of coevolution between hummingbirds and their
principal food plants.
Numerous hummingbird species have exquisitely
adapted to the harsh conditions of montane and high-
elevation ecosystems. These tiny, hyperactive birds
endure cold winds and sweeping rain— and appear to
thrive. Many species are found throughout the Andes
Mountains and routinely survive the cold nights by
entering a state of torpor, lowering body temperature
and reducing their heart rate and body metabolism
to conserve energy. In the morning they awaken and
rapidly regain their normal metabolic rate and go
about feeding as the temperature warms. Some, such
as the Ecuadorian Hillstar (Oreotrochilus chimborazo),
which lives at elevations of 3,600– 4,600 m (11,810–
15,090 ft) in the windswept puna (described below)
of the Ecuadorian Andes, will roost in holes in rocks,
protected from wind.
The 13.5 cm (5.3 in) long Sword- billed Hummingbird
(Ensifera ensifera; plate 13- 17) is remarkable for its
extraordinarily long bill, measuring 9– 10 cm (3.5– 4
in). The uniquely long bill is adapted to obtain nectar
from large, elongate tubular flowers, particularly in the
genus Datura, though the species also feeds on other
flowers with long corollas. Swordbills are uncommon,
as their flowers are relatively widely scattered, but they
may be seen coming to hummingbird feeders around
ecotourism lodges at mid elevations in the central
Andes, particularly near Quito, Ecuador.
The Giant Hummingbird (Patagona gigas; plate 13-
18) is well named, being by far the largest member
of its huge family. It measures about 23 cm (9 in) in
length, and its wingspread is about 21.5 cm (about
8.5 in). Hummingbirds are closely related to swifts,
and indeed the Giant Hummingbird is sometimes
mistaken for a swift, given its large size. It is the only
hummingbird that occasionally glides in flight, rather
than constantly beating its wings. But in all respects it
is a hummingbird, and a relatively common one along
the Andes. It occupies mid to relatively high elevations
along both slopes, feeding on a variety of flowers but
often relatively focused on flowers of the genus Puya.
The helmetcrests of the genus Oxypogon form a group
of four species that have adapted their behavior to cope
with the cold realities of high- elevation living (plate 13-
19). They are found among the tall, shrubby Espeletia
plants (described later in the chapter) that abound in
the high páramo (3,600– 4,500 m/11,810– 14,760 ft) of
Venezuela and Colombia. All are small (11.4 cm/4.5Plate 13- 17. Sword- billed Hummingbird. Photo by Edison
Buenaño.Plate 13- 18. Giant Hummingbird. Photo by Andrew Whittaker.Plate 13- 19. Helmetcrest. Photo by Edison Buenaño.chapter 13 scaling the andes 241