Observations of the echolocation, feeding behaviour, and habitat use of Euderma maculatum (Chiroptera: Vespertilionidae) in southcentral British Columbia

1981 ◽  
Vol 59 (6) ◽  
pp. 1099-1102 ◽  
Author(s):  
G. C. Woodsworth ◽  
G. P. Bell ◽  
M. B. Fenton
Keyword(s):  
British Columbia ◽  
Ponderosa Pine ◽  
Feeding Behaviour ◽  
Low Frequency ◽  
Breeding Population ◽  
Moderate Intensity ◽  
Echolocation Call ◽  
Feeding Site ◽  
Call Structure ◽  
High Level

A record of the spotted bat, Euderma maculatum, from Oliver, British Columbia, is the first for Canada, extending its known range approximately 900 km. The specimen was obtained from a well-established breeding population in this area and does not represent an accidental or stray record. Observations of the foraging bahaviour of E. maculatum suggest that it may change its strategy from a rapid traplining approach in the spring, to spending more time per feeding site later in the summer, always foraging in ponderosa pine montane woodland. In the study area, E. maculatum appeared to roost in areas with high steep cliffs. The echolocation calls of this species are of low frequency (fundamental from 15 to 8 kHz) and moderate intensity (80–90 dB). Our observations and the theoretical implications of its echolocation call structure suggest that E. maculatum is a fast-flying, high-level forager that may include a high proportion of tympanate moths in its diet.

Roost-site selection and roosting ecology of forest-dwelling bats in southern British Columbia

1996 ◽  
Vol 74 (10) ◽  
pp. 1797-1805 ◽  
Author(s):  
Maarten J. Vonhof ◽  
Robert M. R. Barclay
Keyword(s):  
British Columbia ◽  
Ponderosa Pine ◽  
Tree Height ◽  
Canopy Closure ◽  
Ambient Conditions ◽  
White Pine ◽  
Roosting Ecology ◽  
Site Preferences ◽  
Roost Trees ◽  
Lasionycteris Noctivagans

We used radiotelemetry to examine the roost-site preferences of four species of tree-roosting bats (Eptesicus fuscus, Lasionycteris noctivagans, Myotis evotis, and M. volans) in southern British Columbia, Canada, by radio-tracking bats to their day roosts. We found a total of 21 roost trees: 14 roosts were beneath loose bark, 5 were in cavities excavated by woodpeckers, and 2 were in natural cavities. Entrance height increased with tree height, but roost entrances tended to be situated below the level of the canopy. Of the 22 tree and site variables examined, only 3 significantly discriminated between roost trees and available trees: tree height, distance to the nearest available tree, and percent canopy closure. Bats preferred tall trees associated with low percent canopy closure and a short distance to the nearest available tree. Bats roosted in western white pine, and to a lesser extent ponderosa pine and western larch, in intermediate stages of decay more often than would be expected at random. Bats switched roosts frequently. The distance between subsequent roost trees was short, suggesting a degree of fidelity to a particular group of trees or area of forest. The number of days of rain during the roosting period significantly influenced the number of days spent in a particular roost, and thus ambient conditions may restrict the frequency with which bats can switch roosts.

Combining Distributed Acoustic Sensing and Beamforming in a Volcanic Environment on Mount Meager, British Columbia.

2021 ◽  
Author(s):  
Sara Klaasen ◽  
Patrick Paitz ◽  
Jan Dettmer ◽  
Andreas Fichtner
Keyword(s):  
British Columbia ◽  
Power Distribution ◽  
High Frequency ◽  
Low Frequency ◽  
Volcanic Tremor ◽  
Extreme Environment ◽  
Volcanic Complex ◽  
Acoustic Sensing ◽  
Distributed Acoustic Sensing ◽  
Volcanic Environment

<p>We present one of the first applications of Distributed Acoustic Sensing (DAS) in a volcanic environment. The goals are twofold: First, we want to examine the feasibility of DAS in such a remote and extreme environment, and second, we search for active volcanic signals of Mount Meager in British Columbia (Canada). </p><p>The Mount Meager massif is an active volcanic complex that is estimated to have the largest geothermal potential in Canada and caused its largest recorded landslide in 2010. We installed a 3-km long fibre-optic cable at 2000 m elevation that crosses the ridge of Mount Meager and traverses the uppermost part of a glacier, yielding continuous measurements from 19 September to 17 October 2019.</p><p>We identify ~30 low-frequency (0.01-1 Hz) and 3000 high-frequency (5-45 Hz) events. The low-frequency events are not correlated with microseismic ocean or atmospheric noise sources and volcanic tremor remains a plausible origin. The frequency-power distribution of the high-frequency events indicates a natural origin, and beamforming on these events reveals distinct event clusters, predominantly in the direction of the main peaks of the volcanic complex. Numerical examples show that we can apply conventional beamforming to the data, and that the results are improved by taking the signal-to-noise ratio of individual channels into account.</p><p>The increased data quantity of DAS can outweigh the limitations due to the lower quality of individual channels in these hazardous and remote environments. We conclude that DAS is a promising tool in this setting that warrants further development.</p>

Neuronal correlates of siphon withdrawal in freely behaving Aplysia

1979 ◽  
Vol 42 (6) ◽  
pp. 1538-1556 ◽  
Author(s):  
J. E. Kanz ◽  
L. B. Eberly ◽  
J. S. Cobbs ◽  
H. M. Pinsker
Keyword(s):  
Low Frequency ◽  
Short Latency ◽  
Moderate Intensity ◽  
Efferent Activity ◽  
Nerve Cuff ◽  
Tactile Stimuli ◽  
Cuff Electrodes ◽  
Neuronal Mechanisms ◽  
Wide Range ◽  
Freely Behaving

1. Central neuronal mechanisms of siphon withdrawal in Aplysia were studied for the first time in intact, freely behaving animals by means of population recordings from implanted whole-nerve cuff electrodes. Intracellular follow-up studies were then conducted when the same animal was reduced to a semi-intact preparation. 2. Background spontaneous activity in the siphon nerve consisted of low-frequency firing of a population of efferent units containing identified siphon motoneurons. 3. Spontaneous patterned bursts of efferent activity occurred irregularly and were associated with all-or-nothing contractions of the parapodia, gill, and siphon. Spontaneous bursts were due to centrally generated activity in the interneuron II (INT II) network, an oscillatory network with endogenous pacemaker properties. 4. In intact animals, even weak tactile stimuli to the siphon typically triggered an INTII burst shortly after the stimulus-locked efferent activity. Thus, the stimulus can phase-advance the INT II oscillator. In semi-intact preparations, short-latency INT II bursts were triggered less less frequently and required more intense stimuli. 5. With weak to moderate-intensity stimuli in intact animals, the presence of short-latency triggered INT II bursts largely determined the duration of the siphon component and amplitude of the gill component of the withdrawal reflex. 6. When stimuli were repeated over a range of interstimulus intervals (from 60 to 1 min), the likelihood of triggering a short-latency INT II burst die not change systematically. Thus, the ability of the siphon stimulus to stably entrain the all-or-none INT II component over a wide range of intervals will interact behaviorally with the decrement of the monosynaptic component of the reflex with repetition.

Rare earth element concentrations in Quaternary volcanic rocks of southwestern British Columbia

1984 ◽  
Vol 21 (6) ◽  
pp. 731-736 ◽  
Author(s):  
Nathan L. Green ◽  
Paul Henderson
Keyword(s):  
British Columbia ◽  
Earth Element ◽  
Volcanic Rocks ◽  
Crustal Contamination ◽  
Lake Area ◽  
Calc Alkaline ◽  
Lower Light ◽  
The Individual ◽  
High Level ◽  
Ree Patterns

A suite of hy-normative hawaiites, ne-normative mugearite, and calc-alkaline andesitic rocks from the Garibaldi Lake area exhibits fractionated, slightly concave-upward REE patterns (CeN/YbN = 4.5–15), heavy REE contents about 5–10 times the chondritic abundances, and no Eu anomalies. It is unlikely that the REE patterns provide information concerning partial melting conditions beneath southwestern British Columbia because they have probably been modified substantially by upper crustal processes including crustal contamination and (or) crystal fractionation. The REE contents of the Garibaldi Lake lavas are not incompatible with previous interpretations that (1) the hawaiites have undergone considerable fractionation of olivine, plagioclase, and clinopyroxene; and (2) the individual andesitic suites were derived from separate batches of chemically distinct magma that evolved along different high-level crystallization trends. In general, however, the andesites are characterized by lower light REE contents than the basaltic andesites. These differences in LREE abundances may reflect different amounts of LREE-rich accessory phases, such as apatite, sphene, or allanite, assimilated from the underlying quartz diorites.

Seiche Excitation in Port San Juan, British Columbia

1979 ◽  
Vol 36 (10) ◽  
pp. 1223-1227
Author(s):  
D. D. Lemon ◽  
P. H. LeBlond ◽  
T. R. Osborn
Keyword(s):  
British Columbia ◽  
Water Waves ◽  
Pressure Gauge ◽  
Low Frequency ◽  
San Juan ◽  
External Forcing ◽  
Edge Waves ◽  
Rectangular Basin ◽  
Juan De Fuca ◽  
Juan De Fuca Strait

Seiche motions observed in San Juan Harbour with a bottom-mounted pressure gauge have been Fourier-analyzed and interpreted in terms of a theoretical model of oscillations in a rectangular basin with an exponential depth profile. Two of the observed periods (at 14.6 and 38.5 min) are identified with resonances of the basin; two other significant low frequency peaks (at 21 and 55 min) do not coincide with resonant periods of the basin and must be due to strong external forcing. Higher frequency fluctuations (20–160 s) are attributed to swell and to its subharmonic interactions with edge waves. Key words: water waves, seiches, mathematical model, Juan de Fuca Strait, British Columbia

The litoria ewingi complex (Anura : Hylidae) in south-eastern Australia V. Interactions between northern L. ewingi and adjacent taxa

1978 ◽  
Vol 26 (1) ◽  
pp. 175 ◽  
Author(s):  
GF Watson ◽  
MJ Littlejohn
Keyword(s):  
Small Area ◽  
Character Displacement ◽  
Reproductive Character Displacement ◽  
Genetic Compatibility ◽  
Natural Interaction ◽  
Call Structure ◽  
Environmental Features ◽  
Mating Call ◽  
Eastern Australia ◽  
High Level

A small area of overlap with hybridization characterizes the interaction between northern L. ewingi and L. paraewingi. Although significant levels of postmating isolation exist between the taxa, no evidence of reproductive character displacement in mating-call structure is apparent within the contact zone. No obvious environmental features appear to correlate with the position of the zone. Northern L. ewingi and L. verreauxi alpina also form a hybrid zone where their ranges meet, and the position of the zone appears to be correlated with altitude. The taxa are characterized by a high level of genetic compatibility and no mating-call differentiation is evident. However, despite hybridization with adjacent taxa, the distinctness of northern L. ewingi is maintained away from the areas of interaction, and hence it is considered specifically distinct from L. paraewingi and L. v. alpina. No natural interaction between northern L. ewingi and L. ewingi has been located. However, they are considered to be conspecific because of: their morphological resemblance; the high level of genetic compatibility between them; and, the similarity of each of their interactions with L. paraewingi and with L. v. alpina.

scholarly journals Cochlear compound action potentials from high-level tone bursts originate from wide cochlear regions that are offset toward the most sensitive cochlear region

2019 ◽  
Vol 121 (3) ◽  
pp. 1018-1033 ◽  
Author(s):  
C. Lee ◽  
J. J. Guinan ◽  
M. A. Rutherford ◽  
W. A. Kaf ◽  
K. M. Kennedy ◽  
...  
Keyword(s):  
High Frequency ◽  
Action Potentials ◽  
Tuning Curve ◽  
Low Frequency ◽  
Sound Level ◽  
Frequency Tone ◽  
Compound Action Potentials ◽  
High Level ◽  
Level Tone ◽  
Compound Action

Little is known about the spatial origins of auditory nerve (AN) compound action potentials (CAPs) evoked by moderate to intense sounds. We studied the spatial origins of AN CAPs evoked by 2- to 16-kHz tone bursts at several sound levels by slowly injecting kainic acid solution into the cochlear apex of anesthetized guinea pigs. As the solution flowed from apex to base, it sequentially reduced CAP responses from low- to high-frequency cochlear regions. The times at which CAPs were reduced, combined with the cochlear location traversed by the solution at that time, showed the cochlear origin of the removed CAP component. For low-level tone bursts, the CAP origin along the cochlea was centered at the characteristic frequency (CF). As sound level increased, the CAP center shifted basally for low-frequency tone bursts but apically for high-frequency tone bursts. The apical shift was surprising because it is opposite the shift expected from AN tuning curve and basilar membrane motion asymmetries. For almost all high-level tone bursts, CAP spatial origins extended over 2 octaves along the cochlea. Surprisingly, CAPs evoked by high-level low-frequency (including 2 kHz) tone bursts showed little CAP contribution from CF regions ≤ 2 kHz. Our results can be mostly explained by spectral splatter from the tone-burst rise times, excitation in AN tuning-curve “tails,” and asynchronous AN responses to high-level energy ≤ 2 kHz. This is the first time CAP origins have been identified by a spatially specific technique. Our results show the need for revising the interpretation of the cochlear origins of high-level CAPs-ABR wave 1. NEW & NOTEWORTHY Cochlear compound action potentials (CAPs) and auditory brain stem responses (ABRs) are routinely used in laboratories and clinics. They are typically interpreted as arising from the cochlear region tuned to the stimulus frequency. However, as sound level is increased, the cochlear origins of CAPs from tone bursts of all frequencies become very wide and their centers shift toward the most sensitive cochlear region. The standard interpretation of CAPs and ABRs from moderate to intense stimuli needs revision.

scholarly journals Feeding habits of Stellifer rastrifer (Perciformes, Sciaenidae) at Guaratuba mangrove, Parana, Brazil

1998 ◽  
Vol 41 (4) ◽  
pp. 423-428 ◽  
Author(s):  
Paulo de Tarso C. Chaves ◽  
Ana Lúcia Vendel
Keyword(s):  
Feeding Behaviour ◽  
Food Item ◽  
Feeding Habits ◽  
Fish Populations ◽  
The Individual ◽  
High Level ◽  
Individual Size

Feeding habits of Stellifer rastrifer (Perciformes, Sciaenidae) at Guaratuba mangrove, Parana, Brazil, were studied from February 1996 to February 1997. It was observed that its diet was based on invertebrates, mainly Decapoda non-Brachyura and Polychaeta. In a smaller proportion there were plants, Copepoda, Gammaridea and Mollusca. The level of contribution of each food item changed according to the season and the individual size. Such plasticity in feeding behaviour was similar to that described to some fish populations from other estuaries, and could be an indicator of the high level of instability presented by this kind of ecosystem.

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