The Experts below are selected from a list of 444 Experts worldwide ranked by ideXlab platform
Isabel Castro - One of the best experts on this subject based on the ideXlab platform.
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captivity reduces diversity and shifts composition of the brown kiwi microbiome
Animal Microbiome, 2021Co-Authors: Priscilla San A Juan, Isabel Castro, Manpreet K DhamiAbstract:Captive rearing is often critical for animals that are vulnerable to extinction in the wild. However, few studies have investigated the extent to which captivity impacts hosts and their gut microbiota, despite mounting evidence indicating that host health is affected by gut microbes. We assessed the influence of captivity on the gut microbiome of the Brown Kiwi (Apteryx mantelli), a flightless bird endemic to New Zealand. We collected wild (n = 68) and captive (n = 38) kiwi feces at seven sites on the north island of New Zealand. Using bacterial 16 S rRNA and fungal ITS gene profiling, we found that captivity was a significant predictor of the kiwi gut bacterial and fungal communities. Captive samples had lower microbial diversity and different composition when compared to wild samples. History of coccidiosis, a gut parasite primarily affecting captive kiwi, showed a marginally significant effect. Our findings demonstrate captivity’s potential to shape the Brown Kiwi gut microbiome, that warrant further investigation to elucidate the effects of these differences on health.
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Mixed Mating in a Multi-Origin Population Suggests High Potential for Genetic Rescue in North Island Brown Kiwi, Apteryx mantelli
'Frontiers Media SA', 2021Co-Authors: Isabel Castro, Malin Undin, Peter J. Lockhart, Simon F. K. Hills, Doug P. ArmstrongAbstract:Reinforcement translocations are increasingly utilised in conservation with the goal of achieving genetic rescue. However, concerns regarding undesirable results, such as genetic homogenisation or replacement, are widespread. One factor influencing translocation outcomes is the rate at which the resident and the introduced individuals interbreed. Consequently, post-release mate choice is a key behaviour to consider in conservation planning. Here we studied mating, and its consequences for genomic admixture, in the North Island brown kiwi Apteryx mantelli population on Ponui Island which was founded by two translocation events over 50 years ago. The two source populations used are now recognised as belonging to two separate management units between which birds differ in size and are genetically differentiated. We examined the correlation between male and female morphometrics for 17 known pairs and quantified the relatedness of 20 pairs from this admixed population. In addition, we compared the genetic similarity and makeup of 106 Ponui Island birds, including 23 known pairs, to birds representing the source populations for the original translocations. We found no evidence for size-assortative mating. On the contrary, genomic SNP data suggested that kiwi of one feather did not flock together, meaning that mate choice resulted in pairing between individuals that were less related than expected by random chance. Furthermore, the birds in the current Ponui Island population were found to fall along a gradient of genomic composition consistent with non-clustered representation of the two parental genomes. These findings indicate potential for successful genetic rescue in future Apteryx reinforcement translocations, a potential that is currently under utilised due to restrictive translocation policies. In light of our findings, we suggest that reconsideration of these policies could render great benefits for the future diversity of this iconic genus in New Zealand
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Captivity reduces diversity and shifts composition of the Brown Kiwi microbiome
'Springer Science and Business Media LLC', 2021Co-Authors: Priscilla San A Juan, Isabel Castro, Manpreet K DhamiAbstract:Abstract Background Captive rearing is often critical for animals that are vulnerable to extinction in the wild. However, few studies have investigated the extent to which captivity impacts hosts and their gut microbiota, despite mounting evidence indicating that host health is affected by gut microbes. We assessed the influence of captivity on the gut microbiome of the Brown Kiwi (Apteryx mantelli), a flightless bird endemic to New Zealand. We collected wild (n = 68) and captive (n = 38) kiwi feces at seven sites on the north island of New Zealand. Results Using bacterial 16 S rRNA and fungal ITS gene profiling, we found that captivity was a significant predictor of the kiwi gut bacterial and fungal communities. Captive samples had lower microbial diversity and different composition when compared to wild samples. History of coccidiosis, a gut parasite primarily affecting captive kiwi, showed a marginally significant effect. Conclusions Our findings demonstrate captivity’s potential to shape the Brown Kiwi gut microbiome, that warrant further investigation to elucidate the effects of these differences on health
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description of four new species of coccidia apicomplexa eimeriidae from brown kiwi Apteryx mantelli in new zealand
Parasitology Research, 2017Co-Authors: K J Morgan, L Howe, M R Alley, W E Pomroy, Isabel CastroAbstract:This study used morphological techniques to describe and name four new species of coccidia from the brown kiwi (Apteryx mantelli). Four distinct eimerian oocyst species were recovered that we describe as new species. The largest of these, Eimeria paraurii n. sp. measured 32.2 × 19.8 μm and is morphologically similar to gametocytes previously described histologically in colorectal polyps (Morgan et al. in Parasitol Res 111(4):1689–1699, 2012). Eimeria Apteryxii n. sp. measured 23.9 × 14.9 μm and is similar to renal oocysts described histologically in brown, rowi (A. rowii) and Haast tokoeka kiwi (A. australis “Haast”) (Morgan et al. in Avian Pathol 42(2):137–146, 2013). Eimeria kiwii n. sp. measured 14.8 × 13.9 μm and resembled gametocytes described previously in kiwi intestinal epithelial cells in brown kiwi (Morgan et al. in Parasitol Res 111(4):1689–1699, 2012). Eimeria mantellii n. sp. measured 17.8 × 10.7 μm and did not appear similar to any coccidia previously described in histological studies in kiwi. These are the first species of Eimeria to be described and named from brown kiwi. Because the morphological descriptions in the present study were determined from a limited number of kiwi droppings from two geographical locations, it is likely that these represent only a portion of Eimeria species present in other populations of both brown kiwi and other Apteryx species from around New Zealand.
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Apteryx spp kiwi possess an uropygial gland anatomy and pathology
European journal of anatomy, 2017Co-Authors: Sian M Reynolds, Isabel Castro, M R Alley, Susan J CunninghamAbstract:The uropygial gland is a prominent feature of the avian anatomy but there is limited information on its structure and function. The gland is of current interest because it provides a source for volatile chemicals that can be used by birds in communication. We examined the anatomy of uropygial glands in Apteryx for the first time. The gland was located immediately caudal to the cloaca and surrounding the coccygeal bone rather than rostral to the coccygeal bone and above the posterior free caudal vertebrae as in other birds. This may explain why it has not been recognised until relatively recently. Like most uropygial glands Apteryx’s were bilobar but possessed eight primary sinuses, each opening through its own orifice in the gland’s papilla. Primary ducts were compact and branches of connective tissue extending from the capsule internally formed interfollicular septae that were thicker in some areas, grouping follicles into discrete lobules. Striated muscle was present in the capsule, a characteristic so far unique to Apteryx that may be used in controlling the expulsion of secretion. There were significant differences in the architecture of the follicles between species and sexes that suggest differences in the production, storage and availability of uropygial gland secretion. This was supported by variations in live bird’s gland volume between two years of sampling. Atrophy of the uropygial gland was seen in two birds in poor condition suggesting that health impacts the functioning of the gland. This finding suggests an adaptive significance for the gland and offers a possible way for birds to communicate their health status through the production or composition of the secretion. More research is needed to fully understand the relationship between the anatomy of the gland in Apteryx and its function, but we propose that it plays roles in both feather maintenance and sociality.
Christian Frelin - One of the best experts on this subject based on the ideXlab platform.
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THE EGG WHITE PROTEIN EVIDENCE FOR RATITE AFFINITIES
Ibis, 2008Co-Authors: Charles G. Sibley, Christian FrelinAbstract:Summary The egg white proteins of the large ratites (Struthio, Casuarius, Dromaius, Rhea), the kiwis (Apteryx) and several tinamous (Tinamidae) were compared with one another and representatives of several other groups of birds using the technique of isoelectric focusing in acrylamide gel. The tryptic peptides of the ovalbumins of the same groups were compared by thin-layer electrophoresis. The results indicate that the large ratites are more closely related to one another than any one of them is to any other living bird; that the kiwis are not closely related to any of the other groups with which they were compared; and that the tinamous are not closely related to any of the large ratites but may be distantly related to the Galliformes.
Stuart Parsons - One of the best experts on this subject based on the ideXlab platform.
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Histological sections of North Island brown kiwi (Apteryx mantelli) and bar-tailed godwit (Limosa lapponica) bill-tips.
2013Co-Authors: Susan J Cunningham, Isabel Castro, Jeremy R. Corfield, Andrew N. Iwaniuk, Maurice R. Alley, Tim R. Birkhead, Stuart ParsonsAbstract:A: Diagram of three coronal sections through a North Island brown kiwi bill, taken at: (1) 9 mm from the tip of the upper bill rhamphotheca (showing upper bill above, lower bill beneath); (2) 6 mm from tip of the upper bill rhamphotheca , sectioned through the sensory pad area forward of the tip of the rhamphotheca of the lower bill); (3) 3 mm from the tip of the upper bill rhamphotheca. Black areas represent the premaxilla and dentary bones. Dark grey shaded areas represent cross sections through the major nerves. Areas of soft tissue are shaded pale grey, the keratin and major blood vessels are left white. Herbst corpuscles (in 3) are white, with a central black line to represent the nerve axon. Bold lines indicate the outer surface of the keratin layer, finer lines indicate the junction between the dermal and keratin layers and the outlines of major blood vessels, nerves, and Herbst corpuscles. In (1), the premaxilla is perforated by the two nasal passages, bordered with bold lines and colored white. B: Sagittal section through a sensory pit in the North Island brown kiwi premaxilla, stained with Masson’s trichrome and C: a sensory pit in the bar-tailed godwit dentary, stained with haematoxylin and eosin. Abbreviations: N: nerves, B: bone. Examples of Herbst corpuscles are highlighted with white arrows. Scale bars = 100 µm.
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Sagittal sections of the brains of six species of birds examined in this study.
2013Co-Authors: Susan J Cunningham, Isabel Castro, Jeremy R. Corfield, Andrew N. Iwaniuk, Maurice R. Alley, Tim R. Birkhead, Stuart ParsonsAbstract:Photomicrographs of sagittal sections stained with cresyl violet through the brain of six species of birds examined in this study. The top panel shows the principal sensory trigeminal nucleus (PrV) and the bottom panel the nucleus basorostralis (Bas). The broken black lines indicate the borders of each of the regions present in the sections. Brain sections are shown from North Island brown kiwi (Apteryx mantelli), bar-tailed godwit (Limosa lapponica), Eurasian woodcock (Scolopax rusticola), South Island oystercatcher (Haematopus finschi), black-winged stilt (Himantopus himantopus), and masked lapwing (Vanellus miles). Abbreviations: A: arcopallium, N: nidopallium, H: hyperpallium, E: entopallium, SPC: striatopallidal complex, M: mesopallium, C: caudal, R: rostral, D: dorsal, V: ventral. Scale bars; top panel = 1 mm, bottom panel = 2 mm.
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Micro CT coronal sections through bill-tips of five probe-foraging bird species.
2013Co-Authors: Susan J Cunningham, Isabel Castro, Jeremy R. Corfield, Andrew N. Iwaniuk, Maurice R. Alley, Tim R. Birkhead, Stuart ParsonsAbstract:A: North Island brown kiwi (Apteryx mantelli), B: bar-tailed godwit (Limosa lapponica), C: Eurasian woodcock (Scolopax rusticola), D: black-winged stilt (Himantopus himantopus), and E: South Island oystercatcher (Haematopus finschi). Consecutive slices are 3 mm apart. Mid-grey areas = keratin and soft tissue, dark-grey to black areas = bone. Scale bar = 2 mm.
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3D reconstructions of the bill-tips of five probe-foraging bird species.
2013Co-Authors: Susan J Cunningham, Isabel Castro, Jeremy R. Corfield, Andrew N. Iwaniuk, Maurice R. Alley, Tim R. Birkhead, Stuart ParsonsAbstract:A1-4: the North Island brown kiwi (Apteryx mantelli), B1-4: Eurasian woodcock (Scolopax rusticola), C1-4: bar-tailed godwit (Limosa lapponica), D1-4: South Island oystercatcher (Haematopus finschi), and E1-4: black-winged stilt (Himantopus himantopus). Panel one shows a lateral view, panel two a dorsal view, panel three a ventral view, and panel four a rostral view. The dark grey structure represents the bone and the transparent structure the keratin.
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3D reconstructions of brain structures in six species of birds examined in this study.
2013Co-Authors: Susan J Cunningham, Isabel Castro, Jeremy R. Corfield, Andrew N. Iwaniuk, Maurice R. Alley, Tim R. Birkhead, Stuart ParsonsAbstract:3D reconstructions of the telencephalon (transparent), nucleus basorostralis (green), striatopallidal complex (blue) and the hyperpallium (red) in six species of birds. Models are shown in a lateral view in the top half of the panel and in a rostral view in the bottom half. Models are shown for North Island brown kiwi (Apteryx mantelli), bar-tailed godwit (Limosa lapponica), Eurasian woodcock (Scolopax rusticola), South Island oystercatcher (Haematopus finschi), black-winged stilt (Himantopus himantopus), and masked lapwing (Vanellus miles).
Wouter H. Hendriks - One of the best experts on this subject based on the ideXlab platform.
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Gastrointestinal tract of the brown kiwi (Apteryx mantelli)
Journal of Zoology, 2006Co-Authors: Murray A. Potter, Roger G. Lentle, Charlotte Jane Minson, M.j. Birtles, D. V. Thomas, Wouter H. HendriksAbstract:The caeca of the brown kiwi Apteryx mantelli increased in length isometrically with body mass, but wall mass and thus mucosal thickness increased allometrically. Kiwi caeca are sacculate, with greater thickness of mucosa in the proximal portions. The caecal mucosa is similar to the small intestinal mucosa, with welldeveloped mucosal folds, villi, and crypts of Lieberk ¨ uhn or intestinal glands. The solid matter in caecal digesta contained disproportionately large quantities of material that was not retained by a 75mm sieve. The per cent of incombustible material (total ash) within the caeca digesta did not differ significantly from those within adjacent small intestinal or rectal segments. The fine particles within the caeca were not composed of fine crystalline uric acid; chemical analyses showed only low levels of uric acid in caecal digesta. These findings indicate that the caeca of this flightless insectivorous ratite are a site for the sequestration and fermentative digestion of fine particulate material, such as plant fibre, fragmented chitin or uric acid crystals.
Bart Kempenaers - One of the best experts on this subject based on the ideXlab platform.
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Avian olfactory receptor gene repertoires: evidence for a well-developed sense of smell in birds?
Proceedings of The Royal Society B: Biological Sciences, 2008Co-Authors: Silke S. Steiger, Mihai Valcu, Andrew E. Fidler, Bart KempenaersAbstract:Among vertebrates, the sense of smell is mediated by olfactory receptors (ORs) expressed in sensory neurons within the olfactory epithelium. Comparative genomic studies suggest that the olfactory acuity of mammalian species correlates positively with both the total number and the proportion of functional OR genes encoded in their genomes. In contrast to mammals, avian olfaction is poorly understood, with birds widely regarded as relying primarily on visual and auditory inputs. Here, we show that in nine bird species from seven orders (blue tit, Cyanistes caeruleus; black coucal, Centropus grillii; brown kiwi, Apteryx australis; canary, Serinus canaria; galah, Eolophus roseicapillus; red jungle fowl, Gallus gallus; kakapo, Strigops habroptilus; mallard, Anas platyrhynchos; snow petrel, Pagodroma nivea), the majority of amplified OR sequences are predicted to be from potentially functional genes. This finding is somewhat surprising as one previous report suggested that the majority of OR genes in an avian (red jungle fowl) genomic sequence are non-functional pseudogenes. We also show that it is not the estimated proportion of potentially functional OR genes, but rather the estimated total number of OR genes that correlates positively with relative olfactory bulb size, an anatomical correlate of olfactory capability. We further demonstrate that all the nine bird genomes examined encode OR genes belonging to a large gene clade, termed g-c, the expansion of which appears to be a shared characteristic of class Aves. In summary, our findings suggest that olfaction in birds may be a more important sense than generally believed.