Two sets of experiments are reported that show that the small green bee-eater ( Merops orientalis, a small tropical bird) can appreciate what a predator can or cannot see. Bee-eaters avoid entering the nest in the presence of a potential nest predator. In the first set of experiments bee-eaters entered the nest more frequently when the predator was unable to see the nest from its position, as compared to an approximately equidistant position from which the nest could be seen. In the second set of experiments bee-eaters entered the nest more frequently when the predator was looking away from the nest. The angle of gaze from the nest was associated significantly positively with the probability of entering the nest whereas the angle from the bird was not. Birds showed considerable flexibility as well as individual variation in the possible methods of judging the predator's position and direction of gaze.

PUNE-411 005 (M.S.India). observations of well over six years, in certain localities in Maharashtra State (M.S.) a southwestern region of India. It forms a part of 'Survey, Taxonomy and Etho-ecological studies on Tetrigids,' an ongoing research project (F.I-20/79-PP) supported by Indian Council of Agricultural Research, New Delhi. Potua sabulosa belongs to sub-family Cladonotinae. The species was first taxonomically described by Hancock (1915) and the habitat was recorded as Venna valley, Mahabaleshwar (M'shwar), Dist. Satara. In our extensive survey, we collected P. sabulosa not only from Venna valley but also from other valleys in M'shwar, namely Blue valley, Krishna valley and Koyana valley. In the region under survey, we also collected these insects from certain other localities of Western Ghats of Maharashtra, such as, Pratapgad, Panchgani in Dist. Satara and Sinhagad, in Dist. Pune. Our collection of P. sabulosa from these new localities constitutes a first record. MATERIALS AND METHODS Samples of living Potua were collected from the above mentioned localities. The insects are somewhat difficult to locate on account of

Various aspects of the feeding and breeding behaviours in Orthoptera with special reference to Acridoidea and Tetrigoidea are discussed. The changes in the incisor and molar mandibular surfaces, laciniae and galeae of the maxillae, in relation to graminivory, herbivory and omnivory are cited as specific manifestations of the feeding behaviour. Similarly, in sharp contrast to Acridoids the rather poor foregut armature and small and compact feculae in Tetrigoids is suggested as an evidence indicating the correlation between food and feeding habits. While describing the breeding behaviour a generalized comparison of the utilization of the acoustic sexual signals in crickets and grasshoppers causing attraction and copulation or otherwise is made. Differences in the ovipositors, mode of egg-laying and the types of eggs in Acridoids and Tetrigoids are stated as characteristic features of reproductive behaviour. Factors influencing these behaviours in Orthoptera as well as the behaviours bringing about succession and changes in the patterns of life-forms are mentioned.Tools of behavioural investigations leading to the formulation of ethograms are briefly stated. Methods and techniques generally adopted in studying these aspects of behaviours are referred to as application of such ethological studies. The causative effect of feeding and breeding behaviours is depicted by proposing the adaptive radiation diagrams for the order Orthoptera.The article, in conclusion, points out certain areas related to these behaviours on which, work would seemingly be useful. For example, determination of the cues that bring about mating in grouse-locusts in the absence ofstridulatory and tympanal organs; the energy budget on account of their peculiar diet; and diapause are few such areas. The possibility of these forms turning out to be good models for experimental, lab-oriented studies is suggested. Since, as compared to Acridoids very little studies in the areas of economic and ecological impact in terms of population dynamics have been made on the Tettigonioids and Tetrigoids, it is further suggested that these if undertaken, would also furnish valuable information.

AbutractThis note propOsee a new model for summarising data on survival distribution. A simple graphical method (or equivalently a linear-regression-based method) for estimation of parameters is given. The model is shown to describe adequately data on Survivorship of Starling Birds reported by LACK (1943) and data on power generators reported by DHILLON (1981). A comment is added toillustrate how one can obtain a goodness of fit statistic which has a chi-squared distributions.

The correlation between nutrition and reproduction with reference to two grouse locusts, EU$celimena harpaqo (Tetrigidae: Scelirneninae) and Potua sabulosa (Tetrigidae: Cladonotinae) is assessed. As far as Euscelimena harpaqo is concerned the impact of nutrition on reproduction is presented with reference to ovarian development in certain nymphal stages and in the adult. On the other hand, the impact is evaluated from an altogether different angle as far as Potua sabulosa is concerned. This pigmy locust prefers moss as food and tides over winter and hazardous summer as adult. During this period it almost does not feed. This peculiar feature is used as a parameter to assess the nature of impact in P. sabulosa.