• Species diversity continued to drop this week, falling into single digits on Friday.  Weather, again, negatively impacted banding, in particular, on Friday and over the weekend when much of banding was precluded by wind and rain storms.  Despite fewer species and comparatively less banding effort (due to weather) than last week, we still managed to band 100 more birds than last week.  This was due, in large part, to the heavy fallouts of Yellow-rumped Warblers (163) and White-throated Sparrows (94) that were grounded here at Powdermill for much of the week.  Ruby-crowned Kinglets, with 77 banded, also helped boost the totals for this week.

• We thank Mike Comley, Randi Gerrish, Felicity Newell, Matt Shumar and Powdermill's Director, Dave Smith, for help with banding this week.

• The week started off somewhat promising with the banding of a new species for the season on Tuesday, October 12.  This hatching year White-crowned Sparrow, one of two banded today, will carry these brown crown stripes until its prealternate molt in the spring, when it will replace all but a few of the brown feathers in the hind crown with the more characteristic bright black and white head plumage.  We recorded this bird as a possible gambelli x leucophrys intergrade based on the paleness of the lores (a gambelli characteristic), but the bill was not as orange as we would expect to see in a pure Gambell's.

• One of 14 Song Sparrows banded today was our second case for the fall of a bill deformity, the first being an Eastern Phoebe banded last week.  Again, not as severe as witnessed in some birds last fall, this bird's upper mandible was only slightly elongated.

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• Wednesday, October 13, was our busiest day this week, netting us 192 birds and our 106th species for the season.  One of two adult Fox Sparrows banded is pictured below.

• Of the 192 birds, 38 were kinglets and 67 were Yellow-rumped Warblers.  An adult male (left) and adult female (right) are pictured below.

• As one of the most variably plumaged warblers, sexing these birds, especially in the fall, is often a complicated assessment of multiple plumage characteristics and wing length.  Wing length can be helpful.  Summarized in "Relationships among body mass, fat, age, sex, and wing length for 170 species of birds banded at Powdermill Nature Reserve" and based on sample sizes ranging from 850 to 3270, the average wing length for an adult female is 70.0, an adult male is 74.2, an immature female is 68.6, and an immature male is 72.5.  Wing length is used as a factor in determining the sex of fall birds, but because of significant overlap, and because we not infrequently capture birds of this species of the much larger Alaskan race, Dendroica coronata hooveri, we typically make determinations of sex in this species only when wing length and plumage characteristics (like the ones shown below) agree.

• Males (bird on the left in both pictures below) tend to have broader and darker black side streaking than females (bird on the right in both pictures below).  The yellow spot under the wings also tends to be much brighter and cleaner in males.  In addition to side streaking, upper tail coverts are useful in sexing some birds.  Males have feathers with broad, dark black centers that are neatly and cleanly edged in gray.  Female upper tail coverts have a narrow dark center band and are broadly edged in gray with buffy/brown.

 

The sets of photos above are individuals that show the possible differences between sexes and are not intended to represent the many individual, geographic, and age-related variations in plumage for this species.  Because of these many sources of variation, a fairly large number of YRWAs cannot be confidently sexed in the fall.

• There weren't many highlights from the second half of the week because of the poor weather conditions, so we're concluding this week's highlights with a few birds banded on Thursday, October 14.  The first of which, like the adult male Eastern Towhee a couple weeks ago, makes it onto the website simply for being such a great looking guy!  This adult male Purple Finch.

• This adult Blue-headed Vireo was one of four banded today, bringing our season total to 70 birds (we banded our 71st BHVI three days later and expect we haven't caught our last one yet).  This total setting, yet another, fall record for this year, well exceeding the previous fall total of 53 in 1985!

• This adult Savannah Sparrow pictured below was our second for the fall, this one having the much more characteristic yellow lore which was absent on the one banded earlier this fall.

• The photos below feature a couple characteristics unique to grassland sparrows and other ground dwelling finch species.   The tertials (the three feathers lined on top of one another at the bottom of the picture) on these birds are much longer than most other passerines, extending almost as long as the outer primaries (long outer flight feathers at the top of the picture).  The bottom picture is of the SAVS's foot, highlighting the elongated claw on the hind toe, or hallux, which is unlike those seen on most "perching" birds.  This is a characteristic of other grassland birds, like longspurs and pipits, that probably aids in stability and movement across the flat, open areas where they feed and nest.

• Finally, we end with a bird (the second banded for the fall) that is common breeding and wintering bird in Pennsylvania, and also a frequent feeder visitor.
  
  

"I am easily and frequently misidentified because of my bright red head." 

 
 

"Who you callin' Red-headed?!"
 
 
 

"This feature of mine, rarely seen in the field, is nowhere near as obvious as my red head"
 
 
 

"But, of course, I am a Red-bellied Woodpecker"

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Last Updated on 10/20/04
By Adrienne J. Leppold