| 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 |
| 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 |
| regional epigenetic differentiation of the z chromosome between sexes in a female heterogametic system. | in male heterogametic systems, the x chromosome is epigenetically differentiated between males and females, to facilitate dosage compensation. for example, the x chromosome in female mammals is largely inactivated. relative to well-studied male heterogametic systems, the extent of epigenetic differentiation between male and female z chromosomes in female heterogametic species, which often lack complete dosage compensation, is poorly understood. here, we examined the chromosomal dna methylation l ... | 2019 | 31548356 |
| chromosomal polymorphism and comparative chromosome painting in the rufous-collared sparrow (zonotrichia capensis). | zonotrichia capensis is widely distributed in the neotropics. previous cytogenetic studies demonstrated the presence of polymorphisms in two chromosome pairs (zca2 and zca4). here, we report results based on comparative chromosome painting, using probes derived from gallus gallus and leucopternis albicollis, focused on characterizing the chromosome organization of z. capensis. our results demonstrate the conservation of ancestral syntenies as observed previously in other species of passerine. sy ... | 2020 | 30534855 |
| influence of the agricultural conservation easement program wetland practices on winter occupancy of passerellidae sparrows and avian species richness. | wetlands enrolled in the agricultural conservation easement program (acep) are established as a means of restoring wetland ecosystems and wildlife habitat on private, agricultural land. in west virginia, usa, acep wetlands have never been evaluated to determine how they function as wildlife habitat in comparison to other available wetland habitat in the state. we measured the wintering occupancy of passerellidae species and apparent avian species richness on acep wetlands and a set of reference ... | 2019 | 30677050 |
| stress-induced hyperglycemia in white-throated and white-crowned sparrows: a new technique for rapid glucose measurement in the field. | organisms experience stressors, and the physiological response to these stressors is highly conserved. acute stress activates both the sympathetic nervous system and the hypothalamic-pituitary-adrenal axis, increasing epinephrine, norepinephrine, and glucocorticoids, collectively promoting glucose mobilization. while this is well characterized in mammals, the hyperglycemic response to stress in avian and nonavian reptiles has received less attention. a number of factors, ranging from time of day ... | 2018 | 29847208 |
| inside the supergene of the bird with four sexes. | the white-throated sparrow (zonotrichia albicollis) offers unique opportunities to understand the adaptive value of supergenes, particularly their role in alternative phenotypes. in this species, alternative plumage morphs segregate with a nonrecombining segment of chromosome 2, which has been called a 'supergene'. the species mates disassortatively with respect to the supergene; that is, each breeding pair consists of one individual with it and one without it. this species has therefore been ca ... | 2020 | 32937166 |
| a supergene-linked estrogen receptor drives alternative phenotypes in a polymorphic songbird. | behavioral evolution relies on genetic changes, yet few behaviors can be traced to specific genetic sequences in vertebrates. here we provide experimental evidence showing that differentiation of a single gene has contributed to the evolution of divergent behavioral phenotypes in the white-throated sparrow, a common backyard songbird. in this species, a series of chromosomal inversions has formed a supergene that segregates with an aggressive phenotype. the supergene has captured esr1, the gene ... | 2020 | 32817554 |
| animal culture: how a new birdsong went viral. | a new white-throated sparrow song has overtaken most of canada in less than 20 years. the explanation for this remarkably fast spread may lie in the southern migratory grounds, where populations from across canada converge each winter. | 2020 | 32810461 |
| stopover refuelling, movement and departure decisions in the white-throated sparrow: the influence of intrinsic and extrinsic factors during spring migration. | differential migration timing between sex or age classes is an example of how migratory movement strategies can differ among subgroups within a population. however, in songbirds, evidence for intrinsic differences in en route migratory behaviour is often mixed, suggesting that the local environmental context may play a role in accentuating or diminishing patterns. we evaluated how multiple intrinsic and extrinsic variables influenced refuelling rates, local movement behaviour and departure decis ... | 2020 | 32770676 |
| continent-wide shifts in song dialects of white-throated sparrows. | hypotheses on regional song variation ("dialects") assume that dialects remain stable within regions, are distinct between regions, and persist within populations over extensive periods [1-3]. theories to explain dialects focus on mechanisms that promote persistence of regional song variants despite gene flow between regions [4-6], such as juveniles settling in non-natal populations retaining only those songs from their repertoires that match neighbors [7, 8]. it would be considered atypical for ... | 2020 | 32619475 |
| time course of photo-induced egr-1 expression in the hypothalamus of a seasonally breeding songbird. | many seasonally-breeding species use daylength to time reproduction. light-induced release of progonadal hormones involves a complex cascade of responses both inside and outside the brain. in this study, we used induction of early growth response 1 (egr-1), the protein product of an immediate early gene, to evaluate the time course of such responses in male white-throated sparrows (zonotrichia albicollis) exposed to a single long day. induction of egr-1 in the pars tuberalis began ∼11 h after da ... | 2020 | 32422399 |
| vasoactive intestinal peptide as a mediator of the effects of a supergene on social behaviour. | supergenes, or linked groups of alleles that are inherited together, present excellent opportunities to understand gene-behaviour relationships. in white-throated sparrows (zonotrichia albicollis), a supergene on the second chromosome associates with a more aggressive and less parental phenotype. this supergene includes the gene for vasoactive intestinal peptide (vip), a neuropeptide known to play a causal role in both aggression and parental behaviour. here, using a free-living population, we c ... | 2020 | 32259472 |
| experimental malaria infection affects songbirds' nocturnal migratory activity. | migratory animals encounter multiple parasite communities, raising concerns that migration may aid transport of infectious disease. how migration affects disease spread depends fundamentally on how disease affects migration, specifically whether infection alters individuals' migratory physiology and behavior. we inoculated white-throated sparrows (zonotrichia albicollis) with avian malaria parasites (plasmodium sp.), monitored parasite loads for 5 wk as the birds reached spring migratory conditi ... | 2020 | 32013740 |
| parent and offspring genotypes influence gene expression in early life. | parents can have profound effects on offspring fitness. little, however, is known about the mechanisms through which parental genetic variation influences offspring physiology in natural systems. white-throated sparrows (zonotrichia albicollis, wtsp) exist in two genetic morphs, tan and white, controlled by a large polymorphic supergene. morphs mate disassortatively, resulting in two pair types: tan male × white female (t × w) pairs, which provide biparental care and white male × tan female (w × ... | 2019 | 31421010 |
| a chromosomal inversion predicts the expression of sex steroid-related genes in a species with alternative behavioral phenotypes. | in white-throated sparrows, a chromosomal rearrangement has led to alternative phenotypes that differ in sex steroid-dependent behaviors. the rearrangement has captured the genes estrogen receptor alpha and 5-alpha reductase, making these genes strong candidates for mediating the behavioral phenotypes. we report here that of the two genes, expression of estrogen receptor alpha mrna differs between the morphs and predicts behavior to a much greater extent than does expression of 5-alpha reductase ... | 2019 | 31348983 |
| extrapair mating and the strength of sexual selection: insights from a polymorphic species. | extrapair mating could drive sexual selection in socially monogamous species, but support for this hypothesis remains equivocal. we used lifetime fitness data and a unique model species, the dimorphic white-throated sparrow (zonotrichia albicollis), to examine how extrapair mating affects the potential for sexual selection. in this species, the morphs employ distinct reproductive strategies, with white males pursuing extrapair mating at higher rates than tan counterparts. social and extrapair ma ... | 2020 | 30971857 |
| actuarial senescence in a dimorphic bird: different rates of ageing in morphs with discrete reproductive strategies. | it is often hypothesized that intra-sexual competition accelerates actuarial senescence, or the increase in mortality rates with age. however, an alternative hypothesis is that parental investment is more important to determining senescence rates. we used a unique model system, the white-throated sparrow (zonotrichia albicollis), to study variation in actuarial senescence. in this species, genetically determined morphs display discrete mating strategies and disassortative pairing, providing an e ... | 2018 | 30518574 |
| developmental stress and telomere dynamics in a genetically polymorphic species. | a central objective of evolutionary biology is understanding variation in life-history trajectories and the rate of aging, or senescence. senescence can be affected by trade-offs and behavioural strategies in adults but may also be affected by developmental stress. developmental stress can accelerate telomere degradation, with long-term longevity and fitness consequences. little is known regarding whether variation in developmental stress and telomere dynamics contributes to patterns of senescen ... | 2019 | 30417475 |
| alternative reproductive strategies in white-throated sparrows are associated with differences in parasite load following experimental infection. | immune defences often trade off with other life-history components. within species, optimal allocation to immunity may differ between the sexes or between alternative life-history strategies. white-throated sparrows (zonotrichia albicollis) are unusual in having two discrete plumage morphs, white-striped and tan-striped. within each sex, white-striped individuals are more aggressive and provide less parental care than tan-striped individuals. we extended immunocompetence handicap models, which p ... | 2018 | 29973391 |
| comparative genomics reveals a burst of homoplasy-free numt insertions. | mitochondrial dna sequences are frequently transferred into the nuclear genome, giving rise to numts (nuclear mitochondrial dna segments). in the absence of whole genomes, avian numts have been suggested to be rare and relatively short. we examined 64 bird genomes to test hypotheses regarding numt frequency, distribution among taxa, and likelihood of homoplasy. we discovered 100-fold variation in numt number across species. two songbirds, geospiza fortis (darwin's finch) and zonotrichia albicoll ... | 2018 | 29860531 |
| morph-specific patterns of reproductive senescence: connections to discrete reproductive strategies. | how reproductive strategies contribute to patterns of senescence in natural populations remains contentious. we studied reproductive senescence in the dimorphic white-throated sparrow, an excellent species for exploring this issue. within both sexes the morphs use distinct reproductive strategies, and disassortative pairing by morph results in pair types with distinct parental systems. white morph birds are more colorful and aggressive than tan counterparts, and white males compete for extrapair ... | 2018 | 29750559 |
| sound-induced monoaminergic turnover in the auditory forebrain depends on endocrine state in a seasonally-breeding songbird. | sensory responses to courtship signals can be altered by reproductive hormones. in seasonally-breeding female songbirds, for example, sound-induced immediate early gene expression in the auditory pathway is selective for male song over behaviourally irrelevant sounds only when plasma estradiol reaches breeding-like levels. this selectivity has been hypothesized to be mediated by release of monoaminergic neuromodulators in the auditory pathway. we previously showed that in oestrogen-primed female ... | 2018 | 29738608 |
| rapid effects of 17β-estradiol on aggressive behavior in songbirds: environmental and genetic influences. | contribution to special issue on fast effects of steroids. 17β-estradiol (e2) has numerous rapid effects on the brain and behavior. this review focuses on the rapid effects of e2 on aggression, an important social behavior, in songbirds. first, we highlight the contributions of studies on song sparrows, which reveal that seasonal changes in the environment profoundly influence the capacity of e2 to rapidly alter aggressive behavior. e2 administration to male song sparrows increases aggression wi ... | 2018 | 29605636 |
| rapid regulatory evolution of a nonrecombining autosome linked to divergent behavioral phenotypes. | in the white-throated sparrow (zonotrichia albicollis), the second chromosome bears a striking resemblance to sex chromosomes. first, within each breeding pair of birds, one bird is homozygous for the standard arrangement of the chromosome (zal2/zal2) and its mate is heterozygous for a different version (zal2/zal2m). second, recombination is profoundly suppressed between the two versions, leading to genetic differentiation between them. third, the zal2m version is linked with phenotypic traits, ... | 2018 | 29483264 |
| multiple signaling functions of song in a polymorphic species with alternative reproductive strategies. | vocal traits can be sexually selected to reflect male quality, but may also evolve to serve additional signaling functions. we used a long-term dataset to examine the signaling potential of song in dimorphic white-throated sparrows (zonotrichia albicollis). we investigated whether song conveys multifaceted information about the vocalizing individual, including fitness, species identity, individual identity, and morph. we also evaluated whether song traits correlate differently with fitness in th ... | 2018 | 29375804 |
| rapid effects of estradiol on aggression depend on genotype in a species with an estrogen receptor polymorphism. | the white-throated sparrow (zonotrichia albicollis) represents a powerful model in behavioral neuroendocrinology because it occurs in two plumage morphs that differ with respect to steroid-dependent social behaviors. birds of the white-striped (ws) morph engage in more territorial aggression than do birds of the tan-striped (ts) morph, and the ts birds engage in more parenting behavior. this behavioral polymorphism is caused by a chromosomal inversion that has captured many genes, including estr ... | 2018 | 29277700 |
| negative-assortative mating in the white-throated sparrow. | nonrandom mating based on phenotype has been observed in a number of organisms, but a very high proportion of these examples are of assortative mating. the strongest example of negative-assortative mating is for white-striped versus tan-striped crown in the white-throated sparrow, where about 98% of the observed pairings (mated pairs or social pairs) are between mates with different phenotypes and the correlation between mating types is -0.964. although nonrandom mating has been explored theoret ... | 2018 | 29040605 |
| 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 |