Debs Park Audubon Center, located in downtown Los Angeles, counts the Allen’s Hummingbird as a frequent visitor to the center grounds. The good news: This little bird seems to be comfortable in suburban and urban areas, so habitat loss along the coast need not spell complete disaster for the species. Since the Allen’s Hummingbird is a range restricted species (it breeds in California and southern Oregon, but is an occasional vagrant elsewhere in the U.S.), there is some concern that its habitat and population numbers could be impacted by changes going on around them. As the climate space to which the bird has evolved shifts, this species will also need to follow along to new areas to find the plants that provide favored nectar and insects. According to Audubon’s climate models, the Allen’s Hummingbird could lose up to 90 percent of its current breeding range in this century. It is also one of four species of hummingbird highlighted in Audubon’s Birds and Climate Change Report and is listed as climate endangered. While direct comparison to the 20 studies of butterfly visitation preferences was not possible due to experimental design, data trends suggest a possible relationship between sugar composition, inflorescence nectar production and visitation from native butterfly species.Allen’s Hummingbird is a tiny juggernaut in rust and emerald, visiting a narrow stretch of the Pacific Coast to breed every spring before heading back south again. Sucrose and total sugar concentrations were greatest in recently opened inner flowers compared to middle and outer flowers. The sucrose to hexose ratio for recently opened inner flowers was double that of middle and outer flowers. The lowest ratios of sucrose to hexose were found for ‘Irene’, ‘Hot Country’, and ‘Carlos’, while similar to ‘Cherry’ and ‘Radiation’. The ratio of sucrose to hexose (fructose and glucose) in nectar from ‘Weeping Lavender’, ‘White Doves’, and ‘New Gold’ was greater than that of the remaining Lantana. Of ten Lantana evaluated, ‘Carlos’ and ‘Confetti had the largest inflorescence nectar volumes combined from nine flowers while ‘New Gold’, ‘White Doves’, and ‘Weeping Lavender’ had the smallest. In a separate study conducted in 2003 using the same lantana as in the visitation study, nectar volume, carbohydrate composition, and sucrose and fructose concentrations differed among inflorescences. Based on correlation analysis, the cultivar characteristics that did not contribute to visitation differences included inflorescence width, corolla width, and corolla tube length. Percentage light reflectance of flowers for the wavelengths of green, yellow, orange, and red correlated with visitation in 2003. Flower lightness and flower chroma correlated sporadically with visitation in late September and October 20. Cultivar differences that consistently correlated with visitation preferences were inflorescence number in 20, flower number per inflorescence in 2003, percentage of yellow flowers per inflorescence in 20, and growth index in 2003. Plant characteristics including inflorescence number, number of flowers per inflorescence, percentage of yellow flowers per inflorescence, growth index, flower morphology, and flower color characteristics differed among cultivars. Total visit duration by one randomly selected butterfly was greater for ‘New Gold’, ‘Radiation’, ‘Firewagon’, and ‘White Doves’ than the remaining lantana. In general, the lowest visitation was experienced by L. camara ‘White Doves’, ‘Firewagon’, ‘Confetti’, and Lantana montevidensis (Spreng.) ‘Weeping Lavender’. Other lantana visited preferentially but not as consistently included L. In landscape studies conducted in 20, Lantana camara (L.) ‘New Gold’ and ‘Radiation’ were visited by native butterflies to a greater extent than the remaining eight lantana in the studies.
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