Moran, Jonathan

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    DNA metabarcoding allows non-invasive identification of arthropod prey provisioned to nestling Rufous hummingbirds (Selasphorus rufus)
    (Peer J, 2019) Moran, Alison J.; Prosser, Sean J. W.; Moran, Jonathan
    Hummingbirds consume sugars from nectar, sap and honeydew, and obtain protein, fat and minerals from arthropods. To date, the identity of arthropod taxa in hummingbird diets has been investigated by observation of foraging or examination of alimentary tract contents. Direct examination of nestling provisioning adds the extra complication of disturbance to the young and mother. Here, we show that arthropod food items provisioned to Rufous hummingbird (Selasphorus rufus) nestlings can be identified by a safe and non-invasive protocol using next-generation sequencing (NGS) of DNA from nestling fecal pellets collected post-fledging. We found that females on southern Vancouver Island (British Columbia, Canada) provisioned nestlings with a wide range of arthropod taxa. The samples examined contained three Classes, eight Orders, 48 Families, and 87 Genera, with from one to 15 Families being identified in a single pellet. Soft-bodied Dipterans were found most frequently and had the highest relative abundance; hard-bodied prey items were absent from almost all samples. Substantial differences in taxa were found within season and between years, indicating the importance of multi-year sampling when defining a prey spectrum.
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    Potential effects of climate change on members of the Palaeotropical pitcher plant family Nepenthaceae
    (PLoS ONE, 2017-08-17) Moran, Jonathan A.; Gray, Laura K.; Clarke, Charles; Wint, G. R. William
    Anthropogenic climate change is predicted to have profound effects on species distributions over the coming decades. In this paper, we used maximum entropy modelling (Maxent) to estimate the effects of projected changes in climate on extent of climatically-suitable habitat for two Nepenthes pitcher plant species in Borneo. The model results predicted an increase in area of climatically-suitable habitat for the lowland species Nepenthes rafflesiana by 2100; in contrast, the highland species Nepenthes tentaculata was predicted to undergo significant loss of climatically-suitable habitat over the same period. Based on the results of the models, we recommend that research be undertaken into practical mitigation strategies, as approximately two-thirds of Nepenthes are restricted to montane habitats. Highland species with narrow elevational ranges will be at particularly high risk, and investigation into possible mitigation strategies should be focused on them.
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    Ion fluxes across the pitcher walls of three Bornean Nepenthes pitcher plant species : flux rates and gland distribution patterns reflect nitrogen sequestration strategies
    (Journal of Experimental Botany, 2010) Moran, Jonathan A.; Hawkins, Barbara J.; Gowen, Brent E.; Robbins, Samantha L.
    Nepenthes pitcher plant species differ in their prey capture strategies, prey capture rates, and pitcher longevity. In this study, it is investigated whether or not interspecific differences in nutrient sequestration strategy are reflected in the physiology and microstructure of the pitchers themselves. Using a non-invasive technique (MIFE), ion fluxes in pitchers of Nepenthes ampullaria Jack, Nepenthes bicalcarata Hook.f., and Nepenthes rafflesiana Jack were measured. Scanning electron microscopy was also used to characterize the distribution of glandular and other structures on the inner pitcher walls. The results demonstrate that nutrient sequestration strategy is indeed mirrored in pitcher physiology and microstructure. Species producing long-lived pitchers with low prey capture rates (N. ampullaria, N. bicalcarata) showed lower rates of NH4 + uptake than N. rafflesiana, a species producing short-lived pitchers with high capture rates. Crucially, species dependent upon aquatic commensals (N. ampullaria, N. bicalcarata) actively manipulated H+ fluxes to maintain less acid pitcher fluid than found in ‘typical’ species; in addition, these species lacked the lunate cells and epicuticular waxes characteristic of ‘typical’ insectivorous congeners. An unexpected finding was that ion fluxes occurred in the wax-covered, non-glandular zones in N. rafflesiana. The only candidates for active transport of aqueous ions in these zones appear to be the epidermal cells lying beneath the lunate cells, as these are the only sites not visibly coated with epicuticular waxes.
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    Foliar reflectance and vector analysis reveal nutrient stress in prey-deprived pitcher plants ( nepenthes rafflesiana )
    (International Journal of Plant Sciences, 1998-11) Moran, Jonathan A.; Moran, Alison J.
    Pitcher plants of the genus Nepenthes trap invertebrate prey in pitchers formed from modified leaf tips. This study investigates the benefits of carnivory to Nepenthes rafflesiana, a common Bornean lowland species. Plants were denied prey capture in their natural habitat for 18 wk and were compared with a control group that was allowed to trap, digest, and assimilate prey as usual over the same period. Resource limitation was demonstrated in prey‐deprived plants, which produced significantly fewer and smaller pitchers than did control plants. Analysis of foliar spectral reflectance showed increased reflectance within part (608–738 nm) of the photosynthetically active wave band in the prey‐deprived plants, signifying a reduction in chlorophyll content. Decreased reflectance at 550 nm in the prey‐deprived plants also indicated increased production of anthocyanins, denoting possible nitrogen or phosphorus limitation. Although no difference was found in tissue concentrations of nitrogen or phosphorus between treatments, vector analysis identified a reduction in content of both elements as a result of reduced biomass production in prey‐deprived plants. Our findings demonstrate the key role carnivory plays in the nutrition of this species in its natural habitat.
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    From carnivore to detritivore? Isotopic evidence for leaf litter utilization by the tropical pitcher plant Nepenthes ampullaria
    (International Journal of Plant Sciences, 2003-07) Moran, Jonathan A.; Clarke, Charles M.; Hawkins, Barbara J.
    Nepenthes pitcher plants trap prey in specialized leaves formed into pitchers. Most lowland species live in open, sunny habitats and capture prey to obtain nutrients, principally nitrogen (N). Nepenthes ampullaria is commonly found under closed canopy forest and possesses morphological traits that indicate adaptation to trap leaf litter as a nutrient source. We tested this hypothesis by comparing foliar stable N isotope abundance (δˆ15N) between plants growing under forest canopy at 20 sites (litterfall present) and those growing in 20 open areas (no litterfall) in Borneo. Foliar δˆ15N values were significantly lower and total N concentrations were higher for the plants with access to litterfall. Using a mixing model, we estimated that N. ampullaria plants growing under forest canopy derived 35.7% ± 0.1% of their foliar N from leaf litter inputs.