Ioana Chiver

Ioana Chiver

Doctor of Philosophy

About

28
Publications
1,813
Reads
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242
Citations
Additional affiliations
June 2014 - present
University of California, Los Angeles
Position
  • Research Associate
Education
September 2006 - December 2011
York University
Field of study
  • Biology

Publications

Publications (28)
Preprint
Full-text available
SARS-CoV2, severe acute respiratory syndrome coronavirus 2, is frequently associated with neurological manifestations. Despite the presence of mild to severe CNS-related symptoms in a cohort of patients, there is no consensus whether the virus can infect directly brain tissue or if the symptoms in patients are a consequence of peripheral infectivit...
Article
Full-text available
The song control nucleus HVC of songbirds has emerged as a widespread model system to study adult neurogenesis and the factors that modulate the incorporation of new neurons, including seasonal state, sex differences or sex steroid hormone concentrations. However, the specific function of these new neurons born in adulthood remains poorly understoo...
Article
Organismal behavior, with its tremendous complexity and diversity, is generated by numerous physiological systems acting in coordination. Understanding how these systems evolve to support differences in behavior within and among species is a longstanding goal in biology that has captured the imagination of researchers who work on a multitude of tax...
Preprint
Full-text available
The song control nucleus HVC of songbirds has emerged as a widespread model system to study adult neurogenesis and the factors that modulate the incorporation of new neurons, including seasonal state, sex differences or sex steroid hormone concentrations. However, the specific function of these new neurons born in adulthood remains poorly understoo...
Article
Temperate-zone birds display marked seasonal changes in reproductive behaviors and the underlying hormonal and neural mechanisms. These changes were extensively studied in canaries (Serinus canaria) but differ between strains. Fife fancy male canaries change their reproductive physiology in response to variations in day length but it remains unclea...
Article
Full-text available
Songbirds learn their vocalizations during developmental sensitive periods of song memorization and sensorimotor learning. Some seasonal songbirds, called open-ended learners, recapitulate transitions from sensorimotor learning and song crystallization on a seasonal basis during adulthood. In adult male canaries, sensorimotor learning occurs each y...
Preprint
Full-text available
Songbirds learn their vocalizations during sensitive periods of song memorization and sensorimotor learning during development. Some seasonal songbirds, called open-ended learners, recapitulate transitions from sensorimotor learning and song crystallization on a seasonal basis during adulthood. In adult male canaries, sensorimotor learning occurs e...
Article
Numerous studies have evaluated changes in time of testicular development in birds by exploratory laparotomy or post-mortem autopsy. The invasive nature of these approaches has obviously limited the frequency at which these measures can be collected. We demonstrate here that accurate assessment of gonadal size can be reliably and repeatedly obtaine...
Article
Full-text available
Synopsis Gonadal hormones can activate performance of reproductive behavior in adult animals, but also organize sex-specific neural circuits developmentally. Few studies have examined the hormonal basis of sex differences in the performance of elaborate, physically complex, and energetic male courtship displays. Here we describe our studies over mo...
Article
Vocal signals are important in territoriality and mate attraction across animal taxa. Vocalizations are particularly elaborate in some groups, such as songbirds, which learn their songs, but much remains to be known about the physiological mechanisms that produce variation, especially in vocalizations of nonlearners. We address the extent that andr...
Article
Many species perform elaborate physical displays to court mates and compete with rivals, but the biomechanical mechanisms underlying such behavior are poorly understood. Here we address this issue by studying the neuromuscular origins of display behavior in a small tropical passerine bird called the golden-collared manakin (Manacus vitellinus). Mal...
Article
Sexual selection can drive the evolution of novel traits, including behaviours, that may arise in sex-specific patterns and be under sex-steroid hormone control. In some polygynous species, males actively manipulate their display environment, likely to influence female perception of male sexual traits. As a presumptive appetitive reproductive behav...
Article
Birds often mob potential predators, which alerts other prey individuals of the danger and drives the predator away. Participation in, or increased intensity of mobbing is often associated with breeding activity suggesting an important function in the defense of nests and young. Less is known about bird mobbing of snakes, however, although these ar...
Article
Sexual dimorphism is common but evolutionarily labile in vertebrates. While it is well established that gonadal hormones exert considerable influence on the development and expression of sexual traits, studies of animals with exceptional sexually dimorphic neural or neuromuscular phenotypes are limited. We studied the extent to which androgen treat...
Article
Full-text available
Recent studies of tropical birds with year-round territoriality indicate that song rate is relatively low year-round in association with lower seasonality and relatively stable social environment over the year. We examined seasonal variation in the song rate of Red-throated Ant-tanagers (Habia fuscicauda), a socially monogamous species in which mal...
Article
Testosterone is important in mediating investment in competing activities such as territoriality, parental care, and maintenance behavior. Most studies of testosterone function have focused on temperate species and less is known about the role of testosterone in territoriality or variation in mating systems of tropical species. Results of studies o...
Article
Full-text available
We investigated sexual conflict over parental care in blue-headed vireos (Vireo solitarius) and documented the first example of unvarying unisexual brood desertion in passerines. Females at all nests (N = 24) that were monitored closely near fledgling, deserted their broods on or near the day of fledging leaving males alone to complete parental car...
Data
A blue-headed vireo illustrating the radio transmitter attached as a “back pack” with loops of embroidery thread around the legs. Color bands were placed on the right leg for males, as in this case, and left leg for females.
Article
Full-text available
Extra-pair fertilizations are common in many socially monogamous species, and paternity studies have indicated that females may use male vocal performance and plumage ornaments as cues to assess male quality. Female off-territory forays may represent a key component of female choice and male extra-pair mating success, and female foray behaviour is...
Article
Animals often face trade-offs during reproduction between activities such as parental care and territory defence. In species that are socially monogamous, males and females are faced with the additional problem of coordinating their respective contributions to such activities. Here, we examined male incubation behaviour in a passerine that shows ge...
Article
Mechanisms used by birds to rang their distance from singing conspecifics are being debated. In particular, the idea that an incoming song must be in a bird's repertoire for it to be ranged accurately is controversial, but important to our appreciation of the role ranging plays in song evolution. We tested the relation between ranging accuracy and...

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