Designing Habitats in Urban Environments - Design with the Desert: Conservation and Sustainable Development - page 391

FIGURE 22.5
Variety of plants (fairy duster, ocotillo, and penstemon) that produce nectar at various times of the year for
hummingbirds.
Because of this heavy reliance on constant and plentiful food sources, habitats should
emphasize a wide variety of flowering species to maintain an extended flowering season
(Figure 22.5), and a healthy plant community to promote the presence of insects.
The resourceful Anna's hummingbirds will seek out remnants of pollen or nectar on
half-frozen blossoms if fresh blooms are not available at the end of the warm season. 9 In
some cases, noninvasive exotics that flower during late winter, such as aloe vera ( Aloe vera )
and cape honeysuckle ( Tecomaria capensis ), are used to extend the flowering season of these
areas. Species choices should be guided by hummingbird preference of pink, red, purple,
or orange color and single flowers of a trumpet or tubular shape. 9
Nectar in plants that attract hummingbirds has a sugar content that matches a ratio
of about three or four parts water to one part white cane sugar. 9 If sufficient food is not
provided by plant nectar, syrup feeders can be used as supplement. If this is the case,
feeders should be properly cleaned every 3-4 days to prevent spread of disease and spoiled
syrup (due to high temperatures). Table 22.3 provides a list of plants that would provide
the variety in growth type and nectar for a southwestern hummingbird habitat.
22.3.3 Butterfly Habitats
There have been dramatic reductions in the ranges of rarer butterflies due to the modification
and devastation of their habitats. 11 Increases in agriculture and other land uses have led
certain butterfly species to be restricted to isolated areas. Due to the highly varied plant
communities in this area, southeastern Arizona is considered a critical region in terms
of butterfly habitat, providing an environment for more than 240 species of butterflies
in 6 counties. 12 Butterfly habitats in urban communities can supplement adjacent natural
environments and provide extended habitats during the colder months. For example, it has
been noted that some species are able to expand their populations and thrive in a human-
dominated landscape. 11
Habitats should accommodate various life cycles and activities of the butterflies,
typically associated with seasonal changes. 12 Butterfly activity increases in the spring due