FEATURED PHOTO Identifying Sparrows in Juvenile Plumage Even as adults, these “LBJs” can be tricky. To identify the juveniles, pay special attention to the flight feathers and subtle facial patterns. Priscilla Lai • Fort McMurray, Alberta • [email protected] Peter Pyle • Bolinas, California • [email protected] Kenneth R. Foster • Fort McMurray, Alberta • [email protected] Christine M. Godwin • Fort McMurray, Alberta • [email protected] parrows in the family Emberizidae con- program is the Boreal MAPS initiative, and involves the capture of juveniles just Sstitute a large group of “little brown jobs” which we have undertaken in habitats of before and as they undergo their prefor- that range across the Americas, with mul- varying vegetative age and complexity in mative molt—the unique first-cycle molt tiple species often occurring in the same loca- northeastern Alberta since 2011 (Foster clarified by Howell et al. (2003). Juvenile tion. Their skulking behavior and preference et al. 2012, 2016). Because inaccurate sparrows are characterized by their rather identification of tricky species and plum- plain and streaky plumage, and they are for dense habitats can make identifying them a ages would compromise our analyses of typically a lot harder to identify to species challenge, even as adults. Many of the features productivity and survivorship, we make than adults. we use to identify adults are not fully developed every effort to properly identify all birds The preformative molt in most North in juveniles, making their identification even we capture. As with juvenile trickier! For example, juvenile sparrows of most warblers (Pyle et al. 2015), species have uniformly streaky breasts, which identifying juvenile sparrows may or may not be expressed in later plumages. can be a challenge, but sub- Here we provide a primer on the identifica- tle differences offer clues that tion of juvenile sparrows found in northeastern permit accurate and confi- dent species identification. Alberta. Our findings are based on extensive Sparrows are widespread notes we have taken on birds captured for and speciose in northeastern banding. Although we rely heavily on measure- Alberta. Generalists like the ments and morphology for adult birds in the White-throated Sparrow are hand, we have found that many of these tradi- present in a diversity of habi- tional metrics may not apply to juveniles that tat types, whereas others like have not fully developed. We therefore concen- the Le Conte’s Sparrow prefer trate on plumage features, and we anticipate specific wet, grassy breeding that these will be especially useful for birders habitats. Lincoln’s, Swamp, Featured Photo—Juvenile Song Sparrow. Although adult and Song sparrows, species who encounter juvenile sparrows in the field. and first-winter (formative) Song Sparrows are boldly pat- that can pose identification terned, juveniles are amorphously marked. In this article, we ccurate identification of mist-netted challenges even in adult apply lessons from the Boreal MAPS (Monitoring Avian Produc- Abirds is a critical component of the plumages, share habitats that tivity and Survivorship) program to the identification of spar- Monitoring Avian Productivity and Sur- range in vegetative age and rows in juvenile plumage. Differences are slight and variation vivorship (MAPS) program (tinyurl.com/ complexity, providing that is considerable, but with good study—ideally, in conjunction with analysis of digital photos—many juvenile sparrows may MAPS-banding), an intensive continental wetter areas are available. be field-identifiable. On this bird, note the relatively long tail, bird-banding program aimed at measur- The MAPS program operates brown wings, un-streaked throat, and broad malar streaks, fea- ing landbird vital rates (DeSante et al. during the breeding season tures that separate it from juvenile Lincoln’s and Swamp spar- 2015). One part of the broader MAPS (spring and summer months) rows. Brooklyn, New York; August 2014. Photo by © Laura Meyers. 62 BIRDING • JUNE 2017 M expandedem content. be rs -o nl y A B C Fig. 1. Juvenile Lincoln’s Sparrows (Fig. 1a), Swamp Sparrows (Fig. 1b), and Song Sparrows (Fig. 1c) resemble each other closely. As adults, these species differ morphologically (Pyle 1997a), with Lincoln’s Sparrow having a finer bill, moderately long tail, and longer wing morphology; Swamp Sparrow having a moderately stout bill and shorter tail and wing morphology; and Song Sparrow having a larger and stouter bill, lon- ger tail, and shorter wing morphology. As juveniles, however, the bill, tail, and primaries may not be fully grown, requiring plumage features to be examined for accurate identifications. Fig. 1a: July 20, 2012. Fig. 1b: July 7, 2012. Fig. 1c: July 12, 2016. Photos courtesy of © Boreal MAPS Program. American sparrows is partial, including whether a bird in hand is a juvenile Lin- also have some streaking in the chin and most to all body feathers and upper-wing coln’s, Swamp, or Song sparrow is not throat, an indistinct malar streak, and secondary coverts, and sometimes one or always an easy task. High intraspecific moderate streaking to the breast, often more tertials and central rectrices (Rising variability occurs in juveniles of all three with heavier streaks than in juvenile 1996; Pyle 1997a, 1997b). Juvenile flight species, and juveniles are often present Swamp Sparrows, but with thinner (al- feathers differ subtly—primarily in shape, in relatively good numbers in the same beit often denser) individual streaks than wear, and fading—from the flight feathers habitat and at the same MAPS station—so in juvenile Song Sparrows (Fig. 3a). The of adults. So one of the best ways to identi- lots of juveniles appear at the same time! tail is longer than in Swamp Sparrow but fy juvenile sparrows is by looking for clues What follows is a summary of the most shorter and with more pointed rectrices among the flight feathers, in particular the useful criteria in distinguishing these than in Song Sparrow (Fig. 4a), and the coloration of feather fringing along with three species. edging to both the rectrices (Fig. 4a) and the morphology of individual tail feath- secondaries (Fig. 5a) can be duller brown ers and the effect this has on tail shape. incoln’s Sparrow juveniles tend to be and not as rusty–red as in Swamp and The bill size, body shape, and facial profile Lrelatively browner than the others, cov- some Song sparrows. All of these char- provide additional clues to a juvenile spar- ered in fine dark streaks and with an in- acteristics are variable and can approach row’s identity, although these features may distinct gray superciliary stripe (Fig. 1a). those of the other two species; they must not be fully developed in juveniles. Here The crown tends to show distinct streak- be used with caution and consideration we present our “Juvenile Sparrow Chal- ing and usually shows an indistinct me- of all features simultaneously. lenge” and describe the morphological dian stripe (Fig. 2a), which can become As with the Lincoln’s Sparrow, Swamp and plumage-related characteristics that more prominent as the preformative molt Sparrow juveniles (Fig. 1b) show high we find useful for quickly and accurately progresses. Juvenile Lincoln’s Sparrows variability in plumage among individu- identifying recently fledged sparrows. ur biggest challenges involve the sepa- Oration of juvenile Lincoln’s, Swamp, and Song sparrows, and one of these spe- cies is the subject of our challenge bird. Both Lincoln’s and Swamp sparrows prefer various types of wetland habitats. Song Sparrows, while able to nest in a wider variety of open habitats, also breed in wetland and riparian habitats. As can be seen in Fig. 1, deciding PUBLICATIONS.ABA.ORG 63 FEATURED PHOTO als. We have found that the mainly un- other two species. The tail is longer than toring avian productivity and survivorship in streaked dark crowns of the juvenile in the other two species, and the rectrices the oil sands region of northeastern Alberta, Swamp Sparrow (Fig. 2b), usually with are not as pointed (Fig. 4c). The edging pp. 563–571 in: A. B. Fourie and M. Tibbett, eds. a more-distinct median stripe than in to the rectrices (Fig. 4c) and secondaries Mine Closure 2012. Australian Centre for Geo- juvenile Lincoln’s and Song sparrows, is (Fig. 5c) are variable, but tend to be not mechanics, Perth. one of the best ways to identify a juvenile as rusty as with Swamp Sparrow. Foster, K. R., C. M. Godwin, P. Pyle, and J. F. Saracco. Swamp Sparrow. Juvenile Swamp Spar- 2016. Reclamation and habitat-disturbance ef- rows also usually lack streaking on the n working through the differences among fects on landbird abundance and productivity chin and throat, and have an indistinct Ithe three Melospiza sparrows, we hope indices in the oil sands region of northeastern malar streak and finer streaking to the we’ve given you a feel for some of the issues Alberta, Canada. Restoration Ecology–open breast than the other two species (Fig. involved in identifying juvenile sparrows. access (onlinelibrary.wiley.com/doi/10.1111/ 3b). The breast streaking is usually spars- The task is challenging, but not impos- rec.12478/full). er than on juvenile Lincoln’s Sparrow, the sible—and it’s rewarding. Also, it doesn’t Howell, S. N. G., C. Corben, P. Pyle, and D. I. Rog- tail is shorter than in the other two spe- end with the genus Melospiza! In the ex- ers, D. I. 2003. The first basic problem: A review cies and with more pointed rectrices than panded version of this article, available of molt and plumage homologies. Condor in Song Sparrow (Fig. 4b), and both the online (publications.aba.org), we present 105: 635–653. rectrices (Fig. 4b) and secondaries (Fig. field marks for juveniles of other spar- Pyle, P. 1997a.