Search

Toxoplasma gondii has been reported as a cause of morbidity and mortality in New Zealand's native avifauna, including the ground-dwelling Kiwi (Apteryx spp.). To better understand the extent of T. gondii infection in Little Spotted Kiwi (Apteryx owenii), a prevalence survey of kiwi living inside a 200-ha predator-proof mainland ecosanctuary (Zealandia Te Māra a Tāne, Wellington, New Zealand) was undertaken. Antibodies to T. gondii were detected by a latex agglutination test (LAT) with a cutoff positive titer of ≥1:64, and T. gondii DNA was detected by PCR. In total, 16/19 (84.2%) birds tested were positive for T. gondii by LAT (10/11), PCR (10/19), or both (4/11). Antibody titers ranged from 1:32 to ≥1:2,048. These results suggest widespread exposure of T. gondii in this population of Little Spotted Kiwi and, in conjunction with earlier reports of toxoplasmosis causing mortality in kiwi, raise important questions as to the effect this parasite may be having on this rare endemic species. Further information on the epidemiology of T. gondii infections within free-living and managed kiwi populations is urgently needed. [ABSTRACT FROM AUTHOR]

Abstract Background Kiwi (Apteryx spp.) are flightless ratites from New Zealand whose numbers and distributions have declined following human arrival. Some of the kiwi species are known to hybridise but the extent of hybridization is unknown. Methods We reviewed hybridisation in kiwi (Apteryx spp.) and present new genetic data examining the extent of hybridisation between Rowi (A. rowi) and Little Spotted Kiwi (A. owenii) at Okarito, the location of the only remaining natural population of the threatened Rowi. We also genetically examined the syntype specimens of A. haastii Potts, 1872, collected from near Okarito in the 1870s, which have unusual morphologies. Results We found evidence of recurrent hybridisation between Rowi and Little Spotted Kiwi over the last 150 years, including one F1 hybrid found in the last 15 years, despite Little Spotted Kiwi’s likely extinction on the mainland in the 1970s. However, we found little evidence of introgression of Little Spotted Kiwi alleles into the extant Rowi population. The syntype specimens of A. haastii were also found to be hybrids between Little Spotted Kiwi and Rowi. Conclusions Our genetic analyses indicate that, although we detected multiple instances of hybridisation between Rowi and Little Spotted Kiwi, it does not appear to be an ongoing threat to Rowi. Because the syntype specimens of A. haastii are hybrids and therefore not representative of the prevailing usage of the name for the Great Spotted Kiwi (A. haastii), we resurrect the nomen oblitum A. maxima Sclater and Hochstetter, 1861 for the large spotted kiwi species.

Abstract Apteryx is a genus of flightless birds endemic to New Zealand known to lay very large eggs in proportion to body weight. The eggshell of Apteryx is unusually thin and less porous than allometrically expected possibly as a compensation for a very long incubation period. Past studies have been carried out on Apteryx australis, a species which once comprised all kiwi with brown plumage, now separated into three distinct species. These species use different habitats and live at different latitudes and altitudes, therefore generating a need to revise our knowledge of the attributes of their eggshells. In this study, we measured the physical characteristics and water conductance on eggshell fragments of these three species and Great‐spotted Kiwi and relate them to the environmental conditions of their respective environments; we also measured the water vapor conductance of Brown Kiwi eggs of late stages of incubation. We found that several trade‐offs exist between incubation behavior, environmental conditions, and eggshell structure. We found differences between species in eggshell water vapor conductance seemingly related to altitude; Brown Kiwi and Rowi generally inhabiting lower altitudes had the highest conductance and Tokoeka, generally living in montane environments, the lowest. This is achieved by an increased eggshell thickness rather than a pore area reduction. Finally, the water vapor conductance late in incubation was 58% higher than infertile unincubated eggs, suggesting a drastic increase in conductance throughout the long incubation period. Using the values previously reported, we calculated the embryonic eggshell thinning to be 32.5% at the equatorial region of the eggshell. We describe several new features, such as triangular mineral particles in the cuticle, reported for the extinct Trigonoolithus amoei, and confirmed the existence of plugged pores. We suggest that these structures provide microbial protection needed by a burrow nesting species with a long incubation period.

In 2013 there was an outbreak of crusting ventral dermatitis among a group of juvenile rowi (Apteryx rowi), a species of the endangered New Zealand kiwi, that were being raised on an off-shore island sanctuary. Biopsies taken at the time found nematodes migrating within the epidermis of affected skin but the specific identity and origin of the organisms was not established, and sporadic cases of similar skin disease continue to occur on the island. On examination of additional sections from the original skin biopsies, adult nematodes and eggs were identified, the histomorphology of which was consistent with Capillaria sensu lato. PCR was performed on DNA extracted from archived formalin-fixed, paraffin-embedded tissue blocks of skin from eight affected rowi, using primers targeting the 18S region of nuclear ribosomal DNA and the COI gene of mitochondrial DNA of capillarid nematodes. The 18S sequences from all rowi samples were identical and matched sequences from members of the genus Eucoleus. In contrast, two distinct capillarid COI sequences were obtained, in one case both from the same rowi skin biopsy. While there were no close matches, both COI sequences also aligned nearest to sequences identified as Eucoleus spp. It is considered unlikely that two different nematode species are involved in the rowi skin lesions and the possible amplification of a COI pseudogene or “numt” is discussed. A species-level identification of the capillarid nematodes causing skin disease in rowi was not obtained, however based on histological evaluation the infections include reproductively-active adult nematodes. This finding indicates the possibility of perpetuation of the skin disease in the absence of the original source, as well as raising potential for the transfer of infection from the island when the juvenile rowi are translocated to their new habitats.

Osteohistology, the study of bone microstructure, provides an important avenue for assessing extinct and extant vertebrate growth and life history. Cortical vascularity and collagen fibre organization are direct reflections of growth rate, while bone growth marks are indicative of absolute age. However, each skeletal element has its own ontogenetic trajectory and microstructure of certain bones may not be a true representation of whole body growth. Extensive comparative study of modern taxa is required to resolve intraskeletal discrepancies among age, vascularity and tissue organization in extinct vertebrates. Despite their comparative utility, studies of bone microstructure in modern taxa are severely lacking. Here, we add to a growing comparative osteohistological database by describing (1) bone tissue organization, (2) growth mark count, (3) sexually dimorphic bone (e.g. medullary bone) and (4) secondary cortical reconstruction in the bone microstructure of a 14‐year‐old male and 5‐year‐old female North Island Brown Kiwi (Apteryx mantelli). Transverse and longitudinal histological ground sections were processed and described for femora, tibiotarsi, tarsometatarsi, humeri, ulnae and radii in both kiwis. Cortical bone can generally be described as parallel‐fibered tissue, interrupted by cyclical growth marks, with vascular canals oriented longitudinally within primary and secondary osteons. Tissue morphologically resembling medullary bone is present in the hindlimbs of the female, and coarse compacted cancellous bone (CCCB) is found sporadically in the male and female hindlimbs. Lines of arrested growth (LAGs) are present in all hindlimb bones of both kiwi, but remodelling has obliterated all LAGs in the male ulnae and radii. LAG count varies intraskeletally, but large weight bearing elements such as femora and tibiotarsi have less remodelling and, thus, higher number of LAGs. LAG count did not match absolute age in any skeletal element; a maximum of seven LAGs are present in the male kiwi and a maximum of seven LAGs in the female kiwi. The tissue organization within the forelimbs and hindlimbs is reflective of the protracted growth strategy of the North Island Brown Kiwi and congruent with previous studies of the kiwi. LAGs were highly variable throughout the skeleton of the kiwi and a decoupling of age and LAG deposition is apparent from the male kiwi samples. Excess LAGs in the 5‐year‐old female kiwi may be a product of hatching, egg laying or captivity. Regardless, LAG count variation in the kiwi stresses the importance of intraskeletal sampling when assessing growth patterns of extinct taxa. An extensive ontogenetic sampling of kiwi is necessary for future investigations of bone growth patterns, CCCB formation, medullary bone and LAG deposition and obliteration in these elusive birds. [ABSTRACT FROM AUTHOR]

Background: Kiwi (Apteryx spp.) are flightless ratites from New Zealand whose numbers and distributions have declined following human arrival. Some of the kiwi species are known to hybridise but the extent of hybridization is unknown. Methods: We reviewed hybridisation in kiwi (Apteryx spp.) and present new genetic data examining the extent of hybridisation between Rowi (A. rowi) and Little Spotted Kiwi (A. owenii) at Okarito, the location of the only remaining natural population of the threatened Rowi. We also genetically examined the syntype specimens of A. haastii Potts, 1872, collected from near Okarito in the 1870s, which have unusual morphologies. Results: We found evidence of recurrent hybridisation between Rowi and Little Spotted Kiwi over the last 150 years, including one F1 hybrid found in the last 15 years, despite Little Spotted Kiwi's likely extinction on the mainland in the 1970s. However, we found little evidence of introgression of Little Spotted Kiwi alleles into the extant Rowi population. The syntype specimens of A. haastii were also found to be hybrids between Little Spotted Kiwi and Rowi. Conclusions: Our genetic analyses indicate that, although we detected multiple instances of hybridisation between Rowi and Little Spotted Kiwi, it does not appear to be an ongoing threat to Rowi. Because the syntype specimens of A. haastii are hybrids and therefore not representative of the prevailing usage of the name for the Great Spotted Kiwi (A. haastii), we resurrect the nomen oblitum A. maxima Sclater and Hochstetter, 1861 for the large spotted kiwi species. [ABSTRACT FROM AUTHOR]

Apteryx is a genus of flightless birds endemic to New Zealand known to lay very large eggs in proportion to body weight. The eggshell of Apteryx is unusually thin and less porous than allometrically expected possibly as a compensation for a very long incubation period. Past studies have been carried out on Apteryx australis, a species which once comprised all kiwi with brown plumage, now separated into three distinct species. These species use different habitats and live at different latitudes and altitudes, therefore generating a need to revise our knowledge of the attributes of their eggshells. In this study, we measured the physical characteristics and water conductance on eggshell fragments of these three species and Great‐spotted Kiwi and relate them to the environmental conditions of their respective environments; we also measured the water vapor conductance of Brown Kiwi eggs of late stages of incubation. We found that several trade‐offs exist between incubation behavior, environmental conditions, and eggshell structure. We found differences between species in eggshell water vapor conductance seemingly related to altitude; Brown Kiwi and Rowi generally inhabiting lower altitudes had the highest conductance and Tokoeka, generally living in montane environments, the lowest. This is achieved by an increased eggshell thickness rather than a pore area reduction. Finally, the water vapor conductance late in incubation was 58% higher than infertile unincubated eggs, suggesting a drastic increase in conductance throughout the long incubation period. Using the values previously reported, we calculated the embryonic eggshell thinning to be 32.5% at the equatorial region of the eggshell. We describe several new features, such as triangular mineral particles in the cuticle, reported for the extinct Trigonoolithus amoei, and confirmed the existence of plugged pores. We suggest that these structures provide microbial protection needed by a burrow nesting species with a long incubation period. [ABSTRACT FROM AUTHOR]

Kiwis (Apterygidae) are an enigmatic family of flightless birds endemic to New Zealand. Apterygidae is made up of a single genus, Apteryx with five species, four of which are characterised as at risk of greater by the New Zealand Department of Conservation. These five species are further separated into two morphologically and genetically distinguishable clades, containing A.haastii, and A.owenii in one and A.rowi, A.mantelli, and A.australis in the other. We reconstructed 17 kiwi mitochondrial genomes from previously published genomic data, nine from A.rowi and eight from A.owenii. Mitochondrial diversity analyses uncovered low levels of genetic diversity consistent with their reduced ranges and conservation concern. We further used one of the assembled A.rowi mitochondrial genomes together with mitochondrial genomes from A.haastii, A.owenii, A.mantelli, and several other individuals from Palaeognathae to estimate the within and between clade divergence times of kiwis. Our study exemplifies how available published data can be used in novel ways to provide new and complementary evolutionary insights to previous studies. [ABSTRACT FROM AUTHOR]

In 2013 there was an outbreak of crusting ventral dermatitis among a group of juvenile rowi (Apteryx rowi), a species of the endangered New Zealand kiwi, that were being raised on an off-shore island sanctuary. Biopsies taken at the time found nematodes migrating within the epidermis of affected skin but the specific identity and origin of the organisms was not established, and sporadic cases of similar skin disease continue to occur on the island. On examination of additional sections from the original skin biopsies, adult nematodes and eggs were identified, the histomorphology of which was consistent with Capillaria sensu lato. PCR was performed on DNA extracted from archived formalin-fixed, paraffin-embedded tissue blocks of skin from eight affected rowi, using primers targeting the 18S region of nuclear ribosomal DNA and the COI gene of mitochondrial DNA of capillarid nematodes. The 18S sequences from all rowi samples were identical and matched sequences from members of the genus Eucoleus. In contrast, two distinct capillarid COI sequences were obtained, in one case both from the same rowi skin biopsy. While there were no close matches, both COI sequences also aligned nearest to sequences identified as Eucoleus spp. It is considered unlikely that two different nematode species are involved in the rowi skin lesions and the possible amplification of a COI pseudogene or "numt" is discussed. A species-level identification of the capillarid nematodes causing skin disease in rowi was not obtained, however based on histological evaluation the infections include reproductively-active adult nematodes. This finding indicates the possibility of perpetuation of the skin disease in the absence of the original source, as well as raising potential for the transfer of infection from the island when the juvenile rowi are translocated to their new habitats. Image 1 • Dermatitis associated with nematode migration has been diagnosed in juvenile rowi kiwi. • Histological and molecular analysis indicates a member of Capillaria sensu lato. • The possible amplification of a COI pseudogene is discussed. [ABSTRACT FROM AUTHOR]

Sporadic cases of visceral and neural nematode larva migrans have been diagnosed at necropsy in the endangered New Zealand kiwi (Apteryx spp.), but the causative organisms have not yet been definitively identified. From an initial group of five affected kiwi, PCR was performed on DNA extracted from archival formalin-fixed paraffin-embedded tissue sections in which larval nematodes had been histologically identified. Sequencing of positive results from four out of the five kiwi aligned with sequences from Toxocara cati , a nematode parasite whose definitive host is the domestic cat. PCR was then performed on a second group of 12 kiwi that had histologic inflammatory lesions consistent with larva migrans , but variable larval presence. Repeatable positive PCR results were only achieved in one tissue, in which larval organisms were histologically confirmed. This study supports the use of PCR as an alternative or adjunct to the morphological identification of nematode larvae in formalin-fixed histopathological samples, as well as showing that in investigation of larva migrans , PCR has greatest chance of success from sections where nematode larvae are evident histologically. The identification of Toxocara cati from lesions of larva migrans in kiwi reflects an indirect, parasite-mediated effect of an invasive mammalian species on a native species. Image 1 • Cases of nematode larva migrans have been diagnosed in the New Zealand kiwi. • PCR was performed on archival formalin-fixed paraffin-embedded tissue blocks. • Results identified Toxocara cati , a parasite of cats, as the causative agent. • PCR had greatest success from tissues where larvae were identifiable histologically. [ABSTRACT FROM AUTHOR]

Aims: To investigate the presence of Campylobacter spp. in captive kiwi (Apteryx spp.) and compare their genotypic profiles with those of human and animal origin, in order to assess their potential for zoonotic or zooanthroponotic transmission. Methods: Conventional selective enrichment and filter-based isolation methods were applied to isolate Campylobacter spp. from fresh faecal samples from 12 North Island brown kiwi (Apteryx mantelli) and one great spotted kiwi (A. haastii), housed in one of five different areas in a kiwi sanctuary in Christchurch, New Zealand. Isolates were identified using multiplex PCR and 16S rRNA gene sequencing. High-resolution rapid genotyping using multiplex ligation-dependant probe amplification-based binary typing (MBiT) was applied and profiles compared with similar results from 2,165 Campylobacter spp. isolates contained in a database derived from human clinical, veterinary and environmental samples. Results: One isolate of C. jejuni, and one belonging to the C. lari phylogenetic group were recovered from faeces from two kiwi. High-resolution rapid genotyping by MBiT demonstrated these to be indistinguishable from isolates obtained previously from human cases of diarrhoea, and others from chicken, cattle, sheep and water. Conclusions: These data provide evidence for potential zoonotic or zooanthroponotic transmission of Campylobacter spp. in kiwi with implications for management of birds kept in captivity. We believe this is the first formal report of C. jejuni and a C. lari-like organism in kiwi. Abbreviations: MBiT: Multiplex ligation-dependant probe amplification-based binary typing [ABSTRACT FROM AUTHOR]

AIM: To assess the efficacy of toltrazuril against the Eimeria spp. affecting brown kiwi (Apteryx mantelli). METHODS: Droppings were collected from three brown kiwi, aged <6 months old, at a captive rearing facility in the North Island of New Zealand, between 22 February and 20 April 2017, on 14 sampling dates. Only droppings (n=30) that were excreted between 03:00 and 07:00, as determined using video surveillance, were included for analysis, reflecting the peak time for shedding of coccidial oocysts for brown kiwi. Oocysts were quantified in each sample and Eimeria species identified on the basis of oocyst morphology. All samples were collected between 2 and 10 days after the birds had been treated with 25 mg/kg toltrazuril. RESULTS: Eimeria spp. oocysts were identified in 28/30 individual samples and on 14/14 sampling dates. Oocyst counts varied from 0 to 328,080 oocysts per gram (opg), and at least one oocyst count >10,000 opg was measured on 12/14 sampling dates. Three species of Eimeria were observed, with Eimeria apteryxii and E. kiwii most commonly encountered, whereas only one sample contained E. paraurii. CONCLUSIONS AND CLINICAL RELEVANCE: In the three birds monitored at this research site, there was a high abundance of E. apteryxii and E. kiwii oocysts in droppings despite recent administration of toltrazuril. These results suggest that the populations of Eimeria spp. affecting brown kiwi at this location appear to possess an ability to survive exposure to toltrazuril. Toltrazuril is widely used at captive rearing facilities to limit the effects of coccidiosis in juvenile kiwi. If a lack of efficacy is confirmed, it will be necessary to investigate alternative treatment regimens alongside broader environmental management strategies. [ABSTRACT FROM AUTHOR]

Captive rearing of wild brown kiwi (Apteryx mantelli) is widely carried out to assist in the recovery of this declining species. As a consequence, high densities of immunologically naïve kiwi are commonly housed in semi-captive conditions, with the potential to result in substantial morbidity and mortality from coccidiosis caused by multiple species of Eimeria. Previous research has described circadian variation in oocyst shedding across multiple avian host species. The aim of this research was to describe any circadian variation in oocyst shedding in brown kiwi. Droppings were collected from brown kiwi (n = 4) at a single captive rearing facility using video surveillance to determine the time of excretion, and oocyst counts were undertaken. Results show that two of the Eimeria spp. affecting brown kiwi exhibit a peak in oocyst shedding between 03.00 and 07.00 with few or no oocysts shed between 08.00 and midnight. These results are not able to be explained by the current hypotheses theorising the evolutionary forces behind the development of this adaptive trait. Our findings increase the current understanding of the biology of the Eimeria spp. affecting brown kiwi and have important implications for the management of captive-reared kiwi, in particular for the accurate interpretation of faecal oocyst counts. [ABSTRACT FROM AUTHOR]

Carotenoids have important roles in bird behavior, including pigmentation for sexual signaling and improving color vision via retinal oil droplets. Yellow carotenoids are diet-derived, but red carotenoids (ketocarotenoids) are typically synthesized from yellow precursors via a carotenoid ketolase. Recent research on passerines has provided evidence that a cytochrome p450 enzyme, CYP2J19, is responsible for this reaction, though it is unclear if this function is phylogenetically restricted. Here I provide evidence that CYP2J19 is the carotenoid ketolase common to Aves using the genomes of 65 birds and the retinal transcriptomes of 15 avian taxa. CYP2J19 is functionally intact and robustly transcribed in all taxa except for several species adapted to foraging in dim light conditions. Two penguins, an owl and a kiwi show evidence of genetic lesions and relaxed selection in their genomic copy of CYP2J19 , and six owls show evidence of marked reduction in CYP2J19 retinal transcription compared to nine diurnal avian taxa. Furthermore, one of the owls appears to transcribe a CYP2J19 pseudogene. Notably, none of these taxa are known to use red carotenoids for sexual signaling and several species of owls and penguins represent the only birds known to completely lack red retinal oil droplets. The remaining avian taxa belong to groups known to possess red oil droplets, are known or expected to deposit red carotenoids in skin and/or plumage, and/or frequently forage in bright light. The loss and reduced expression of CYP2J19 is likely an adaptation to maximize retinal sensitivity, given that oil droplets reduce the amount of light available to the retina. [ABSTRACT FROM AUTHOR]

Molecular dating largely overturned the paradigm that global cooling during recent Pleistocene glacial cycles resulted in a burst of species diversification although some evidence exists that speciation was commonly promoted in habitats near the expanding and retracting ice sheets. Here, we used a genome-wide dataset of more than half a million base pairs of DNA to test for a glacially induced burst of diversification in kiwi, an avian family distributed within several hundred kilometers of the expanding and retracting glaciers of the Southern Alps of New Zealand. By sampling across the geographic range of the five kiwi species, we discovered many cryptic lineages, bringing the total number of kiwi taxa that currently exist to 11 and the number that existed just before human arrival to 16 or 17. We found that 80% of kiwi diversification events date to the major glacial advances of the Middle and Late Pleistocene. During this period, New Zealand was repeatedly fragmented by glaciers into a series of refugia, with the tiny geographic ranges of many kiwi lineages currently distributed in areas adjacent to these refugia. Estimates of effective population size through time show a dramatic bottleneck during the last glacial cycle in all but one kiwi lineage, as expected if kiwi were isolated in glacially induced refugia. Our results support a fivefold increase in diversification rates during key glacial periods, comparable with levels observed in classic adaptive radiations, and confirm that at least some lineages distributed near glaciated regions underwent rapid ice age diversification. [ABSTRACT FROM AUTHOR]

Background: Kiwi represent the most basal extant avian lineage (paleognaths) and exhibit biological attributes that are unusual or extreme among living birds, such as large egg size, strong olfaction, nocturnality, flightlessness and long lifespan. Despite intense interest in their evolution and their threatened status, genomic resources for kiwi were virtually non-existent until the recent publication of a single genome. Here we present the most comprehensive kiwi transcriptomes to date, obtained via Illumina sequencing of whole blood and de novo assembly of mRNA sequences of eight individuals from each of the two rarest kiwi species, little spotted kiwi (LSK; Apteryx owenii) and rowi (A rowi). Results: Sequences obtained were orthologous with a wide diversity of functional genes despite the sequencing of a single tissue type. Individual and composite assemblies contain more than 7900 unique protein coding transcripts in each of LSK and rowi that show strong homology with chicken (Gallus gallus), including those associated with growth, development, disease resistance, reproduction and behavior. The assemblies also contain 66,909 SNPs that distinguish between LSK and rowi, 12,384 SNPs among LSK (associated with 3088 genes), and 29,313 SNPs among rowi (associated with 4953 genes). We found 3084 transcripts differentially expressed between LSK and rowi and 150 transcripts differentially expressed between the sexes. Of the latter, 83 could be mapped to chicken chromosomes with 95% syntenic with chromosome Z. Conclusions: Our study has simultaneously sequenced multiple species, sexes, and individual kiwi at thousands of genes, and thus represents a significant leap forward in genomic resources available for kiwi. The expression pattern we observed among chromosome Z related genes in kiwi is similar to that observed in ostriches and emu, suggesting a common and ancestral pattern of sex chromosome homomorphy, recombination, and gene dosage among living paleognaths. The transcriptome assemblies described here will provide a rich resource for polymorphic marker development and studies of adaptation of these highly unusual and endangered birds. [ABSTRACT FROM AUTHOR]

All five species of kiwi ( Apteryx spp.) are listed as threatened or near threatened, and an important aspect of kiwi conservation is understanding the biology of parasites because of their potential to act as disease vectors and hinder kiwi survival. Although the ectoparasite fauna on kiwis has been categorized, there is a paucity of information on the biology of the kiwi tick, Ixodes anatis, and other parasites found on this unusual avian host. Here we explore the presence of I. anatis in burrows known to be used by North Island brown kiwi, Apteryx mantelli. There was a significant positive correlation between the frequency with which burrows were used by kiwi and both tick intensity and prevalence. The potential consequences of extended use of burrows by kiwi for nesting and tick intensity are discussed. Monthly tick distributions for varying age/sex classes are described as well as age/sex class distribution in different burrow types, with other invertebrates found in burrows also noted. Given the conservation risk for kiwi and the endemic status of I. anatis, understanding the impact of this tick species on kiwi as well as its natural history should be a priority for future research. [ABSTRACT FROM AUTHOR]

AIMS: To identify risk factors associated with coccidiosis in kiwi (Apteryxspp.) using a retrospective analysis of historical data from kiwi examined post-mortem, and to determine the prevalence of coccidial oocysts in the droppings of wild and captive kiwi. METHODS: Necropsy reports were examined from kiwi submitted to the National Wildlife Mortality Database of New Zealand (Huia) between February 1977 and May 2011. All cases that reported histological examination of one or more hepatic, intestinal or renal tissues were included in the study (n=372). Data collated for analysis included the presence or absence of coccidiosis in one or more tissues, age, host species, habitat, and season of submission. Fisher's exact test was used to determine the association between each independent variable and the prevalence of coccidiosis. Droppings opportunistically collected from wild and captive kiwi between January 2008 and June 2010 were also examined for the presence of coccidial oocysts. RESULTS: Coccidiosis was evident in 47/372 (12.6%) kiwi examined post-mortem and was considered the primary cause of death in 12/47 (26%) infected cases. Examination of 412 droppings from wild and captive kiwi collected over a 29-month period revealed that 98 (23.8%) samples contained coccidia at the time of sampling. Enteric (n=27) coccidiosis was the most common form diagnosed using histology, followed by renal (n=19) and hepatic (n=11), with splenic (n=2) and pulmonary (n=1) infections infrequently seen. Many kiwi demonstrated infections in multiple tissues. The prevalence of coccidiosis was greater in juvenile kiwi (36/148, 24.3%) than adults (8/133, 6.0%) or chicks (2/83, 2.4%) (p<0.001), although there was no difference in mortality between age groups. Season of year was also associated with overall prevalence (p=0.05), with most cases being diagnosed in the autumn and winter. Coccidiosis was histologically evident in four of five species of kiwi examined, and in all host species upon analysis of droppings. Host species or habitat (captivevs.wild) did not influence the prevalence of disease detected histologically. CONCLUSIONS: Age and season were the only factors that influenced the prevalence of coccidiosis in kiwi in this study. Coccidiosis was present in all species of kiwi, and this is the first report of coccidiosis in rowi (Apteryx rowi). [ABSTRACT FROM PUBLISHER]

Supervolcanoes are volcanoes capable of mega-colossal eruptions that emit more than 1,000 km3 of ash and other particles. 1 The earth's most recent mega-colossal eruption was the Oruanui eruption of the Taupo supervolcano 25,580 years before present (YBP) on the central North Island of New Zealand. 2 This eruption blanketed major swaths of the North Island in thick layers of ash and igneous rock, 2,3 devastating habitats and likely causing widespread population extinctions. 4–7 An additional devastating super-colossal eruption (>100 km3) of the Taupo supervolcano occurred approximately 1,690 YBP. 8 The impacts of such massive but ephemeral natural disasters on contemporary population genetic structure remain underexplored. Here, we combined data for 4,951 SNPs with spatially explicit demographic and coalescent models within an approximate Bayesian computation framework to test the drivers of genetic structure in brown kiwi (Apteryx mantelli). Our results strongly support the importance of eruptions of the Taupo supervolcano in restructuring pre-existing geographic patterns of population differentiation and genetic diversity. Range shifts due to climatic oscillations—a frequent explanation for genetic structure 9 —are insufficient to fully explain the empirical data. Meanwhile, recent range contraction and fragmentation due to historically documented anthropogenic habitat alteration adds no explanatory power to our models. Our results support a major role for cycles of destruction and post-volcanic recolonization in restructuring the population genomic landscape of brown kiwi and highlight how ancient and ephemeral mega-disasters may leave a lasting legacy on patterns of intraspecific genetic variation. [Display omitted] • Two supervolcanic eruptions left a legacy on the genetic structure of brown kiwi • Volcanic eruptions reshaped pre-existing patterns of population differentiation • Genetic signatures of ancient eruptions persist to the present day • Recent anthropogenic range fragmentation had little impact on genetic structure Bemmels et al. model changing landscapes in New Zealand to understand genetic structure in brown kiwi. Two prehistoric eruptions of the Taupo supervolcano devastated habitats and modified existing patterns of genetic diversity and population differentiation. Signatures of these ancient eruptions persist in genetic structure to the present day. [ABSTRACT FROM AUTHOR]

Assaying diversity at functional genomic regions, such as those of the immune system, allows us to test hypotheses about processes that determine the distribution of genetic diversity in threatened populations, and the fitness consequences of those distributions. Toll-like receptors (TLR) are a family of genes responsible for initiating innate and acquired immune responses to a diversity of pathogens. We provide 30 new primers, which, along with cross-species application of published primers, amplify TLR gene sequences in nine bird species of conservation concern in New Zealand. By including one member each of Apterygiformes and Gruiformes, two members of Psittaciformes, and five members of Passeriformes, our data significantly expand the number of avian species for which TLR sequences are available, and facilitates study of these genes in a greater diversity of taxa. [ABSTRACT FROM AUTHOR]

Six museum kiwi (Apteryxspp.) specimens of unknown or uncertain provenance were assigned to species using ancient DNA methods in conjunction with a reference database of modern and ancient kiwi DNA sequences. Four of the five species of kiwi exhibit a substantial overlap in bone morphology but can be identified with DNA sequences. The origin of one specimen, an articulated kiwi skeleton, was determined to be Stewart Island, a region that is currently poorly represented in museum collections. This study demonstrates that DNA analyses can add value to museum collections by determining species and provenance of specimens. [ABSTRACT FROM AUTHOR]

Abstract: Dogs (Canis familiaris) pose a significant threat to kiwi (Apteryx spp.) through predation. In an attempt to balance kiwi conservation and the need for dogs to be used for hunting purposes in kiwi habitat, the New Zealand Department of Conservation (DOC) developed the Kiwi Aversion Training (KAT) programme. KAT involves a training session in which a dog is presented with KAT stimuli (stuffed kiwi, frozen kiwi, and kiwi feathers) and a brief period (0.5–1.5s) of aversive electrical stimulation from an electric shock collar is applied when the dog makes contact with the training stimuli. This paper reports three experiments: (1) investigating whether dogs can learn to avoid the KAT stimuli through aversion training; (2) investigating maintenance of aversion to the KAT stimuli 1 month after initial training; and (3) investigating maintenance of aversion to the KAT stimuli 1 year after initial training. All dogs showed aversion responses to the KAT stimuli during the initial KAT training and also when exposed to the KAT stimuli 1 month after training without an electric collar being worn. 1 year after initial training, 87% (48/55) of dogs avoided the KAT stimuli. This research indicates that KAT effectively produces aversion towards the KAT stimuli that generalizes to another location, is independent of the electric collar being worn, and that lasts at least 1 year after training. [Copyright &y& Elsevier]

Major histocompatibility complex (MHC) genes are important for vertebrate immune response and typically display high levels of diversity due to balancing selection from exposure to diverse pathogens. An understanding of the structure of the MHC region and diversity among functional MHC genes is critical to understanding the evolution of the MHC and species resilience to disease exposure. In this study, we characterise the structure and diversity of class II MHC genes in little spotted kiwi Apteryx owenii, a ratite bird representing the basal avian lineage (paleognaths). Results indicate that little spotted kiwi have a more complex MHC structure than that of other non-passerine birds, with at least five class II MHC genes, three of which are expressed and likely to be functional. Levels of MHC variation among little spotted kiwi are extremely low, with 13 birds assayed having nearly identical MHC genotypes (only two genotypes containing four alleles, three of which are fixed). These results suggest that recent genetic drift due to a species-wide bottleneck of at most seven birds has overwhelmed past selection for high MHC diversity in little spotted kiwi, potentially leaving the species highly susceptible to disease. [ABSTRACT FROM AUTHOR]

The article presents a study on the presence of bone growth marks in New Zealand kiwi which indicates arrested growth. The study found that the full adult body size of kiwi is not reached until age 5 to 6. The slow rate of reproduction and low rate of metabolism in kiwi are discussed. The authors speculate that protracted growth in kiwi and moa convergently evolved since the Middle Miocene period due to climatic cooling and the absence of predators.

Conservation genetics typically seeks to map the distribution of contemporary genetic variation across space, and to use the resulting genetic parameters to infer any likely short-term evolutionary consequences for rare and endangered species. Recent developments in the study of ancient DNA now enable the extension of genetic variation studies backwards in time and provide a context by which to interpret contemporary levels of genetic variation, in addition to any patterns of genetic change over time. Ancient DNA research can also help to determine past levels of genetic diversity, identify species’ boundaries and reveal former ranges among morphologically cryptic taxa. Ancient DNA sequence data for the New Zealand kiwi ( Apteryx spp.) are presented and we show that most ancient populations of rowi and tokoeka exhibited private mitochondrial DNA haplotypes. Moreover, we illustrate that the extinction of these populations has led to the loss of considerable genetic variation. We also use ancient DNA methodology to determine past species distributions for brown kiwi and great spotted kiwi whose bones are morphologically indistinguishable. [ABSTRACT FROM AUTHOR]