scholarly journals Dung analysis of the East Milford mastodons: dietary and environmental reconstructions from central Nova Scotia at ~75 ka yr BP.

Author(s):  
Scott L. Cocker ◽  
Michael F.J. Pisaric ◽  
Francine McCarthy ◽  
Jesse C. Vermaire ◽  
Patrick Beaupre ◽  
...  

To reconstruct a mastodon diet and provide a ‘snapshot’ view of environmental conditions in eastern Canada prior to the onset of the Wisconsinan glaciation, we analysed the faunal and floral components of dung associated with juvenile mastodon remains from East Milford, Nova Scotia, dated to 74.9 ± 5.0 ka cal BP. The diverse assemblage of pollen, non-pollen palynomorphs, plant macrofossils and macroinvertebrate remains in the dung suggests that the mastodons lived in a spruce-dominated mixed coniferous-deciduous forest with a strong boreal aspect interspersed with wetlands rich in charophytes, sedges, cattails, bulrushes and bryophytes. The abundance of spruce needles and birch samaras in the dung sample is consistent with an inferred browsing behaviour, having been reported for other mammutid species previously. The limited diversity and near-absence of coprophilous fungi, such as <i>Sporormiella</i>, in the dung could have an impact on understanding the influence of feeding strategies on the presence of coprophilous taxa in sedimentary records, and thus interpretations of megafaunal abundance. The dung also yielded the earliest known Canadian remains of the bark beetle <i>Polygraphus </i>cf. <i>rufipennis</i>, gemmulae of the freshwater sponge <i>Eunapius </i>cf. <i>fragilis </i>and loricae of the rotifer <i>Keratella cochlearis</i>.

2012 ◽  
Vol 144 (6) ◽  
pp. 779-791 ◽  
Author(s):  
G.C. Cutler ◽  
J.M. Renkema ◽  
C.G. Majka ◽  
J.M. Sproule

AbstractThe Carabidae (Coleoptera) are a diverse family of beetles with almost 300 species identified in Nova Scotia, Canada. Carabid beetle communities have been studied in several agricultural systems, but not wild blueberries, an important crop in eastern Canada. In the interest of potentially developing conservation biological control programs in wild blueberry, we collected Carabidae in crop (fruit-bearing) and sprout (vegetative) blueberry fields in Nova Scotia in order to assess species diversity and abundance over space and time. Over 3200 specimens were collected, representing 51 species. A large portion of collected specimens (39%) were nonnative, and the most abundant species were generally predacious and synanthropic. Species diversity tended to be higher near forest edges than further into fields, but not for all abundant species. Several of the most prominent predators showed significant differences in preference of crop versus sprout fields, distribution throughout fields, and seasonable abundance. These findings have implications for conservation biological control efforts with carabid beetles against several insect pests in wild blueberry.


Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 769
Author(s):  
Suzanne Blatt ◽  
Kim Hiltz

(1) Background: The European apple sawfly, Hoplocampa testudinea Klug (Hymenoptera: Tenthredinidae), can be an economically important pest in eastern Canada and shows preference for apple cultivars in Nova Scotia, Canada. We hypothesized that this preference could be due to oviposition by female H. testudinea (preference-performance hypothesis) during the bloom period or differential larval survival during development due to fruitlet physicochemical properties. (2) Methods: Fifteen commercial and experimental apple (Malusdomestica Borkh.; Rosaceae) cultivars located at the Kentville Research and Development Centre (Kentville, Nova Scotia) were chosen and examined for H. testudinea oviposition, larval performance during fruitlet development, fruitlet physicochemical properties and damage assessment at harvest from 2016–2019, inclusive. (3) Results: H. testudinea showed significant cultivar preference during oviposition, during development and at harvest, but the ranking of these cultivars was not the same throughout the season. Total impact by H. testudinea was consistent for most cultivars over multiple years of the study. (4) Conclusion: Correlation of oviposition with damage provided weak evidence for the preference-performance hypothesis. We propose that this relationship is weak due to differential survival of larvae during development.


2020 ◽  
Vol 152 (3) ◽  
pp. 374-388
Author(s):  
Suzanne Blatt ◽  
Deney Augustine Joseph ◽  
G. Christopher Cutler ◽  
A. Randall Olson ◽  
Scott White

AbstractCarrot weevil, Listronotus oregonensis (LeConte) (Coleoptera: Curculionidae), is a pest of carrot (Daucus carota var. sativus Hoffmann; Apiaceae) throughout eastern Canada. Carrot weevil emergence and oviposition were monitored in commercial carrot fields in Nova Scotia. Cumulative degree days were calculated using a base temperature of 7 °C (DD7), and models were developed to predict cumulative emergence and oviposition using nonlinear regression. Cumulative emergence and oviposition were adequately explained as functions of DD7 by a three-parameter sigmoidal Hill equation. Our emergence model predicted initial and peak adult emergence at 35 and 387 DD7, respectively, with oviposition on carrot baits occurring as early as 42 DD7. Models were then validated to evaluate how well they performed. Oviposition on carrot plants began at the fourth true-leaf stage (342 DD7) and continued until eleventh true-leaf stage. Growers using these models can identify their window of opportunity to manage their carrot weevil populations targeting the majority of emerged adults before oviposition begins in the field.


2011 ◽  
Vol 125 (1) ◽  
pp. 58 ◽  
Author(s):  
Jean-David Moore ◽  
John Gilhen

Three colour morphs of the Eastern Red-backed Salamander, Plethodon cinereus, are known in eastern Canada: red-backed, lead-backed, and erythristic. Anomalies, including two albino and four leucistic individuals, are also known from eastern Canada. We report the first salamander individuals exhibiting amelanism, which is a lack of black skin pigment, but with black eyes, one from Quebec and one from Nova Scotia, Canada.


1976 ◽  
Vol 33 (6) ◽  
pp. 1278-1283 ◽  
Author(s):  
P. A. Breen ◽  
K. H. Mann

Destruction of kelp beds by sea urchins has been documented in St. Margaret’s Bay, Nova Scotia, and also appears to be taking place in other parts of eastern Canada. Continued sea urchin settlement onto grazed areas prevents the return of kelp and other algae for long periods. Because of the large contribution of kelp beds to coastal productivity, the disappearance of kelp from large areas is alarming. Dynamics of sea urchin grazing are discussed.


1997 ◽  
Vol 34 (12) ◽  
pp. 1630-1643 ◽  
Author(s):  
Stig M. Bergström ◽  
Warren D. Huff ◽  
Dennis R. Kolata ◽  
Michael J. Melchin

The most extensive succession of K-bentonite beds known in the Silurian of North America occurs at Arisaig on the northern coast of Nova Scotia. At least 40 ash beds are present in the Llandoverian Ross Brook Formation and at least four in the early Ludlovian McAdam Brook Formation. Most of the beds are thin (< 5 cm), but one bed (the Smith Brook K-bentonite bed) in the late Llandoverian crenulata Zone and another (the McAdam Brook K-bentonite bed) in the early Ludlovian nilssoni Zone each reach a thickness of 20 cm. New graptolite collections provide critical information on the biostratigraphic position of the K-bentonite beds in the Ross Brook Formation. Geochemical data show that the Arisaig ash beds represent calc-alkaline magmas from plate margin, subduction-related volcanic vents. Differences in K-bentonite stratigraphic distribution, combined with paleogeographic considerations, suggest that the volcanoes were located much farther to the south in the Iapetus than the source volcanoes of the British–Baltoscandian Llandoverian K-bentonites.


1989 ◽  
Vol 67 (7) ◽  
pp. 1793-1800 ◽  
Author(s):  
S. L. Poynton ◽  
J. Lom

Trichodina murmanica Polyanskiy, 1955 (= Trichodina domerguei subsp. saintjohnsi Lom and Laird, 1969) and Trichodina cooperi n.sp. were commonly encountered on skin and fins of Atlantic cod, Gadus morhua L., near Halifax, Nova Scotia, Canada. A third species of Trichodina, probably new, was recorded from the skin of one fish. This is believed to be the first report of the genus Trichodina from the body surface of gadoid fish from eastern Canada, and the known geographic range of T. murmanica is extended. Trichodina cooperi n.sp. has an adoral ciliary spiral of 370–380° and is relatively large, the mean diameter of the body is 110 μm, of the adhesive disc (with dark center), 95 μm, and of the denticulate ring, 59 μm. The denticulate ring consists of 24–29 denticles (usually 27), with 7–9 radial pins per denticle. Each denticle has a broad blade, a large central part, and a slightly curved thorn of moderate to broad width, with a central rib when mature. The thorn is approximately twice the length of the blade. The horseshoe-shaped macronucleus has a diameter of 80.0 μm and the micronucleus is in the +y position. Trichodina spp. infected 26% of 39 wild fish 20 to < 60 cm long. Most wild fish yielded less than five ciliates per 24 × 50 mm smear.


1939 ◽  
Vol 71 (8) ◽  
pp. 175-178 ◽  
Author(s):  
John W. H. Rehn
Keyword(s):  

The orthopterous fauna of this area of eastern Canada and of Newfoundland is exceedingly limited but at the same time is of considerable interest to those who are interested in the faunistics and ecology of this group.


2012 ◽  
Vol 144 (4) ◽  
pp. 526-537 ◽  
Author(s):  
Kathleen R. Aikens ◽  
Christopher M. Buddle

AbstractVertical gradients in biotic and abiotic factors may create small-scale spatial variation in arthropod communities, a phenomenon that continues to be understudied. We investigated heterogeneity in the vertical distribution of spider and beetle assemblages in the canopy of sugar maples (Acer saccharum Marshall) (Aceraceae) in a deciduous forest in eastern Canada. Comparisons across four strata (understorey [UN] through upper canopy [UC] crown) documented variation in density, diversity, and species composition. Density of all common families decreased significantly with height and overall species richness of both spiders and beetles was highest in the UN and lowest in the UC crown. We observed greater spatial variation in spider assemblages compared with beetle assemblages and documented differences in spider guild structure: web-spinning spiders were most common in the UN and jumping spiders dominated the canopy. Our results suggest that arthropod assemblages are not homogeneous with respect to vertical space and that heterogeneity exists even at the scale of several metres.


1992 ◽  
Vol 29 (5) ◽  
pp. 909-924 ◽  
Author(s):  
A. M. Grist ◽  
P. H. Reynolds ◽  
M. Zentilli ◽  
C. Beaumont

Apatite fission track and 40Ar/39Ar age spectrum data from sandstone drill-core minerals taken from depths of 2–5 km in nine wells from the Scotian Basin are presented and interpreted in terms of the thermal history of the basin and the provenance of its sediments. The focus of the study is a comparison of the data from these thermochronometers with each other and with previously published vitrinite reflectance and aromatization–isomerization (A–I) reactions in biomarker compounds from the same or nearby wells.Apatite fission track ages are generally in agreement with expectations in that they trend to zero at a depth of ~4 km (corrected bottom-hole temperature ~120 °C). Shallower (lower present temperature) samples are partially annealed; the degree of partial annealing correlates closely with the degree of A–I reactions. Both thermal indicators are activated over the temperature range 60–120 °C.Samples from two wells, Mic Mac J-77 and Erie D-26, are anomalous. They are more annealed than present formation temperatures would predict, an anomaly that is also indicated by the A–I data. These samples are interpreted as having experienced higher than present temperatures subsequent to deposition, possibly resulting from the passage of hot fluids related to localized volcanism or the sudden venting of an overpressured reservoir.K-feldspars record minor (< 20%) argon loss as a result of burial heating in the basin only at the greatest depths of the sampled range (> 4.3 km). This result is in agreement with the thermal models of the Scotian Basin and extrapolation of the A–I and fission track data to greater depths. The inferred argon loss implies an activation energy of 40 ± 4 kcal/mol for the smallest diffusion domains.The argon age spectra for samples that have not lost argon during residence in the basin provide evidence on the provenance of the sediments. K-feldspars from the Early Cretaceous Missisauga Formation have spectra that are similar to those obtained from K-feldspars from the Grenville Province of the Canadian Shield, whereas muscovites from the same formation give Cambrian to Carboniferous argon ages (mean 387 Ma), an indication of contributions from other source rocks. Corresponding data from the Jurassic Mohican Formation are similar to those reported for plutons from the southern Nova Scotia mainland (ca. 250–350 Ma argon ages). By implication, the Mohican Formation, which is the earliest postrift deposit, was derived from local sources inferred to be adjacent flank uplifts, whereas the Missisauga Formation was derived in part either directly or indirectly from the Grenvillian-aged interior of eastern Canada.


Sign in / Sign up

Export Citation Format

Share Document