Although White-faced Ibis have made near annual visits to Columbia NWR and
the wetlands around Othello, the breeding record Jon refers to was of nest
building at Kahlotus Lake, Franklin County, but the wetland dried up and the
ibis abandoned. There are many scattered and isolated wetlands in Eastern
Washington that offer habitat for a portion of the breeding season,
including "Crab Lake" near Wilson Creek where Tricolored Blackbirds were
first found nesting in WA, and the Potholes area of Grant County where
irrigation water maintains rather than reduces groundwater. Some of these
wetlands are on private land that are not visited by birders. As climate
change moves southern species farther north I would expect White-faced Ibis
to be one that establishes from drought events to the south and east.



Randy Hill

Ridgefield



From: inland-nw-birders-bounces at uidaho.edu
[mailto:inland-nw-birders-bounces at uidaho.edu] On Behalf Of Jonathan B.
Isacoff
Sent: Saturday, August 11, 2012 9:45 AM
To: inland-nw-birders at uidaho.edu
Cc: tweeters at u.washington.edu
Subject: [inland-NW-birders] Mann Lake Ibis



I am not a "dark ibis expert" but I do see both species, including
juveniles, nearly annually at various locations around the US. From the
discussions threads on INWB, most of the key facts are already there:



* 1st year ibis's look very similar, hence are tough to ID

* as many have already noted, dark iris on a juvenile WF Ibis is typical
until around February

* juveniles of both species can show a mottled bicolored bill. At this
stage, the two species are virtually indistinguishable



With 99% confidence the Mann Lake bird is a typical juvenile White-faced:



* First and foremost: when analyzing 2 extremely similar species, good
birders assume the ID to be the "expected species" unless there is something
strikingly atypical to suggest otherwise

* There is nothing atypical on this ibis to suggest anything other than
White-faced. More specifically:

(1) The dark iris is typical of White-faced at this stage;

(2) Once the bi-coloration of the bill has matured into a solid color,
White-faced, nearly always show a gray or blueish-gray as the Mann Lake bird
does. Glossy show a pinkish, brownish, or pinkish-brown bill. Guides don't
mention this because a "true juvenile" has a mottled bi-colored bill, but
once the more mature solid color is established, bill color is a diagnostic
key of dark ibises. Glossy Ibis's never have a gray of blueish-gray bill.

(3) There was some mention of white loral lines on young Glossies, which can
be helpful if all other factors are unclear. Perhaps some other observer can
detect these but I see no hint of white loral lines on the Mann Lake bird.



A note on why White-faced is clearly the "expected species;"



* White-faced Ibis is a regular established breeder at Malheur in Eastern
OR, Freezeout Lake in Western MT, and a host of locations in Southwestern
ID. I'd have to double check but I believe there is a recent historical
breeding record from Columbia NWR in WA. It is expected that juvenile birds
will drift from these relatively nearby breeding sights to places like Mann
Lake. Indeed, it is surprising that juvenile birds have not been seen there
before.

* The closest breeding site for Glossy Ibis is Southeastern TX.



I'd be happy to learn a new fact about ibis's that help with ID, but the
Mann Lake bird looks to be a perfectly typical juvenile White-faced.



Good birding,

Jon Isacoff, Spokane



Jonathan B. Isacoff

Chair, Environmental Studies

Associate Professor, Political Science

Gonzaga University, Box 52

Spokane, WA 99258-0052

isacoff at gonzaga.edu