2012

The favourable habitat management that has been carried out over the last few years, including the actions of the LIFE Steppe Project, has had a positive impact on the population trends of the Great Bustard, Bustard and Lesser Kestrel, especially in the Castro Verde SPA. Over the last few years, the population trend recorded for the bustard in the Castro Verde SPA has been one of growth. However, it is possible to see the impact of the extreme drought of 2005 on the decrease in 2006. In the Mourão/Moura/Barrancos SPA, changes to the habitat led to the disappearance of the species from nesting areas, but in 2011 individuals were seen again in this area, probably from Spanish populations. In the Piçarras SPA, the fluctuation was associated with difficulties in counting, but may also reflect movements of birds to the Castro Verde SPA. In the Guadiana Valley SPA, the population has seen fluctuations in the number of individuals, especially in the number of young birds. The breeding population of Little Bustards in the Castro Verde, Piçarras and Vale do Guadiana SPAs has been increasing. In the Mourão/Moura/Barrancos SPA, the population of breeding males has decreased. This decrease may be associated with habitat loss and degradation, due to the conversion of rainfed cereal crops into permanent plantations, such as olive groves. The largest Lesser Kestrel colonies in Portugal have been on an upward trend. As a general rule, increases in the number of pairs are due to the implementation of measures to improve nesting sites by providing more cavities. Some of the negative fluctuations reflect the collapse of nest walls or are the result of extreme drought events (2005).

The watering holes and supplementary feeding sites installed as part of Actions A4 and C1 were monitored using camera traps during the summer of 2011 and 2012. In the summer of 2011, 12 species were detected consuming water and 5 consuming seeds. In 2012, 8 and 6 species were recorded consuming water and seeds respectively. Of particular note were the records of small flocks of bustards consuming seeds both around drinking troughs and suvadouros. The fact that no target species were found consuming water in the troughs may mean that this resource was available during the monitoring period in other places where these species usually resort. The kingfishers implemented under Action C1 were also monitored using the camera trap technique. However, it was only possible to verify the occupation of these structures by wild rabbits through evidence (fresh droppings and apparent use of the entrances to the hammocks).

Action A3 was monitored using two different methods. With regard to collisions, a methodology was implemented to determine the mortality rate of birds and assess the effectiveness of anti-collision signalling, by means of walking surveys of predefined fence sections. The results obtained were inconclusive as to the effectiveness of the monitoring, and it is probably necessary to increase the sampling effort employed, both in terms of the extent sampled and the periodicity of the surveys. Monitoring of the use of fence crossings was carried out using camera traps. The data obtained shows that the "Door" type crossings (for farms with cattle) are used by the bustard, fulfilling the proposed objectives, but for the others there was no confirmation of use by the bustard. Although the "Mismatched Sticks" crossings (for sheep farms) have been adjusted, increasing the "inter-stick" space, no bustards have crossed them. For the "Porta Pequena" crossings, the monitoring period does not seem to have been long enough to prove that they were used by bustards.

For the monitoring of Action C6, around 20.6 kilometres of power lines were studied over 38 months, distributed over sections corrected with different anti-collision devices. 270 incidents were detected, of which 90 per cent were collisions and 10 per cent electrocutions. 45 species of birds were identified during the surveys, but among the birds with conservation status of concern, the bustard and the bustard were the most affected (n=18 and n=29 respectively). The comparison of different anti-collision devices through an ANOVA resulted in the identification of rotating FBFs as those associated with lower mortality of birds in general and bustards and bustards in particular. A comparison of mortality before and after line signalling again identified rotating FBFs as the only ones that significantly reduced overall bird mortality, as well as that of bustards and bustards.