English and Scientific names:

Shiny Cowbird (Molothrus bonariensis minimus)

Number of individuals: 

1 adult male

Locality: LOUISIANA: 

Jefferson Parish

Specific Locality:

terminus of Landry Ln. (19 Apr), Cemetery Ln. (20 Apr), Grand Isle

Date(s) when observed:

19,20 April 2008

Time(s) of day when observed:  

~3:30 PM CDT (19 Apr), 9:10 AM CDT (20 Apr)

Reporting observer and address:

Devin Bosler

Baton Rouge, LA

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

 

Justin Bosler (19,20 Apr), EJ Raynor (20 Apr)

Other observers who independently identified the bird(s):

Marty Guidry (21 Apr)

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

Clear sky w/ optimal afternoon sunlight.  Sun angle high and opposite the bird (19 Apr).  Fair w/ bright, mid-morning sunlight.  Again, the sun angle was fairly high and not a factor (20 Apr). 

 

Optical equipment: 

Zeiss Victory FL 8x42, Canon ZR830 digital video camcorder (all equipment in excellent condition)

Distance to bird(s): 

ca. 15 meters (19 Apr), 6-8 meters (20 Apr)

Duration of observation:

~3 min. (19 Apr), ~7-8 min. (20 Apr)

Habitat: 

Open, residential lawns and coastal woodlot w/ primarily scattered live oaks, honey locusts, Chinese tallow and other cultivated shrubs. 

Behavior of bird: 

 

The cowbird was observed at rest, in display, and in flight.  On 19 April, it was observed singing and displaying toward a male Brown-headed Cowbird.  It followed closely behind the male Brown-headed throughout the encounter.  Within a minute or two, it flew off after the male Brown-headed and continued on out of sight into a residential backyard.  On 20 April, presumably the same individual male was observed again, singing and displaying from the top branches of a mature live oak at the cemetery on Cemetery Ln.  Eventually, it flew off toward the west and disappeared into another woodlot.

 

Description:

A relatively small, stocky, entirely glossy black cowbird w/ violet-blue iridescence on head, breast, and upperparts.  A longish, wedge-shaped tail.  Thick, sharply-pointed dark bill, dark brown irides, and black tarsi/feet.  The distinctive, liquid bubbling song was heard several times throughout the observation.  The cowbird would raise its head feathers and ruffle body feathers when singing and displaying in typical cowbird fashion. 

Voice:

A very subtle, unusual sounding liquid gurgle and bubbling.  Song began w/ a few bubbly notes followed by a series of high-pitched, barely audible notes.  A thin whistle note was given in flight.

Similar species:

All N.A. blackbirds and grackles can be eliminated by its small, stockier size and dark iris.  Song also separates Shiny Cowbird (SHCO) from Brewer’s Blackbird (BRBL) and all other blackbirds.  A male Brown-headed Cowbird (BHCO) can be eliminated by its entirely glossy black plumage and lack of a brown head.  Bronzed Cowbird (BROC) can be eliminated by its glossy black plumage, its dark brown, rather than red iris color, and smaller bill.  Song also eliminates both BHCO and BROC. 

Photographs or tape recordings obtained?

Video obtained by Devin Bosler.  Video images attached.   

Previous experience with this species: 

Familiar w/ SHCO from s. Fl and two previous encounters in LA.  Observed a single adult male twice before at Grand Isle (Jefferson) in April (on 30 Apr 2006 and 14 Apr 2007).  Observed at least two males at Florida City (Miami-Dade) on 23 Aug 2006. 

Identification aids:

National Geographic Complete Birds of N.A. (Alderfer et al. 2005).

This description is written from: 

notes made during the observation

notes made after the observation

memory

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

 

Yes, very confident.

Reporter: 

Devin Bosler

 

Date and time: 

10 May 2008 

11:00 PM CDT