The British Journal of Animal Behaviour最新文献

Summary

• 1.

  The stridulation of the grasshoppers Stenobothrus lineatus, Omocestus virudulus, Chorthippus brunneus and Chorthippus parallelus was recorded on magnetic tape and analysed oscillographically and with an audio-spectrometer.

• 2.

  The various types of songs are described and inter- and intra-specific differences as revealed by physical analysis are shown to reside almost completely in differing pulse repetition frequencies.

• 3.

  The behaviour of adult mature males on stimulation with the normal song of their species is described. Normally this behaviour leads to group singing, with no locomotor movement, but males of all species except O. viridulus when segregated from their fellows for 24 hours or more show taxic locomotor reactions to the source of sound. The locomotor movements cease when a male joins a singing group.

• 4.

  It is suggested that this reaction may be related to the distributional ecology of the insects.

Four normal monkeys and six with extensive unilateral decortication plus destruction of the contralateral frontal and posterior association areas were studied in a series of twelve experiments. As compared with the normal controls, the operated animals were (a) neither seriously nor permanently impaired in their performance on visual search or patterned string problems, (b) slightly, but to a significant degree, retarded on discrimination reversal, (c) not permanently deficient in the discrimination of tridimensional objects, (d) significantly inferior in discriminating bidimensional patterns, particularly those which did not differ in colour, (e) impaired on delayed response tests in which the delay intervals were varied randomly, and (f) markedly and consistently inferior on two- and three-choice oddity problems. Performance on the double alternation problem did not differentiate the normal and operate groups.

It was pointed out that all the operated monkeys were deficient in their ability to reverse response tendencies to previously rewarded stimuli. The restricted applicability of the concepts of localization, mass action, and equipotentiality is discussed in terms of the results of this study.

Summary

• 1.

  The rumination pattern has been studied in three goats before and after ablation of the orbito-frontal lobes of the cerebral cortex.

• 2.

  The animals were able to ruminate within a few hours of the cortical ablation and devoted about the same amount of time in ruminating in a day as normal animals.

• 3.

  The rumination cycle length shows an obvious irregularity following lobectomy. This irregularity of rumination cycle length is synchronised with an irregularity of reticuloruminal contractions.

• 4.

  Following lobectomy a variation in jaw movements was apparent during remastication; this disfunction may have been due to the very fluid nature of the regurgitatied food mass which was noticeable at this time.

• 5.

  The part played by the cerebrum in controlling the many and varied reflexes associated with rumination is discussed.

Summaryo

1. 1.

   The rumination pattern was studied by means of records of jaw movements in 24 young goats.

2. 2.

   The total time spent ruminating, the distribution of this time throughout a 24-hour period, and the length of rumination cycles were studied.

3. 3.

   The pattern of rumination in goats was found to be similar to those of cattle and sheep reproted in the literature.

4. 4.

   The goats spent an average of 7 hours 44 minutes ruminating in 24 hours, an average of 75 per cent. of which was performed at night.

5. 5.

   Large differences between rumination behaviour of different goats and considerable variation in the behaviour of any one goat on different days were observed.

6. 6.

   The duration of the rumination cycle was shorter during the day.

7. 7.

   The pattern of rumination in these goats showed no important change during the period of observation.