HAPPY WREN Pheugopedius felix lawrencii

(vs. P. f. pallidus total score 8)

Coloration.—White mid-breast and mid-belly vs. rufous breast and belly in pallidus (Fig. 13; Grant 1965a, based on 43 male and 30 female lawrencii vs. 37 male and 18 female pallidus [not scored]). Among 18 lawrencii at IBUNAM, a few are washed warm on the breast, but are still usually paler than the palest pallidus. Even if there is warm colour across part of the breast, there is much white on the mid-breast and mid-belly. Examination of the ‘warmest’ specimens of lawrencii (P016585) revealed a diagnostic character not previously mentioned in the literature (e.g. Nelson 1898, Ridgway 1904, Grant 1965a): the colour of the underwing-coverts. In lawrencii, these are white or whitish, contrasting with the warm breast-sides, whereas pallidus has cinnamon / rufous underwing-coverts concolorous with the breast (score 3) (Fig. 14). Ear-coverts have significantly more white than black feathers vs. black and white feathers approximately equally prominent (score 2) (Fig. 13). One or other of these differences between lawrencii and pallidus is of somewhat similar magnitude to those between certain subspecies of, e.g., Coraya Pheugopedius coraya, Rufous-and-white Thryophilus rufalbus, Buff-breasted Cantorchilus leucotis, Carolina Thryothorus ludovicianus and White-browed Wrens T. albinucha, but in those cases there are zones of intergradation and smooth clines, whereas between lawrencii and pallidus the differences are abrupt and occur in both characters simultaneously. Grant (1965a) noted that in both plumage features, juveniles from the mainland approach those of Tres Marías birds.

Morphometrics.—Longer wing, tail and, especially in females, bill (score 2) but tarsus relatively shorter (not significantly different in female and only slightly bigger in male [score 1]).