Doñana National Park in south-west Spain is one of the last remaining strongholds of the Spanish Imperial eagle <i>Aquila</i><i> adalberti</i>, which is one of the world’s rarest birds with only around 150 pairs remaining.  Lead poisoning is known to be a problem that affects other eagle species, and the purpose of this thesis is to determine whether this is a potential problem for the Doñana population of eagles. Bird exposure to lead in this area is estimated to come from two main sources, soil and sediment lead from upriver mining operations including the 1998 Aznalcollar toxic spill, and resident lead shot due to long-term hunting activity.  a soil lead distribution model is constructed for the whole Doñana, using known principles of pollution deposition in combination with satellite imagery analysis and a training dataset of soil samples dating from 1983 to the present.  A lead shot distribution model is also constructed for the whole Doñana, using a simple rule-based approach to estimate the maximum niche of availability for this lead source. A Monte Carlo simulation model is developed to model the processes of transfer of lead to eagles via their prey species Greylag geese <i>Anser anser </i>and Mallard ducks <i>Anas platyrhynchos.  </i>The model predicts potentially high (5.2%) probability of an eagle being lead poisoned.  A GIS-based ecological risk assessment model quantifies the spatial pattern of lead shot ingestion for Greylag geese and Mallard ducks and grades each of Doñana’s eagle territories according to their lead risk value. The sensitivity, uncertainty and error for all of the above models are assessed in detail.  Finally, future research needs are identified, conservation actions prioritised and management decisions recommended.

Avian flight cannot fail to impress; from the huge migratory distances covered by albatrosses to the dexterity shown by a feeding hummingbird, the performance of birds in flight is remarkable. Until now research into free flight (i.e. not in a wind tunnel or other artificial environment) has been limited to observations from the ground. Here I use a collection of novel techniques, based on the use of onboard instrumentation carried by the bird, to explore if and how this performance might be underpinned by their flexible flight configuration. In the Introduction (chapter 1) to the thesis I investigate previous work into the stability and control of birds in flight. In chapter 2 I investigate a selection of manoeuvres seen commonly in flight, and describe the ways in which they exploit the flexible configuration of the eagle. Then (chapter 3), using an Inertial Measurement Unit (IMU) containing an integrated camera and Pilot-tube I measure the forces acting on the body of the bird in flight, the airspeed of the bird, and using custom-written software, I extract the configuration of the tail from the video. Using the measured configuration of the tail I estimate the lift generated by the tail according to a series of simple aerodynamic models. These are good predictors of the variation in the normal load factor acting on the bird. This suggests that the tail of the eagle is used primarily in soaring flight to balance the bird along the pitch axis. In chapter 4 I further investigate the configuration of the tail, I find that the spread and angle of attack of the tail covary, but that the twist of the tail is adjusted independently. In chapter 5 I explore one manoeuvre, the wing tuck, in more detail. With reference to a 'mean wing tuck' of the key variables I suggest that it is a response to a drop in wing loading, which suggests that it may be a response to atmospheric turbulence. I then investigate the frequency of wing tucking and our principal finding is that it is increased on days when the wind speed is greater, further suggesting that it is a response to atmospheric turbulence. Finally in the Discussion (chapter 6) I summarise the thesis. I also consider future avenues for research into the control and stability of avian flight and discuss some of the limitations of the methods used in this thesis.