This video from the Netherlands is called Red deer rut.
Starting today hikers in Oostvaardersveld nature reserve may encounter red deer. Via a tunnel under the railway line, the red deer from the “Triangle” [in Oostvaardersplassen national park] now have the ability to go to the Oostvaardersveld. For [Heck] cattle and [konik] horses from the Oostvaardersplassen this does not apply. At the Praamweg road additional signs have been posted to alert motorists about the risk of big game crossing.