Arnold O. Haugen

Reproductive performance of white-tailed deer in Iowa.

Reproductive biology of the white-tailed deer ( Odocoileus virginianus ) in Iowa and the Nebraska-owned portion of DeSoto National Wildlife Refuge on the Iowa side of the Missouri River was determined from female reproductive organs of deer killed on highways and by hunters from 1959 to 1963, 1965, and 1966. Rut for fawn does extended from mid-November into early January but peaked between 3 to 18 December. Presence of corpora lutea indicated 82 percent of the fawns had ovulated. Corpora albicantia in ovaries of 1½-year-old does indicated that 65 percent of the fawns had breed successfully. The peak of breeding by 1½-year-old does was about 24 November, and for 2½-year-old does about 22 November. Fertilization frequency for does (all ages) that had been in estrus was 92 percent. A primary sex ratio for 178 embryos from 109 does of all ages was 1.23 males:1 female. Corpora lutea counts and fertilization rates indicated fawns from Iowa may produce up to 30 percent of the annual increment.

Influence of Light and Weather on Observability of Iowa Deer

The individual and combined effects of light intensity and various weather phenomena on numbers of white-tailed deer (Odocoileus virginianus) seen per observation were correlated by multipleregression analysis using the model with deer sighted (adults, juveniles, anterless, antlered, and unknown) versus sunset or sunrise time, time of sighting, location, lunar phase, minimum daily temperature, maximum daily temperature, wind direction, wind velocity, nebulosity, type of precipitation, amount of precipitation, type of ground cover, and amount of snow on the ground. Observations were made from a blind during crepuscular periods from September through May. A significant relationship (P < 0.05) to the number of deer sighted per sighting existed with the effects of: time of sunrise, time of sunset, maximum temperature, minimum temperature, wind direction, wind velocity, and ground cover. These effects were not the same for all age and sex classes, and in some instances, different effects were observed for the dawn and dusk periods. J. WILDL. MANAGE. 38(2):220-228 The influence of daily light intensity and various weather phenomena on deer movement has been cited by several authors (Darling 1937, red deer; Linsdale and Tomich 1953, mule deer; Loveless 1964, mule deer; Dasmann 1954, black-tailed deer; Moen 1968, white-tailed deer; Buss and Harbert 1950, black-tailed deer). Because of the current emphasis on the esthetic aspect of wildlife and on the intensive management of white-tailed deer in many states it is appropriate to investigate what environmental factors influence the chances of one observing deer in their natural habitat. To obtain this information, various light and weather criteria thought to influence deer activity were considered as one aspect of a general study (Zagata 1972) of deer movement in the intensively farmed region of north-central Iowa. Deer were observed from December 1969 through May 1972 to provide basic information for deer management in north-central Iowa. The objectives were to: (1) determine if light intensity and various selected weather parameters were related to the number of deer sighted during crepuscular periods, (2) secure data useful for effective deer management. Thanks are due the Iowa State Conservation Commission and the U.S. Bureau of Sport Fisheries and Wildlife for funding the study and to J. Anderson of the Iowa State Conservation Commission for his field assistance. Special acknowledgment is given to H. Clausen and L. Yerxa for their help in preparation of this manuscript.

Distinguishing Juvenile from Adult Bobwhite Quail

years the data may provide justification for continued open seasons, despite poor hunting success early in the season. The separation of juvenile and adult bobwhite quail has been based primarily on wing-feather characteristics. Dwight (1900) apparently was the first to make an intensive study of plumage changes in quail. He reports that the two distal primaries in all quail and grouse are retained in the postjuvenal molt, but he makes no mention of how these feathers differ from those on older birds. Stoddard (1931) calls attention to the shape of the outer two primaries as a criterion for separating young (pointed) from older birds (blunted). Van Rossem (1937) reports that the juvenal primary coverts in native quail are retained until the first annual molt the second fall (about August). Leopold (1939) reports that the buffy fringe on the tip of greater upper primary coverts 1 through 7 (counting from inside--outward) provides the best means for identifying young of the year. Thompson and Kabat (1950) made detailed studies of the molt of bobwhite quail and enumerated some irregularities in e wing molt of trapped wild birds. Studies on over 11,000 quail in Alabama have shown that the degree of marking on these coverts and the pointedness of the outer two primaries vary sufficiently to introduce a small error in separating young from old. This condition led to efforts to improve further on techniques for recognizing young of the year. Results of that study are here reported. A total of 7,037 quail wings sent in by cooperators during the 1954-55 hunting season (Nov. 25--Feb. 20) in Alabama was examined for age-ratio data. The wings were received in special postage-reply envelopes. Age was determined by methods described by Stoddard, Leopold, and Thompson and Kabat. Young of the year were recognized by whitish or buffish tips on the coverts (Fig. 1), and by pointedness and slight fading of the outer two primaries. A fluorescent light was used to help distinguish the faded brownish color of the outer two primaries in young of the year. Adult birds were recognized by the even slatish gray coverts, and rounded tips and similar shading on all primaries (including Nos. 9 and 10). Even when all these characteristics were used, some quail could not be aged with accuracy because of the intergradation of characteristics. Such birds were recorded

Autumn Roosting Flight Counts as an Index to Wood Duck Abundance

Roosts and roosting flights of wood ducks (Aix sponsa) were studied during autumn, 1959-64. Observations were made during 768 flight periods at 52 roosts. The primary study area was a 100-mile segment of Mississippi River bottoms in northeastern Iowa. Roosts were in many species of emergent vegetation. Barring major changes in habitat, autumn roost sites were usually the same each night and each year. Autumn migrants used roosts established in late summer by local birds. Seasonal changes in roosting populations were similar each year. September 20 is recommended for making roosting flight counts to be used as an index to annual changes in abundance of wood ducks. Evening counts were superior to morning counts. Numbers at a roost ranged up to 5,400. Sampling units, sampling schemes, sensitivity, and use of roosting flight counts for estimating abundance of wood ducks are discussed. The Mississippi Flyway Council stated that adequate information on population levels of wood ducks was not provided by techniques used to census other waterfowl (Yancey et al. 1958). In response, the Iowa Cooperative Wildlife Research Unit initiated a study of some methods of censusing wood ducks. This is a report of an investigation of wood duck roosting phenomena in northeastern Iowa and adjacent areas during August-November, 1959-64. The main objective was to evaluate roosting flight counts as a method of estimating abundance of wood ducks. We are grateful to Refuge Manager Don Gray and his staff on the Upper Mississippi River Wildlife and Fish Refuge for their assistance and support of this study.

Corpora Lutea Variations of White-Tailed Deer

The reproductive tracts of 404 female white-tailed deer (Odocoileus virginianus) were studied for information on size, shape, and coloration of corpora lutea. Corpora lutea in fawns are regarded as regressing if they are less than 4.0 mm in diameter at the time when the rut for that age-class is nearing its end. In all age-groups of does where fetal membranes or embryos are present, corpora lutea smaller than 6.0 mm are regarded as regressing. These small ones are regarded as corpora lutea of an earlier heat and not as corpora lutea of the current pregnancy. Regressing corpora lutea of a previous ovulation also appear to have an irregular surface shape. Color is not a dependable criterion for differentiation of the two types of corpora lutea. During an investigation of reproduction in white-tailed deer in Iowa, information was obtained on the physical characteristics of their corpora lutea. In attempting to correlate fertilization rate with ovulation rate, difficulty has been encountered in differentiating corpora lutea of ovulation of a previous heat from corpora lutea of pregnancy. In sheep, corpora lutea of ovulation are formed in ruptured follicles within 4 days following ovulation (Asdell 1946:366-367) and are fully developed by the eighth day following ovulation (Harrison 1962:169). In deer, corpora lutea of ovulation begin regressing after about 14-15 days (Cheatum 1949:285) if fertilization does not occur. When fertilization and implantation take place, corpora lutea of ovulation persist as corpora lutea of pregnancy (Amoroso and Finn 1962:454). The corpus luteum has a glandular function, secreting progesterone hormone which is essential for implantation and early development of the fertilized ovum. This hormone also suppresses further follicular development and ovulation. After parturition, corpora lutea of pregnancy regress and become corpora albicantia. Ability to identify corpora lutea of ovution of a previous heat from those of pregnancy of a later heat would eliminate a possible source of error when using corpora lutea counts as an index to reproductive rates of deer. Golley (1957) found the use of the corpora lutea dependable for determining the ovulation incidence of the black-tailed deer (Odocoileus hemionus columbianus) but detected an error when using the corpora albicantia to indicate ovulation. Golley used histological techniques to determine the differences between the two types of tissue. This paper will discuss gross size, shape, and color variations of corpora lutea in white-tailed deer ovaries as a possible means for distinguishing the two types. The assistance of Eldie Mustard, former Iowa State Conservation Commission Biologist, is appreciated. Several of Iowas Conservation Commission officers and biologists also assisted materially by collecting reproductive tracts from wild deer. The cooperation of deer hunters who saved tracts for the study was indispensable. Calvin Rayburn, Ronald Schara, Harold Prince, and David Bolton, students 1Journal paper J-4604 of the Iowa Agricultural and Home Economics Experiment Station, Ames, Iowa. A contribution from the Iowa Cooperative Wildlife Research Unit, which is jointly sponsored by Iowa State University of Science and Technology, U. S. Bureau of Sport Fisheries and Wildlife, the Iowa State Conservation Commission, and the Wildlife Management Institute. Financial support for Trauger was provided by the National Science Foundation Undergraduate Research Participation Program.

MUSKRATS IN RELATION TO FARM PONDS1

Most muskrats in farm ponds studied dug burrows for homes instead of building houses. Owners of ponds with muskrats have frequently complained of muskrat damage to their dams. Therefore, the primary objective of the study was to determine the effects of muskrat burrows on dams of farm ponds. Secondary objectives were to obtain information on productivity and economic value of farm pond muskrats. Field studies were carried on from October, 1950, through June, 1951. Data were secured mainly from farm ponds located within 10 miles of Auburn, in Lee County, Alabama. The 143 ponds on the Agricultural Experiment Station of the Alabama Polytechnic Institute were av ilable for study. Additional inform tion was obtained by excavation of burrows in dams of several ponds in Bullock and Montgomery Counties, Alabama.

Parturition and Early Reactions of White-Tailed Deer Fawns

Although literature is replete with information on the life history of many animals, records of the process of parturition and the early reactions of young are rare. Life at this stage may hang in a critical balance for both fawn and doe. For these reasons records were made on the parturition and early moments of life of the white-tailed deer, Odocoileus virginianus . In a study of the breeding season, gestation period and growth of fawns, three to four adult does were kept in small pens at the Alabama Cooperative Wildlife Research Unit Headquarters. A 5-year-old doe, “Tater,” was expected to fawn early in July, 1955. At 4:30 pm on July 11, the doe was noted nervously moving about the pen. She alternately stopped and walked, with her tail held …

Ammate in the Diet of Deer

both from game authorities and the general public. Because the die-off coincided with a period when Ammate (ammonium sulfamate) was used by the U. S. Forest Service to kill certain trees on the area, circumstantial evidence indicated this chemical may have been responsible for the mortality. Ammate was used in the forest from June 28 to August 15. It was applied to oaks and other broad-leaved species of trees for the purpose of timber stand improvement.

ANTIBODIES OF PULLORUM AND NEWCASTLE DISEASE VIRUS IN PHEASANTS

Whole-blood saturated serodiscs and fluid serum collected from 446 wild and 435 game-farm Iowa pheasants (Phasianus colchicus) were tested for pullorum disease, Newcastle disease, Eastern and Western equine encephalomyelitis, PPLO disease (pleuropneumonia-like organisms), infectious bron- chitis, and quail bronchitis (CELO). Serum samples from three pheasants on private game farms were positive to tests for Newcastle disease, whereas samples from wild pheasants were all negative. Four serum samples from pheasants on private game farms were suspect for pullorum, and 15 pullorum- positive whole-blood samples were secured from wild birds. A limited number of samples were tested for other diseases; 2 of 61 were positive for Eastern equine encephalomyelitis and 7 of 65 to CELO. All 93 samples tested for Western equine encephalomyelitis, infectious bronchitis, and PPLO were negative.