Heavy Vegetation Research Articles

Movements, Habitat Use, and Predation on Pronghorn Fawns in Alberta

Sixty-two pronghorn (Antilocapra americana) neonates were fitted with radio collars in southeastern Alberta and located daily for 58 days or until death. The mean distance between bedded siblings was 73.4 m; they were first seen bedded together at 7 days of age and after 24 days they were together habitually. Mean daily movements and home ranges of fawns increased (P < 0.001) with age. Bedding-site selection and vegetation used by fawns did not change markedly during the 58-day observation period. Fawns preferred heavy native vegetation and under-used cultivated land. Predation by coyotes (Canis latrans) and bobcats (Felis rufus) caused the death of at least 43.5% of 62 marked fawns. Predation was highest on 4-15-day-old fawns, but remained important for animals between 16 and 57 days of age. During the past 10 years in Alberta, annual fawn mortality has approximated 50%. This rate of fawn mortality has not limited the growth of the provincial pronghorn population. J. WILDL. MANAGE. 48(2):542-550 Since the advent of miniaturized telemetry systems (Mech 1967) researchers have shown that predation can be a locally important cause of mortality for pronghorn fawns (Beale and Smith 1973, Barrett 1978, Beale 1978, Bodie 1978, Von Gunten 1978). Beale and Smith (1973) observed that radio collars did not alter the behavior of marked fawns nor change their mortality rate when compared with unmarked animals. Bromley (1978) theorized that bed-site selection by fawns was influenced by predation pressure and habitat structure. In Alberta, the mean mortality of fawns in the first 60 days following parturition approaches 50% (Barrett 1978). Mitchell (1980:139) and Barrett (1981) suggested that increased survival of fawns was a reflection of larger quantities of forb and browse cover. In Idaho, Bodie (1978) related differences in predation rates on fawns to cover type. This paper reports the spatial and behavioral relationships of free-ranging pronghorn fawns for 58 days after birth until they have been integrated into doefawn summer groups. The relationships of fawns to key habitat components of their environment and the effect of predation are also examined. Many individuals of the Alberta Fish and Wildlife Division assisted with fieldwork. Particular thanks go to E. H. Bruns, R. J. Clark, A. R. Cook, K. R. Froggatt, L. D. Gudmundson, D. E. Hofman, H. G. Vriend, and L. A. Windberg. J. P. Chenier, Computing Serv., Univ. of Alberta, assisted with statistical analyses. G. A. Chalmers, Anim. Health Div., Alberta Dep. of Agric., assisted with fieldwork, necropsies, and reviewed the manuscript. G. L. Langford, of G. L. Langford and Associates, Edmonton, assisted with the digitizing and analyses of occupied areas. W. M. Samuel, Univ. of Alberta, Edmonton, B. W. O'Gara, Univ. of Montana, Missoula, and M. J. Dorrance and A. W. Hawley of the Alberta Environ. Cent. reviewed the paper. STUDY AREA AND METHODS The study was conducted during 1975 and 1976 in a 1,054-km2 area of southeastern Alberta. The study area was in the Brown soil zone in part of the mixed-grass prairie region. Mean annual precipitation 542 J. Wildl. Manage. 48(2):1984 This content downloaded from 157.55.39.102 on Mon, 03 Oct 2016 05:11:50 UTC All use subject to http://about.jstor.org/terms PRONGHORN FAWN BEHAVIOR AND MORTALITY * Barrett 543 (1941-70) was 327 mm as measured by the Agriculture Canada research substation at Onefour. Western wheatgrass (Agropyron smithii), blue grama (Bouteloua gracilis), and needle-and-thread (Stipa comata) were the dominant grass species. The primary shrub was silver sagebrush (Artemisia cana), but western snowberry (Symphoricarpos occidentalis) and rose (Rosa spp.) were present in bottomlands and along the many intermittent water courses that transect the area. Topography varied from gently rolling plains to limited hills at an altitude of <1,100 m. This general area has been described by Coupland (1950, 1961) and Mitchell and Smoliak (1971). The study area was divided into large pastures by conventional threeor fourstrand barbed-wire fence and by a few roads. Domestic cattle ranged throughout the area during the summer grazing sea-

Relationship of Runoff and Soil Loss to Ground Cover of Native and Reclaimed Grazing Land1

AbstractVegetation cover is a dominant factor in controlling runoff and water erosion from agricultural land and an important criterion for determining adequate reclamation of strip−mined land. A simulated rainfall study was conducted near Center, N.D. to determine the relationship of ground cover factors to runoff and soil loss. The point frame technique was used to estimate vegetation cover as measured by either the first contact (first hit) of the sliding pins with live vegetation, litter, or bare soil and rock or by a similar contact of the sliding pins at the soil surface (surface hit). Artificial rainfall was applied at the rate of 46 mm/h to 4.0 × 22.1 m runoff plots located on 9 to 12% slopes within reclaimed and unmined pastures. Reclaimed treatments were ungrazed or grazed at light, moderate, or heavy intensity plus vegetation and litter removed by burning. Native range treatments were ungrazed, closely grazed, and burned. Native ungrazed plots had greater live surface cover than ungrazed or lightly grazed reclaimed plots but similar soil loss, runoff, and soil loss/runoff ratio (SL/RO). Best fit techniques revealed some cover factors linearly related to soil loss, runoff, and SL/RO; others logarithmically related. Live surface cover estimates were poorly related to runoff and soil loss. Adequacy of soil protection can be best estimated by percentage of bare soil. Runoff or soil loss estimates were similar whether total cover was estimated by surface hits or first hits; however, surface hits were easier to determine in tall vegetation under windy conditions. The point frame technique is satisfactory for estimating whether the cover is adequate to maintain soil stability on reclaimed land or native range. Its use can be extended to estimate ground cover in other erosion studies.

Physical modeling of em wave propagation over the earth

To obtain experimental data for correlation with the theoretical results obtained from mathematical ground wave propagation models, it is often expedient to conduct experiments on laboratory models using microwaves. Besides the obvious convenience and reduced cost, practical difficulties encountered in full‐scale experiments are avoided (e.g., weather and other uncontrolled parameters such as path nonhomogeneities, earth curvature, buildings, right‐of‐ways, etc). There is no need to use exact similitude scaling; the media and geometries are generally chosen to test the limits of validity of the theory. The designs of several such models in the frequency range of 4–5 GHz are discussed, and typical experimental results are compared with the corresponding theory. Specific examples are propagation in the earth‐ionosphere waveguide and propagation over planar and curved surfaces (including stratified media, for example, layered earth and sea ice), mixed paths (including media having abrupt discontinuities such as land‐sea boundaries and gradual nonuniformities such as sloping beaches), uniaxially anisotropic media, and media having an index of refraction near unity (e.g., heavy vegetation). When using such models, instrumentation systems and field probing techniques are key factors in their success. These are also discussed.

Radar Scattering from a Diffuse Vegetation Layer over a Smooth Surface

A simple model is presented for the oblique backscatter and bistatic scatter from a smooth surface overlain by a diffuse layer. Only single scattering in the diffuse layer is taken into account. The model analysis shows that the combination of volume scattering and oblique reflection at the surface may increase appreciably the waves scattering. The scattering strongly depends on the properties of the smooth surface. These results support some of the observations made with the Seasat spaceborne imaging radar over flooded regions with heavy vegetation cover.

Resource Partitioning in Two Coexisting Sunfish: Pumpkinseed (Lepomis gibbosus) and Northern Longear Sunfish (Lepomis megalotis peltastes)

Qualitative surveys of 22 lakes in southern Michigan indicated that relative abundances of the northern longear sunfish (Lepomis megalotis peltastes) and pumpkinseed (L. gibbosus) depended upon amount of plant cover and sediment type. The longear sunfish occurred only in lakes with marl sediments and regions of sparse vegetation cover. The pumpkinseed occurred in all lakes surveyed and increased in abundance in lakes with greater vegetation density and/or more organic sediments. Quantitative measurements of habitat and food use were made in five lakes with sympatric populations. Data from underwater transects indicated that large (&gt; 75 mm standard length) longear sunfish occurred primarily in shallow regions containing moderate to low vegetation cover whereas large pumpkinseeds were concentrated in deeper areas with heavy vegetation cover. The smaller size-classes of both species occupied the vegetation in deeper areas of the littoral zone. Large longears consumed predominantly large, sediment-dwelling mayfly or odonate nymphs regardless of the lake or habitat types. Pumpkinseeds consumed mainly gastropods and other prey from the vegetation. Preliminary studies of seasonal food use indicated that the pumpkinseed and longear sunfish both consumed more food in the spring and exhibited greater overlap in diet during this period. The relationship between foraging behaviors of these two species and the types of prey consumed is discussed as well as the complications of assessing competition between species when food and habitat use are dependent on size.Key words: Habitat use, size-class, lake types, food overlap, competition, Lepomis, Michigan

Movements of Grass Carp, Ctenopharyngodon idella, in an Open Reservoir System as Determined by Underwater Telemetry

Abstract Ultrasonic transmitters were placed in the peritoneal cavity of twelve adult grass crap in a Florida reservoir. Tagged grass crap ranged in size from 3.68 kg to 12.72 kg. No mortality of tagged grass carp was observed, but some difficulty was encountered with sound reception due to heavy vegetation and thermoclines. Fish took long rest periods between moves during both day and night. They were more active during the day than at night, with water temperatures limiting activity more than any other parameter tested. Displacement ranged from 182.9 m to 18,292.6 m.

A study of the green area effect in the Black Hills of South Dakota

Bimonthly sampling of Aitken and larger particles for a twelve-month period in the Black Hills of South Dakota has revealed several possible particle removal mechanisms. The measurements were made using a Gardner small particle counter at thirteen stations surrounding and within the Black Hills proper. The results indicate that the Black Hills area is a significant source of clean air and that observed low levels of particle concentrations are primarily the result of precipitation and in-cloud scavenging, elevation variation, and the particle removal mechanism of vegetation (greenarea effect). After correcting the data for elevation changes, precipitation scavenging, and local pollution sources, present analysis suggests the operation of a significant particulate filtering mechanism by the heavy vegetation of the Black Hills. The green area effect alone may serve to reduce ambient Aitken particle concentrations by as much as 50%.

Lead and zinc contamination of vegetation in the southern Pennines

Three types of heavy metal tolerant vegetation occurring on the spoil heaps in the Pennines are described sociologically and ecologically and their distribution in the Peak District National Park mapped. Concentrations of lead and zinc extractable from soils by acetic acid are recorded, as are total values for these two heavy metals in the tissues of the main component phanerogams and cryptogams of the vegetation. The range of values for zinc in plant tissues are uniformly higher than those for lead. Concentrations of lead accumulated by these plants are higher than those reported for the accumulation of atmospheric lead. The differences in heavy metal absorption, retention and excretion between ectohydric and myxohydric mosses are shown to be quite distinct. The heavy metals are excreted in the former type and form a crust in periods of drought with up to 6% lead and 1·5% zinc content, whilst, in the latter, the metals tend to be located mainly in the older growth at the base of the moss carpets. The concentrations of the two metal ions in two Peak District rivers proved to be less than 1 ppm in all samples.

Studies on the effect of ground vegetation on infestations of Oryctes rhinoceros (L.) (Col., Dynastidae) in young oil palm replantings in Malaysia

Oryctes rhinoceros (L.) breeds in the rotting stumps of oil palms and rubber trees, and is a potentially devastating pest of young oil palm replants, the unopened leaves of which are attacked by the adults. In view of the planters' belief that the pest is controlled by heavy ground vegetation, the effects of cover (natural, legume or grass) and bare ground on beetle populations in rotting logs and incidence of beetle attack on young palms were compared in a series of four experiments.

Ökologische Untersuchungen an Pflanzengesellschaften unterschiedlich stark gestörter schwermetallreicher Böden in Großbritannien

Summary In different areas of Great Britain comparing ecological studies have been made on disturbed and undisturbed heavy metal contaminated soils. In Grizedale (Pennine), sampling of an undisturbed transect having high levels of major nutrients showed marked differentiation within a small area, only related to the plant available levels of zinc, copper, and lead. However, studies on disturbed heavy metal soils and spoil-heaps revealed a low water capacity and a low supply of major nutrients, particularly of N and P. These suggest that here both the enrichment of heavy metals and the considerable decrease of other nutrients are important in determining the heavy metal vegetation, and in maintaining it against other species. The quantity of zinc in plants is not related to the total or plant-available amount of zinc in soil, but confirmed physiological experiments on the influence of phosphorus and different zinc compounds (complexed or inorganic) on the uptake and distribution of zinc in Thlaspi alpestre and Minuartia verna . Also an antagonism between lead and copper was revealed.

Haemaphysalis nepalensis sp. n. from a Himalayan Rodent and Man, and Description of the Male of H. aponommoides Warburton (n. comb.) (Ixodoidea, Ixodidae)

Haemaphysalis nepalensis sp. n., described herein, and H. aponommoides Warburton, the only known male of which is also described, are of exceptional interest owing to their primitive phylogenetic position in this genus. Both, excellent indicators of stepwise evolution among haemaphysalids, occur in the Himalayan highlands, which are within the general center of haemaphysalid distribution. I am grateful to Dr. Robert L. Fleming of the United Mission Hospital, Kathmandu, Nepal, for sending these fine specimens and for the following collecting notes. Mr. Glen Kohls of the Rocky Mountain Laboratory kindly read the manuscript and furnished specimens of H. aponommoides from Formosa for study. The localities in which these specimens were taken are in Ramechap District. Thodung (10,000 feet elevation) and Serping (10,800 feet elevation) lie just east and above Kimpti Khola, on a spur running directly towards Gauri Shankar peak. This is a region of heavy rhododendron and evergreen forest with barberry bushes in more open, grassy areas. Thodung and Serping have Swiss dairy installations where numerous herds collect, and swarm with leeches during wet weather. Rainfall is heavy and much vegetation grows above tree line, 12,000 feet elevation, in summer. Specimens of H. aponommoides were collected from a serow and from domestic cattle in this area.

The Pushnet, a One-Man Net for Collecting in Attached Vegetation

T HE pushnet, apparently unknown to most ichthyologists, is an efficient one-man net for collecting in shallow water and in attached aquatic vegetation, including cattails. Its operation (Plate I) is identical to that of a man-powered lawn mower, with the same ease of control and maneuverability. It operates much like a trawl but can be used in shallower water and its course is easier to control. A seine dragged in heavy vegetation tends to ride high off the bottom and to roll up, whereas the leading edge of a pushnet in the same situation stays on the bottom and the webbing remains fully spread from the start to the end of a push. Operating a pushnet in heavy vegetation is much less fatiguing than using a seine.

A New Anole from Mexico

N 1939 Edward H. Taylor and the senior author spent several days collecting in the hills above Acapulco, Guerrero. Some of the ravines in these hills are provided with extraordinarily heavy vegetation which results in a remarkable obscurity despite the glaring sunshine without. Huge boulders piled irregularly upon each other line the walls of the ravines, and provide secure hiding places for animals of many kinds. The most typical reptile was a species of anole that clung unobtrusively to the boulders, its dull colors blending almost perfectly into its dark habitat. In recognition of the extensive support afforded by Dr. Taylor to the pursuance of field work by the senior author and his wife, we name this anole

A Fossil Araucarian Wood Fro Western Wyoming

A few years ago the senior author made a collection of silicified woods from the Gros Ventre Canyon in western Wyoming. We were attracted to the region partly by some petrified log fragments on display outside the Jenny Lake Post Office, which were said to have been collected in the canyon, and partly by a landslide that presents a conspicuous scar on the lower end of the canyon, a landmark readily seen from the vicinity of Teton Park. Although two visits to the slide area failed to reveal anything of paleobotanical interest, certain regions farther up the canyon proved more productive. Approximately twelve miles up the road there is a second and considerably older slide now partially concealed by a fairly heavy vegetation. When this older landslide occurred the Gros Ventre Canyon was blocked and a lake formed in Cole Hollow. At the time of our 1936 visit a petrified trunk some three feet in diameter was exposed approximately 200 yards from the south bank of the river. The slide area was subsequently followed up to its apparent origin, a point about one mile from the river (Mt. Leidy quadrangle, R 112 W, T 42 N). There, a small badlands area, some few acres in extent and light gray color, is quite prominent when viewed from the opposite side of the valley. Sections of silicified trunks and small twigs are comparatively abundant in the gullies, weathering out of rocks of Cretaceous age. A more precise determination of the horizon is not possible at present, since neither the stratigraphy nor paleontology of the region has been studied in detail. Very small-scale coal-mining operations have been carried out on the opposite side of the river, likewise in Cretaceous strata. A seam some four feet thick outcrops about one-half mile north of the river and has been exploited in the past. The seam includes a number of bands of sandy clay some of which contain fern and dicot

Consumers' Complaints and How to Meet Them

Journal AWWAVolume 25, Issue 12 p. 1630-1635 Article Consumers' Complaints and How to Meet Them E. F. Dugger, E. F. Dugger General Manager Waterworks Commission, Newport News, Va.Search for more papers by this author E. F. Dugger, E. F. Dugger General Manager Waterworks Commission, Newport News, Va.Search for more papers by this author First published: 01 December 1933 https://doi.org/10.1002/j.1551-8833.1933.tb14749.xAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume25, Issue12December 1933Pages 1630-1635 RelatedInformation

INFLUENCE OF VARYING SOIL CONDITIONS ON NIGHT-AIR TEMPERATURES

SYNOPSIS A relation shown to exist between the temperature of the soil and the ensuing minimum temperature of the air immediately above, as affected by the varying conditions of the former—constituent character of the soil, moisture content, and the amount and character of the vegetal cover. Low night-air temperatures in gardens and truck farms may often be prevented in the first place by the selection of soil in which there is sandy component, as sand and sandy laoms are warmer than other soils and give off heat in the nighttime by conduction to the air above, thus diminishing the probability of critical temperatures and the formation of damaging frosts. Secondly, the land in use should be well drained of surplus moisture, as wet soils are invariably cold soils and more susceptible to frost damage. Lastly, any soil, whether it be sand, loam, or clay is warmer when it is clean and free from weeds and unnecessary vegetation, as bare soils are productive of higher night-air temperatures than those covered with a rank growth, form which the heat received in the daytime is lost at night by radiation to space. Finally, there may be several reasons why frost forms on one side of a street and not on the other, or in one section of a level farm and not in another. If there are contrasting soils, one productivity relatively high night-air minima and the other relatively low readings, or if the land differs even slightly in the amount of moisture, or in the kind and extent of the surface covering, or amount of insolation received, frost will appear in the sections which have wet, colds soils, covered with heavy vegetation or uncultivated, while, on the same night and under the same meteorological conditions, frost may not form on other ground close by where the soil is relatively dry, warm, and clean.