Turdus naumanni naumanni and Carduelis flammea

This may be a great year to see Carduelis flammea.
In some years they never even arrive in Sounkyo, but this year they are here in considerable numbers.
Yesterday I heard Carduelis flammea calling during a walk; their call sounds something like “chu-een.” When my eyes went in that direction, I saw that the birds were feeding together with what looked to be Emberiza cioides.
I looked more closely and noticed that they are much larger than the Emberiza cioides. I approached quietly and heard a call that, though infrequent, sounded like that of Turdus eunomus.
When I moved even closer, I saw that the birds were Turdus naumanni naumanni, a species that only rarely comes to Japan.
Ordinary Turdus eunomus have a black band on their breast; however, Naumann’s thrushes have a reddish brown color. The birds in the photograph have a slightly red coloring. There is considerable variation among individuals, with some having an intermediate coloring among Turdus eunomus. They are playfully referred to as “six-mat thrushes,” “four-and-a-half-mat thrushes,” etc., (referring to tatami mats) depending on their coloring. (It appears that their Japanese name tsugumi came from their initial discovery on Hachijojima Island; however, there are also claims that their first recorded sighting in Japan was in Hakodate.)
Just then, “one-on-one combat” broke out among some of the Carduelis flammea.
Or so I thought. Actually, they had begun mating.
The whole encounter was over in a moment, but it was an indicator that spring has arrived for the birds.
Photos: Turdus naumanni naumanni (left) and Carduelis flammea (right) Mar. 17