Luis Ortiz-Catedral

First report of beak and feather disease virus (BFDV) in wild Red-fronted Parakeets (Cyanoramphus novaezelandiae) in New Zealand

Abstract Psittacine beak and feather disease (PBFD) is a highly infectious and potentially fatal viral disease of parrots and their allies caused by the beak and feather disease virus (BFDV). Abnormal feather morphology and loss of feathers are common clinical symptoms of the disease. PBFD also damages the lymphoid tissue and affected birds may die as a result of secondary bacterial or fungal infections. The disease is therefore of concern for conservation biologists and wildlife managers, as it is immunosuppressive and can become an additional threatening factor among critically endangered psittacines. We conducted a PCR-based screening for BFDV in a wild population of the Red-fronted Parakeet (Cyanoramphus novaezelandiae) on Little Barrier Island, New Zealand, during a translocation of this species. Fifty-four parakeets were captured and feather samples collected for molecular screening. We detected BFDV DNA from 15 individuals, but only two showed external signs attributable to PBFD, namely abnormal feather morphology or colouration, loss of feathers and haemorrhagic feathers. Our survey represents the first positive identification of BFDV in wild New Zealand endemic psittacines and confirms the risk of spread of the virus between wild populations within this global hotspot of endemic psittacine diversity.

A new isolate of beak and feather disease virus from endemic wild red-fronted parakeets (Cyanoramphus novaezelandiae) in New Zealand

Psittacine beak and feather disease (PBFD) is a viral disease distributed worldwide with a potentially critical impact on many rare parrots. While efforts have been made to determine its prevalence in wild and captive psittacines, only limited work has been done to document complete genomes of its causative agent, beak and feather disease virus (BFDV). Here, we describe five full genomes of BFDV isolated from wild specimens of an endemic New Zealand parrot, the red-fronted parakeet (Cyanoramphus novaezelandiae). The isolates share >99% nucleotide similarity amongst themselves and ~91–92% similarity to BFDV isolates from southern Africa, Europe and Australia. A maximum-likelihood (ML) phylogenetic tree including 42 other full-genome sequences indicated that the five isolates from red-fronted parakeets represent an undescribed genotype of BFDV. These isolates are evolutionarily most closely related to the Cacatuini isolates from Thailand and the Lorinae isolates from Australia in the rep gene ML tree; however, in the cp ML tree, the evolutionary relationship is closer to viruses found in the Psittacini.

Nesting sites and nesting success of reintroduced red‐crowned parakeets (Cyanoramphus novaezelandiae) on Tiritiri Matangi Island, New Zealand

Abstract We studied red‐crowned parakeets (Cyanoramphus novaezelandiae) reintroduced onto Tiritiri Matangi Island, New Zealand from 2004 to 2006, in order to provide baseline information regarding nesting sites and nesting success of this population. We found 48 nests both in natural nesting sites and in nest boxes, in all three major habitat types on the island. Clutch size declined as the breeding season progressed, but laying date did not affect nesting success. This means that a breeding pair could fledge at least one young even from a small clutch laid late in the breeding season. Overall nesting success was 60%. Nesting success varied between breeding‐seasons. Most of the 17 nesting attempts that failed did so during incubation. Red‐crowned parakeets made use of a wide diversity of nesting sites and few sites were re‐used, which suggests that suitable nest sites were not limiting. Overall, our results indicate that red‐crowned parakeets are good candidates for reintroductions to areas lacking introduced predators, even during the early stages of revegetation.

Clutch parameters and reproductive success of a translocated population of red-crowned parakeet (Cyanoramphus novaezelandiae)

At least four populations of the red-crowned parakeet (Cyanoramphus novaezelandiae) have been established via translocation within New Zealand over the last 40 years, but reproductive parameters of these populations have not been documented. We quantified differences in clutch parameters and reproductive success for a translocated population of this species on Tiritiri Matangi Island over two breeding seasons. Overall clutch parameters and estimates of reproductive success were consistent with reported values from natural populations. However, we found previously unreported differences in clutch size, hatching success and brood size between breeding seasons. The number of fledglings produced per breeding pair increased significantly from 1.4 to 3.4 fledglings during our two-year study. In contrast, egg volume and fertility per clutch did not vary during the same period. Overall, 7 eggs were laid per breeding pair but only 2.22 nestlings fledged, representing a 63.8% loss of initial reproductive potential. Losses during the incubation stage were caused by partial and total hatching failure, whereas starvation of nestlings caused all losses during the brood-rearing stage. Hatching success during our study was lower than that reported for wild populations of this and other parrot species, and remained lower even during the most productive breeding season. We found no cases of predation on eggs or nestlings during our study despite the presence of native and exotic avian predators on Tiritiri Matangi Island. We show that clutch size, brood size and changes in loss between breeding seasons are determinants of reproductive output in translocated red-crowned parakeet and also that reproductive output can vary greatly between breeding seasons. Finally, if reduced hatching success is the result of small founder size, management of parakeets should consider the movement of larger and more genetically diverse flocks.

Reduced total genetic diversity following translocations? A metapopulation approach

Translocation is the movement of a group of individuals from one site to another. Conservationists and wildlife managers around the world use translocation to new and/or newly safe habitats as a tool for preserving and propagating threatened species whose populations are surviving at only few and vulnerable localities. The success of translocations is typically defined as the establishment of a self-sustaining population. However, this definition overlooks the genetic consequences of translocations at the metapopulation scale, especially when maintaining genetic diversity is one of the specific aims of immediate and/or long-term management goals for the translocated population. We evaluated the potential effects of translocation on the total genetic diversity of a metapopulation in an increasingly common scenario: a small island as the source site, and a nearby predator-proofed, large island as the target site. Specifically, we tested the counterintuitive hypothesis that translocation and subsequent migration between an expanding, recently established population and the original population might actually result in the suppression of genetic diversity in the metapopulation relative to the temporal course of genetic drift in the small island population without translocation (control). Our simulations confirm that the directional genetic consequences of translocations are complex and depend on the combination of parameter estimates used for the modelling. Critically, however, under a lower rate of migration, lower rate of growth and higher carrying capacity on the translocation site, and smaller initial size of the translocated population, the total genetic diversity of the metapopulation may become suppressed following a translocation, relative to the control. At the same time, when translocations are carried out under a broader set of conditions, the metapopulation genetic diversity will typically exceed that of the control. Our approach is also informative about the genetic consequences of natural re-/colonisation events between small source and nearby large target sites and the resulting metapopulation. Overall, these results confirm the importance of translocation as a potentially effective and successful conservation genetic tool.

Breeding biology of the critically endangered Malherbe's parakeet on Maud Island, New Zealand, following the release of captive-bred individuals

We studied a population of the critically endangered Malherbe’s parakeet (Cyanoramphus malherbi), following the release of 62 captive-bred individuals on Maud Island, New Zealand, to identify and characterise nesting sites in a novel island environment. Previous work on Malherbe’s parakeets consisted of limited observations on remnant mainland populations. The age of breeding pairs on Maud Island was 7.2 ± 4.7 months and included both captive-bred individuals of the first release flock and individuals hatched on Maud Island within a year of the first release. Nests were found in hollows of mamaku (Cyathea medullaris), vacant nests of sacred kingfisher (Todiramphus sanctus), a hole in the ground and a hollow in a kohekohe (Disoxylum spectabile). Active nests were found in the austral spring, summer and autumn. Clutch size was 5 eggs. The fledging of three Malherbe’s parakeets was confirmed for one nest 43 days after hatching. Observations of newly fledged individuals around the island indicate that at least seven successful nesting attempts occurred. Consistent with other studies in Cyanoramphus parakeets, our results suggest that availability of nesting sites on small islands may not be a limiting factor for the establishment of additional populations of Malherbe’s parakeets via captive breeding and translocation. The formation of breeding pairs at an early age, the use of diverse nesting sites in regenerating vegetation, and the evidence of successful breeding shortly after release on an island represent encouraging prospects for the conservation of New Zealand’s rarest parakeet.

Avian malaria in a remnant population of red-fronted parakeets on Little Barrier Island, New Zealand

Avian malaria is recognised as a potential threatening factor for endangered New Zealand birds; nevertheless, analyses of its prevalence are few and often retrospective, following outbreaks in managed species. We conducted an opportunistic polymerase chain reaction (PCR)-based survey for Plasmodium on a remnant population of red-fronted parakeet (Cyanoramphus novaezelandiae) on Little Barrier Island alongside an analysis of haematology profiles as a first assessment of the effects of this parasite on parakeets. We sampled 22 parakeets and detected Plasmodium relictum DNA in nine samples (prevalence 40.9%; 95% CI = 20.49–61.51%). One successfully amplified sequence corresponded to P. relictum haplotype GRW4. Lymphocyte and heterophil to lymphocyte counts did not differ between PCR-positive and PCR-negative parakeets. However, it is unclear which state of the infection cycle the parakeets experienced during our sampling scheme. From a management perspective, our results indicate that translocation of parakeets from Little Barrier Island to sites where introduced reservoirs of P. relictum occur is a sound management option given the current exposure to this microorganism at the source site.

Visual sensitivity, coloration and morphology of red-tailed tropicbirds Phaethon rubricauda breeding on the Kermadec Islands

Abstract Subtle sexual dimorphism and its perception in apparently monomorphic bird species warrant assessment of how birds identify the sex of conspecifics, particularly of prospective mates. Visual sensitivity and its potential co-variation with cryptic sexual dichromatism are still uninvestigated in most avian taxa. Using molecular sexing, reflectance spectrometry and perceptual modelling based on the sequencing of short wavelength visual pigments, we assessed the sex-specificity of coloration and colour perception in the red-tailed tropicbird Phaethon rubricauda. We also measured morphological dimorphism at a previously unstudied breeding locality for this species. Our data are in line with both physical and avian-perceived monochromatism with a potential indication of achromatic sex differences in plumage reflectance. The moderate extent of size dimorphism is consistent with reports from other Pacific breeding populations, and morphological measurements from live specimens in this study are in line with reports on museum specimens from the same sample location. Potential differences between individuals of the same sex in size and coloration warrant the assessment of sexual dimorphism in larger sample sizes of this species.

Phylogenetic relationships of the genus Mohoua , endemic hosts of New Zealand’s obligate brood parasitic Long-tailed Cuckoo ( Eudynamys taitensis )

AbstractThe three species of New Zealand’s endemic Mohoua genus are sole hosts of the obligate brood parasitic Long-tailed Cuckoo (Eudynamys taitensis), making their intrageneric phylogenetic relationships particularly important for coevolutionary studies. Also, recent molecular phylogenetic analyses have not identified the family-level placement of this genus. To resolve both intrageneric and family relationships, we generated new nuclear and mitochondrial sequence data and conducted phylogenetic analyses using Bayesian inference among representatives of endemic New Zealand passerines and Australasian ‘core Corvoidea’ lineages. The results establish strong intrageneric relationships of all three Mohoua species, confirm the monophyly of the genus, and suggest its placement in a re-erected monotypic family: Mohouidae.ZusammenfassungPhylogenetische Beziehungen der GattungMohuoa, endemische Wirte des neuseeländischen obligat brutparasitischen Langschwanzkoels (Eudynamys taitensis) Die drei Arten der für Neuseeland endemischen Gattung Mohoua sind die alleinigen Wirte des obligat brutparasitischen Langschwanzkoels (Eudynamys taitensis), was die phylogenetischen Beziehungen innerhalb der Gattung besonders wichtig für co-evolutionäre Studien macht. Neuere molekulare phylogenetische Analysen erlaubten keine Einordnung dieser Gattung auf Familienebene. Um sowohl die Beziehungen innerhalb der Gattung als auch die Familienzugehörigkeit zu klären, haben wir neue Kern- und Mitochondrien-DNA-Sequenzdaten gewonnen und phylogenetische Analysen von Vertretern endemischer neuseeländischer Sperlingsvögel und australasiatischer „Core- Corvoidea“ mittels Bayesscher Statistik durchgeführt. Die Ergebnisse etablieren solide intragenerische Beziehungen aller drei Mohoua Arten, bestätigen die Monophylie der Gattung und schlagen ihre Einordnung in die wieder eingerichtete monotypische Familie Mohouidae vor.

Pseudogenisation of the Short-wavelength Sensitive 1 (SWS1) Opsin Gene in Two New Zealand Endemic Passerine Species: the Yellowhead (Mohoua ochrocephala) and Brown Creeper (M. novaeseelandiae)

ABSTRACT Perception of ultraviolet (UV) light, mediated by the avian short-wavelength sensitive-1 (SWS1) opsin, is important for birds in a range of functional contexts, including foraging, mate choice, and offspring recognition. The maximum absorption wavelength of avian SWS1 opsins can shift in and out of UV wavelengths because of residue changes at functionally critical positions in the SWS1 second transmembrane domain. Indeed sequencing of a short SWS1 gene ‘spectral tuning’ coding region allows assignment of avian vision as either ultraviolet sensitive (UVS) or violet sensitive (VS). Here, we report frameshift mutations in the SWS1 ‘spectral tuning’ regions of two endemic New Zealand passerine species: the Yellowhead or Mohua (Mohoua ochrocephala) and the Brown Creeper or Pipipi (M. novaeseelandiae). The findings indicate a total absence of functional SWS1 opsins in these two species in contrast to their congeneric, the Whitehead or Popokotea (M. albicilla) which is predicted to have UVS vision. Associated alternations in light perception might have critical implications for color-associated behaviors in these two Mohoua species, including discrimination of their own eggs from those of the genus’ specialist brood parasite, the Pacific Long-tailed Cuckoo or Koekoea (Urodynamis taitensis). In combination with recent evidence for frameshift based loss of opsin functioning in penguins, we suggest that loss of opsin function in avian lineages may be more widespread than previously assumed and may be of adaptive significance.