The Hawk Conservancy Trust - Biodiversity Survey

A lot of excellent research has been taking place at the Trust this summer, Campbell and Sam being assisted by some very able and committed students. Here Eleanor Warren-Thomas tells us about her project based on environmental enrichment, and Anastarsia Kelly introduces herself and her research into raptors' dietary needs …

With the prospect of a long vacation stretching before me at the end of my first year at university studying biology, I was hoping to find something relating to my love of animals and wildlife to fill the four months of summer. I’d been really inspired by my course, and was hoping to find somewhere to spend my time where I might be able to work around animals, and perhaps put some of my new knowledge to some use.

Eleanor installing the feeder above the Burrowing Owls' aviary

Whilst searching through the web for any sort of biology research project that I might be able to help with, I came across the Hawk Conservancy Trust’s research pages. I couldn’t believe that although I live only 20 miles from Andover, I had never heard of the Trust, or the work that it did! After reading about the exciting research projects that were going on here with birds of prey, I sent off an email to the Chief Scientific Officer, Campbell Murn, asking if there might be any work I could usefully help with over my long summer break, and I was absolutely delighted when I received a reply to discuss it further. After a visit and an interview in my Easter holidays, it was decided that I would be given a project to work on myself– more than I had possibly hoped for – as well as being asked to help around the park with the birds. I was extremely excited - I had wanted to be a zookeeper since I was little, and here was a chance to try it!

As the start date came nearer I was more nervous – Campbell had given me the general outline of the project, but had suggested that I think about it myself before I was given any instructions on how to do it – having never done a research project before this was a little daunting! The aim of the project was to investigate ways to enrich the environment of the captive birds. In the wild, birds are stimulated by the need to eat, avoid predation, and mate. In captivity, these are easy! A lack of stimulation can lead to problems for captive animals, a clear example being the stereotypical pacing behaviour that some large mammals such as lions may do in zoo enclosures. Other problems can include obesity, due to animals having limited exercise, or sore spots on the feet of birds that spend a large part of the day perched and inactive.

Eleanor loading mealworms into the feeder

Finding food is one of the most time consuming activities for many birds of prey, so it was decided to introduce new ways of presenting food to some of the species in the park, to try and encourage them to move around more within their aviary, as well as having stimulation to exhibit foraging or hunting behaviour. Some creative ways of presenting food to birds had already been installed in the African Harrier Hawk enclosure, where food was stuffed into hollow tree trunks, and nests of straw, enabling the birds to exhibit the inquisitive foraging behaviour that they show in the wild – reaching down into the holes with their double jointed limbs to fish out the food. Even at the end of the day when I had visited the park, the birds were still engaged with hunting through all the hiding places.

By the time I arrived, I was relieved to find that Judy and Sam, both researchers here, along with Campbell, had already come up with an idea for presenting food to three species in the park: the Burrowing Owls, the Striated Caracaras, and the Tropical Screech Owl. The birds were to be fed live insects – mealworms or cockroaches. A device was designed that allowed mealworms to ‘drip’ from a box into a tray below, where the birds could retrieve them. The worms would drop at random, through their own movements, and the birds should therefore be stimulated by the noise of the worms falling through, or by the sight of them.

In order to establish whether or not this system worked, I was to observe the birds for a period of time before the feeder was installed, and record their behaviour throughout the day, especially the amount of time spent feeding, and the amount of time spent inactive. Then the device was installed, and I observed again, to see what effect the new feeding had on the birds’ behaviour.

Mealworms for the Burrowing Owls

The feeder was installed before I began any observations, so that the birds were used to its presence. The tray in the Burrowing Owls’ aviary in fact became a new favourite perch! The owls reacted really well to the mealworm feeder – sometimes dramatically swooping across the aviary to retrieve a fallen worm, and sometimes, less dramatically, being surprised by one falling onto their heads… It was clear that the worm feeder increased the amount of time spent each day feeding, as well as keeping them interested in food throughout the day, rather than just for the few minutes in the morning when their usual meat was given.

For the Caracaras, very inquisitive birds, the results were also interesting. The female of the pair guarded the feeder fiercely, and became gradually more inquisitive with it. She even began jumping up to the mesh at the bottom of the box, to retrieve worms that were dangling just above the tray.

The final species, the Tropical Screech Owl, has yet to be studied, but the plan is to use the feeding of cockroaches into an open plastic trough, to enable the birds to show hunting behaviour, as they do in the wild, where insects make up the largest part of their diet. These owls are also mostly nocturnal, so we are hoping that the introduction of live food during daylight hours may encourage the birds out in the daytime. This wouldn’t cause any problems for the owls, which can be active in the daytime in the wild, especially when they have young to feed, and it would be great for visitors and staff alike to see these very pretty birds out and about.

Look out for the results when you visit the park next!

All in all, I have had a tremendous time here – I’ve really enjoyed my time watching the birds, and it’s really encouraged me to follow the study of animal or bird behaviour in my future career. I’ve also had a great time helping out on the park – it’s been brilliant to learn so much about the birds from the incredibly knowledgeable people here, and to get so close to these impressive creatures!

Eleanor Warren-Thomas

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	A web site last modified on Thursday, 9 September, 2010

Research - September 2008