An analysis of records of three passage migrants in Thailand: Tiger Shrike Lantus tigrinus, Yellow-rumped Flycatcher Ficedula zanthopygia and Mugimaki Flycatcher Emugimaki

Abstract

Records of three passage migrants in Thailand are analysed to show seasonal and geographical differences in their distribution. While two of these, Tiger Shrike Lanius tigrinus and Yellow-rumped Flycatcher Ficedula zanthopygia, are early autumn migrants, the third species, Mugimaki Flycatcher F. mugimaki, is a much later autumn migrant and, in contrast to the other two, comprises birds that winter in Thailand as well as passage migrant individuals that winter beyond the country's southern border. Disproportionately more Mugimaki Flycatchers are recorded on spring migration than the other two species. Definitive-plumaged males of both flycatcher species were recorded earlier on spring and autumn migration than others (grouped female or immature birds). Although in recent decades the numbers of migrants reported have increased due to increased ornithological recording, the numbers of Tiger Shrikes have not increased in proportion to those of Yellow-rumped Flycatchers, possibly indicating a decline in numbers.