English and Scientific names:

Black-whiskered Vireo (Vireo altiloquus)

Number of individuals: 

1 fresh spring adult

Locality: LOUISIANA: 


Specific Locality:

TNC Grilletta Tract (Lafitte Woods), Grand Isle

Date(s) when observed:

20 April 2008

Time(s) of day when observed:  

7:45-8:15 AM CDT

Reporting observer and address:

Justin Bosler,

Lancaster, PA 

Other observers accompanying reporter who also identified the bird(s):

Devin Bosler and E.J. Raynor

Other observers who independently identified the bird(s)

Steven W. Cardiff and Donna L. Dittmann

Light conditions (position of bird in relation to shade and to direction and amount of light):

Excellent morning light with the bird viewed in both shaded and well-lit conditions.

Optical equipment: 

Zeiss Victory FL 8x42 (excellent condition)

Distance to bird(s): 

Within 2 meters at closest point.

Duration of observation:

Approximately 30 minutes.


Early successional patch of mature, coastal woodlot with sugarberries, mulberries, honey locusts, and live oaks. 

Behavior of bird: 

The vireo was actively foraging on mulberries in the large red mulberry close to the parking area where it was found on 19 Apr by SWC and DLD.  It actually had pinkish stains on its breast and belly from the juicy mulberries.  Despite its obvious appetite for mulberries, it spent a greater percentage of time foraging for insects in the low, weedy brush.


A ‘red-eyed’-type vireo w/ dull olive-green upperparts and pale underparts.  Upperparts appeared more dingy, or grayish-brown than accompanying Red-eyed Vireos.  Sides, flanks, and undertail coverts showed a slight yellow wash typical of fresh spring plumage.  Bold, white supercilium (eyebrow) bordered by a black loral stripe (extending through postocular) below and a silvery gray crown above.  Dark malar stripes were indistinct but noticeable at close range.  The bill appeared largish.


The vireo was silent while foraging.

Similar species:

Most vireos can be eliminated by the bold, white supercilium; blackish lateral crown stripes and eyeline bordering supercilium; and silvery gray cap.  The superficially similar Red-eyed Vireo can be eliminated by the duskier upperparts, dark malar stripes, and slightly larger and paler bill.

Photographs or tape recordings obtained?

Photos obtained by Justin Bosler and attached.

Previous experience with this species: 

Roughly a dozen seen between Key Largo, Key West, and Sanibel Is., FL with two prior observations in LA.

Identification aids:


This description is written from: 

notes made after the observation and memory.

Are you positive of your identification? If not, explain: 


Yes, 100% positive.


Justin Bosler   

Date and time: 

14 September 2008   

2:10 AM EDT