Little is known about sandgrouse despite the group having a broad geographical range. Their most well known feature is that they arrive at water at regular intervals, sometimes in large numbers, to drink. In the Arabian Oryx Sanctuary at Jaaluni in the central Oman desert, hundreds of sandgrouse are seen on most days drinking at the water pools provided for other wildlife. Coupled with Natural Research Ltd’s existing links with Omani biologists, this makes it an ideal place to learn more about sandgrouse behaviour and ecology. Four species of sandgrouse occur in the sanctuary (crowned, Pterocles coronatus; spotted, P. senegallus; chestnut-bellied, P. exustus; and Lichtenstein’s, P. lichtensteinii), with the crowned sandgrouse apparently being the most common.
An initial 13-day field effort was put in at Jaaluni in November and December 2006 by biologists from NR and the Arabian Oryx Sanctuary. The main thrust of this work was to fit some sandgrouse with small radio transmitters and to follow them.
Crowned sandgrouse were trapped at water pools at Jaaluni using noose carpets, and 10 were fitted with 4.5 g necklace radio tags that have a nominal life of 5 months. Captured sandgrouse were sexed, weighed and measured, fitted with the transmitter and released.
Once tagged we attempted to determine the time of arrival of tagged birds at the watering pools each day, the time of departure after drinking, and the direction of and ultimately the location of places where sandgrouse spent their time when they were not at Jaaluni. Determining these locations was difficult because of the range of the radio tags and the speed and distance that the sandgrouse flew, so we tried to build up, over a number of days, a map of their route to and from the pools. This was a slow process, but was working and in future should eventually realize results. We also tried to determine more generally the earliest arrival time and latest departure times of sandgrouse and get a daily estimate of the maximum number of sandgrouse using the pools in the camp areas. In general, sandgrouse started to arrive at Jaaluni around 07.50 and left between 11.00 and 14.00, though some left before this, sometimes without drinking.
All birds fitted with tags returned to Jaaluni in the days subsequent to capture. On many days we were able to determine time of arrival and departure of tagged birds, arriving as early as 08.25 as and departed as late as 13.07. Individual tagged birds visited Jaaluni for from just a few minutes to up to 4.5 hours. Although not a hard and fast rule, most visits were made by tagged birds every two days. On 2-4 December windy, cold and at times rainy conditions appeared to change the pattern of attendance at Jaaluni. Fewer birds arrived, and these arrived and departed later.
The maximum number of birds that visited Jaaluni was between 38 and 240, and this maximum was generally achieved between 10.00 and 11.00. We did not try to determine species composition but these were almost entirely crowned sandgrouse. A maximum of 30 chestnut bellied sandgrouse were counted, and there was a suggestion that they might arrive later than the crowned sandgrouse. At least two spotted sandgrouse were identified. There was no big effort to determine sex ratios, though it appeared to be near 50:50. As confirmed by our observations of radiotagged birds, not all birds drank.
The results were encouraging. We are able to catch sandgrouse and radiotrack them, and the results are consistent with data collected by a previous worker. As a result of this initial work Salah a Mahdoury, a biologist at the Arabian Oryx Sanctuary, has commenced a PhD on sandgrouse ecology at Cardiff University.
Support for this work was provided by the Office of the Adviser for the Conservation of the Environment, Petroleum Development Oman, LLC, and Natural Research Ltd.We would like to thank Faisal al Lamki, Andrew Spalton, Mukadam Juma al Hikmani, Yassir al Kharousi, Salah al Mahadoury and the Arabian Oryx rangers and support staff for thier help in this project.
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Photos: M. McGrady