Orange Tail Research Articles

Diet-Related Plumage Erythrism in the Western Tanager and Other Western North American Birds

Consumption of the berries of two exotic bush honeysuckles (genus Lonicera) containing the red carotenoid pigment rhodoxanthin has resulted in abnormal erythristic plumages in several species of birds in eastern North America. Here we report 12 examples of plumage erythrism in the Western Tanager (Piranga ludoviciana), in both live birds (5) and museum specimens (7), that we suspect have the same etiology. The erythristic tanagers feature overtly orange to red feathers variously scattered on the head, rump, wing coverts, and/or underparts, areas of the plumage normally colored by carotenoid pigments. All were in their year of hatching, so the reddened feathers, including replaced median coverts with orange tips, represent formative plumage grown on or near the breeding grounds where berries containing rhodoxanthin are available. By contrast, adult Western Tanagers undergo body molt primarily in the Mexican monsoon region in fall and on their winter grounds in early spring where bush honeysuckles are nonexistent. We also report examples of Red-breasted Sapsuckers (Sphyrapicus ruber) with anomalous red pigmentation on their backs and of Cedar Waxwings (Bombycilla cedrorum) with orange tail bands, as previously documented in the East. In these species, the reddened areas are typically yellow or green, colors based on carotenoid pigments that can be altered through the consumption of fruits containing rhodoxanthin. We conclude that these reddened feathers are the result of the consumption of honeysuckle berries or possibly the red arils of the Pacific Yew (Taxus brevifolia), representing a first report of diet-related erythrism in western North America.

Ontogeny and Dynamics of the Gonadal Development, Embryogenesis, and Gestation in Xenotoca eiseni (Cyprinodontiformes, Goodeidae)

We characterized the ontogeny and dynamics of gonadal development, embryogenesis, and gestation in captive stocks of the viviparous redtail splitfin, Xenotoca eiseni. Using histology, we showed that gonads were fully differentiated at the time of birth with a male:female sex ratio of 1:1 in the captive stock. External secondary sex features included a modified anal fin and a distinctive orange tail coloration. These features first appeared at 4 weeks after birth and were discriminative for males thereafter. There was no sex-related dichotomy in body size, and X. eiseni reached sexual maturity at approximately 12 weeks of age. We found no evidence for sperm storage in females. Gestation normally took 6 weeks, and there was a positive correlation between female body size and the number of offspring produced, with up to 27 offspring for a single pregnancy. Yolk is the main food source for developing embryos for the period up to 2 weeks, and thereafter, trophotaeniae in embryos act as nutrient exchange surfaces in the ovarian lumen, which subsequently undergo complete regression within 2 weeks of birth. In our final analysis, we discuss the great potential of X. eiseni as a model for studying the effects of chemicals on sexual development.

A New Species of Long-glanded Coralsnake of the GenusCalliophis(Squamata: Elapidae) from Dinagat Island, with Notes on the Biogeography and Species Diversity of PhilippineCalliophisandHemibungarus

Abstract We describe a new species of coralsnake from northern Dinagat Island, southeastern Philippines. The discovery of this new species comes as a surprise because it is phenotypically distinct from all other Philippine coralsnakes and has a close phylogenetic affinity to the blue coralsnakes of the Sunda Shelf. The new species is distinguished from all Philippine and other Southeast Asian taxa by its large body size and ventral scale counts; its black head and neck; an alternating, broadly banded color pattern of black and off-white; and a bright orange tail. We use DNA sequence data to investigate the phylogenetic placement of the new species and that of several other populations of Philippine coralsnakes with respect to other Southeast Asian and Australasian elapids. Our results corroborate the uniqueness of the new species with respect to all other Philippine and Sundaic taxa, including the species most closely related to it: Calliophis bivirgatus, C. bilineatus, C. philippinus, and C. suluensis. W...

Cedar Waxwings with Orange Tail Tips

Cedar Waxwings with Orange Tail Tips

Sciurus pyrrhinus(Rodentia: Sciuridae)

Abstract: Sciurus pyrrhinus O. Thomas, 1898 is a rodent commonly called the Junin red squirrel or ardilla rojiza. This large-bodied, arboreal species is characterized by a rufous dorsum and an orange tail, and is 1 of 28 species in the genus Sciurus. Endemic to Peru, S. pyrrhinus is found on the eastern slopes of the Andes between 600 and 1,500 m above sea level, spanning rain forest and montane forest habitat. Described as common within its limited distribution, the Peruvian Ministry of the Environment classifies S. pyrrhinus as “Vulnerable” and the International Union for Conservation of Nature and Natural Resources considers it “Data Deficient.”

New species of titi monkey, genus Callicebus Thomas, 1903 (Primates, Pitheciidae), from Southern Amazonia, Brazil

The genus Callicebus is one of the most diverse Neotropical primate groups, with 31 recognized species. However, large knowledge gaps still exist regarding the diversity of this genus. Such gaps are gradually being filled due to recent intensification of sampling efforts. Several geographic distributions have been better delimited, and six new species have been described in the last 15 years. The goal of the present study is to describe a new species of Callicebus belonging to the Callicebus moloch species group, recently discovered in an area previously considered to be part of the geographic distribution of C. cinerascens. Data collection was conducted through direct observations, specimen collection and interviews with local residents during four expeditions. Specimens were deposited in the mammalian collection of the Museu Paraense Emilio Goeldi.. For a comparative evaluation, we examined specimens of the other species of the Callicebus moloch species group, especially the geographically neighboring forms, C. bernhardi and C. cinerascens. We examined 10 chromatic characters of the fur. In addition to body mass, we verified the conventional external variables and 26 craniometric variables. The new species differs from all other Amazonian Callicebus by an exclusive combination of characters, being easily distinguished by the light gray line of the forehead, dark ocher sideburns and throat, dark gray portions of the torso and flanks, and uniformly orange tail. The geographic distribution of the new species is limited by the Roosevelt and Aripuana rivers, in the states of Mato Grosso and Amazonas, Brazil. Approximately 25% (1,246.382 ha) of this area falls within conservation areas, with five areas of sustainable use (746,818 ha) and three of integral protection (499,564 ha). Furthermore, a considerable portion of the distribution area is located within indigenous lands (1,555.116 ha - 32%). Therefore, 57% (2,801.498 ha) of the occurrence area of the new species falls within protected areas.

Sciurus spadiceus(Rodentia: Sciuridae)

Sciurus spadiceus Olfers, 1818, is a sciurid commonly known as the southern Amazon red squirrel. S. spadiceus is a large-bodied tree squirrel with a variable color pattern, but typically has a reddish brown dorsum, a dark midline, a white venter, and a brown and orange tail. S. spadiceus ranges from southern Colombia and Venezuela, south through Peru, western Brazil, Ecuador, and Bolivia in lowland rain forest. This species is listed as “Least Concern” by the International Union for Conservation of Nature and Natural Resources.

A colorful new species of insular rock gecko (Cnemaspis Strauch 1887) from southern Vietnam

A new species of endemic, insular Cnemaspis is described from Hon Khoai Island, Ca Mau Province, Ngoc Hien District, 18 km off the southern tip of the Ca Mu Peninsula in southern Vietnam. Cnemaspis psychedelica sp. nov. is the most uniquely colored of all southeast Asian Cnemaspis in that both sexes and all age classes have bright orange forelimbs, forelegs, hands and feet; a bright orange tail; a dense, yellow reticulum on the neck overlying thick, black, longitudinal lines; and a blue-gray to light purple trunk bearing yellow transverse bars on bright-orange flanks. It also differs from all other species of Cnemaspis in aspects of size and squamation. Cnemaspis psychedelica is the third insular endemic species of Cnemaspis from Vietnam and brings the total number of species in Vietnam to six. Its occurrence on one of the 92 islands in Rach Gia Bay underscores the necessity for continued surveys of these poorly known islands that are beginning to show a surprising degree of endemism and diversity.

A New Species of Proablepharus (Squamata: Scincidae) from the Northern Territory of Australia

Proablepharus naranjicaudus sp. nov. (Squamata: Scincidae), is distinguished from all its known congeners in having supraoculars four, first two contacting frontal; frontoparietals and interparietal fused into a single scale; supraciliaries usually six; upper preocular small or absent; postsupralabials usually one, and subdigital lamellae of pestri-mucronate. Juveniles have striking pale and dark stripes through the centre of each dorsal scale and a orange tail; both pattern elements may become muted in adults. The species is apparently endemic to areas of cracking-clay soils in the Ord-Victoria region of the north-western part of the Northern Territory. A key to the species in the genus is provided.

A New Species of Dixonius (Squamata: Gekkonidae) from Kanchanaburi Province, Western Thailand

A new species of the endemic Southeast Asian gekkonid lizard genus Dixonius Bauer et al., 1997 is described on the basis of material from Kanchanaburi Province in western Thailand. It is characterized by a distinctive orange tail and a prominent dark stripe from the snout to at least the level of the ear. It occurs sympatrically with its larger and more widely distributed congener, D. siamensis.

Predator induced phenotypic plasticity in the pinewoods tree frog, Hyla femoralis: necessary cues and the cost of development.

Predator-induced defenses can result from non-contact cues associated with the presence of a feeding predator; however, the nature of the predator cue has not been determined. We tested the role of two non-contact cues, metabolites of digestion of conspecific prey released by the predator and alarm pheromones released by attacked conspecific prey, in the development of inducible defenses by exposing pinewoods tree frog (Hyla femoralis) tadpoles to non-lethal dragonfly (Anax junius) larvae fed either inside experimental bins or removed from the bins for feeding to eliminate alarm pheromones. The costs associated with the development of the induced morphology were also investigated by providing the tadpoles with two food levels intended to provide adequate or growth limiting resources. The generalized morphological response of H. femoralis tadpoles to predators included the development of bodies and tails that were both deeper and shorter, smaller overall body size, and increased orange tail fin coloration and black tail outline. Metabolites of digestion were sufficient to initiate development of inducible defenses; however, the combination of metabolites and alarm cue resulted in a greater response. Furthermore, growth and development were slowed in tadpoles that expressed the induced morphology; however, this growth cost was insufficient to preclude the development of the induced morphology when food resources were low. These results indicate that two aspects of the indirect predator cue work together to trigger a morphological anti-predator response.

Consequences of an Alien Shrub on the Plumage Coloration and Ecology of Cedar Waxwings

-Cedar Waxwings (Bombycilla cedrorum) with orange (instead of the normal yellow) tail bands have appeared in eastern North America in the last 35 years. Biochemical studies have implicated a dietary cause (Hudon and Brush 1989), specifically the fruits of Lonicera morrowii (Brush 1990), for this novel color variant. I show that rectrices replaced while Cedar Waxwings are feeding on L. morrowii fruits develop orange tips. Rectrices replaced subsequent to switching the diet of molting waxwings from L. morrowii fruits to dog chow were yellow, showing close temporal correspondence between dietary input of rhodoxanthin and the coloration of growing feathers. In the Ithaca vicinity, fruits of L. morrowii are eaten by wild Cedar Waxwings from June until mid-October. The extended pattern of availability and consumption of Lonicera in this region appears to explain my unique observations of adult Cedar Waxwings growing orange tails during the fall months. Cedar Waxwings maintained body condition and molted while on an extended diet of L. morrowii fruits (36 days for two birds and 64 days for two others). Three birds initiated tail molt while on this diet, including one that molted all of its flight feathers. These results emphasize the nutritional specialization of Cedar Waxwings to a diet of sugary, low-protein fruits, and show that molt occurs in an apparently normal manner when birds are eating a low-protein fruit diet. Received 30 September 1994, accepted 15 April 1995. CEDAR WAXWINGS (Bombycilla cedrorum) normally have a yellow terminal band on their tails. Within the past 35 years, Cedar Waxwings with orange tail bands have appeared in the northeastern United States and southeastern I Present address: Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming 82071, USA. E-mail: waxwing@uwyo.edu Canada (Yunick 1970, Hudon and Brush 1989, Pittaway 1991, Mulvihill et al. 1992). Carotenoid pigments (i.e. xanthophylls) cause the yellow tail bands of Cedar Waxwings (Hudon and Brush 1989), as well as the red tips of their secondaries (Brush and Allen 1963). The coloration of the novel orange-tipped rectrices of Cedar Waxwings is caused by the inclusion of a red carotenoid pigment (rhodoxanthin) in the FRONTISPIECE. Tail colors of Cedar Waxwings. Bird in upper left (Bird 1) was fed only Lonicera fruits during tail molt. Bird in upper right (Bird 2) was switched from Lonicera fruits to chow diet midway through tail molt. Bird in lower left is wild bird with orange tail band (Cornell University Vertebrate Collection [CVC] no. 30194; juvenile male, 9 November 1961, Chemung Co., New York). Bird in lower right is wild bird with normal yellow tail band (CVC no. 14422, adult male, 1 June 1942, Tompkins Co., New York).