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Estimating the abundance and density of mountain ungulates is difficult because of rugged and remote terrain, high elevations, and rapidly changing weather. Helicopter surveys could overcome these problems, but researchers have seldom applied helicopter‐based survey methods at large spatial scales in mountain terrain. We used helicopters to count introduced Himalayan tahr (Hemitragus jemlahicus) at 117 plots, each of 4 km2, in New Zealand's Southern Alps during 2016–2019. The sampling frame was 7,844 km2 and we located the plots at the vertices of an 8‐km grid superimposed over the sampling frame (i.e., a systematic random sampling design). We conducted 3 repeat counts at each plot during summer–autumn. We used the repeat counts to estimate tahr abundance and density, corrected for imperfect detection, using a dynamic N‐mixture model for open populations. We estimated the population of tahr in the sampling frame using design‐based, finite sampling methods and model‐based inference procedures. The mean estimated density of tahr on each plot varied from zero to 31.7 tahr/km2. The mean densities of tahr varied among management units, ranging from 0.3 to 10.7 tahr/km2, and exceeded specified intervention densities in 6 of the 7 management units. The total design‐based estimate of tahr abundance in the sampling frame was 34,500 (95% CI = 27,750–42,900), with a coefficient of variation (CV) of 0.11. The corresponding model‐based estimate of total abundance was similar (34,550, 95% CI = 30,250–38,700) but was substantially more precise (CV = 0.06) than the design‐based estimate. The precision of the estimates for the individual management units was also better than that of the design‐based estimates, with CVs of <0.20 for all but 1 management unit. Our study provides a repeatable method for sampling mountain ungulates. More generally, robust estimation of abundance and density of mountain ungulates is possible by combining aerial surveys and open population models with an objective, probabilistic sampling design. [ABSTRACT FROM AUTHOR]

To report a rare case of Birt-Hogg-Dubé Syndrome (BHD) with progressive chorioretinopathy. Case report. A 55-year-old woman presented with longstanding nyctalopia attributed to a congenital retinal dystrophy, but no prior genetic testing. Her posterior pole examination demonstrated retinal pigment epithelium (RPE) mottling with extensive macular drusen and paracentral chorioretinal atrophy, consistent with a fleck retinopathy. Her past medical history was remarkable for nephrectomy for unilateral renal malignancy, parotid tumors and thyroid nodules. Dark adaptation time was prolonged, and electroretinography (ERG) revealed abnormal waveforms with depressed amplitudes. Genetic testing confirmed a deletion mutation in the folliculin (FLCN) gene and was negative for other relevant mutations, including EFEMP1 responsible for autosomal dominant macular and peripapillary drusen in Doyne honeycomb retinal dystrophy and TIMP3 responsible for Sorsby Fundus Dystrophy. BHD is a rare autosomal-dominant disorder with multi-systemic clinical manifestations caused by a mutation in the FLCN gene. Affected individuals are prone to renal and pulmonary cysts, renal cancer, and fibrofolliculomas. Reports on ocular manifestations of BHD include eyelid fibrofolliculomas, flecked chorioretinopathy, choroidal melanoma, choroidal melanoma with sector melanocytosis, and retinal pigment epithelial micro-detachments. In this case of BHD, we note a fleck retinopathy with bilateral chorioretinal atrophy, displaying a phenotype of extensive chorioretinopathy associated with impaired dark adaptation and ERG abnormalities. BHD: Birt-Hogg-Dubé syndrome; FLCN: Folliculin. RPE: retinal pigment epithelium; OD: Oculus dexter (right eye); OS: Oculus sinister (left eye). OU: Oculus uterque (both eyes); ERG: electroretinogram; mfERG: multifocal electroretinography. ffERG: full-field electroretinography; FAF: fundus autofluorescence; OCT: optical coherence tomography; FA: fluorescein angiography; DA: dark-adapted; LA: light-adapted; mTOR: mammalian target of rapamycin; EFEMP1: epithelial growth factor-containing fibulin-like extracellular matrix protein 1; VPS13B: Vacuolar Protein Sorting 13 Homolog B; AGBL5: AATP/GTP-Binding Protein Like 5; ALMS1: Alstrom Syndrome 1; COL1BA1: Collagen Type I Beta, Alpha Chain 1; PDE6A: Rod Phosphodiesterase 6-alpha; USH2A: Usherin 2a; VCAN: Versican; RP: Retinitis pigmentosa; AR: Autosomal recessive. [ABSTRACT FROM AUTHOR]

Rapid increases in native riverine fish populations associated with trophic upsurge immediately following reservoir construction are well documented. Repeated upsurge periods and extended benefits to populations are, however, less understood. We used sclerochronology to investigate fish growth and netting surveys to estimate recruitment and abundance of a lacustrine population of an Australian riverine fish, the Macquarie perch (Macquaria australasica) in Lake Dartmouth. Record low inflows from 1997 to 2008 caused the reservoir to shrink to its lowest volume since construction. Refilling began in 2008, reaching 99% capacity in 2013. We hypothesized that fish growth, recruitment, and abundance would increase in response to the refilling of the lake, reproducing a similar response to the initial filling period. Our findings supported this hypothesis. Macquarie perch growth, recruitment, and abundance were enhanced during the refilling of Lake Dartmouth. Growth, best explained by the effects of dam height, change in dam height, temperature (and their interactions), and recruitment, were highest during the first years of refilling when lake levels and temperatures were low. We propose one or a combination of varying levels of intraspecific competition (low during initial filling and high following population expansion) and improved riverine conditions for reproductive success as the most plausible explanation. Our results suggest extended periods of low lake levels followed by rapid inundation events are likely to enhance recruitment and population growth opportunities for this species. While reservoir construction in general impacts negatively on native fish populations, the potential to offset these impacts for conservation management purposes should be considered. Les augmentations rapides de populations de poissons de riviere indigenes associees a la poussee trophique qui suit immediatement la construction d'un reservoir sont bien documentees. La comprehension de periodes de poussee trophique successives et de leurs avantages pour les populations demeure toutefois plus limitee. Nous avons utilise la sclerochronologie pour etudier la croissance des poissons et des releves au filet pour estimer le recrutement et l'abondance d'une population lacustre d'un poisson de riviere australien, la perche de Macquarie (Macquaria australasica) dans le lac Dartmouth. Des debits entrants d'une faiblesse record de 1997 a 2008 ont fait diminuer le volume du reservoir jusqu'au point le plus bas enregistre depuis sa construction. Le nouveau remplissage a debute en 2008, pour atteindre 99% de la capacite du reservoir en 2013. Nous avons postule que la croissance, le recrutement et l'abondance des poissons augmenteraient en reponse a ce nouveau remplissage du lac, une reaction semblable a celle observee durant le remplissage initial. Nos constatations appuient cette hypothese. La croissance, le recrutement et l'abondance des perches de Macquarie ont augmente durant le nouveau remplissage du lac Dartmouth. La croissance, qu'expliquent le mieux les effets de la hauteur du barrage, des changements de cette hauteur et de la temperature (et leurs interactions), ainsi que le recrutement etaient a leur plus fort durant les premieres annees du nouveau remplissage, quand les niveaux et les temperatures du lac etaient faibles. Nous proposons que les variations du degre de concurrence intraspecifique (faible durant le remplissage initial, plus eleve apres l'expansion de la population) et (ou) l'amelioration des conditions fluviales necessaires au succes de reproduction constituent l'explication la plus plausible. Nos resultats donnent a penser que de longues periodes de faibles niveaux du lac suivies par des inondations rapides sont susceptibles d'accroitre les possibilites de recrutement et de croissance de la population pour cette espece. Si, en general, la construction de reservoirs a une incidence negative sur les populations de poissons indigenes, la compensation possible de ces impacts aux fins de gestion et de conservation devrait etre prise en consideration. [Traduit par la Redaction], Introduction The construction of large dams and subsequent creation of reservoirs has been a major driver of reductions in the range and abundance of native riverine fishes globally. The detrimental [...]

To present a semi-automated method of image alignment to aid in monitoring the progression of inherited retinal degenerations (IRDs). A 22-year-old woman presented with nyctalopia and a family history of retinitis pigmentosa (RP), but with no prior genetic testing. Fundus examination showed a sectoral retinal degeneration involving the inferior and nasal retina with rare, pigmented deposits. Goldmann kinetic perimetry demonstrated corresponding superotemporal visual field defects. The best-corrected visual acuity was 20/20 in both eyes. Multimodal imaging delineated geographically restricted peripheral retinal degeneration extending to the inferior edge of the macula. Central visual function remained intact with normal multifocal electroretinography findings. Optical coherence tomography (OCT) through the leading edge of the retinal degeneration confirmed loss of the photoreceptor layer and associated retinal pigment epithelium. In the region of retinal degeneration, loss of vascular flow density was noted on optical coherence tomography angiography (OCTA). Genetic testing identified a pathologic sequence variant in RHO (c.68C>A, p.Pro23His), confirming autosomal dominant sector retinitis pigmentosa (SRP). Image alignment allowed for precise measurement of the progression of SRP over a period of 18 months. SRP is a rare subtype of RP characterized by focal, typically inferior and nasal, retinal degeneration of the peripheral retina. Although the onset and extent of peripheral retinal degeneration varies, compared with RP, SRP typically progresses more slowly to involve the macula. In this report, we highlight the utility of image registration and alignment to aid in monitoring disease progression in IRDs by means of multimodal imaging. [ABSTRACT FROM AUTHOR]

Since their introduction in 1859, European rabbits (Oryctolagus cuniculus) have had a devastating impact on agricultural production and biodiversity in Australia, with competition and land degradation by rabbits being one of the key threats to agricultural and biodiversity values in Australia. Biocontrol agents, with the most important being the rabbit haemorrhagic disease virus 1 (RHDV1), constitute the most important landscape-scale control strategies for rabbits in Australia. Monitoring field strain dynamics is complex and labour-intensive. Here, using phylodynamic models to analyse the available RHDV molecular data, we aimed to: investigate the epidemiology of various strains, use molecular data to date the emergence of new variants and evaluate whether different strains are outcompeting one another. We determined that the two main pathogenic lagoviruses variants in Australia (RHDV1 and RHDV2) have had similar dynamics since their release, although over different timeframes (substantially shorter for RHDV2). We also found a strong geographic difference in their activities and evidence of overall competition between the two viruses. [ABSTRACT FROM AUTHOR]