English and Scientific names:	MacGillivray’s Warbler Oporornis tolmiei
Number of individuals:	1—immature male? adult female?
Locality: LOUISIANA:	Cameron Parish
Specific Locality:	Private land in West Jetty Woods
Date(s) when observed:	12/15/2007
Time(s) of day when observed:	11:00-11:05
Reporting observer and address:	Paul Conover Lafayette, LA
Other observers accompanying reporter who also identified the bird(s):	Mac Myers
Other observers accompanying reporter who independently identified the bird(s):
Light conditions (position of bird in relation to shade and to direction and amount of light):	Overcast with dark edge of a front halfway overhead. A sudden rush of wind and rain cut the observation short, but the light up to that point was excellent muted light.
Optical equipment:	Zeiss 10s, and Nikon D50 with 55-200 lens.
Distance to bird(s):	5 yards.
Duration of observation:	5 minutes, although 5 minutes with an Oporornis is a few seconds here and there.
Habitat:	Chenier-type woodlot with mostly deciduous canopy—thus without leaves at this date—and understory thick with dead ragweed stalks and a scattering of baccharis, rose, honeysuckle, etc. The bird was foraging along ragweed stalks as it moved from green to green.
Behavior of bird:	When we first walked up, I saw a bird dart ahead a few feet. My only look was at its tail and part of the undertail, which matched Orange-crowned Warbler to some extent, but seemed a little too vivid green and yellow for our wintering OCWA. As we approached, an Orange-crowned gave a series of calls about 20 yards to our left, and either in response to that or to our approach, this bird began calling. I wasn’t familiar with the call, and I could see that Mac was trying to place it. I couldn’t tell if it was an odd OCWA call, a weird Yellowthroat, or what, but it remained close ahead of us foraging and calling for a half-minute or so. It popped out in the wide open for a few seconds, and we saw immediately what it was. I began to photograph the bird, although it managed to keep even the smallest dead ragweed stalks between it and me. It fed along the edge of the woods, moving a few feet at a time and concealing itself between moves. At one point, it hid in a tangle of stalks and peered out at me, allowing me to get a few head shots. Then it began to forage and hide a bit more. It seemed to have disappeared, but after about a minute I saw it slip out of the back of a thick bush where it had apparently been sitting quietly. I tried to follow, but I was trying to move quickly as bad weather had hit us, and my loud and clumsy efforts probably spooked it. I wasn’t able to relocate it, and it had moved into an area of dense rose thickets. Attempts to call it out with a Screech Owl were useless, as were attempts with a MacGillivray’s song and call.
Description:	A medium-sized warbler, about the size of a Kentucky Warbler. Vivid medium green or olive-green above, fairly bright yellow below, but with greenish flanks and a light greenish wash beneath. Undertail bright yellow, extending only to about the end of the folded wing. Hooded appearance, with upper part of head medium gray, upper breast banded slightly lighter gray, and chin and throat whitish or very pale gray. Bill pale, though exact pattern was impossible to detect on moving bird, and hard to discern in photos. Eyes dark brown, with white feathering forming distinct white arcs above and below eye, not extending to sides of eyes. Broad ‘eyeline’ on sides of eyes separating eye crescents, possibly slightly darker than surrounding gray. It appears in the photos as if there are small black flecks in malar and on breastband, but that may be noise on photo. Legs pale, yellowish or pinkish in photos but they appeared pinkish in the field.
Voice:	The bird began calling loudly and frequently when we first jumped it. The call was different to me, but my mind was trying to turn it into a more expected local bird. In volume, it was possibly equal to a Orange-crowned call, but the quality of the call was harder, almost like a compressed Yellowthroat call. It was definitely a strange call to my ears. Once we saw it, I recalled Dittmann and Cardiff having described the call of this species and it fit their description. Mac knew the call, but couldn’t place it until we saw the bird, then he realized it was the typical MacGillivray’s call. It matched the call on the tape we tried to lure the bird out with, as well.
Similar species:	Connecticut Warbler ruled out by size, behavior, morphology, and plumage features, among them the lack of eyerings. Mourning Warblers can have eye-crescents, but these are much narrower, confined largely to the lids, and are more narrowly separated by the eyeline. Mourning Warbler also generally brighter yellow on flanks, and have shorter undertail coverts. Brightly colored western Orange-crowned Warbler with different face pattern, not hooded. Other warblers bearing superficial resemblance to MacGillivray’s: Nashville Warbler smaller with complete eyering, usually yellow throat, white belly. Yellow-breasted Chat larger, only superficially similar. Magnolia with strongly patterned tail, Prairie with different facial pattern, Northern Parula with eye-crescents but different pattern throughout, much smaller.
Photographs or tape recordings obtained?	A few photos including a lucky few showing the face and eye are well.
Previous experience with this species:	Not a lot. I’ve seen them on a half-dozen or so trips out west, but rarely got really great looks. I’ve banded a few Mournings over the years and I’ve been able to get a good idea of the range of eyerings in that species, and have compared them to numerous photos of MacGillivray’s.
Identification aids:	I checked out the Peterson warbler guide, Sibley, Geo, the Pyle and Henderson article on young Oporornis in Birding (22:5) to try to figure out age and sex.
This description is written from:	Memory, and consulting the photos.
Are you positive of your identification? If not, explain:	Yes.
Reporter:	Paul Conover
Date and time:	12/16/2007