The threats to the conservation of these steppe birds include:
- Loss and fragmentation of the habitat due to:
Transformation of dry farming (cereals rotating with pasture) into irrigated or permanent crops such as olive plantations and vineyards. The adoption of irrigated crops represents the loss of appropriate feeding and breeding habitat, the reduction or disappearance of fallow lands, the alteration of the vegetation structure and the use of agrochemicals that reduce food availability. The conversion of annual dry crops into permanent crops like olive plantations and vineyards also represent the loss of suitable habitat.
- Afforestation of farming lands.
- Abandonment of the rural environment, with the appearance of scrub forests replacing the pastures and cereal crops.
- The building of roads and dams represents the direct loss of habitat in the implantation areas but it also plays a part on populations’ fragmentation and disturbance.
- Disappearance of the nesting sites for the Lesser Kestrel, due to the recuperation of the edified patrimony or to the collapse of the rural buildings that accommodated colonies.
- Fragmentation of the populations due to the existence of fences and roads. During the last years the number of fences in agricultural holdings has increased significantly, functioning as barriers to bird circulation, mainly to the Great Bustard but also to the Little Bustard, causing mortality by collision.
- Degradation of the habitat due to overgrazing and inappropriate use of agrochemicals which reduce food availability. Overgrazing also causes changes in the vegetation cover that makes it inappropriate for birds to nest, and cattle trample may represent the loss of eggs.
- Collision with power lines and electrocution.
- Disturbance and plunder of nests (including intentional destruction). The disturbance on nesting locations may cause the separation of females and their hatchlings, which will become more vulnerable to predation, in the case of the Great Bustard and of the Little Bustard, or cause nest abandonment on all three species. Nest plundering for captive breeding or for collections still occur nowadays.
- Climate changes represent a new threat for these species because we are witnessing an increase on the frequency of extreme droughts or more intense out-of-season climate phenomenons (such as heat waves), which bare consequences in what concerns habitat (for example on structure and vegetation cover) and birds (for example, hatchlings that are yet very small and vulnerable).