Geology topics
Ray B. Owen
Publications and source records attributed to Ray B. Owen.
The relationship between body mass and annual survival in American Black Ducks
No abstract available.
Habitat Suitability Index Models: American eider (breeding)
INTRODUCTION The common eider (Somateria mollissima) consists of five subspecies; four are found in North America (Palmer 1976). Six management populations of common eiders have recently been defined in eastern Canada and the United States (Reed and Erskine 1986). The American edier (S. mollissima dresseri), of which three populations are recognized (Reed and Erskine 1986), is the southernmost subspecies and the focus of this paper. The common eider is a member of the order Anseriformes, family Anatidae, and the tribe Mergini. A seabird of the northern latitudes of the world, the common eider is the largest duck of North America, ranging in weight from 1.2 to 2.8 kg and having a total length from 53.3 to 68.6 cm (Bellrose 1980). The American subspecies averages 2.0 kg and 61.0 cm for males, and 1.5 kg and 57.0 cm for females (Bellrose 1980). The drake is distinctly patterned,, having a white back and breast and a black belly and sides. The smaller female is brown and heavily barred with dark brown. Both sexes have a leathery extension of the bill which forms a Y-shaped frontal shield that reaches almost to the eyes. Maine, which supports part of the Atlantic population of common eiders (Reed and Erskine 1986), is the only major eider breeding population in the lower 48 States. American eiders are colonial nesters and use a variety of nesting sites, but they prefer relatively small, uninhabited islands (Mendall 1976). The coastal islands of Maine, which are essential to the eider's life cycle, are increasingly subjected to recreation and development, creating potential disturbances to eider breeding colonies. During recent years, aesthetic and sporting interest in eiders has increased. Sea ducks in Maine are experiencing increased hunting pressure. Compared to hunting seasons and bag limits for inland ducks, sea duck seasons and limits are liberal (Maine Department of Inland Fisheries and Wildlife [MDIFW] 1983).
Seasonal carcass composition and energy balance of female black ducks in Maine
Female Black Ducks ( Anas rubripes ) collected in Maine during the summer, fall, and winter of 1974-1976 showed significant seasonal variation in body weight, nonfat dry weight, gizzard and pectoral muscle weight, and fat, moisture, and protein content. Variation of body weight within and among seasons was correlated more strongly with carcass protein content, and with fat content during seasons of heavy lipid deposition, than with three structural size variables ( culmen, tarsus, and sternum ). Regression equations including fat and protein as independent variables accounted for 80-90% of the annual and seasonal variation in body weight; structural size variables alone accounted for less than 30%.
Food use and nutrition of black ducks nesting in Maine
Based on 32 adult black ducks ( Anas rubripes ) collected during the nesting seasons of 1974-76, the proportion of macro invertebrates (as aggregate [average] percent of dry weight) in the diet of males, egg-laying females, and postlaying females was 60, 75, and 55%, respectivey. Sample sizes were small, and the differences associated with sex and reproductive condition were not signficant. Molluscs, Isopods, ephemeropteran and odonate nymphs, and coleopteran, trichopteran, and dipteran larvae contributed 74% of the dry weight and 64% of the gross energy ingested. Data from proximate analyses of 9 invertebrate and 9 plant foods were combined with food habits data to estimate the nutrients available to breeding hens. We concluded that females with access to an adequate amount of natural food including invertebrates and the seeds and tubers of aquatic plants would obtain sufficient minerals, protein, and energy for reproduction. Food quality does not appear to limit the density of black ducks nesting in Maine.
Experimental woodcock management at the Moosehorn National Wildlife Refuge
The purpose of this study is to develop woodcock(Philohela minor) management techniques that can be easily used by the small landowner or incorporated with other land management operations such as commercial timber harvesting. The Moosehorn National Wildlife Refuge contains areas which are characteristic of the abandoned farms now being purchased for recreation or retirement as well as areas suitable for commercial forest management. Woodcock management, beginning in 1973, has centered on rejuvenation of diurnal habitat and creation of summer fields and singing grounds. Strips (10 mwide, 25 to 125 mlong and separated by 40 m) were clear~cut in two alder (Alnus sp.) stands resulting in increased diurnal use in at least one cover, increased singing male use and good alder regeneration. Small clear-cuts (30 X30 m) in a large contiguous woodland (1200 ha) with a history of few singing males resulted in an increased number of singing males despite an overall decrease in the number of singing males throughout the refuge. Management strategies and recommendations also are given.
Woodcock utilization of commercial timberlands in the northeast
This paper reports the results of studies in Maine (1975-77) and New Brunswick (1974) on the utilization of commercial timber areas by woodcock (Philohela minor). Openings created by logging operations were utilized for singing grounds and nocturnal roosting habitat. Singing male densities of 3.4 birds/1oo ha on were found on New Brunswick elearcuts, 0.24 birds/IOO ha on northern Maine elearcuts, and 1.8-2.1 birds/IOO ha on central Maine selective cuts. Singing male densities in New Brunswick were greater on cuts smaller than 20 ha than on larger cuts. Compared to abandoned agricultural land and alder thickets, earthworm biomass on timber harvest areas was lower and fewer birds used the cuts as diurnal habitat. Regenerating stands provided low quality diurnal habitat, which appeared to limit woodcock numbers on the study areas. The importance of commercial timber harvest operations to future woodcock populations is discussed.
Summer behavior of adult radio-equipped woodcock in central Maine
The behavior of 26 adult American woodcock ( Philohela minor ) was studied in central Maine during the summers of 1971-73 using radiotelemetry. Adults used diurnal covers and nocturnal sites that were similar to those previously recorded for immature woodcock. The adults, however, were more active during the daylight hours and moved to nocturnal sites later in the evening. Adult woodcock seemed to be less susceptible than immatures to capture by banding crews at night, because adults walked more often between diurnal and nocturnal sites and remained close to the brushy edges at night. Adult birds occupied a smaller composite summer range than the immatures, did not move as far from their capture sites dunng the observation penods, and traveled shorter distances between diurnal and nocturnal sites.
Influence of night-lighting and banding on woodcock movements
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Summer behavior of immature radio-equipped woodcock in central Maine
The behavior of 15 immature American woodcock ( Philohela minor ) was studied in central Maine during the summers of 1969 and 1970 using radiotelemetry. The monitored birds used a variety of nocturnal sites including old fields, bogs, powerlines, highway medians, woods roads, and fore clearings. Old fields were occupied more often than any other type of opening. Second growth-hardwoods, alders, hardwood-conifers, and conifers were utilized as diurnal cover. Diurnal locations of radio-equipped woodcock averaged 15 m from major breaks in the forest canopy. Four birds were monitored continuously during the day and night to determine periods of activity. Although the birds were active throughout the day, very little activity was recorded after they moved to nocturnal sites. No apparent difference was found in the daily patterns of movement between immature male and female woodcock. Crepuscular movements between diurnal covers and nocturnal areas averaged 332 m. A composite summer range for the 15 woodcock during 183 woodcock-days was 1060 hectares. The data suggest that immature woodcock are quite mobile during the summer and utilize most of the forest openings occurring within 1-3 km of good nesting habitat. Most of these openings are also used for singing grounds by males in the spring.
Molt patterns and weight changes of the American woodcock
A study of molt and changes in body weight of American Woodcock was conducted to better understand the summer and fall behavior of these birds and to indicate periods of physiological stress. The postnuptial molt of adults was a complete molt beginning in late June and ending by the middle of October. In contrast, the postjuvenal molt was a less intensive partial molt beginning in mid-July but also extending to the middle of October. Both male and female adult birds experienced weight loss in August during peak molt. Young birds gradually gained weight throughout the summer. Fat deposition was negatively correlated with molt while fall body weights were positively correlated with fat deposition. The data indicated that the majority of Maine woodcock are not physiologically prepared for migration until mid-October. Weights of adult males during the spring suggested that this is an important period of stress for these birds.
Any woodcock in your back forty tonight?
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