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European Forest Institute Research Reports are reports of final results of EFI projects. These reports are peer-reviewed by three external reviewers chosen by EFI's Scientific Advisory Board:
Prof. Dr Frits Mohren, The Netherlands, Chairman
Prof. E.P. Farrell, Ireland
Dr Eeva Hellström, Finland
Dr David Humphreys, United Kingdom
Ass. Prof. Dr Elena G. Kulikova, Russian Federation
Prof. Dr Jari Kuuluvainen, Finland
Prof. Davide Pettenella, Italy
Prof. Dr Hubert Sterba, Austria
Prof. Göran Ståhl, Sweden
Ass. Prof. Dr Margarida Tomé, Portugal
Information on Research Reports volume 1 to 7 can be found at EFI’s website: www.efi.int.
Information on Research Reports volume 8 and higher can be obtained from Brill and EFI.
Abstract
To resist forward displacement of their body during non-locomotor behaviors such as feeding, American alligators (Alligator mississippiensis) hold their hindfeet vertical, then push the foot into the substrate so that the dorsum of the foot forms a contact area with the substrate. Herein this form of bracing is termed pedal anchoring. The purpose of the present study was to describe pedal anchoring and to demonstrate whether it entailed interaction between the hindfoot (pes) of Alligator and the substrate that differed from the interactions seen during locomotion. Alligator tracks were studied in the wild, during controlled field trials, and on a mud trackway in the laboratory; in each setting locomotor and pedal anchoring tracks were photographed, cast in Plaster of Paris, then features of the casts quantified. Statistical analysis demonstrated greater variation in the wild tracks, presumably reflecting the larger size and velocity ranges of the alligators involved, and suggested that the mud trackway used during the locomotor trials did not create significant artifact. Tracks produced during locomotion and pedal anchoring by the same alligators, on the same substrate, yielded significantly different quantitative features, different matrices of Pearson correlation coefficients, and different patterns of character distribution following Principal Component Analysis. These results all support the conclusion that pedal anchoring involves fundamentally different interaction between the pes and the substrate than occurs during locomotion.
Abstract
Mobbing is a prevalent anti-predatory behaviour in birds where prey actively engage in harassing predators. Functional traits have been shown to affect prey species’ tendency to engage in mobbing, but empirical studies have largely neglected to assess the influence of some other potentially important functional traits, such as intraspecific and interspecific sociality, on mobbing or measured different aspects of the behaviour. In this study, we performed playback experiments that elicited mobbing responses from a forest bird community in southern China, to investigate the influence of body mass, foraging strata, as well as intra- and interspecific sociality, on the prevalence of mobbing, as well as the intensity of aggression and vocalness. We found that species with small body masses engaged in more frequent and intense mobbing behaviours. Notably, interspecific sociality was negatively associated with birds’ mobbing prevalence and tended to be negatively associated with vocalness.
Abstract
Sexual conflict over mating may induce male mate-guarding prolonged in time in the absence of males, via devices such as mating plugs, widespread in insects. In most Lepidoptera, internal plugs are common, while in some butterfly families large external devices, called sphragides, evolved independently. Lack of, or incomplete sphragis in a few individuals were reported in sphragis-bearing species. Previous studies focused on typifying species-specific devices in a few specimens of many species. In contrast, we investigated alternative mate-guarding devices in detail of a sphragis-bearing butterfly. We conducted a six-year observational field study in a Clouded Apollo Parnassius mnemosyne population. Inspecting 492 females, we identified 3 different devices, filament, stopple and shield (i.e., sphragis) increasing in size and structure complexity, implying differential male investment and effectiveness in securing paternity. Shield dimensions, colour and all devices’ shapes varied considerably. Shields were far more frequent than other devices. Some devices were lost, and a few were video-recorded when removed by males, showing the role of different parts of male external genitalia. We discuss potential causes of device variation and the role of removal attempts, and assess potential costs and benefits for both sexes.
Abstract
Amphibians exhibit diverse parental care behaviours, which may be performed by the female, male or both parents. In the Neotropical family Leptodactylidae, frogs in the genus Leptodactylus exhibit different parenting behaviours. The repertoire of care behaviours includes egg/nest attendance, nest chamber sealing, tadpole feeding with trophic eggs, and tadpole attendance associated with complex behaviours, such as pumping behaviour and channel digging. Based on the available information, we found that 23.8% of Leptodactylus species are known to exhibit post-fertilization parental care. Future studies should focus on mechanisms involved in parent-offspring communication, including acoustic and chemical signals. Moreover, behaviours such as provisioning with trophic eggs are not well understood and deserves further investigation. Because of these complex parental care behaviours, tadpole schooling, and relative easy observation, frogs in the genus Leptodactylus represent excellent models for studies interested in parent-offspring communication and evolution of parental care.
Abstract
This brief report describes the occurrence of an idiosyncratic behaviour, labelled tongue-flicking, that was performed by one subadult male long-tailed macaque living in a free-ranging population in Bali, Indonesia. Tongue-flicking may serve a similar purpose as a displacement behaviour in which the subject sticks his tongue out of his mouth and moves it either slightly up and down or in and out without bringing it all the way back into the mouth. Additionally, while abnormal behaviours in non-human animals are almost exclusively reported in captive individuals, the investigation of idiosyncratic behaviours such as tongue-flicking allows us to explore the potential occurrence of abnormal behaviours in free-ranging populations. This preliminary descriptive analysis of tongue-flicking aims to highlight the need for understanding the motivational bases and affective implications (e.g., welfare) of abnormal behaviours in captive and free-living animals.