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subject: I visited Senegal from September 2 until September 29 2003 with the purpose of helping to reinforce the monitoring of the reintroduced oryx antelopes (and dama gazelles if convenient) in the Ferlo-North faunal reserve. The accent would be on setting up systematic behavioral observations that should document the social structure of the group, its evolution in time and this in a scientific but feasible manner. methods: Due to weather conditions and transportation limitations I was only present in the Ferlo-North faunal reserve between September 9 and September 22 2003. I was supported by the National Parks Service, with whom I was collaborating closely, especially Jacques Gomis, conservator, and Seck Mane, park ecologist. I stayed at the Katane outpost, right next to the enclosure of approximately 500 hectares in which the 8 oryxes (1 male and 7 females) and the 5 damas (2 males and 3 females) live at the moment. No reproduction of oryxes or damas was recorded since the reintroduction. The oryxes and damas originated from Guembeul, a national park's facility where endangered species are kept, bred and serve as founding and back up stock for reintroductions.The enclosure at Ferlo is surrounded by mesh wire which is checked very regularly. So far there have been very little problems. This is partly due to good collaboration between staff and population. To prevent intrusions the enclosure only includes a part of a local marsh, leaving the rest for the people, and limited cutting of vegetation inside the enclosure is allowed during the dry season to supplement the diet of the live stock. Inside the enclosure several concrete watering points are provided, in which water is supplied daily during the dry season. The area has a big local population of jackals, which are active inside and outside the enclosure. Park staff report very little problems with domestic dogs. This is partly due to regulations by which an owner of a dog found inside the enclosure, has to pay a considerable fine (in comparison to their income). Working conditions for staff and potential researchers are less than optimal. There is no fresh water, no electricity, no means of communication and insufficient means of transport (1 jeep and 1 bike which are not available all the time). The present number of staff also doesn't allow extensive patrolling and monitoring of the animals at the same time. A lot of their time is used to communicate with the local population and this with reasonable success. To improve the reintroduction of endangered species in Ferlo the Katane outpost should be better equipped urgently. I started off by assessing the response of the oryxes (and damas to a lesser extent) to human observers and consequently worked on improving the habituation. For this I spent an increasing amount of time near the oryxes, trying to get closer and moving around as would be needed for detailed behavioral observations. During this time I observed the animals to work out an appropriate set of behaviors to be used in a feasible protocol for further study. The only tools used were a binocular, pencil and paper, as this is all the staff has to work with. Beside the work with the oryxes and damas, I experimented with the use of fototraps in order to assess their usefulness in these surroundings. I used two Trailmaster devices, a combination of TM550 passive infrared trail monitor and TM35-1 camera kit. They were placed low on trees at open areas and set to take pictures during night time. They were installed in 3 different locations, both of the devices a few hundred metes apart each time. After initial try out the sensitivity and period to take pictures were increased. results: September is the last month of the June-September rainy season, which had been exceptionally wet this year. The park and surroundings were covered in lush vegetation as a result, making observations harder. The animals also had been visited much less by the park staff the last months, as provisioning water was not needed. As a result the animals were much shyer than they had been before (according to park staff). This made it necessary to put much more effort in the habituation. Because of the limited time I was at the reserve and their reaction to my attempts, habituation was not completed at my departure and I was unable to start real data collection during this stay. To improve habituation I visited the oryxes once or twice a day. Because of their history of close contact with human caretakers combined with the short time available, I tried to speed up the habituation by moving closer, staying longer en following more often than I would have done with wilder animals. It seemed to work the first few days: I could get closer and stay longer without visibly disturbing the animals. However, after some days of extending the period and decreasing the distance, the animals started to react to my presence by regularly moving out of sight and generally behaving more tense (staring at me, forming a thighter formation). After 2 days of altered behavior I decided that habituation would take more time and I started responding very carefully to their reactions. I would stay further away, not following when they moved off, not staying very long and going away if they seemed nervous. On one occasion I observed at least 2 individuals that from a distance appeared to be eating soil. After they moved away, I went to check the signs. There were some indications that this could have happened, but they were not conclusive. Proof of geophagy would be interesting and positive for their adaptation. The park staff informed me that before the rainy season they would put out salt near the watering points, but the last months this had not been done. Several times the group would react to my presence by what seemed a form of mobbing. If I got too close for them or I appeared closer to them after they lost sight of me, they would gang up and move closer to me, even following as I moved away. In general, they would be more spread out when they were not disturbed and would move closer together if something disturbed them. They would form a tight formation, looking at what worried them. Another pattern in their behavior was a constant vigilance while feeding or resting. When they were all feeding or lying down, one or more individuals would very regularly look up or even stand up to check the surroundings. When moving, one female usually started walking away, followed by the rest of the group at a short distance. They seemed uneasy to go in dense vegetation where visibility was poor. They would stop at the edge and look around. Most of the time they would not move into a dense zone and if they did, they did not stay in there very long. They did respond to presence and movement of other species. The damas (foraging right next to the oryxes) ran off on one occasion after an agonistic interaction between the 2 male damas. The oryxes looked up and ran in the same direction as the damas. Another time, the group was foraging near the fence when a man passed by with 2 donkeys pulling his cart.As he passed and even stopped for a minute, the oryxes (especially the leading female) looked at it and even moved closer. Once I also observed them staying near the fence, close to a group of horses foraging on the other side of the fence. They would follow the movements of the horses until the horses moved away from the fence. The oryxes were most regularly found in the NW corner of the enclosure, which is the largest open part of the enclosure. Very often they are near the fence and don't move away from passing people or live stock. After the initial days of habituation they moved further into the less open part, but it is not clear if this was a reaction to our presence, to the heavy rain during the same period, to a general tendency to move around or any other reason. The damas were in the vicinity of the oryxes regularly. One younger male dama,who wasn't accepted by the dominant male of the damas, was with or near the oryxes most of the time but would run off if we approached. In general the damas were more shy and more difficult to approach, even though on my last visit I managed to get up to about 30 m from them. With the oryxes there were days I could get as close as about 40 m without disturbing them, but sometimes they reacted when I was still at 100 m or more. The fototraps registered 29 and 14 events, taking 4 and 5 pictures. Of these pictures 3 show animals: one with the group of oryxes, one with a golden jackal and one with a hare. Daily checking did not give any evidence of larger animals passing by unrecorded regularly, which indicates the system functioned well. conclusions: The oryx group at the Ferlo-Norht faunal reserve seemed to behave as a real group on first sight. They stayed together all the time, ajusting their group structure to the circumstances.Confirmation and more detailed information will depend on continuing the observations, collecting systematic data and analyzing them. I explained the necessary methodology and a proposal for protocol to the park staff (see annex). Even though they were used to close human contact, the oryxes were not comfortable with one or two observers nearby for longer periods of time. The difficulties with the habituation could be caused by the fact that the animals were only used to people getting close for a short time to bring water or salts. My longer and passive presence was unusual to them and after a few days they seemed uncomfortable with that. I got the impression that they reacted stronger to 2 persons approaching than when I went alone, especially if we moved around independently. In contrast, they seemed undisturbed by and sometimes even attracted to passing people or animals outside the fence. This could be because of their awareness of the presence of the fence or because they initiated and controlled their proximity on these occasion themselves. The test with the Trailmasters indicates the system is also useful in local conditions. The relatively open area without clear paths along which animals travel makes it hard to capture animals but despite this difficulty events were recorded regularly and 3 species of larger mammals were caught on film at night. Considering the experimental use and the short period this makes it a promissing method to register local faunal activity. Marc Pierard. Senior biologist.Nature
Division Ministry of Flemish Community annex: proposed protocol for behavioral data collection I explained some basic principles of behavioral data collection to the park staff (the conservator and park ecologist) and devised a basic protocol for them to use. The proposed data sheet was kept very simple:
The time with the animals is from when the animals are first sighted to when they are last seen during this session. This gives an accurate indication of the contact time. An optional, but useful, addition could be to give a categorized judgement on the weather condition (sunny, cloudy, hot, windy, rainy, ...). To use the available time in the most efficient way and gather more data, I advised a combination of 2 data collection methods: scan sampling and ad libitum sampling. Categories should be marked by their abbreviation (1 or 2 letters). For the scan sampling I would wait about 10 minutes after arriving to start taking data to allow the animals to settle down and have less influence of the arrival of the observer. After that the activity of all the individuals should be noted every 10 minutes. Ideally this should be done for 1 or 2 hours to have some continuity in the data. Proposed activities are: -lying down -standing -walking -running -foraging (potentially distinguishing between grazing and browsing) -drinking -interacting -out of sight Every 10 minutes on the second every animal in the group has to be scored in one of the categories and the numbers noted (see example above). The categorie interacting is a general categorie because it is described in more detail in the ad libitum sampling. The ad libitum sampling is devised to get a clearer picture of the interactions between the group members. They should be noted when they are observed, irrespective if they overlap with the scan samples or not. Proposed categories are: -displacement (separate or as subcategorie of next) -agonistic interactions (if feasible with several subcategories like threaten without real movement, moving towards opponent, actual fight) -allogrooming -sexual interactions (potentially with subcategories like flehmen, smelling genital area, foreleg lifting, copulation) To increase interobserver reliability and keep the protocol manageable for a group of 8 individuals, the number of categories is restricted. I suggested the observers to use the first period, necessary to improve habituation, to try out the sampling methods and work out a feasible set of (sub)categories. I emphasized the importance of clearly defining each (sub)categorie before actual data collection starts and only changing categories or definitions for fundamentel reasons and keeping accurate records of such changes. | |||||||||||||