1 Introduction: Animal Behavior: Biology 3401 Laboratory 4: Social behaviour of young domestic chickens In many species, social interactions among siblings and (or) between siblings and their parents during early life are necessary for the proper development of social behaviour. In particular, precocial birds (those whose young are mobile shortly after hatching) are dependent on early social experience, and may have a critical or sensitive period during the first few days of life when they are most sensitive to stimuli from their siblings and parents. Visual stimuli and vocalizations are two important categories of stimuli involved in the social interactions among siblings and between siblings and parents in precocial birds. This laboratory exercise concerns the study of two aspects of social interaction among newly hatched (< 3 day old) domestic chickens (Gallus domesticus). (1) stimulus control of a simple social response: that of the approach of one chick towards another. (2) stimulus control of distress calling in chicks. The probable ancestor of the domestic fowl is the Burmese Red Jungle Fowl. The Jungle Fowl is one of a large number of species of ground nesting birds which have precocially developed chicks. On hatching the chicks are covered in fluffy feathers, have their eyes open and, within a couple of hours of hatching, are walking around and feeding themselves. This contrasts with the chicks of trendsetting species such as the passerines, whose newly hatched chicks are blind, naked and helpless. Jungle Fowl chicks belonging to a particular brood remain in close association with one another and with their mother for at least one month. The role of the mother is initially to indicate the presence of food to the chicks and, for the whole period of maternal care, to warn chicks of approaching danger. The male plays no part in the care of chicks. Essentially the same hen and chick behaviour has been observed in feral domestic fowl. The principal vocalizations of the chick of the domestic fowl, as in the case of the young of many other bird species, are the distress calls and the pleasure notes. These sounds reflect the basic security-insecurity balance that governs chick behaviour in general (Collias and Joos, 1953). Distress calls ( cheeps ) differ from pleasure notes ( twitterings ) in that distress calls are composed of descending frequencies only and reach lower frequencies. They are also much louder and are given at a lower rate than pleasure notes. Sometimes a chick may give notes which appear intermediate between distress calls and pleasure notes. These transitional notes are most likely to occur briefly when a chick is changed from one stimulus situation favoring pleasure notes to the opposite type of situation favoring distress notes.
2 Domestic chicks can usually be obtained from local hatcheries. They are easy to keep, as they do not readily escape. Newly hatched chicks can be kept for 48 hours without feeding, while they use up the remnants of the yolk sac. Chicks should, however, always be provided with water and be kept warm (about 25ºC). The laboratory exercise: Materials Per group of students - 4 newly hatched chicks - cardboard boxes - stopwatch - desk lamp to keep the chicks warm - hand digital counter - marking pens - thermometer - large jar - cardboard arena PART A. Stimulus control of approach behaviour in chicks Purpose: (1). Determine the relative importance of different stimuli in eliciting the approach behaviour of chicks in choice tests. Methods: (1). Mark each chick somewhere on their feathers with a different colour using a marking pen. (2). All tests described below are to be conducted at room air temperature. Record this temperature. (3). Test 1: Test the approach response of a test chick when presented with a choice of another chick placed in an open jar and a piece of cardboard using the triangular arrangement illustrated in Figure 1. Record whether the test chick approached the other chick or the cardboard. Repeat with the other 3 chicks as the test animals. (4). Test 2: Test the approach response of a test chick when presented with a choice of one chick and two chicks, placed in separate open jars, using the above triangular arrangement. Record whether the test chick approached the jar with one chick or two chicks in it. Repeat with the other 3 chicks as the test animals. (5). Test 3: Test the approach response of a test chick when presented with another chick placed into a circular cardboard arena (visual isolation) 25 cm in front of the test chick. Record the behaviour of the test chick for 2 min. Then remove the cardboard arena and record the behaviour of the test chick. Repeat with the other 3 chicks as the test animals. For this test you can record whether the chick is going toward, away from the cardboard arena, or is just at rest. Record duration of these movements
3 (focal animal sampling!!!). When the arena is lifted, record whether or not the chick went towards the other chick, away from it, or showed no change. (6). Report your own data in a summary table showing the frequency of the approach response of the test chicks (out of 4 trials, each with a different chick) towards each of the choice stimuli (e.g. 1 chick vs. 2 chicks) for each of the above three tests. (7). Which of the tested stimuli appear to be important in eliciting an approach response in newly hatched chicks? 25 cm Figure 1 - Triangular arrangement of chick, card and test chick spaced to give the test chick a choice of another chick or a card to approach. PART B. Stimulus control of distress calling in chicks Purpose: (1). Determine the effect of different types of isolation on the frequency of distress calling in chicks. Methods: (1). For the following tests, each group of students should obtain the necessary materials and go to separate rooms so as not to disturb each other s birds. For each test the chicks should be given a 2 min. acclimation period before their distress calls are recorded with a hand counter. (2). Test 1: Place one chick in a cardboard box out of visual and auditory contacts with all other chicks. Wait 2 min and then record the number of distress calls given by the test chick for 5 minutes. Record the air temperature in the box.
4 (3). Test 2: Place one chick at one end of the cardboard box with 3 other chicks in a glass jar with lid at the other end of the box (visual but non auditory contact). Wait 2 min and then record the number of distress calls given by the test chick for 5 min. (4). Test 3: Divide the cardboard box in the centre with an opaque partition. Place a test chick in one half of the box and place the 3 other chicks on the other side of the partition (auditory but non visual contact). Wait 2 min and then record the number of distress calls given by the test chick for 5 min. (5). Test 4: Remove the centre partition so that now all 4 chicks are in the box together (auditory, visual, tactile contacts, etc.). Wait 2 min and then record the number of distress calls given by one of the individually marked chicks (focal animal) for 5 min. (6). Repeat only Test 1 at a higher temperature and again at a lower temperature (Perhaps near an open window). Record air temperatures in both instances. (7). Enter your data for all tests on the blackboard and obtain class totals, means and SE for all test situations. Present your data for Tests 1 to 4, obtained at room temperature, on one graph. Secondly, plot separately the relationship between the mean (+SE) frequency of distress calling (calls/5 min) and the three different mean (+SE) air temperatures (cold, room, warm) obtained in Test 1. (8). Interpret and discuss your findings from Parts A and B. Feel free to use the literature listed below. Pay particular attention to the ecological significance of your results. Questions for your consideration (Please incorporate the answers to these questions into your discussion AND provide references not the lab manual!!!) a) Is social behaviour in the chick learned or innate? b) What is the ecological significance of distress calling? c) Is the lack visual or auditory contact more stressful to the chick? Any thoughts on why this is? d) Why does the temperature affect distress calling? Were high or low temperatures more stressful to the chick? e) We observed distress calling in very young chicks. Is distress calling something you might see in an older chicken? f) Distress calling is the vocalization of stress in young chicks. In young chicks and older chickens, are there other methods of indicating stress, danger, etc?
5 References: Bermant, G. 1963. Intensity and rate of distress calling in chicks as a function of social contact. Anim. Behav., 11: 514-517. Collias, N. and M. Joos. 1953. The spectrographic analysis of sound signals of the domestic fowl. Behaviour, 5: 175-188. Kaufman, E.C. and R.A. Hinde. 1961. Factors influencing distress calling in chicks, with special reference to temperature changes and social isolation. Anim. Behav., 9: 197-204. Assignment: Write a formal discussion and provide graphs (no formal results) for this laboratory. Please use the formatting guidelines you have used all semester.