ML43773931
作者
日期
地点
- 年龄
- 未说明
- 性别
- 未说明
- 标签
- 多个鸟种
媒体文件注释
Bird in back with leg raised suspected hybrid, Ross’ in front also notable on this bird is size of legs, very thin, good for Ross’ best comparison shot I could find. According to some literature intermediate birds tend to show larger tarsus and feet unlike Ross’. https://sora.unm.edu/sites/default/files/journals/auk/v088n04/p0856-p0875.pdf page
观察细节
This Ross’ candidate ( found by Tom Wetmore) is distant digiscoped and can easily be changed if consensus is hybrid. After some questions arose about whether or not pure Ross’ I did some research and I believe it is ok for Ross’( the right hand bird ) and within the range for Ross’ The other one (the left hand bird ) seems like a possible hybrid/intermediate. I superimposed a crop of right hand bird's head on Sibley’s drawing of Lesser, intermediate and Ross’ for comparison from his website http://www.sibleyguides.com/2011/12/identification-of-white-geese/. I also compared to Phil Brown’s photos from MARC report #10 here http://www.maavianrecords.com/home/annual-reports/report-10 I believe the right hand bird is with in the variation for Ross’ but as always am open to disagreement. It is a tricky id when considering hybrids. These are the things I note good for Ross’ Nice straight vertical line along base of bill, little to no grin patch, conical shaped bill, although some what elongated near tip but still seems “ok” for Ross’, peaked rounded head, short thin legged appearance compared to proposed hybrid near it.
技术信息
- 型号
- NIKON D7100
- ISO
- 1250
- 焦距
- 300 mm
- 闪光
- Flash did not fire, auto
- 光圈
- f/6.3
- 快门速度
- 1/2500 sec
- 尺寸
- 828 pixels x 477 pixels
- 原始文件大小
- 107.05 KB