Publications

genetic characterization of a herpesvirus isolate from a superb starling (lamprotornis superbus) as a psittacid herpesvirus genotype 1.	four genotypes of the psittacid herpesvirus (pshv) cause pacheco disease in parrots. viruses that are serologically cross-reactive to the pshvs have also been isolated from passerine species. dna was amplified from a herpesvirus isolated from a superb starling (lamprotornis superbus) with pshv-specific primers and polymerase chain reaction. a comparison of the partial sequence of the ul 16 gene from this herpesvirus with sequences from viruses of known pshv genotypes showed that the herpesvirus ...	2004	15077818
stress hormones and sociality: integrating social and environmental stressors.	in cooperatively breeding species, reproductive decisions and breeding roles may be influenced by environmental (food resources) or social factors (reproductive suppression of subordinates by dominants). studies of glucocorticoid stress hormones in cooperatively breeding species suggest that breeding roles and hormone levels are related to the relative costs of dominance and subordination, which are driven primarily by social interactions. few studies, however, have considered how environmental ...	2007	17251100
female extrapair mate choice in a cooperative breeder: trading sex for help and increasing offspring heterozygosity.	sexual conflict between males and females over mating is common. females that copulate with extrapair mates outside the pair-bond may gain (i) direct benefits such as resources or increased paternal care, (ii) indirect genetic benefits for their offspring, or (iii) insurance against infertility in their own social mate. few studies have been able to demonstrate the different contexts in which females receive varying types of benefits from extrapair mates. here, i examined sexual conflict, female ...	2007	17526455
temporal but not spatial environmental variation drives adaptive offspring sex allocation in a plural cooperative breeder.	cooperatively breeding birds have been used frequently to study sex allocation because the adaptive value of the sexes partly depends upon the costs and benefits for parents of receiving help. i examined patterns of directional sex allocation in relation to maternal condition (trivers-willard hypothesis), territory quality (helper competition hypothesis), and the number of available helpers (helper repayment hypothesis) in the superb starling, lamprotornis superbus, a plural cooperative breeder ...	2007	17853999
environmental and hormonal correlates of immune activity in a cooperatively breeding tropical bird.	because climatic patterns in temperate regions are generally predictable, species can allocate resources adaptively among competing physiological processes before environmental conditions change. in the semi-arid tropics where environments are seasonal, but highly unpredictable, allocation decisions may be more sensitive to short-term fluctuations in conditions. we asked (i) whether investments in immune function were affected by inter-annual variation in rainfall and (ii) whether corticosterone ...	2008	18713633
reproductive conflict and the costs of social status in cooperatively breeding vertebrates.	conflict over reproduction is an inherent part of group living. in many social vertebrates, conflict may be reflected as allostatic load, or the costs of social status and dominance rank, which may be quantified by measuring glucocorticoid stress hormones. here, we develop the first quantitative model of allostatic load based on the tug-of-war model of reproductive skew to generate insights into the mechanisms underlying reproductive conflict in cooperative breeders and to determine whether gluc ...	2009	19296735
spatiotemporal environmental variation, risk aversion, and the evolution of cooperative breeding as a bet-hedging strategy.	in cooperatively breeding systems in which some individuals delay reproduction to help raise others' offspring, environmental variation in space and time influences individual reproductive strategies as well as interspecific patterns of sociality. although most environmental explanations for cooperative breeding emphasize the mean fitness gains of living socially, the fittest individuals are not always those that produce on average the highest number of offspring. at times, variance in fecundity ...	2011	21690415
sex determination in 58 bird species and evaluation of chd gene as a universal molecular marker in bird sexing.	the aim of this research was to test the chd gene (chromo helicase dna-binding gene) as a universal molecular marker for sexing birds of relatively distant species. the chd gene corresponds to the aim because of its high degree of conservation and different lengths in z and w chromosomes due to different intron sizes. dna was isolated from feathers and the amplification of the chd gene was performed with the following sets of polymerase chain reaction (pcr) primers: 2550f/2718r and p2/p8. sex de ...	2015	22553188
pitch- and spectral-based dynamic time warping methods for comparing field recordings of harmonic avian vocalizations.	quantitative measures of acoustic similarity can reveal patterns of shared vocal behavior in social species. many methods for computing similarity have been developed, but their performance has not been extensively characterized in noisy environments and with vocalizations characterized by complex frequency modulations. this paper describes methods of bioacoustic comparison based on dynamic time warping (dtw) of the fundamental frequency or spectrogram. fundamental frequency is estimated using a ...	2013	23927136
flight calls signal group and individual identity but not kinship in a cooperatively breeding bird.	in many complex societies, intricate communication and recognition systems may evolve to help support both direct and indirect benefits of group membership. in cooperatively breeding species where groups typically comprise relatives, both learned and innate vocal signals may serve as reliable cues for kin recognition. here, we investigated vocal communication in the plural cooperatively breeding superb starling, lamprotornis superbus, where flight calls-short, stereotyped vocalizations used when ...	2013	24137044
description of two new isospora species causing visceral coccidiosis in captive superb glossy starlings, lamprotornis superbus (aves: sturnidae).	isospora greineri sp. n. and isospora superbusi sp. n. are described from captive superb glossy starlings, lamprotornis superbus, from the toronto zoo succumbing to visceral coccidiosis. sequence data from nuclear 18s recombinant dna (rdna) and mitochondrial cytochrome c oxidase subunit i (coi) loci from sporulated oocysts and infected tissues (liver, lung, or spleen) demonstrated two distinct isospora sp. genotypes that varied in their relative abundance. in the tissues of one affected bird, as ...	2014	24948107
a comparison of single nucleotide polymorphism and microsatellite markers for analysis of parentage and kinship in a cooperatively breeding bird.	the development of genetic markers has revolutionized molecular studies within and among populations. although poly-allelic microsatellites are the most commonly used genetic marker for within-population studies of free-living animals, biallelic single nucleotide polymorphisms, or snps, have also emerged as a viable option for use in nonmodel systems. we describe a robust method of snp discovery from the transcriptome of a nonmodel organism that resulted in more than 99% of the markers working s ...	2015	25224810
quill mites of the subfamily picobiinae (acari: syringophilidae) parasitising african birds, with description of two new species.	two new species of the subfamily picobiinae (acari: prostigmata: syringophilidae) are described: picobia ploceus sp. n. from ploceus ocularis smith (passeriformes: ploceidae) and picobia lamprotornis sp. n. from lamprotornis superbus (rüppell) (passeriformes: sturnidae), both from kenya. additionally, new hosts are recorded: turdoides jardineii (smith) (passeriformes: leiothrichidae) from kenya and tanzania, t. rubiginosa (rüppell) from kenya, t. leucopygia (rüppell) from zambia and namibia, for ...	2014	25549496
bateman's principle is reversed in a cooperatively breeding bird.	bateman's principle is not only used to explain sex differences in mating behaviour, but also to determine which sex has the greater opportunity for sexual selection. it predicts that the relationship between the number of mates and the number of offspring produced should be stronger for males than for females. yet, it is unclear whether bateman's principle holds in cooperatively breeding systems where the strength of selection on traits used in intrasexual competition is high in both sexes. we ...	2015	25904321
the fitness consequences of kin-biased dispersal in a cooperatively breeding bird.	cooperative alliances among kin may not only lead to indirect fitness benefits for group-living species, but can also provide direct benefits through access to mates or higher social rank. however, the immigrant sex in most species loses any potential benefits of living with kin unless immigrants disperse together or recruit relatives into the group in subsequent years. to look for evidence of small subgroups of related immigrants within social groups (kin substructure), we used microsatellites ...	2015	26179800
sex-specific fitness effects of unpredictable early life conditions are associated with dna methylation in the avian glucocorticoid receptor.	organisms can adapt to variable environments by using environmental cues to modulate developmental gene expression. in principle, maternal influences can adaptively adjust offspring phenotype when early life and adult environments match, but they may be maladaptive when future environments are not predictable. one of the best-studied 'maternal effects' is through modification of the offspring's hypothalamic-pituitary-adrenal (hpa) axis, the neuroendocrine system that controls responses to stress ...	2016	26588348
morphological and molecular characterization of isospora neochmiae n. sp. in a captive-bred red-browed finch (neochmia temporalis) (latham, 1802).	a new isospora (apicomplexa: eimeriidae) species is described from a single red-browed finch (neochmia temporalis) (subspecies n. temporalis temporalis), that was part of a captive population in western australia. sporulated oocysts of this isolate are spherical, 18.3 (18.2-18.9) × 18.2 (18.2-18.6) μm, with a shape index (length/width) of 1.0; and a smooth and bilayered oocyst wall, 1.2 μm thick (outer layer 0.9 μm, inner 0.3 μm). a polar granule is present, but the oocyst residuum and a micropy ...	2016	27107929
testosterone, social status and parental care in a cooperatively breeding bird.	the steroid hormone testosterone not only plays an important role in gamete production, but also influences social and aggressive behavior. testosterone varies seasonally, peaking when competition for mates is high and declining during parental care. surprisingly, little is known about how testosterone mediates social conflict and parental care behavior in highly social species like cooperative breeders, where group members compete for breeding opportunities and provide parental or alloparental ...	2018	29054796
multiple benefits of alloparental care in a fluctuating environment.	although cooperatively breeding vertebrates occur disproportionately in unpredictable environments, the underlying mechanism shaping this biogeographic pattern remains unclear. cooperative breeding may buffer against harsh conditions (hard life hypothesis), or additionally allow for sustained breeding under benign conditions (temporal variability hypothesis). to distinguish between the hard life and temporal variability hypotheses, we investigated whether the number of alloparents at a nest incr ...	2018	29515910
morphological and molecular characterisation of isospora butcherae n. sp. in a silvereye (zosterops lateralis) (latham, 1801).	a new isospora (apicomplexa:eimeriidae) species is described from a silvereye (zosterops lateralis) in western australia. sporulated oocysts of this species are spherical, 24.2 (23.1-25.2) × 23.3 (22.8-23.9) μm, with a shape index (length/width) of 1.02, and with a smooth bi-layered oocyst wall, 1.2 μm thick (outer layer 0.9 μm, inner 0.3 μm). a polar granule is present, but the oocyst residuum and a micropyle are absent. the ovoid-shaped sporocysts are 16.1 (15.7-17.3) × 10.5 (15.7-17.3) μm and ...	2018	29527641
the oxidative costs of parental care in cooperative and pair-breeding african starlings.	the cost of parental care has long been thought to favor the evolution of cooperative breeding, because breeders can provide reduced parental care when aided by alloparents. oxidative stress-the imbalance between reactive oxygen species and neutralizing antioxidants-has been proposed to mediate the cost of parental care, though results from empirical studies remain equivocal. we measured changes in oxidative status during reproduction in cooperatively breeding superb starlings (lamprotornis supe ...	2018	29858694
no short-term physiological costs of offspring care in a cooperatively breeding bird.	the cost of reproduction results in a life-history trade-off where investment in current reproduction via costly parental care decreases subsequent fitness. although this trade-off is thought to occur ubiquitously across animals, there is equivocal evidence that parental care behaviours are costly. a major challenge of studying the cost of parental care has been a lack of consensus over which physiological mechanisms underlie this trade-off. here, we compare four traits believed to mediate the c ...	2018	30190315
survival benefits of group living in a fluctuating environment.	group living is predicted to arise only when the fitness benefits outweigh the costs of sociality. group-living species-including cooperatively breeding and family-living birds and mammals-occur most frequently in environments where climatic conditions fluctuate unpredictably from year to year. the fitness consequences of group living are thus expected to vary with changing environmental conditions, though few studies have examined this possibility. we examined whether living in large social gro ...	2020	32469654