Ringing recoveries of house sparrow (Passer domesticus) in the Faroe Islands during the years 1963-2007 / Ringmerkingar av føroyskum gráspurvum (Passer domesticus) árini 1963-2007

Abstract

Úrtak: Gráspurvurin (Passer domesticus) má metast at vera ein tann støðufastasti búfuglurin í Føroyum. Síðan 1963 eru tilsamans 2.167 gráspurvar ringmerktir í 12 ymiskum føroyskum bygdum, spjaddar kring landið. 17% vórðu merkt í reiðrinum, 39% vóru ungfuglar og 39% vaksnir fuglar. 225 (10%) av teimum merktu gráspurvunum vórðu fingnir ella sæddir aftur; allir í Føroyum, og einans tveir í aðrari bygd enn henni, har teir upprunaliga vórðu merktir. Helvtin av fráboðanunum komu tær fyrstu 8 vikurnar eftir merkingina, 25% fyrstu 3 vikurnar. Í flestum førum (68%) doyðu fuglarnir av ókendum ávum, men har deyðaatvoldin var kend, var ketta vanligasta atvoldin. Miðallívstíðin hjá føroyska gráspurvinum er 1,3 ár. Helvtin av spurvunum, sum vórðu merktir í reiðrinum ella sum ungfuglar, doyðu eftir 4,1 mánaðum. Tann elsti gráspurvurin, vit vita um í Føroyum, varð fingin aftur næstan tíggju ár eftir, at hann varð merktur í reiðrinum.Abstract: The house sparrow (Passer domesticus) is one of the most sedentary species of wild birds in the Faroe Islands. Since 1963, 2,167 house sparrows (17% nestlings, 39% juveniles and 39% adults) have been ringed at 12 places, scattered over the Faroe Islands. 225 (10%) have been recovered, dead or resighted/ recaptured, all within the Faroe Islands, and only two outside the villages where they were ringed. Half of the recoveries were reported within 8 weeks, 25% already within 3 weeks. In most cases (68%), the cause of death was unknown. However, “killed by cat” was the most common known cause. The median life-span for the Faroese house sparrows is 4.1 months, and average age at death is 1.3 years. The oldest house sparrow recorded in the Faroe Islands was found dead almost ten years after it was ringed as nestling.