| Home | [11–20] << 21 22 23 24 25 26 27 28 29 30 >> [31–40] |
|
Passilongo, D., Mattioli, L., Bassi, E., Szabó, L., & Apollonio, M. (2015). Visualizing sound: counting wolves by using a spectral view of the chorus howling. Front. Zool., 12(1), 22.
Abstract: Monitoring large carnivores is a central issue in conservation biology. The wolf (Canis lupus) is the most studied large carnivore in the world. After a massive decline and several local extinctions, mostly due to direct persecutions, wolves are now recolonizing many areas of their historical natural range. One of the main monitoring techniques is the howling survey, which is based on the wolves' tendency to use vocalisations to mark territory ownership in response to howls of unknown individuals. In most cases wolf howling sessions are useful for the localisation of the pack, but they provide only an aural estimation of the chorus size.
|
|
Passilongo, D., Buccianti, A., Dessi-Fulgheri, F., Gazzola, A., Zaccaronii, M., & Apollonio, M. (2010). The Acoustic Structure Of Wolf Howls In Some Eastern Tuscany (Central Italy) Free Ranging Packs. Bioacoustics, 19(3), 159–175.
Abstract: Italian wolf howls are described for the first time from observations between 2003–2008 of a population living in eastern Tuscany, central Italy. A sample of 37 howls selected among single responses and 128 howls included in the choruses of 7 free ranging packs was recorded and analysed. The mean fundamental frequency of the howls ranged between 274–908 Hz. Two main structures recognised by means of multivariate explorative analysis, in particular Principal Component and Cluster Analysis, were ascribed to breaking and flat howls. Discriminant Function Analysis was applied to the recognised groups with the aim to find a general rule for classification. Howls with different features were correctly assigned to the groups obtained by explorative analysis in 95.8% of cases. The analysis of the variables characterising the structure of the howls suggests that maximum frequency and range of fundamental frequency are the most important parameters for classification, while duration does not appear to play any significant role.
|
|
Myslajek, R. W., Tracz, M., Tracz, M., Tomczak, P., Szewczyk, M., Niedzwiecka, N., et al. (2018). Spatial organization in wolves Canis lupus recolonizing north-west Poland: Large territories at low population density. Mamm. Biol., 92, 37–44.
Abstract: Monitoring of the wolf Canis lupus is a demanding task as it lives in low densities, utilizes vast home ranges and disperses over large areas. These factors make obtaining accurate data about population parameters over the whole distribution area of the species impossible. Thus detailed local studies on socio-spatial organization are essential to calibrate information obtained over a larger area. We applied GPS/GSM telemetry, non-invasive genetic sampling, year-round tracking, camera trapping and howling stimulations to determine the number of family groups, population density and home-range sizes of wolves in the Drawa Forest (DF, western Poland, 2500 km2), an area recently recolonized by the species. Home ranges of three collared male wolves ranged from 321.8 to 420.6 km2 (MCP 100%) and from 187.5 to 277.5 km2 (Kernel 95%), but core areas had a size of 30.5-84.7 km2 (MCP50%) and 35.0-88.8 km2 (Kernel 50%). Mean near neighbour distance between centres of 6 tracked pack homesites was 15.3 km. The number of wolves in DF increased from 14 individuals in 2013/2014 to 30 in 2016/2017. The annual rate of increase varied from 43% in 2014/2015 to 7% in the final year. Population density for the whole study area was relatively low (1.2 indiv./100 km2 in 2016/2017), but densities within territories of two packs studied with telemetry were 1.9 and 1.5 indiv./100 km2. Mean pack size varied between 3.5 and 5.6 individuals, with the largest pack comprising 8 wolves. Mean number of pups observed in summers (June-August) was 4.5. Differences in home range sizes between wolves in western and eastern Poland indicate that results of regional studies cannot be freely extrapolated despite close genetic relationships. Thus, decisions related to management of wolf habitats should be based on intensive local studies.
|
|
Crowell-Davis, S. L. (1985). Nursing behaviour and maternal aggression among Welsh ponies (Equus caballus). Appl Anim Behav Sci, 14(1), 11–25.
Abstract: Nursing behaviour and related aggression of mare-foal pairs was studied from birth (n = 21) to 24 weeks of age (n = 15) of the foal. Foals exhibited a decreasing length and frequency of nursing as they grew older. Mares rarely aggressed against their foals during nursing in the foal's first 4 weeks of life, but did so increasingly through Weeks 13-16, after which the rate of aggression during nursing decreased. Mares terminated nursing primarily by moving away, and were most likely to do so during the foal's first 4 weeks of life. They became gradually less likely to do so as the foal grew older. It was concluded that mares sometimes flex their hind limb on the side opposite the foal during nursing in order to conserve energy in a situation in which they would be remaining still anyway. There was no difference between colts and fillies in the frequency or duration of nursing or in the frequency with which their mothers aggressed against them or terminated nursing.
|
|
Crowell-Davis, S. L. (1986). Spatial relations between mares and foals of the Welsh pony (Equus caballus). Anim Beh, 34(4), 1007–1015.
Abstract: Welsh pony mares and foals (Equus caballus) were usually found to be within 1 or 5 m of each other during the first week of the foal's life and gradually spent more time at greater distances as the foals became older. There was an overall levelling of the trend during the 9th-15th weeks of life of the foal, followed by a second period of change during weeks 16-24. Through weeks 21-24, mares and foals spent at least half of their time within 5 m of each other. Proximity was primarily due to foal activity except during foal recumbency. During the first 8 weeks of the foal's life, a mare remained close by when it was recumbent, either by grazing in a circle around it or by standing upright beside it. Mares and foals were most likely to be close together when they were resting upright with the other ponies in the herd and most likely to be far apart when the foal was playing. Similarities in patterns of spatial relationship between the foals of a given mare were demonstrated. There was no difference between colts and filies in the development of independence.
|
|
McGreevy, P., & Yeates, J. (2018). Horses (Equus caballus). In Companion Animal Care and Welfare. Companion Animal Care and Welfare.
Abstract: Summary Domestic horses are equid members of the class Mammalia, order Perissodactyla, and family Equidae. Horses are obligate herbivores, with nutritional requirements as listed in a table. Adequate space is necessary for exercise, exploration, flight, sharing resources, play, and rolling. Company is essential for all horses, including stallions. Company provides opportunities for mutual grooming and play and allows horses to stand head-to-tail to remove flies. Unhandled horses may respond to humans as they would to predators, whereas handled horses' responses depend on their previous interactions with humans. Horses can suffer from several diseases as listed in another table. The best method of euthanasia of horses is usually sedation followed by either cranial shooting or the injection of an overdose of pentobarbitone into the jugular vein. Behavioural signs of distress can include increased locomotory activity, vigilance behaviours, neighing, snorting, pawing, nibbling walls and buckets, defaecation, rearing, kicking stable walls or doors, and high-stepping 'prancing'.
|
|
Christensen, J. W., Beekmans, M., van Dalum, M., & VanDierendonck, M. (2014). Effects of hyperflexion on acute stress responses in ridden dressage horses. Physiol. Behav., 128, 39–45.
Abstract: The effects of hyperflexion on the welfare of dressage horses have been debated. This study aimed to investigate acute stress responses of dressage horses ridden in three different Head-and-Neck-positions (HNPs). Fifteen dressage horses were ridden by their usual rider in a standardised 10-min dressage programme in either the competition frame (CF), hyperflexion (“Low-Deep-and-Round”; LDR) or a looser frame (LF) in a balanced order on three separate test days. Heart rate (HR), heart rate variability parameters (HRV), behaviour and rein tension were recorded during the test. Salivary cortisol concentrations were measured 60min before and 0, 5, 15 and 30min after the test. Rein tension was significantly lower in LF and did not differ between CF and LDR; however approx. 15% of recordings in CF and LDR were above the sensor detection limit of 5kg. The horses had significantly higher cortisol concentrations directly after LDR compared to LF. In addition, the horses showed more distinctive head movements, including head waving, during LDR. There were no significant treatment effects on HR and HRV. In conclusion, the results indicate that LDR may be more stressful to these horses during riding.
Keywords: Behaviour; Dressage; Horse; Hyperflexion; Rein tension; Stress
|
|
Amodio, P., Boeckle, M., Schnell, A. K., Ostojic, L., Fiorito, G., & Clayton, N. S. (2018). Grow Smart and Die Young: Why Did Cephalopods Evolve Intelligence? Trends. Ecol. Evol., .
Abstract: Intelligence in large-brained vertebrates might have evolved through independent, yet similar processes based on comparable socioecological pressures and slow life histories. This convergent evolutionary route, however, cannot explain why cephalopods developed large brains and flexible behavioural repertoires: cephalopods have fast life histories and live in simple social environments. Here, we suggest that the loss of the external shell in cephalopods (i) caused a dramatic increase in predatory pressure, which in turn prevented the emergence of slow life histories, and (ii) allowed the exploitation of novel challenging niches, thus favouring the emergence of intelligence. By highlighting convergent and divergent aspects between cephalopods and large-brained vertebrates we illustrate how the evolution of intelligence might not be constrained to a single evolutionary route.
|
|
Plumer, L., Talvi, T., Männil, P., & Saarma, U. (2018). Assessing the roles of wolves and dogs in livestock predation with suggestions for mitigating human-wildlife conflict and conservation of wolves. Conservat. Genet., 19(3), 665–672.
Abstract: Predation on livestock is a cause of serious and long-lasting conflict between farmers and wildlife, promoting negative public attitudes and endangering conservation of large carnivores. However, while large carnivores, especially the grey wolf (Canis lupus), are often blamed for killing sheep and other farm animals, free-ranging dogs may also act as predators. To develop appropriate measures for livestock protection, reliable methods for identifying predator species are critical. Identification of predators from visual examination of livestock wounds can be ambiguous and genetic analysis is strongly preferable for accurate species determination. To estimate the proportion of wolves and dogs implicated in sheep predation, we developed a sensitive genetic assay to distinguish between wolves and domestic dogs. A total of 183 predator saliva samples collected from killed sheep in Estonia were analysed. The assay identified the predator species in 143 cases (78%). Sheep were most often killed by wolves (81%); however, predation by dogs was substantial (15%). We compared the molecular results with field observations conducted by local environmental officials and recorded some disagreement, with the latter underestimating the role of dogs. As predator saliva samples collected from prey are often of poor quality, we suggest using mitochondrial DNA as a primary tool to maximise the number of successfully analysed samples. We also suggest adopting forensic DNA analysis more widely in livestock predation assessments as a legislative measure since misidentification that is biased against wolves can be counterproductive for conservation by enhancing conflict with society and leading to increased culling and poaching.
|
|
Sigurjónsdóttir, H., & Haraldsson, H. (2019). Significance of Group Composition for the Welfare of Pastured Horses. Animals, 9(14).
Abstract: We explore how herd composition and management factors correlate with frequencies of social interactions in horse groups. Since the welfare of horses correlates with low aggression levels and social contact opportunities, information of this kind is important. The data are a collection of records of social interactions of 426 Icelandic horses in 20 groups of at least eight horses. The complexities and limitations of the data prohibit useful statistical modelling so the results are presented descriptively. Interesting and informative patterns emerge which can be of use both in management and in future studies. Of special interest are the low levels of agonistic behaviours in breeding groups where one stallion was present. The horses were less agonistic when in groups with young foals and where group membership was stable. Unfamiliar yearlings in peer groups were especially aggressive. Allogrooming was most frequent in groups with relatively more young horses and in unstable and small groups. Interestingly, the horses allogroomed more if they had few preferred allogrooming partners. The findings show that composition (age/sex) and stability of groups are of great importance with respect to aggression levels and opportunities for establishing bonds.
Keywords: horse welfare; aggression; allogrooming; pastured horses; Icelandic horse
|