16 September 2024: Day 10, Fuente de Piedra, Osuna, and the plains east of Sevilla, WINGS Spain in Autumn Click on right here to look (most often) the place I’m as of late.
Probably the most goal species all through our excursion’s ultimate days is an overly huge fowl that lives at the steppes and grasslands of Spain. The nice bustard (Otis tarda) is essentially the most sexually dimorphic of all birds when it comes to measurement. The men can weigh up to 42 kilos, are the second one heaviest flying fowl on earth(*), and reasonable 2.48 instances the burden of ladies. In addition they stand 3+ ft tall so if one’s available in the market within the grass we must be capable to see it.
Sadly the colourful vary map beneath is a little bit deceptive. The nice bustard (Otis tarda) is Endangered and in low numbers all over the place except for Spain. In step with Wikipedia, “Greater than part the worldwide inhabitants is located in central Spain with round 30,000 people.” Some places in Europe have as few as 100 to one,000 birds.
Nice bustards are well-known for his or her courtship presentations. In March the men acquire on a lek to joust and puff their feathers.
Women folk are attracted via options of the show that we people can not listen or see. As an example, bustards make low frequency sounds that raise a protracted distance in open nation. Most likely she hears him from some distance away.
Bustards’ skill to look UV gentle performs an element of their courtship. The men’ reddish/brownish feathers comprise a pigment known as porphyrin, chemically associated with hemoglobin, that presentations intense crimson fluorescence beneath ultraviolet gentle, as noticed in an experiment beneath.
When a male nice bustard fluffs his throat feathers the ladies see shiny sparkling magenta in UV gentle.
Porphyrin pigment breaks down all through publicity to daylight so this option is misplaced in older feathers as male breeding plumage ages. By the point the glow is long gone, the men don’t want it. Courtship is over till subsequent yr.
(*) p.s. The heaviest fowl able to flight is the Kori bustard.