A Research Student's Field Experience on Lewa
My name is Laura Pratt and I am currently carrying out my Masters research project on Lewa in contribution to my MRes Wildlife Conservation (a joint programme between Marwell Wildlife and University of Southampton).
I am here to investigate the declining population of Grevy's zebra on Lewa. I have had the privilege of working with the fantastic Research Department on Lewa and working in the Conservancy every day, seeing all the fantastic wildlife here. Staying at the Marwell Research camp means that I even have wildlife visiting me at breakfast, Impala, Vervet monkeys and Baboons are very happy to wander about on the lawn. Wonderful to have around even if the monkeys have a tendency to steal food if you leave it unattended, or your face wash from the bathroom!
To investigate the decline of the Grevy's zebra I have been looking at the diet of the lion population on Lewa to see if they are preferring the Grevy's zebra over other species. I have also been looking at the behaviour of the Grevy's zebra, specifically how vigilant they are, to see if they are alert to the threat of predation.
In the first few weeks, working with Saibala, the Predator Officer, I tracked and located the lions on Lewa to help update the whisker spot database (the method used to individually identify the lions). I will never get used to being near lions and could never get bored of seeing them. They are incredible animals. To investigate the diet of the lions on Lewa I am using the data downloaded from their GPS collars to extract likely locations where a kill may have taken place (Davidson et al., 2013). These locations are then investigated, mostly on foot, which can be interesting especially when you bump into a herd of elephants on your way back to the car!
I am very thankful that I am working with knowledgeable and experienced people who have kept me safe. Some of the locations are in pretty remote locations in Lewa, but one thing I have learnt is there always seems to be a road that will get you reasonably close, and it doesn't always appear on the map! If a carcass is found at one of the locations the species, age and sex are recorded, along with other information about the site. If lion scat is found this is also collected and analysed later in the lab (according to Tambling et al., 2012). Together these form as full a picture as possible of the lion diet on Lewa (Bacon et al., 2011).
Kimiri, the then Ungulate Officer for Lewa and he assisted me in forming an ethogram of Grevy's behaviour, a list of all the behaviours they exhibit, in my first weeks on Lewa. To investigate their vigilance behaviour one zebra is observed for half an hour continuously and every behaviour they do is recorded (Altmann, 1974). This is done in the presence and absence of lions. The presence of lions is defined as lions being within 2km of the group of Grevy's zebra (Periquet et al., 2012). Again the lion GPS collars come in handy here as they tell us where the lions are so we can either drive near them to find Grevy's or avoid these areas. The Grevy's are not too bothered by the car and once you have given them a few minutes to get used to it being there you can be pretty sure they are behaving naturally. That is apart from when a child herding goats shouts and whistles very loudly next to the group and causes all of your zebras to run away!
On top of all the amazing things I get to do as part of my project methods I have been involved with deploying new GPS collars on Grevy's zebra, learned to drive a four wheel drive vehicle on a large variety of terrains, seen two cheetahs feeding on an impala they had just killed, approached a wild rhino on foot and gone swimming in the beautiful waterfalls in the Ngare Ndare forest.
Isaac, one of the collared lions on Lewa.
Altmann, J. (1974) “Observational Study of Behavior: Sampling Methods,” Behaviour. Brill, 49(3), pp. 227–266.
Bacon, M. M., Becic, G. M., Epp, M. T. and Boyce, M. S. (2011) “Do GPS clusters really work? carnivore diet from scat analysis and GPS telemetry methods,” Wildlife Society Bulletin, 35(4), pp. 409–415.
Davidson, Z., Valeix, M., Van Kesteren, F., Loveridge, A. J., Hunt, J. E., Murindagomo, F. and Macdonald, D. W. (2013) “Seasonal diet and prey preference of the African lion in a waterhole-driven semi-arid savanna.,” Hayward, M. (ed.) PloS ONE, 8(2): e55182
Periquet, S., Todd-Jones, L., Valeix, M., Stapelkamp, B., Elliot, N., Wijers, M., Pays, O., Fortin, D., Madzikanda, H., Fritz, H., Macdonald, D. W. and Loveridge, A. J. (2012) “Influence of immediate predation risk by lions on the vigilance of prey of different body size,” Behavioral Ecology, 23(5), pp. 970–976.
Tambling, C. J., Laurence, S. D., Bellan, S. E., Cameron, E. Z., du Toit, J. T. and Getz, W. M. (2012) “Estimating carnivoran diets using a combination of carcass observations and scats from GPS clusters.,” Journal of zoology (London, England : 1987), 286(2), pp. 102–109.