Farmland bird populations have halved over the past 40 years in both Europe and Estonia, but new modern monitoring tools make it possible to map the movement of birds more accurately and therefore make better proposals for conserving their populations.
 

The grey partridge intuitively searches for a habitat over a much larger area than previously thought

Fortunately, the grey partridge, being a resident bird here in Estonia, has so far been able to live quite a ‘wild’ and independent life here and therefore its habitat use is quite different from that of its European cousins. ‘While it was previously thought that grey partridges move little and tend to nest in the same area where their parents did, the latest research shows that our birds, unlike their European counterparts, have retained an active dispersal ability, which means that they occupy new nesting areas each spring,’ says Jaanus Elts, leader of the partridge study.

Although they are farmland birds, in spring our grey partridges are surprisingly often found in woodlands, along high voltage power lines and cleared areas, and often their dispersal range is up to 50 km!

In addition to the various crops (they prefer winter cereals) and grasslands (they prefer the Poaceae grasses), the grey partridge also actively uses the transitional areas between them, such as the strips of land between fields and roads, or between fields and shrubland. These transitional areas, with their taller and more diverse vegetation, provide shelter and a feeding ground throughout the year – this is something that needs to be taken into account when organising the conservation of the grey partridge. Such strips of grassland are precisely what we are now creating together with farmers!
 

The corncrake is not a nocturnal bird after all

Studies on the corncrake that arrives to us in early May show that, contrary to previous beliefs, corncrakes are actually more active during the day, and their home range is ten times larger than at night.

Among other things, it appears that there are no ‘grass crakes’ or ‘crop crakes’, ie individuals that use only specific vegetation. The habitat use of the corncrake is dynamic, depending on the vegetation development of surrounding crops and natural habitat patches, as well as the intensity of grassland management.

The corncrakes surveyed preferred grasslands that were mown later in the year or not mown at all – this is information that needs to be taken into account when planning the habitat use and conservation of the species. The corncrake will not go to a newly-mown area, but will return a few weeks later when the vegetation is tall enough for it.

During the season, corncrakes use up to five different crops. As shelter is still scarce in the cultivated landscape in spring when the corncrakes arrive, the edges of fields with taller dead vegetation and young winter cereal fields become an important habitat.

The home ranges of our corncrakes can be very large – up to 60 ha. In previous studies, the corresponding figure has been significantly lower, mainly due to the shorter study period and the tools or methods used to monitor bird movements. During the night, corncrakes used an area of up to 0.29 ha, while during the day the home range was up to 2.1 ha.