Content uploaded by Fernando Angulo
Author content
All content in this area was uploaded by Fernando Angulo on Mar 10, 2016
Content may be subject to copyright.
Purple-backed Sunbeam Aglaeactis aliciae is
endemic to the upper Marañón drainage, dpto. La
Libertad, Peru, where it occurs at three sites in the
temperate zone (c.3,000–3,500m), in vegetation
dominated by montane shrubs and Alnus trees6.
The only location where the species was regularly
recorded in 1979–2005 was El Molino, La Libertad,
where (at least until 2005) it was ‘locally common’3
(C. Bushell in litt. 2006).All three localities lie east
of a broad ridge separating two very deep river
valleys, the upper Chusgón and the Marañón
(Fig. 1). The Chusgón flows north-east and enters
the Marañón north-east of Cajabamba.
Purple-backed Sunbeam is globally threatened.
Until recently, BirdLife International considered
the species Vulnerable due to its limited range, but
this was ‘uplisted precautionarily’ to Critically
Endangered in mid 2006 because of new evidence
that its known habitat, Alnus acuminata woodland,
was being replaced by Eucalyptus plantations3.
Whilst the species has been reported feeding at
Eucalyptus flowers and even to roost there, its
ability to tolerate replacement of natural
vegetation with plantations of exotic Eucalyptus is
unknown, especially in relation to breeding.
Furthermore, in 2005, it was reported that less
than 1 ha of alder woodland remained at El Molino3
(G. Engblom in litt. 2005 to BirdLife International),
and that habitat loss was occurring throughout the
region as Eucalyptus plantations were being
established to provide timber for the mining
industry.
Given increased concern as to the conservation
status of Purple-backed Sunbeam, the American
Bird Conservancy (ABC) and their Peruvian
partner Asociación Ecosistemas Andinos (ECOAN)
proposed urgent survey work be undertaken as
part of their project on threatened and endemic
birds in the Marañón: ‘Conservation corridor of the
threatened and endemic birds in the Marañón and
Alto Mayo rivers’. Thus, we specifically examined
the distribution and status of Purple-backed
Sunbeam, between 26 June and 1 July 2006. This
paper outlines the findings of our brief survey.
Historical distribution
Purple-backed Sunbeam was first collected around
Succha (07º54’S 77º41’W: Collar et al.4) at
10,000–10,500 ft (3,048–3,200 m), by O. T. Baron
between 20 February and 20 March 18951(Fig. 1).
Baron took at least 24 specimens, now distributed
between seven museums. Subsequently, Carriker
collected at least seven near Soquián on 20–21 June
1932, for which coordinates are given as 07º51’S
77º41’W4. There are two unpublished specimens,
collected by Baron, in European collections (Paris,
Warsaw) labelled as from ‘Huamachuco’ (T.
Schulenberg in litt. 2006, BirdLife International
files), which according to Baron1 is c.8 leagues west
of Chusgón, or the equivalent of 38.64 km. Stephens
& Traylor7 place Huamachuco at 3,170 m at the
headwaters of the río Crisnejas, a tributary of the
Marañón: the town is, however, just 18 km west of
Chusgón, not the eight leagues reported by Baron1.
Unfortunately, the specimen from Huamachuco in
the Muséum National d’Histoire Naturelle (Paris)
has no altitudinal data or date (BirdLife
International files), and we have no information on
the other ‘Huamachuco’ specimen, which is in
Cotinga 28
21
Distribution, status and notes on the ecology of Purple-backed
Sunbeam Aglaeactis aliciae in north Peru
Frank R. Lambert and Fernando Angulo Pratolongo
Received 22 August 2006; final revision accepted 20 February 2007
Cotinga 28 (2007): 21–26
Aglaeactis aliciae es un colibrí endémico del área del alto río Marañón y recientemente considerado
como críticamente amenazado. En junio de 2006 llevamos a cabo una evaluación de la distribución
de Aglaeactis aliciae en el departamento de La Libertad, Perú. Visitamos las tres localidades
conocidas para la especie, y además llevamos a cabo búsquedas en zonas adyacentes. En este
artículo se reporta 17 nuevas localidades para la especie, nuevas especies que conforman su dieta
y se hace una re-evaluación de su status de amenaza.
Figure 1. Map of the general range of Purple-backed Sunbeam
Aglaeactis aliciae, between the ríos Marañón and upper
Chusgón, dpto. La Libertad, Peru.
Cotinga28-070608.qxp 6/13/2007 3:43 PM Page 21
Warsaw (T.Schulenberg in litt. 2006). Furthermore,
to confuse the issue of the provenance of the
specimens, Baron1 also indicated that three of his
collecting sites, namely Chusgón, Viña and Succha,
are part of Huamachuco, a subdistrict. Given that
Baron1did not describe Huamachuco as a separate
collecting site, it seems most likely that these two
specimens were collected somewhere close to
Succha.
Apart from these old records, the only
confirmed records were from the vicinity of the
small town of El Molino (07º45’S 77º46’W;
c.3,250 m), north-west of Succha, where the species
was discovered in 1979. Succha, Soquián and El
Molino are all in dpto. La Libertad.
There is also a sight record (A. Goodwin in litt.
to Fjeldså & Kessler5) from the Polylepis zone of
quebrada Llanganuco, Cordillera Blanca, c.140 km
south of the La Libertad sites, in dpto. Ancash. T.
Schulenberg (in litt. 2006) notes that it is possible,
though he considers it unlikely, that Purple-backed
Sunbeam extends south to the east side of the
Cordillera Blanca, and that the Llanganuco bird
had somehow wandered over the crest. Many
birders visit this area annually, yet there have been
no additional records and it is thus possible that
the sighting was a misidentification. In 2000,
searches of alder patches between Buldibuyo
(08º07’S 77º23’W), Tayabamba (08º16’S 77º17’W)
and Huacrachuco (08º29’S 77º13’W) produced no
sightings (G. Engblom in litt. to BirdLife
International).
Results of the 2006 survey
During our brief survey in 2006, we initially visited
El Molino and the environs of Soquián since these
are known sites. The sunbeam was easily found in
remnant patches of Alnus downslope from El
Molino, where we identified several food plants. Of
these, a red-flowered mistletoe that seems to grow
exclusively on Alnus (Tristerix aff. longebracteatus
[Desr.] Barlow & Wiens [Loranthaceae]: Fig. 2) was
clearly a very important food source, with the
majority of the mistletoes in flower at the time of
our visit.
Subsequently, when we visited some scraps of
remnant natural vegetation on the steep slopes
above the village of Cachimarca, itself above
Soquián (south-east of El Molino), we found Purple-
backed Sunbeam to be common. Here, the species
was feeding in a tall shrub / small tree with large
yellowish flowers, locally known as uñico
(Oreocallis grandiflora [Lam.] R. Br. [Proteaceae]:
Fig. 3). A large percentage of the uñico plants at
this site and at others we visited were flowering
during our survey.
Using our knowledge of these two foodplants,
we thereafter explored various similar valleys
north of El Molino and south of Soquián, including
areas around Succha, the other historical locality.
The village of Succha is at 2,600 m, which we
considered too low for Purple-backed Sunbeam and
it is at least 450 m below where Baron1collected his
specimens. Hence, we approached Succha from
above and searched for sunbeams c.5 km north-
west of the village. We identified patches of natural
vegetation with Alnus or uñico from considerable
distances, and accessed these patches whenever
possible. In some places, we were unable to find the
mistletoe or uñico, and in such circumstances
concentrated our search on areas with some
natural habitat that might attract hummingbirds,
including flowering shrubs or herbs. We found
Purple-backed Sunbeam to be relatively common,
and located it at 17 places in these valleys (Fig. 4,
Table 1), but did not see any Shining Sunbeams
Aglaeactis cupripennis at these localities.
We also searched two sites in the very deep
upper Chusgón Valley, which is separated from the
other valleys we visited by a broad high-altitude
ridge, both on the east side of the Chusgón and
therefore adjacent to sites where Purple-backed
Sunbeam was found on the other side of the ridge.
The first site was beside the road between
Sartinbamba and Santa Rosa, where we found
Purple-backed Sunbeam between c.3,342 m and
c.3,409 m, at 07º40’S 77º47’W and 07º39’S 77º47’W,
and between these two points. There was also some
suitable habitat further north that we did not visit.
Higher in the Chusgón Valley, to the south, we
Cotinga 28
22
Distribution and status of Purple-backed Sunbeam in north Peru
Table 1. Geographical coordinates and altitude for the
localities shown in Fig. 4.
Map Locality Locality Altitude
No. coordinates (UTM) coordinates (Deg) (m)
1 18M 0194309 9141510 07°45’27.1S 77°46’16.8W 3,268
2 18M 0202288 9131150 07°51’05.7S 77°41’58.7W 3,092
3 18M 0202054 9132402 07°50’25.0S 77°42’06.1W 3,242
4 18M 0201922 9132620 07°50’17.8S 77°42’10.3W 3,264
5 18M 0201413 9133070 07°50’03.1S 77°42’26.9W 3,098
6 18M 0201010 9132972 07°50’06.2S 77°42’40.0W 3,012
7 18M 0194903 9143436 07°44’24.6S 77°45’57.0W 3,335
8 18M 0914990 9144006 07°44’06.0S 77°45’54.0W 3,213
9 18M 0197307 9148796 07°41’30.7S 77°44’37.5W 2,908
10 18M 0194328 9150230 07°40’43.4S 77°46’14.3W 3,065
11 18M 0193196 9150122 07°40’46.7S 77°46’51.2W 3,253
12 18M 0193128 9150342 07°40’39.6S 77°46’53.4W 3,283
13 18M 0191956 9151194 07°40’11.6S 77°47’31.4W 3,409
14 18M 0191693 9151162 07°40’12.6S 77°47’40.0W 3,384
15 18M 0191506 9151634 07°39’57.2S 77°47’46.0W 3,342
16 18M 0197332 9141144 07°45’39.6S 77°44’38.3W 3,409
17 18M 0194435 9138510 07°47’04.7S 77°46’13.3W 3,395
18 18M 0193771 9141304 07°45’33.7S 77°46’34.4W 3,263
19 18M 0199059 9116998 07°58’45.4S 77°43’47.1W 3,310
20 18M 0199516 9129170 07°52’09.6S 77°43’29.6W 3,345
21 18M 0195295 9139476 07°46’33.4S 77°45’45.0W 2,992
22 18M 0195290 9139466 07°46’33.8S 77°45’45.2W 2,996
23 18M 0212580 9137193 07°47’51.3S 77°36’21.8W 2,970
24 18M 0185342 9141755 07°45’17.2S 77°51’09.1W 3,150
25 18M 0181278 9137584 07°47’31.9S 77°53’22.6W 3,050
Cotinga28-070608.qxp 6/13/2007 3:43 PM Page 22
Cotinga 28
23
Distribution and status of Purple-backed Sunbeam in north Peru
5
23
4
Figure 2. The mistletoe (Tristerix aff. longebracteatus [Desr.]
Barlow & Wiens [Loranthaceae]) used by Purple-backed
Sunbeam Aglaeactis aliciae (Fernando Angulo Pratolongo)
Figure 3. Flower of uñico (Oreocallis grandiflora [Lam.] R. Br.
[Proteaceae]) (Fernando Angulo Pratolongo)
Figure 4. Distribution of Purple-backed Sunbeam Aglaeactis
aliciae: numbered green points relate to those localities where
sunbeams were observed in 2006. Yellow points show two
sites where Purple-backed Sunbeam was not found in 2006
despite the presence of suitable habitat at an appropriate
altitude. The purple-shaded area represents the probable range
of the species, assuming an altitudinal range of 2,900–3,500 m;
parts of the area shaded in grey, within the same altitudinal
limits, may also harbour the species. Geographical coordinates
for points 1–25 are presented in Table 1.
Figure 5. Purple-backed Sunbeam Aglaeactis aliciae (Roger
Ahlman)
Cotinga28-070608.qxp 6/13/2007 3:43 PM Page 23
explored areas at suitable altitude along one of the
roads from El Molino to Huamachuco, passing
through Chugay, Yanasara and Sausacocha. This
part of the valley supported very little natural
vegetation, but we found two areas with uñico,at
c.3,050–3,150 m. Despite two hours intensive
searching these areas and briefly at groups of
flowering Eucalyptus, we did not find Purple-
backed Sunbeam, but Shining Sunbeam occurred at
high density.
Finally, we crossed the río Marañón itself, at
Chagual (c.1,200 m), and attempted to reach an
area with Alnus trees of the same species as at
Soquián, c.12 km away. We accessed appropriate
altitude for Purple-backed Sunbeam above the
villages of San Fernando and Vista Florida, where
there was a very large area of flowering uñico at
c.2,930–3,240 m. Shining Sunbeam was common
here. After four man-hours searching this habitat,
FAP filmed a Purple-backed Sunbeam in the uñico,
at c.2,970 m (07º46’S 77º45’W), confirming for the
first time that the species occurs on both sides of
the Marañón. We did not reach the area of Alnus
that we had observed from across the Marañón, but
subsequently discovered that it was more or less
contiguous with the uñico we had searched, having
been concealed by a ridge.
Feeding ecology
Prior to our field work, Purple-backed Sunbeam
had been reported feeding at mistletoes that
parasitise Alnus1 and other trees. In July near El
Molino, Begazo et al.2observed Purple-backed
Sunbeams feeding at and defending shrubs that
resembled Nicotiana sp., and once a sunbeam
chased a Violet-throated Starfrontlet Coeligena
violifer from an arboreal bromeliad flower, though
these authors2did not specify that it was actually
feeding at the bromeliad. The species has also been
noted feeding and roosting in Eucalyptus at the
same locality3. During our surveys, uñico and
mistletoes (in Alnus) were both flowering and the
easiest foodplants at which to find Purple-backed
Sunbeams.
We found the species at almost every patch of
uñico we visited within the range described above.
Uñico is locally distributed, usually grows in small
patches of scattered individuals (only occasionally
in larger, dense patches) and is more common than
patches of Alnus. We observed uñico as low as 2,685
m, in a deep valley below Aricapampa, but never
found it above c.3,420 m. We gained the impression
that uñico could to some extent tolerate burning or
at least regenerate afterwards, as we observed it in
some areas that had been converted to pasture.
In contrast, Alnus did not survive or appear to
regenerate in areas burnt for pasture. The largest
patch of A. acuminata we saw was estimated at less
than 10 ha, and most patches were considerably
smaller. Within these patches, mistletoes were
sometimes common, but not all remnant patches of
Alnus contained mistletoes. Mistletoes were clearly
important to the sunbeams, because the species
was observed defending flowering mistletoes in
several places, chasing not only other sunbeams,
but also Black-throated Flowerpiercers Diglossa
brunneiventris.
We identified three other flowering plants
utilised by the sunbeams, all of them smaller
shrubs or tall herbs. Two species had relatively
large yellowish-green flowers (Siphocampylus
weberbaueri A. Zahlbruckner [Campanulaceae] and
a Nicotiana sp. [Solanaceae]), whilst the third was
a low, dense shrub found at higher elevations with
small red flowers (Clinopodium obovatum [Ruiz &
Pav.] Govaerts [Lamiaceae]). The sunbeams visited
these intermittently where they occurred with
flowering uñico, but at two localities they were used
by sunbeams in an area where we found no Alnus
(hence no mistletoe) or uñico. At one of these the
birds fed at 3–4 m-tall plants of Nicotiana, and at
the other on the low bushy shrubs of Clinopodium.
Almost no Eucalyptus was flowering within the
range of Purple-backed Sunbeam during our
survey, but we did find the species feeding at a
eucalypt that was in full blossom. There was no
Alnus or uñico near this particular eucalypt, which
was just above the town of El Molino.
Purple-backed Sunbeam was observed feeding
at patches of flowering uñico at 11 sites, compared
with only three sites where it used flowering
mistletoes within Alnus. At one site, the birds used
both mistletoes and uñico, whilst at three sites they
fed on the flowers of uñico and at the flowering
shrubs or herbs mentioned above. We only found
sunbeams at three localities with neither flowering
mistletoes nor uñico (including at the eucalypt
mentioned above). Our observations suggest that,
at least during the period of our survey, uñico is the
most important nectar source for the species.
Though Purple-backed Sunbeam has not
previously been reported feeding on insects, we
observed the species flycatching from perches on
several occasions, but the vast majority of our
feeding observations were at nectar sources.
Discussion
Many of the birds we observed appeared to lack the
brighter purple tones on the back, perhaps
suggesting that we saw a significant number of
juveniles or immatures. Specimen data (accessed
via the BirdLife International files) reveal that
juveniles have been collected on 20 February and
19 March (Baron1), and 20 June (by M.A.Carriker).
Hence, the breeding season may have already
finished by the time of our survey, and the distribu-
tion of the birds we observed, as well as the habitat
used, may not be indicative of its breeding range.
Cotinga 28
24
Distribution and status of Purple-backed Sunbeam in north Peru
Cotinga28-070608.qxp 6/13/2007 3:43 PM Page 24
The range of Purple-backed Sunbeam is
apparently very limited. Outside the core area we
located (namely the one site on the east bank of the
Marañón and in the southernmost part of the
Chusgón Valley that we searched), Shining
Sunbeam was common. That the latter was
common and Purple-backed Sunbeam apparently
rare or absent in these areas suggests that, for
unknown reasons, Shining Sunbeam starts to
replace Purple-backed Sunbeam there. Both areas
are at appropriate altitudes for Purple-backed
Sunbeam, and both held much flowering uñico. It is
conceivable that the rarity of Purple-backed
Sunbeam at these sites may be influenced by the
availability of other food resources at different
seasons. Purple-backed Sunbeam may simply visit
such areas when uñico is flowering or perhaps our
observations indicate post-breeding dispersal into
areas where the species is not resident.
Threat status
It had been suggested that the range of this
sunbeam is tiny, perhaps just 1 km2, though El
Molino and Succha, the most distant of the
historical sites, are separated by 17.8 km. However,
we found the species widespread and locally
common within its reported historical range, and
elsewhere. The distance between the northern- and
southernmost points where we found it is 35.5 km.
Based on this, and assuming a continuous distribu-
tion between the points where we found the
sunbeam, as well as assuming an altitudinal distri-
bution of c.2,900–3,500 m, we estimate the species’
range to be c.178.12 km2(Fig. 4: purple-shaded
area). Within this distribution, sunbeams could be
confidently located at patches of flowering uñico
wherever they were available, as well as in Alnus
patches with flowering mistletoes. We conclude,
therefore, that Purple-backed Sunbeam is not
Critically Endangered and that its threat status
demands re-evaluation. Within the Chusgón Valley,
there is an additional area of 155.47 km2(Fig. 4:
grey-shaded area) within which the species could
potentially occur.
The primary threat to the species’ habitat
appears to be from human-induced fires to provide
grazing pasture, as well as grazing itself. Grazing
may prevent regeneration of native plants, whilst
cattle may be introducing exotic species to the
remaining forest patches. We also observed some
clearance of alder trees, presumably for fuel or
building materials, but this appeared to be much
less of a threat than burning.
There is no doubt that Alnus is gradually disap-
pearing from areas inhabited by Purple-backed
Sunbeam, that remaining patches are increasingly
isolated and that all are relatively small. However,
our survey reveals that such habitat is not the only
one used by the species. At the time of our survey,
uñico appeared more important and at two sites
visited we found Purple-backed Sunbeams in areas
with flowering shrubs and herbs, but no obvious
uñico or Alnus. Nevertheless, the area, extent and
quality of habitat are likely to be declining, and
hence also the Area of Occupancy and the number
of mature individuals.
As burning for grazing is generally small-scale
and localised, the species’ known range can be
interpreted to comprise many (>10) locations as
defined for the purposes of the IUCN Red List.
Although there is probably dispersal between
patches of habitat, these can be considered to be
severely fragmented, especially if the species is
dependent on alder woodland when nesting. Hence,
Purple-backed Sunbeam appears to qualify as
Endangered under criterion B1a+b(ii,iii,v). Further
information on the breeding requirements and
degree of movement between habitat patches may
lead to a further reduction in the estimated
extinction risk of this species.
As discussed above, where sunbeams breed or
what food resources they utilise when mistletoes
and uñico are either rare or unavailable, are both
unknown: according to local people, both plants
flower seasonally. Since nothing is known
concerning the species’ breeding requirements, it is
impossible to ignore the possibility that Alnus may
be important for nesting. Further data are also
required on the flowering phenology of the plant
species that we found to be important in its diet,
and to establish which flowers are important at
times of year when mistletoes and uñico are not
flowering or rarely so. Habitat changes within the
range of this hummingbird, particularly in relation
to the loss of uñico or Alnus, also require further
investigation. Without such knowledge, our
assessment of its conservation status must remain
preliminary.
Acknowledgements
We are grateful for support from the American Bird
Conservancy, the Gordon & Betty Moore Foundation
and Asociación Ecosistemas Andinos which made this
study possible, and to George Wallace and Paul
Salaman for their assistance. We also extend our
special thanks to Luis, Iris & Alfredo Rebaza in El
Molino for their generous hospitality. ECOAN assisted
us to implement this work, in particular Wily
Palomino, who also kindly identified the plants
mentioned herein. Constantino Aucca and David
Guevara both helped with organisation and logistics,
whilst Oscar Uchofen (ECOAN’s GIS department)
produced the maps. We also thank Thomas S.
Schulenberg (Field Museum of Natural History,
Chicago) for providing data on the species’ collecting
sites, and Colin Bushell for sharing his field
experiences near El Molino. Stuart Butchart and Nigel
Collar enabled access to the relevant files at BirdLife
International (Cambridge, UK). Finally, we thank
Cotinga 28
25
Distribution and status of Purple-backed Sunbeam in north Peru
Cotinga28-070608.qxp 6/13/2007 3:43 PM Page 25
Cotinga 28
26
Distribution and status of Purple-backed Sunbeam in north Peru
Pablo Venegas Ibañez and Ralf Rintel Seminario for
assisting us with the survey.
References
1. Baron, O. T. (1897) Notes on the localities visited
by O. T. Baron in northern Peru and on the
Trochilidae found there. Novit. Zool. 4 (1): 4–7.
2. Begazo A. J., Valqui, T., Sokol, M. & Langlois, E.
(2001) Notes on some birds from central and
northern Peru. Cotinga 15: 81–87.
3. BirdLife International (2006) Purple-backed
Sunbeam Aglaeactis aliciae species factsheet.
www.birdlife.org/datazone/species.
4. Collar, N. J., Gonzaga, L. P., Krabbe, N., Madroño
Nieto, A., Naranjo, L. G., Parker, T. A. & Wege, D.
C. (1992) Threatened birds of Americas: the
ICBP/IUCN Red Data book. Cambridge, UK:
International Council for Bird Preservation.
5. Fjeldså, J. & Kessler, M. (1996) Conserving the
biological diversity of Polylepis woodlands of the
highland of Peru and Bolivia. Copenhagen:
NORDECO.
6. Fjeldså, J. & Krabbe, N. (1990) Birds of the high
Andes. Copenhagen: Zool. Mus., Univ. of
Copenhagen & Svendborg: Apollo Books.
7. Stephens, L. & Traylor, M. (1983) Ornithological
gazetteer of Peru. Cambridge, MA: Mus. Comp.
Zool., Harvard Univ.
Frank R. Lambert
E-mail: flambertemail@yahoo.co.uk.
Fernando Angulo Pratolongo
Torres Paz 708, Chiclayo, Peru. E-mail:
Chamaepetes@gmail.com.
Panama Verde
half page b&w ad
NEW
Cotinga28-070608.qxp 6/13/2007 3:43 PM Page 26