Arquivos de periódicos de março 2019

13 de março de 2019

Song Sparrow Study -- Wilkinson Lane

Ever since July of 2017, I have been on a mission to study the Song Sparrows of the interior Pacific Northwest. The reason why I've become so obsessed with this research is because of a very Eastern-looking (Melospiza melodia melodia) Song of that summer. However, when I discussed that bird with several experts, it turned out to be a singing Mountain Song (M. m. montana).

These experts confirmed the Mountain Song's id because of the white supercilium. However, eBird lumped the Mountain and Merrill's Song together as the Song Sparrow (merrilli/montana) or more commonly the Interior West Group. The main id marks of this group is the ashy gray facial stripes, reddish body and heavy underparts streaking. But if my individual is indeed a Mountain Song, why does it differ so much from the Merrill's? Especially when the Mountain looks so much like Eastern.

That's why I'm observing each Song I see very closely. This journal post will show what I saw on March 2, 2018. Location is Wilkinson Lane, a backroad at Ladd Marsh Wildlife Management Unit, Union County, Oregon. Over the course of fifty-three minutes, I counted thirty-two different individual Songs, a huge number in one location. It also helps with my study of these highly complex species.

In Union Co, Oregon, two subspecies reside in the winter. From what I've seen, the Merrill's Song dominates the other subspecies. Roughly 84% of all the Songs I see are Merrill's. The second is the Mountain Song. Both subspecies breed in the county and integration is known in these range overlaps.

Now let's assume that my white supercilium Songs are Mountain and gray for Merrill's. Getting the numbers, I saw five Mountain Songs and twenty-one Merrill's. Neat thing was, the last six individuals had a white lore with gray supercilium, somewhat resembling a White-throated Sparrow's yellow lore and white supercilium. Are these bicolored supercilium Songs intergrades? It is indeed highly probably but without mtDNA testing, we'll never know for sure. One thing though, I will not stop my studying of these beautiful birds because there's almost something new to learn about them!

Posted on 13 de março de 2019, 04:59 AM by birdwhisperer birdwhisperer | 4 observações | 1 comentário | Deixar um comentário

16 de março de 2019

Junco Surprise

Ever since December, juncos have been gorging on my millet feeders. Yet every time I slide the kitchen chair to the backyard door, I see another interesting junco in the mix. Over the course of the winter, I've seen several Cassiar Juncos and the variance between the subspecies/intergrade always amazes me. For a week in February, a Pink-sided Junco decided to hunker in my yard during the heavy snowfall that month. Slate-colors were in high numbers as I once saw eight individuals in the yard. I find that an amazing number for Oregon.

Yet on March 9, I was gifted with something that may be a once in a million experience. I was grilling and at 5:07 pm, I saw a light-colored bird land on the ground just below my bush millet feeder. When I placed my binoculars on it, I saw the white face and know that this was a leucistic Oregon Dark-eyed Junco. Leucism is the condition in which an animal cannot distribute the melanin (dark color pigments) across it's body. This results in a white speckled body (pied) or a washed out look (dilute). I've always liked explaining this to people as many, including experts, would call this aberrant plumage a semi-albino. However, scientifically speaking, that doesn't exist since albinism is the lack of producing melanin at all and the explanation to why the animal will be completely white/cream with pink eyes and extremities. Albinism is also much rarer in the wild.

I always find it awesome to find a leucistic bird. I have seen several in my lifetime excluding the junco. These such observations include a Mourning Dove (with snowy white tail), Red-tailed Hawk (with white p8) and Song Sparrow (juvenile with white speckles on the head and back). Now I've got another bird I can add on to my list of aberrant plumages. Maybe the next one I'll see will have xanthochromism!

Posted on 16 de março de 2019, 11:58 PM by birdwhisperer birdwhisperer | 1 observação | 0 comentários | Deixar um comentário