Applied Animal Ethology最新文献

A total of 24 dogs (11 Komondorok, 9 Great Pyrenees and 4 Akbash Dogs) were placed with rangeland sheep to test their effectiveness in reducing losses of sheep to predators. All but 1 of the dogs (Komondor) had been reared from puppyhood with lambs. Seven of the dogs (4 Komondorok, 1 Great Pyrenees and 2 Akbash Dogs) were determined to be unsuitable for rangeland use after a relatively short period (1–6 weeks), primarily because of their rambunctious behavior and their lack of attentiveness to the sheep. Three of the 24 dogs (2 Komondorok and 1 Akbash Dog) died before their performance could be adequately evaluated. Two of the dogs (Komondorok) were relatively unsuccessful, but details of their performance were not available. The paper focuses on 12 trials with the remaining 12 dogs (3 Komondorok, 8 Great Pyrenees and 1 Akbash Dog). In 7 of the 12 trials, a pair of dogs or a single dog appeared to be influential in reducing the loss of sheep to predators. The effectiveness of the dogs in 2 trials was questionable, and in 3 of the trials, the dogs had little apparent influence on the number of sheep killed by predators. The dogs that appeared most effective barked at night, patrolled the area around the flock, and were aggressive to animals that came near the sheep. A variety of problems occurred when using the dogs, and benefits other than a reduction in predation, such as facilitating trailing and keeping the flock together, were noted in several of the trials. The use of dogs to protect rangeland sheep appears to be a practical technique, however, as with other forms of control, dogs will probably not eliminate predation. Not all dogs will be successful, and their use may be impractical in some situations.

Redundancy of information is liable to be present in successive observations of an animal's behaviour. This redundancy can be tested for, and its effects studied, with a statistical procedure, Markov chain analysis. Efficient sampling frequency and the precision of estimators are both found to be affected by the redundancy present in one typical data set based on video-taped records of a nursing sow. A method of selecting sampling frequencies for observations is described.

Sixteen horses, divided into 2 groups of 8, were used to study observational learning in horses. One group served as controls while the other group served as the treated group (observers). Observers were allowed to watch a correctly performed discrimination task for 5 days prior to testing their learning response using the same task. Discrimination testing was conducted on all horses daily for 14 days, with criterion set at 7 out of 8 responses correct with the last 5 consecutively correct. The maximum number of trials performed without reaching criterion was limited to 20 per day. Mean trials to criteria (MT) by group were: control, 11.25; observer, 10.70. Mean error (ME) scores were: control, 2.37; observer, 2.02. Average initial discrimination error scores were 11.13 for control and 10.38 for observers (P < 0.10). Asymptote was reached by Day 8 for both control and observer groups. Analysis of variance with repeated measures showed an extreme-day effect indicative of learning (P < 0.01), with non-significant differences in learning rate between experimental groups. Whether the initial ability of the horses to perform a discrimination learning task was enhanced by observation of other horses' performance of that task was not obvious from these data.