North American Bird Bander Apr-Sept 2019 Volume 44 Numbers 2 & 3

Feature Articles

An Evaluation of Characters for Age and Sex Determination of the Black-capped Vireo

David A. Cimprich

I evaluated the information in Pyle (1997a) for determining the age and sex of the Black-capped Vireo (Vireo atricapilla). Additionally, I described two new age/sex characters as well as the timing and extent of brood patch development and the range of iris colors in this species.  My results agreed with Pyle (1997a) concerning the width of the green edging on the primary coverts, but disagreed to some extent concerning head plumage pattern, rectrix shape, and primary covert shape.  As was previously known, age and sex groups differed in their head plumage patterns, but more overlap existed among age groups than has been previously described.  For adults, only the extreme patterns were reliable for determining sex, but many patterns were reliable for separating hatching-year males and females.  For separating second-year (SY) and after-second-year (ASY) individuals, head pattern was useful for males, but unreliable for females.  Head pattern was not reliable for separating hatching-year (HY) and after-hatching-year birds (AHY).  Rectrix shape was unreliable for separating SY from ASY but useful for separating HY and AHY.  The shape of primary coverts was not reliable for separating any age groups and was sometimes opposite the description in Pyle (1997a).  A previously unknown character, breast color, was reliable for separating the sexes of all age groups with females having extensive pale buff color and males white.  Another new character, rictus color, was reliable for separating HY and AHY birds.  In HY, this color was pale yellow or flesh not matching any color on the bill whereas it was gray or black on adults and matched a bill color.  These results reveal that much remains to be learned and I encourage banders to evaluate age and sex characters for species they frequently capture.

Flexible Canopy Netting Rig and Audio Lure Placement for Woodpecker Capture

Anastasia A. Rahlin, Alison R. Világ, Delmar Hurd

We describe a new, modern canopy mist-netting rig and audiolure broadcast approach for target netting Red-headed Woodpeckers (Melanerpes erythrocephalus). Using our canopy rig, we captured four adult Red-headed Woodpeckers in six capture attempts versus capturing one adult Red-headed Woodpecker and an additional non-targeted species in five ground-based mist-netting attempts.  Our results demonstrate that a flexible mist-netting approach coupled with audio lures allow for the capture of woodpecker adults, while reducing non-target species captures.  We suggest our technique may be used to capture additional canopy-dwelling bird species during the breeding season.