,2 (basierend auf den geschätzten Randmitteln eines Allgemeinen Linearen Modells). Einige mögliche Ursachen für dieses Verhalten werden diskutiert.Animals usually flee from an approaching human because humans are perceived as potential predators and animals respond accordingly. The distance at which this reaction occurs is termed ‘flight initiation distance’ (FID). Variation in FID represents variation in an individual’s predation hazard assessment and is an excellent metric to quantify an individual’s fearfulness. In this study, I assessed the differences between two populations of Crows (Corvus corone) Carrion/Hooded Crows and controlled statistically for the influence of different environmental and social variables on FID. FID decreased when more persons were around and increased with increasing distance to cover, and with an increasing distance to the nearest urbanisation. Crows in eastern Germany around the city of Leipzig took flight at 86.8 ± 4.2 m and around Stuttgart at 67.2 ± 3.8 m (estimated marginal means from a GLM). These differences on the population level are discussed

How Young “Early Birds” Prefer Preservation, Appreciation and Utilization of Nature

Since the 1990s, the Two Major Environmental Value model (2-MEV) has been applied to measure adolescent environmental attitudes by covering two higher order factors: (i) Preservation of Nature (PRE) which measures protection preferences and (ii) Utilization of Nature (UTL) which quantifies preferences towards exploitation of nature. In addition to the 2-MEV scale, we monitored the Appreciation of Nature (APR) which, in contrast to the UTL, monitors the enjoyable utilization of nature. Finally, we employed the Morningness⁻Eveningness Scale for Children (MESC) which monitors the diurnal preferences and associates with personality and behavioral traits. In this study, we analyzed data from 429 Irish students (14.65 years; ±1.89 SD) with the aim of reconfirming the factor structure of the 2-MEV+APR and monitoring the relationship between the MESC and the environmental values (PRE, UTL, APR). Our findings identified a significant association between PRE and APR with MESC. In addition, we observed a gender difference. Our results suggest that morningness preference students are more likely to be protective of and appreciative towards nature. Recommendations for outreach programs as well as conclusions for environmental education initiatives in general are discussed

How great tits respond to urgency-based information in allopatric Southern house wren mobbing calls

Many species of birds use alarm calls to signal information about predators, including the level of threat. Previous playback experiments suggest that the urgency response towards heterospecific calls is phylogenetically conserved, notably in the Paridae family. Using playback experiments conducted on European great tits (Parus major), we tested whether this species perceives information about urgency in mobbing calls produced by an allopatric non-Paridae species, the Southern house wren (Troglodytes aedon bonariae), by broadcasting calls with high-calling rate (high threat) and calls with low-calling rate (low threat). We found that great tits tend to approach the loudspeaker during playbacks of calls with high-calling rate more often than during playbacks of calls with low-calling rate. Female great tits gave more calls during playbacks of calls with high-calling rate than during playbacks of calls with low-calling rate, whereas there was no significant difference in the number of calls given by males between playbacks of calls with high- and low-calling rates. Thus, our results suggested that great tits perceived the urgency message encoded in calls given by an allopatric non-Paridae species.Fil: Dutour, Mylène. University of Western Australia; AustraliaFil: Fernandez, Gustavo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Randler, Christoph. Eberhard Karls Universität Tübingen; Alemani

Konzeption und Evaluation eines computerunterstützten kooperativen Blockseminars zur Systematik der Blütenpflanzen

Der Einblick in die Systematik der Tiere und Pflanzen einschließlich Bestimmungsübungen gehört zur Biologie-Lehramtsausbildung vieler Hochschulen. In diesem Artikel wird ein computerunterstütztes Konzept vorgestellt, in dem Bestimmungsübungen und ein Überblick über das System der Blütenpflanzen mit Lehr- und Lernmethoden durchgeführt wurden, die sich an aktuellen Befunden der Kognitionspsychologie orientierten. Dies sind konkret die Vermittlung und Strukturierung des Inhaltsgebietes über ein Mind-Mapping-Verfahren, die Erarbeitung der Wissenseinheiten in Form des Gruppenpuzzle als kooperativer Lernform und die Freilandarbeit. Basis war die Selbstbestimmungstheorie von Deci & Ryan (1993). Letztere stellt die selbst bestimmte Tätigkeit als ein wichtiges Bedürfnis dar. Schwerpunkte dieses Ansatzes sind die Aspekte Autonomie erleben und Kompetenzerfahrung. Selbstbestimmte Formen der Handlungsregulation versprechen qualitativ hochwertige Lernergebnisse. Studierende des Blockseminars (n=31) wiesen höhere Werte im Hinblick auf die Skalen Interesse/Vergnügen, wahrgenommene Kompetenz und Anstrengung / Wichtigkeit auf, während Studierende der traditionellen Semester-Lehrveranstaltung (n=62) eine höhere Wahlfreiheit empfanden. Keine signifikanten Unterschiede ergaben sich bei der Skala Druck/Anpassung. Die Leistungen in der Akademischen Zwischenprüfung unterschieden sich nicht signifikant voneinander, allerdings wiesen die Studierenden aus dem Blockkurs weniger Fehler auf. Aus dieser Sicht bietet das Blockseminar vielerlei Vorteile. 25.02.2007 | Steffen SCHAAL & Christoph RANDLER (Ludwigsburg

SARS-CoV2 (COVID-19) pandemic lockdown influences nature-based recreational activity:The case of birders

The new corona virus infection SARS-CoV2 which was later renamed COVID-19 is a pandemic affecting public health. The fear and the constraints imposed to control the pandemic may correspondingly influence leisure activities, such as birding, which is the practice of observing birds based on visual and acoustic cues. Birders are people who carry out birding observations around the globe and contribute to the massive data collection in citizen science projects. Contrasting to earlier COVID-19 studies, which have concentrated on clinical, pathological, and virological topics, this study focused on the behavioral changes of birders. A total of 4484 questionnaire survey responses from 97 countries were received. The questionnaire had an open-ended style. About 85% of respondents reported that COVID-19 has changed their birding behavior. The most significant change in birdwatchers’ behavior was related to the geographic coverage of birding activities, which became more local. People focused mostly on yard birding. In total, 12% of respondents (n = 542 cases) reported having more time for birding, whereas 8% (n = 356 cases) reported having less time for birding. Social interactions decreased since respondents, especially older people, changed their birding behavior toward birding alone or with their spouse. Women reported more often than men that they changed to birding alone or with their spouse, and women also reported more often about canceled fieldtrips or society meetings. Respondents from higher developed countries reported that they spend currently more time for birding, especially for birding alone or with their spouse, and birding at local hotspots. Our study suggests that long lockdowns with strict regulations may severely impact on leisure activities. In addition, a temporal and spatial shift in birding due to the pandemic may influence data quality in citizen science projects. As nature-based recreation will be directed more toward nearby sites, environmental management resources and actions need to be directed to sites that are located near the users, e.g., in urban and suburban areas. The results can be applied with caution to other nature-based recreational activities

Smartphone addiction proneness in relation to sleep and morningness–eveningness in German adolescents

Background Mobile phones are an important part of adolescents’ life. In this study, the relationships among smartphone addiction, age, gender, and chronotype of German adolescents were examined. Materials and methods Two studies focused on two different measures of smartphone addiction. The Smartphone Addiction Proneness Scale (SAPS) was applied to 342 younger adolescents (13.39 ± 1.77; 176 boys, 165 girls, and 1 not indicated) in Study 1 and the Smartphone Addiction Scale was applied to 208 older adolescents (17.07 ± 4.28; 146 girls and 62 boys) in Study 2, both samples in southwest Germany. In addition, a demographic questionnaire and the Composite Scale of Morningness (CSM) and sleep measures were implemented. Results The most remarkable result of this study was that morningness–eveningness (as measured by CSM scores) is an important predictor for smartphone addiction; even stronger than sleep duration. Evening oriented adolescents scored higher on both smartphone addiction scales. In addition, gender is an important predictor for smartphone addiction and girls are more prone to become addicted. In addition, while sleep duration on weekdays negatively predicted SAPS, age, sleep duration on weekends, and midpoint of sleep on weekdays and weekends did not predicted smartphone addiction in both scales. The analysis of covariance revealed statistically significant effects of the covariates gender and age in both studies, as well as the main effect of chronotype. According to the t-test results, girls had higher scores than boys in smartphone addiction. Conclusion Evening types and girls are more prone to become smartphone addicted