Publications

ticks (acari: ixodidae) and spirochetes (spirochaetaceae: spirochaetales) recovered from birds on a georgia barrier island.	from september 1997 through july 1999, 300 individuals and 46 species of birds were mist-netted and screened for ticks and spirochetes on st. catherine's island, liberty county, ga. seventy-six (25%) of the birds were parasitized by a meal intensity of 4.6 ticks. seasonally, more birds were infested with ticks during the summer (50% in 1998, 34% in 1999) than in spring (15% in 1998, 11% in 1999) or fall (21% in 1997, 20% in 1998), mainly because of severe infestations on some birds by immature s ...	2001	11296828
vocal tract function in birdsong production: experimental manipulation of beak movements.	kinematic analyses have demonstrated that the extent to which a songbird's beak is open when singing correlates with the acoustic frequencies of the sounds produced, suggesting that beak movements function to modulate the acoustic properties of the vocal tract during song production. if motions of the beak are necessary for normal song production, then disrupting the ability of a bird to perform these movements should alter the acoustic properties of its song. we tested this prediction by compar ...	2000	10821742
social inertia in white-throated sparrows results from recognition of opponents.	social inertia is a term for the stability of dominance relationships despite changes in the intrinsic dominating abilities of opponents. in a standard test for social inertia, low-ranking birds in an established hierarchy receive implants with testosterone (treated) and high-ranking birds receive empty implants (untreated). social inertia occurs when the treated birds remain subordinate to untreated opponents in these groups, despite evidence that similarly treated birds dominate untreated stra ...	1999	10049486
spring migratory birds (aves) extend the northern occurrence of blacklegged tick (acari:ixodidae).	birds that had migrated northward across lake superior were captured upon reaching landfall at thunder cape (48 degrees 18' n, 88 degrees 56' w) at the southwestern tip of the sibley peninsula, northwestern ontario, from 9 may to 9 june 1995. twenty-one of 530 birds examined (6 of 55 species) had a total of 34 ticks; 1 blue jay, cyanocitta cristata, had a northern fowl mite, ornithonyssus sylviarum (canestrini & fanzago). four blacklegged tick, ixodes scapularis say, larvae were found on an amer ...	1996	8699451
biomechanics of cranial kinesis in birds: testing linkage models in the white-throated sparrow (zonotrichia albicollis).	cranial kinesis in sparrows refers to the rotation of the upper jaw around its kinetic joint with the braincase. avian jaw mechanics may involve the coupled motions of upper and lower jaws, in which the postorbital ligament transfers forces from the lower jaw, through the quadrate, pterygoid, and jugal bones, to the upper jaw. alternatively, jaw motions may be uncoupled, with the upper jaw moving independently of the lower jaw. we tested hypotheses of cranial kinesis through the use of quantitat ...	1996	29852573
white-throated sparrow morphs that differ in song production rate also differ in the anatomy of some song-related brain areas.	white-throated sparrows are unusual among songbirds in that they occur in two color morphs, white-striped and tan-striped, determined by a chromosomal inversion and maintained by negative assortative mating. these differ in several reproductive behaviors, including amount of singing: white-striped males sing frequently, tan-striped females never sing, and tan-striped males and white-striped females sing an intermediate amount. the present study measures the volumes of several nuclei in the avian ...	1995	8537825
adipose monoacylglycerol:acyl-coenzyme a acyltransferase activity in the white-throated sparrow (zonotrichia albicollis): characterization and function in a migratory bird.	although migrating birds use stored triacylglycerol as their primary fuel for flight, they must retain sufficient stores of omega 6 and omega 3 fatty acids to sustain reproduction after the spring migration. hepatic monoacylglycerol:acyl-coenzyme a acyltransferase (ec 2.3.1.22) (mgat) activity is associated with physiological periods in which lipolysis and beta-oxidation are prominent, and it may also play a role in the selective retention of certain essential fatty acids. therefore, we characte ...	1994	7869860
some platyhelminths inhabiting white-throated sparrows, zonotrichia albicollis (aves: emberizidae: emberizinae), from algonquin park, ontario, canada.	twenty-two of 26 white-throated sparrows, zonotrichia albicollis, from algonquin park, ontario, canada, hosted 1 or 2 species of platyhelminths. one species of cestode and 3 of digeneans were collected. anonchotaenia quiscali inhabited 50% of the sparrows. this is the third report of a. quiscali; z. albicollis is a new host. brachylecithum nanum inhabited 43%, zonorchis alveyi 15%, and prosthogonimus macrorchis 8% of the sparrows examined. ontario is a new geographic distribution record from all ...	1993	8331482
kinematics of birdsong: functional correlation of cranial movements and acoustic features in sparrows.	the movements of the head and beak of songbirds may play a functional role in vocal production by influencing the acoustic properties of songs. we investigated this possibility by synchronously measuring the acoustic frequency and amplitude and the kinematics (beak gape and head angle) of singing behavior in the white-throated sparrow (zonotrichia albicollis) and the swamp sparrow (melospiza georgiana). these birds are closely related emberizine sparrows, but their songs differ radically in freq ...	1993	8228778
borrelia burgdorferi in ticks (acari: ixodidae) from coastal virginia.	ixodid ticks removed from hosts and from vegetation during march-november 1987 at sites in coastal virginia and north carolina were examined for borrelia burgdorferi. b. burgdorferi was evident in nine (22%) ixodes cookei packard removed from rice rats (oryzomys palustris), a white-footed mouse (peromyscus leucopus), and raccoons (procyon lotor); four (6%) amblyomma americanum (l.) removed from raccoons; and two (3%) dermacentor variabilis (say) removed from a raccoon and a rice rat. b. burgdorf ...	1991	1941936
brain acetylcholinesterase activity in forest songbirds exposed to a new method of uulv fenitrothion spraying.	brain acetylcholinesterase (ache) activity was measured in forest songbirds exposed to ultra ultra low volume (uulv) aerial spraying of fenitrothion in new brunswick for spruce budworm control. brain ache activity was determined in 324 songbirds from the sprayed blocks and 47 from an unsprayed control area, and represented four species. in most cases, more than half of the individuals of any species sampled were diagnosed as "exposed" (greater than or equal to 20% inhibition) to the fenitrothion ...	1991	1996909
the effect of prolactin and cb154 on in vivo lipogenesis and enzyme patterns in the japanese quail, coturnix coturnix japonica and of photositmulation on enzyme patterns in the white-throated sparrow, zonotrichia albicollis.		1990	175996
control of aggression and dominance in white-throated sparrows by testosterone and its metabolites.	in three experiments, we investigated whether testosterone itself or its metabolites activate aggression and dominance in white-throated sparrows zonotrichia albicollis. groups of five to six sparrows, each treated with a different steroid implanted subcutaneously, were observed in outdoor aviaries during late winter to determine the birds' rates of aggression (supplantations and attacks scaled to the number of available subordinates) and dominance rankings with opponents not previously encounte ...	1988	3235066
plasma androgens and aggressiveness in captive winter white-throated sparrows (zonotrichia albicollis).	captive white-throated sparrows (zonotrichia albicollis), held under a natural photoperiod, were pair tested to evaluate dominance and aggressiveness in relation to plasma androgen levels and plumage morphology. androgen levels were determined in november, 1 week before behavioral testing began; in january, at the conclusion of behavioral testing; and again in march. november plasma androgen levels of captive birds did not differ from those of a group of feral birds and were greater than androge ...	1987	3610058
validation of the doubly labeled water technique for measuring energy metabolism in starlings and sparrows.	i have tested the idea that doubly labeled water (dlw) can accurately predict co2 production in savannah sparrows, song sparrows, white-throated sparrows, starlings, and a single house sparrow by comparing dlw estimates with those obtained simultaneously by capturing expired co2 in ascarite. in addition i used the energy balance method to see if metabolic rates generated from dlw measurements accurately reflected the actual metabolic rates of these birds. i found close agreement in dlw and the g ...	1985	2858313
photoperiodic control of the timing of testicular regression in white-throated sparrows.		1982	7060930
interspecific and intraspecific song discrimination by zonotrichia albicollis and z. leucophrys.		1980	7427830
testosterone treatment blocks the termination of the gonadal photorefractory condition in white-throated sparrows maintained on short days.		1980	7409444
lack of an effect of melatonin treatment via silastic capsules on photic-induced gonadal growth and the photorefractory condition in white-throated sparrows.		1978	656187
daily rhythm of plasma corticosterone binding activity in the white-throated sparrow, zonotrichia albicollis.		1978	565451
differential aggression in genetically different morphs of the white-throated sparros (zonotrichia albicollis).	to see if genetic differences correlate with differences in agonistic behavior, 225 encounters within and between color morphs of the white-throated sparrow (zonotrichia albicollis) were observed in feeding groups of different sizes and morphic compositions. tan morphs lack the m chromosome that replaces either of two chromosomes in the white morph. the data were analysed using quantitative models accounting for the proportions of morphs present, and the principal finding was that morphs are equ ...	1978	566001
daily rhythms of lipogenesis in fat and lean white-throated sparrows zonotrichia albicollis.	lipogenesis was assayed at 6 times a day in the migratory white-throated sparrow zonotrichia albicollis by measuring the incorporation of label in liver and body lipid 4 h after injection of [3h] acetate. there were daily rhythms of 3h incorporation by liver lipid both in fat birds in the vernal migratory condition and in lean birds in the summer photorefractory condition. most of the liver lipid incorporation of 3h was restricted to the late afternoon and early evening in both the fat and lean ...	1977	842625
a cytogenetic study of the white-throated sparrow, zonotrichia albicollis (gmelin).		1975	28563104
changes in the daily rhythm of plasma corticosterone concentration related to seasonal conditions in the white-throated sparrow, zonotrichia albicollis.	circadian variations in concentrations of plasma corticosterone were investigated in the white-throated sparrow maintained on short (10-hr) or long (16-hr) daily photoperiods. in addition, the plasma concentrations of corticosterone were determined throughout a day in birds that were in the reproductively photosensitive spring migratory condition, the reproductively photorefractory post nuptial molt condition, and the fall migratory condition. distinct unimodal rhythms were found in photosensiti ...	1975	1208548
residue accumulation in white-throated sparrows fed ddt for 5 and 11 weeks.		1974	4457180
daily entrainment of the photoinducible phases for photostimulation of the reproductive system in the sparrows, zonotrichia albicollis and passer domesticus.		1973	4710782
dual hypothalamic feeding system in a migratory bird, zonotrichia albicollis.		1972	4569759
temporal synergism of corticosterone and prolactin controlling fat storage in the white-throated sparrow, zonotrichia albicollis.		1971	5095207
diurnal and seasonal variations of plasma adrenal steroid hormone in the white-throated sparrow, zonotrichia albicollis.		1971	5087947
temporal synergism of corticosterone and prolactin controlling gonadal growth in sparrows.	gonadal growth was controlled in two avian species by corticosterone and prolactin injected daily at various times. testicular growth was induced in photorefractory house sparrows (passer domesticus) kept in continuous light by prolactin injected 4 or 8 hours after administration of corticosterone. other temporal patterns were ineffective. gonadal growth was also stimulated in photosensitive white-throated sparrows (zonotrichia albicollis) kept in continuous light by prolactin injected 12 hours ...	1971	5111566
effect of imidazole on bone 45ca release in white-throated sparrow, zonotrichia albicollis.		1970	5426566
antigonadal effects of prolactin in the white-throated sparrow, zonotrichia albicollis.		1969	5403617
seasonal variations in the diurnal rhythm of pituitary prolactin content in the white-throated sparrow, zonotrichia albicollis.		1969	5779820
chromosomal polymorphism in the white-throated sparrow, zonotrichia albicollis (gmelin).	in a study of 35 white-throated sparrows five distinct karyotypes were observed. a chromosomal polymorphism is present which involves at least two pairs of macrochromosomes. this species is phenotypically polymorphic with selective breeding occurring between morphs. phenotype is related to chromosomal constitution, and selective breeding appears to maintain heterozygosity within the population.	1966	17807298
phosphatase activity and neuro-secretion in the hypothalamo-hypophyseal system in relation to the photoperiodic gonadal response in zonotrichia albicollis.		1962	14008062
thyroidal utilization of radioiodine in the white-throated sparrow and weaver finch.		1960	14410275
regulation of refractory period in the photoperiodic responses of the white-throated sparrow.		1958	13654678
relation of lipid metabolism to migration in birds; seasonal variation in body lipids of the migratory white-throated sparrow.		1951	14853661