The Wilson Journal of Ornithology 120(3):613–617, 2008

White-winged Diuca Finch (Diuca speculifera) Nesting on Quelccaya , Peru´

Douglas R. Hardy1,3 and Spencer P. Hardy2

ABSTRACT.—We found evidence of birds nesting . Only the Emperor Penguin (Aptenod- directly on ice of the in the ytes forsteri) is known to routinely nest on ice, Vilcanota, Peru´ at elevations up to 5,300 m. typically frozen sea-ice (i.e., fast-ice) but at Observations during June and July over several years consisted of numerous nests not in situ having obvi- times in association with ice shelves derived ously fallen from the steep and dynamic, retreating from glaciers (Kooyman 1993). Transient birds glacier margin. A typical nest was a bulky structure of have been observed passing over gla- grass and twigs with a dry mass of 160 g. The inner ciers at high elevations outside the polar regions cup was nicely formed and lined with fine grass, mea- or discovered after succumbing to harsh envi- suring 6–7 cm in diameter and 4–5 cm deep. Feathers and entire wings of White-winged Diuca Finch (Diuca ronmental conditions (Krajick 2002; L. G. speculifera) were observed in association with the Thompson, pers. comm.). However, glacier sur- nests; this was the passerine species most commonly faces are usually cold, actively changing seen in the area. The evidence indicates the glacier through accumulation and ablation, and at times nests were built and used by White-winged Diuca wet; conditions that are poorly suited for nesting Finch, probably during the Austral autumn when on- and raising young birds. site automated measurements indicate the wet ends and air temperatures have not yet decreased. This The ornithological literature contains only is the first well-documented case of high-elevation avi- one detailed account of nesting on a glacier. an nesting on glacier ice. Received 30 November 2006. This was the unusual circumstance where gla- Accepted 26 December 2007. ciers advancing into Alaska’s Prince William Sound overran a Black-legged Kittiwake (Ris- sa tridactyla) colony (Irons 1988). Previously- Some birds are well adapted to environments used nest sites were unavailable and 77 kitti- which are seasonally dominated by or sea wake nests were constructed on the glacier ice, but birds are not generally associated with face. All of these nests failed due to ablation and/or meltwater runoff which either dis- 1 Climate System Research Center, Geosciences De- lodged the nests or caused them to disintegrate partment, University of Massachusetts, Amherst, MA (Irons 1988; D. B. Irons, pers. comm.). 01003, USA. The objective of this paper is to present ev- 2 Marion W. Cross School, Norwich, VT 05055, USA. idence of nesting by White-winged Diuca 3 Corresponding author; Finch (Diuca speculifera) directly on glacier e-mail: [email protected] ice of the Quelccaya Ice Cap in Cuzco De- 614 THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 120, No. 3, September 2008

FIG. 1. (A) White-winged Diuca Finch on Quelccaya Ice Cap at ϳ5,200 m on 23 June 2007, (B) the same glacier in June 2005 with arrow indicating the approximate location of the first nest observation in 2005 and the nest described in text. Circled area of margin just above the proglacial lake is enlarged in (C) looking under the ice. The circle on (C) encloses a nest which is likely in situ, 3 m above rock surface with enlarged view in (D); note silt from meltwater runoff. partment, Peru´ (14Њ S, 71Њ W). Observations 5,300 m. Searches were restricted to this were made over several years during the Aus- 1,500 m section; the extent to which this is tral winter (Jun–Jul) in the course of con- representative of the Quelccaya Ice Cap is un- ducting glacier and climate research on the ice known. However, nesting on the ice cap has cap. This is the first well-documented case of likely not been limited to the last 3 years as high-elevation avian nesting on a glacier, cor- L. G. Thompson has occasionally observed roborating a second-hand report of ‘‘ice cave’’ nests over the past ϳ30 years (pers. comm.). nesting by White-winged Diuca Finch (John- Nest remains were most often found on son 1967). rocks at the base of near-vertical sections of ice margin. At least 14 nests were found in OBSERVATIONS 2006 and at least 16 in 2007. These varied in During June 2005, while exploring the re- apparent age from weeks (i.e., previous breed- treating Quelccaya Ice Cap margin, we came ing season) to several years and the 2007 upon a nest which appeared to have fallen re- count almost certainly includes some found cently from the glacier (within weeks- the previous year. Two of the freshest nests in months). Several other older nests were ob- 2006 were only 3 m apart. served nearby including one in a cave under Typically, sections of glacier margin with the ice margin (Fig. 1). More extensive nest nest remains were nearly vertical, somewhat searches were conducted in 2006 and 2007 grooved or fluted, and ϳ5–10 m high. Over- along ϳ1,500 m of glacier margin, resulting hanging icicles and steeply-sloping rock be- in location of numerous nests. Most were low the margin made access to some nest re- along two sections with respective lengths of mains difficult, and nests still attached to the 350 and 530 m, elevation ranges of 50 and glacier could have been overlooked. One nest 100 m, and upper elevations of 5,200 and was found on the glacier 22 m from the mar- SHORT COMMUNICATIONS 615

FIG. 2. (A) Dislodged nest along Quelccaya Ice Cap margin found on 15 July 2006 in inverted position within 1 m of vertical ice wall at 5,190 m. The nest was not present the previous year (26 Jun 2005), although a different residual nest was found ϳ10 m distant. The dark bar on the field book cover is 1.25 ϫ 9.5 cm. (B) Another dislodged nest in position found, 23 Jun 2007 at 5,230 m; note feathers and 13-cm pen for scale. gin, below a steep, step-like section of ice pears that a rough platform is initially con- (i.e., not in situ). structed (32 ϫ 18 cm), which roughly tapers Some nests were entirely intact when upward and becomes increasingly well-woven found, while others were disintegrating or par- towards the top (13 cm outer diameter). Only tially buried by sediment; however, almost all this better-woven upper portion was found in nests were not in situ (cf. Fig. 1D). Net retreat some cases. The inner cup measured ϳ6.5 cm of the ice margin is roughly 1 m/year or more in diameter and was 4.6 cm deep. Overall dry along this part of the Quelccaya Ice Cap and mass of the nest (Fig. 2A) was 160 g. Nests nests constructed on the steeply-sloping mar- consisted of woven grass (ϳ80–90%), partic- gin could only be observed in situ within a ularly the locally abundant Calamagrostis brief interval following construction (i.e., chrysantha. The inner cup was lined with finer breeding season) prior to falling. Evidence for grass and feathers were observed in or adja- this interpretation is that several nests were cent to some nest remains (Fig. 2B). Analysis found in inverted position and, in almost ev- by Carla Dove at the Smithsonian Institution ery case, a vertical trace of nest material was revealed feathers of Rufous-bellied Seedsnipe observed above the nest remains, frozen to the (Attagis gayi), Andean Goose (Chloephaga ice. melanoptera), and tail feathers of White- Remains of varying ages indicate multi-year winged Diuca Finch. This diverse assemblage occupation of favorable sites along the ice mar- suggests that nests are lined with feathers re- gin suggesting that reproductive efforts on the covered from the surrounding landscape. No ice cap are successful. In addition, we observed evidence of camelid fleece was seen in any fecal sacs in one of the fresh nests, presumably nest (cf. Johnson 1967). from nestlings just prior to fledging. No off-gla- cier nesting evidence was found despite search- DISCUSSION ing areas adjacent to the glacier. Although indirect, all evidence indicates that Several nests appeared entirely intact and Quelccaya glacier nests were built and used by the following is based upon one of the fresh- White-winged Diuca Finch. Little information est-appearing nests observed in 2006. Nests exists on nesting habits of this species from any- were bulky structures of grass and twigs with where in the although Johnson (1967: a deep, well-made inner cup (Fig. 2). It ap- 368) reported that in the Parinacota area of 616 THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 120, No. 3, September 2008

Chile, a White-winged Diuca Finch nest was crevasses (Ridgely and Tudor 1989) or glacier found ‘‘on the ground beneath some loose cracks (Fjeldsa˚ and Krabbe 1990). stones on a hillside.’’ In lieu of breeding-season Relatively little is known about the timing observations of White-winged Diuca Finches at of White-winged Diuca Finch nesting in Peru´ Quelccaya, our deduction is based upon their or elsewhere. Johnson (1967) suggested this local presence, feathers, and the species known species nested after the summer rains in the association with glaciers. Parinacota region (–) where Small groups of White-winged Diuca White-winged Diuca Finches were present all Finches of unknown age class were frequently year. Immature White-winged Diuca Finches observed among rocky moraine surfaces and in Bolivia were noted by Fjeldsa˚ and Krabbe bogs in the area. This species is known to not (1990) during July and August (La Paz), and typically retreat northward or to lower eleva- August (Cochabamba). These findings are tions during winter (Johnson 1967, 1972). On consistent with the Quelccaya situation, where one occasion in June 2007, while we were in- climatic conditions present multiple difficul- vestigating an apparent roosting site within a ties for breeding birds, especially snow and crack of the glacier, a flock of ϳ20 White- low temperature (cf. Hendricks and Norment winged Diuca Finches began gathering late in 1992, Martin and Wiebe 2004). the afternoon at the glacier margin, both on We began operating an automated weather and off the glacier (Fig. 1). The birds acted station (AWS) in 2003 at the ice cap summit, ϳ ϳ disturbed by our presence in contrast to their 3 km east of the nest sites and 500 m high- behavior during diurnal feeding. er in elevation. These data permit a close ap- Several feathers observed in proximity to proximation of the climate in which nest the nests were White-winged Diuca Finch building, incubation, and rearing of nestlings wing or tail feathers. In addition, two nearly- occurs on the glacier. Pronounced seasonality of precipitation at entire wings (chord ϭ 105 mm) of White- Quelccaya typically features considerable and winged Diuca Finch were found on the ice at frequent snowfall from late September to early- a 2007 nest site. No feathers were found from mid April. During this wet season, 2 m or more other passerine species (e.g., ground tyrants of snow accumulates at the ice cap summit but, [Muscisaxiola spp.]) observed in close prox- at the slightly lower elevation margin, ablation imity to the glacier. predominates; meltwater flows off during the White-winged Diuca Finch is the only spe- day and freezes at night. Some precipitation at cies to be repeatedly associated in the orni- these nest sites (5,150–5,300 m) may be in the thological literature with Western Hemisphere form of rain, as they are close to a rising at- glaciers. Niethammer (1953) observed an es- mospheric freezing level (Thompson et al. 1993, timated 100 White-winged Diuca Finches Bradley et al. 2006). This would impact the gathering for the night inside a glacier cre- bird’s exposure to moisture, thermal regulation, vasse at Chacaltaya (5,200 m) Bolivia in mid- food availability, and other factors, and the vi- summer. He also collected one male specimen ability of glacier nesting in the area. on 20 December in breeding condition with Diurnal fluctuations in air temperature at Qu- ϫ ϳ enlarged testes (6 4mmvs. 3mmfor elccaya are greater than the annual variation. By another specimen collected in late August). A assuming a constant environmental lapse rate, second association between White-winged summit AWS measurements can be adjusted to Diuca Finch and glaciers was in the mid- the elevation of nesting site, revealing average 1960s when P. R. Parker of the Chacaltaya daily minima of Ϫ3.1Њ and Ϫ6.3Њ C during the Astrophysical Observatory found a nest ‘‘in wet and dry , respectively. Thus, air tem- an ice cave’’ at 5,300 m, leading Johnson perature is low during the night throughout the (1967:368) to postulate the species ‘‘quite year with extreme radiational cooling whenever possibly nests at a higher altitude than any cloud cover is low (especially in the dry sea- other passerine form.’’ Subsequently, several son). Maxima for the same periods reach 2.9Њ sources mention that White-winged Diuca and 0.9Њ C at the nesting sites. Finch has been recorded roosting in glacier Successful nesting in this dynamic environ- fissures (Meyer de Schauensee 1970), glacier ment and extreme climate requires not only SHORT COMMUNICATIONS 617

thermal and mechanical adaptations to the ice Alvaro Jaramillo, and M. A. Plenge was helpful. Carla substrate, but also careful timing within the Dove at the Smithsonian Institution (Washington, seasonal cycle of climate. The AWS data sug- D.C.) undertook feather identification in her laboratory and provided considerable enthusiasm. We also thank gest that Quelccaya glacier nesting by White- G. A. Clark, who encouraged preparation of the man- winged Diuca Finch most likely occurs as the uscript and provided insightful comments on an earlier wet season concludes in April when nesting draft. Two anonymous reviewers considerably im- sites become exposed and drier, as the tran- proved the manuscript. sient snow line elevation rises. Daily mean temperatures decrease after March as decreas- LITERATURE CITED ing cloud cover results in colder nights, but the decrease in daily maximum is consider- BRADLEY, R. S., M. VUILLE,H.F.DIAZ, AND W. V ER- GARA. 2006. Threats to water supplies in the trop- ably more gradual until June (DRH, unpubl. ical Andes. Science 312:1755–1756. data). Young finches had apparently fledged in FJELDSA˚ ,J.AND N. KRABBE. 1990. Birds of the High each of the past 3 years by this date. Andes. Zoological Museum, University of Copen- Note Added in Proof.—Quelccaya field- hagen, and Apollo Books, Svendborg, Denmark. work during June 2008 provided additional HENDRICKS,P.AND C. J. NORMENT. 1992. Effects of a observations. The first nests clearly in situ severe snowstorm on subalpine and alpine popu- were observed on the glacier, in locations and lations of nesting American Pipits. Journal of Field Ornithology 63:331–338. orientation as hypothesized. One contained IRONS, D. B. 1988. Black-legged Kittiwakes nest on two abandoned eggs consistent in size and advancing glacier. Wilson Bulletin 100:324–325. color for White-winged Diuca Finch (Johnson JOHNSON, A. W. 1967. The birds of Chile and adjacent 1967). Also, a single off-glacier nest, similar regions of Argentina, Bolivia and Peru´. Volume to that described above, was found in situ un- 2. Platt Establecimientos Gra´ficos, Buenos Aires, der boulders ϳ500 m from the glacier. A late- Argentina. afternoon gathering of 20–30 White-winged JOHNSON, A. W. 1972. The birds of Chile and adjacent regions of Argentina, Bolivia and Peru´, Supple- Diuca Finch was again observed, 30–60 min ment. Platt Establecimientos Gra´ficos, Buenos Ai- prior to sundown, at the same section of frac- res, Argentina. tured glacier margin where this behavior was KOOYMAN, G. L. 1993. Breeding habitats of Emperor observed in 2007. Several roosts were located Penguins in the western Ross Sea. Antarctic Sci- nearby, all entirely within (vs. beneath) the ence 5:143–148. glacier. One expedition member observed and KRAJICK, K. 2002. Melting glaciers release ancient rel- photographed White-winged Diuca Finch ics. Science 296:454–456. MARTIN,K.AND K. L. WIEBE. 2004. Coping mecha- roosting at the site prior to sunrise (J. A. Cas- nisms of alpine and arctic breeding birds: extreme tan˜eda Gil, pers. comm.). Supplemental ma- weather and limitations to reproductive resilience. terial on glacier-nesting White-winged Diuca Integrative and Comparative Biology 44:177–185. Finch at Quelccaya Ice Cap is available at MEYER DE SCHAUENSEE, R. 1970. A guide to the birds http://www.geo.umass.edu/climate/quelccaya/ of South America. Academy of Natural Sciences diuca.html. of Philadelphia and Livingston Publishing Com- pany, Wynnewood, Pennsylvania, USA. ACKNOWLEDGMENTS NIETHAMMER, G. 1953. Zur Vogelwelt Boliviens. Bon- ner Zoologische Beitra¨ge 4:195–303. This material is based upon work supported by the RIDGELY,R.S.AND G. TUDOR. 1989. The birds of National Science Foundation and NOAA Office of South America. Volume I. The oscine passerines. Global Programs, Climate Change Data and Detection University of Texas Press, Austin, USA. Program (Grant No. 0402557, awarded to DRH). The THOMPSON, L. G., E. MOSLEY-THOMPSON,M.DAVIS,P.- able field assistance of Mathias Vuille, Carsten Braun, N. LIN,T.YAO,M.DYURGEROV, AND J. DAI. 1993. and D. R. Dockstader, along with Mountain Guide Fe- ‘‘Recent warming’’: ice core evidence from trop- lix Vicencio and staff, is gratefully acknowledged. Ini- ical ice cores with emphasis on Central Asia. tial discussion of these observations with Jon Fjeldsa˚, Global and Planetary Change 7:145–156.