A study published in the journal Bird Conservation International warns of a decline of more than 66% in the population of the Dupont's lark (Chersophilus duponti) after the storm Filomena. This meteorological phenomenon was the biggest snowstorm to hit Spain in the last 50 years and was preceded by a week of extreme cold that left temperatures of between -5ºC and -15ºC in the affected areas and records below -33ºC in some localities. The Dupont's lark has recently been listed as an endangered species in Spain.