Ring-necked Pheasant Populations Research Articles

The modulating effect of food composition on the immune system in growing ring-necked pheasants (Phasianus colchicus).

The decline in the population of ring-necked pheasants (Phasianus colchicus) in northwestern Germany since 2007 raises questions about the underlying causes. We therefore studied the growth and immune status of ring-necked pheasant chicks dependent on different feed composition. Here, 490 ring-necked pheasant chicks were raised in five groups up to nine weeks. While control groups C1 and C2 received sufficient crude protein (28%) and energy (12.5 MJ/Kg feed) according to current standards, group C2 was treated with cyclosporine eight hours prior to phythemagglutination (PHA) testing, serving as a positive immune suppressed control. Group V1 was fed with reduced protein (20%) but optimal energy content (12.5 MJ/Kg feed), group V2 was fed with sufficient protein (28%) and reduced energy content (10 MJ/kg feed) whereas group V3 was fed reduced crude protein (20%) and reduced energy content (10MJ/kg feed). On all chicks, health status was checked each week, and 20 birds of each group were weighed randomly per week. PHA-testing was performed on 12 birds of each group to study the in vivo non-specific activation of lymphocytes at week 2, 4, 6, 7, 8 and 9. In addition, hemolysis-hemagglutination-assay (HHA) was performed on each of the PHA-tested chicks, which were subsequently euthanized and dissected. Histopathologic examinations of 5 birds that were randomly chosen were performed. The PHA-test results demonstrate significant differences between control (C1, C2) and experimental groups (V1-V3) in several developmental stages. According to the HHA results, weekly testing detected a significant increase of titres per week in all groups without significant differences. Here, only hemagglutination and no lysis of samples was observed. It seems appropriate to conclude that during their first weeks of life, protein content is of higher importance in ring-necked pheasant chicks than energy intake. In particular T-cell response is significantly reduced, which indicate a weaker immune system resulting in a higher risk for clinical diseases. Therefore, we assume that protein i.e. insect availability is a highly important co-factor in the free-ranging population dynamics, and is linked to declines of the northwestern German population.

Investigation into diseases in free-ranging ring-necked pheasants (Phasianus colchicus) in northwestern Germany during population decline with special reference to infectious pathogens.

The population of ring-necked pheasants (Phasianus colchicus) is decreasing all over Germany since the years 2008/2009. Besides impacts of habitat changes caused by current rates of land conversion, climatic influences or predators, a contribution of infectious pathogens needs also to be considered. Infectious and non-infectious diseases in free-living populations of ring-necked pheasants have been scarcely investigated so far. In the present study, carcasses of 258 deceased free-ranging pheasants of different age groups, predominantly adult pheasants, collected over a period of 4 years in the states of Lower Saxony, North Rhine–Westphalia and Schleswig-Holstein, were examined pathomorphologically, parasitologically, virologically and bacteriologically, with a focus set on infectious pathogens. A periocular and perinasal dermatitis of unknown origin was present in 62.3% of the pheasants. Additional alterations included protozoal cysts in the skeletal musculature (19.0%), hepatitis (21.7%), enteritis (18.7%), gastritis (12.6%), and pneumonia (11.7%). In single cases, neoplasms (2.6%) and mycobacteriosis (1.7%) occurred. Further findings included identification of coronaviral DNA from trachea or caecal tonsils (16.8%), siadenoviral DNA (7.6%), avian metapneumoviral RNA (6.6%), and infectious bursal disease viral RNA (3.7%). Polymerase chain reaction (PCR) on herpesvirus, avian influenza virus (AIV), paramyxovirus type 1 (PMV-1), avian encephalomyelitis virus (AEV), and chlamydia were negative. Based on the present results, there is no indication of a specific pathogen as a sole cause for population decline in adult pheasants. However, an infectious disease can still not be completely excluded as it may only affect reproduction effectivity or a certain age group of pheasants (e.g., chicks) which were not presented in the study.

Hematology and Serum Biochemistry Reference Intervals for Six-Week-Old, Farm-Reared Chinese Ring-Necked Pheasants ( Phasianus colchicus ) from Minnesota.

Chinese ring-necked pheasants ( Phasianus colchicus ) are commonly farmed in intensive operations for purposes such as meat production, hunting preserves, or research. Under these conditions, pheasants frequently suffer medical ailments such as bacterial, viral, and parasitic infections or nutritional or metabolic disorders. Relatively little scientific information exists regarding clinical pathology reference intervals (RIs) for farm-reared pheasants. The objective of this study was to determine RIs for hematologic and serum biochemical variables for Chinese ring-necked pheasants from Minnesota at 6 wk of age. Blood samples from 119 clinically healthy Chinese ring-necked pheasants were analyzed using standard techniques. Reference intervals were generated in Microsoft® Excel® 2013 (Microsoft, Redmond, WA) using Reference Value Advisor freeware version 2.1 (Microsoft). Ninety-five percent RIs were determined using nonparametric methods that followed Clinical and Laboratory Standards Institute guidelines. These RIs will be useful for the monitoring of health and diagnosis of disease in confined Chinese ring-necked pheasant populations that are approximately 6 wk old.

ЕМКОСТЬ СРЕДЫ КАК ПРЕДПОСЫЛКА ДЛЯ УПРАВЛЕНИЯ СОСТОЯНИЕМ ПОПУЛЯЦИЙ

We study the possibility of using the carrying capacity for the state control of species populations important for human. The populations can have multiple states of equilibrium caused by the cumulative effects of the factors. Therefore, it is necessary to appreciate adequately the possible equilibrium states and the reasons for the transition between them. Management arrangements should be divided into two groups: «rise» (improvement of population status) and «decline» (its deterioration). Both groups effects on the organism at the same time. In the course of cognitive modeling it was revealed the existence of the natural restrictions of increasing of the Ring-necked pheasant population in the grounds: neither the hunting ban, nor conducted biotechnical measures do not allow to achieve the increasing of number. Ix the case of cessation of annual releases of this kind in the land, its number will come down to a minimum, and in some areas it will completely disappear. In the bounds of the biotic community of each ecosystem a certain additive summation of carrying capacities of environment of certain types takes place – an integrated capacity is formed. The attempts to increase the carrying capacity of the medium to separate the desired types to integrated capacity may promote degradation of all biological systems.

Density-dependent regulation of fecundity in Syngamus trachea infrapopulations in semi-naturally occurring ring-necked pheasants (Phasianus colchicus) and wild Carrion Crows (Corvus corone).

Previous work has highlighted increased opportunities for the transmission of Syngamus trachea within pheasant release pens, due in part to high levels of environmental contamination around communal areas. Despite this, the distribution of adult worms within their definitive hosts is not significantly different from predicted distributions under Taylor's power law. Therefore, density-dependent processes are probably acting to regulate S. trachea population dynamics. Patterns of nematode fecundity were investigated in a semi-naturally occurring population of ring-necked pheasants (Phasianus colchicus) and a wild population of carrion crows (Corvus carone). Worm length was a reliable indicator of nematode fecundity, and a negative association between mean worm length and mean worm burden was identified within both the species. The stunting of worms at greater parasite densities was present in both immunologically naïve and previously exposed pheasants, so is unlikely to be a function of age-dependent acquired immunity. Interestingly, the effect of parasite crowding in the crow population explained more of the variation in mean worm length, apparently driven by a greater mean worm burden when compared with pheasants. The findings of the present study suggest that fecundity is a function of parasite density, i.e. parasite-mediated competition and not host-mediated heterogeneities in immunocompetence.

Age Structure and Reproduction Rates of the Ring-Necked Pheasant (Phasianus colchicusL.) Population in Agricultural Landscape (Czech Republic)

Detailed knowledge of demographic parameters (such as age structure and reproduction rates) is crucial for guiding conservation and management decisions regarding wildlife populations. Such parameters of wild ring-necked pheasant populations in the current agricultural landscape remain very poorly described. We researched age structure and reproduction rates of predominantly wild populations of the ring-necked pheasant (Phasianus colchicus L.) across the intensively managed agricultural landscape of the Czech Republic. The study area is influenced only marginally by hand-reared pheasants (i.e. as shown by comparison of the average number of released individuals in the study area: 0.3 ♂/yr/1km2 and 0.9 ♀/yr/1km2 and average number of released individuals and harvested in the study area: 8.6 ♂/yr/1km2) and there is a long-term huntable pheasant population. To determine the age of individuals, we used proximal primary feather shaft diameters of 1487 feather samples from males hunted between 2009 and 2011. Moreover, we evaluated the age structure of females as well as both sexes together based on the sex ratio and annual game census. We found a relatively high proportion of adults in the population in comparison with other studies. However, the number of adults decreased throughout the years: 2009 (♂ 44.7%; ♀ 69.5%; ♂♀ 60.7%), 2010 (♂ 35.2%; ♀ 61.3%; ♂♀ 51.5%), 2011 (♂ 29.8%; ♀ 57.4%; ♂♀ 47.0%). The decrease of adults went hand in hand with increase of juveniles and reproduction rates of the study population: 2009 (♂ 124%; ♀ 44%; ♂♀ 65%), 2010 (♂ 184%; ♀ 63%; ♂♀ 94%), 2011 (♂ 236%; ♀ 74%; ♂♀ 113%). Only males were hunted in the study area so we determined higher proportions of females in population for all years. This is the main reason why the reproduction rate of females was lower in percentage expression. Generally, our results showed lower productivity of pheasants in the Czech agricultural landscape in comparison with earlier published studies conducted in the US and UK. However, these studies were published many years ago and thus do not reflect the actual environmental conditions and changes which took place recently (i.e. agricultural intensification).

Effect of habitat and game management practices on ring-necked pheasant harvest in the Czech Republic

The ring-necked pheasant (Phasianus colchicus L.) is one of the most popular small game species both numerically and economically. Pheasant populations are commonly managed in the Czech Republic in order to maximize their harvest. Game managers need to be aware of the possible effects of different management tools on wild pheasant populations. We used data from 38 hunting grounds collected over an 8-year period (2004–2011) and generalized linear mixed effects models (GLMMs) to assess whether pheasant harvest was related to the habitat characteristics and game management practices (release of hand-reared individuals and predator control) in the Czech Republic. The proportion of grasslands, idle lands (spontaneously set-aside lands), and organically farmed lands (i.e., with limited use of industrially made fertilizers and pesticides) and the density of watercourses were positively related to the pheasant harvest. The proportion of forests and road density showed a negative relationship with the pheasant harvest. An important effect of year on the pheasant harvest was also found. In terms of game management practices, predator control intensity (i.e., foxes, martens, corvids) was positively related to the pheasant harvest. The release of hand-reared individuals was not included in the final GLMMs. Our study suggests that the best long-term strategy to reinforce the wild population of ring-necked pheasants would be to concentrate on habitat improvement through the implementation of set-aside management, maintaining the right percentage of shrubby and grass vegetation, to continue with targeted predator control, and to reduce the costly practice of releasing of hand-reared individuals.

ESTIMATING THE RESPONSE OF RING-NECKED PHEASANTS (PHASIANUS COLCHICUS) TO THE CONSERVATION RESERVE PROGRAM

We evaluated associations between the Conservation Reserve Program (CRP) and Ring-necked Pheasant (Phasianus colchicus) populations by modeling Breeding Bird Survey (BBS) counts of Ring-necked Pheasants during 1987–2005 along 388 routes in nine states. Ring-necked Pheasant counts were analyzed as overdispersed Poisson counts in a Bayesian hierarchical model estimated with Markov-chain Monte Carlo methods. This approach allowed for simultaneous estimation of the relationships between BBS counts and various habitat types, including CRP habitat types, for multiple regions and across the entire study area. The predictor variables included a time trend and percentages of major National Land Cover Dataset 1992 and CRP habitat types within a 1,000-m buffer around each route, along with other patch metrics. The deviance information criterion was used as a guide to help identify the most parsimonious model. We estimated that, on average, there was a positive association of Ring-necked Pheasant counts with the amount of CRP herbaceous vegetation within a 1,000-m buffer around a route. The analysis can be repeated periodically to model changes in Ring-necked Pheasant populations associated with new CRP enrollments and expiration of existing CRP contracts on a large scale. Our methodology can also be extended to other species and to other states and regions.

Site Selection and Nest Success of Ring-Necked Pheasants as a Function of Location in Iowa Landscapes

Wildlife managers in the midwestern United States implicitly recognize that large-scale changes in land use have been a major factor in the nesting ecology of the ring-necked pheasant (Phasianus colchicus), but they have lacked models that quantify the relation between nest success and landscape variables at multiple scales. We used data from 288 nests of radiomarked female pheasants during the 1990-94 breeding seasons in Iowa to study nest-site selection and nest success. We quantified habitat and landscape metrics within the 485-m radius of a home range around nests by using aerial imagery and FRAGSTATS. We screened potential landscape variables by using principal component and classification and regression tree (CART) analyses before developing logistic regression models to predict nest-site selection and success as a function of landscape conditions. A 5-variable logistic regression model incorporating nesting patch size, mean grassland patch size, landscape core area, landscape shape index, and distance to edge predicted nest-site locations at a 77% posterior concordant rate. The CART analyses suggested nest success was best modeled by splitting nest observations into nests in patches ≤15.6 ha and >15.6 ha. For nests in patches ≤15.6 ha, a logistic regression model with site cover type and mean core area index predicted nest success with a 73% posterior concordant rate (P 15.6 ha, a model with site cover type, core area standard deviation, and distance from the nest to the edge predicted nest success best (concordant rate = 64%, P = 0.069), although the effect of distance to edge was very slight (conditional odds ratio = 1.003, 95% CI = 0.997-1.009). Our models suggest managers should strive to provide undisturbed grassland blocks ≥15 ha for nesting pheasants, but our observation was that success was highest in fields 4 times that size. Furthermore, cover in several large grassland blocks within the nesting home range is preferable to concentrating cover in 1 large block. Landscape models like ours could be used to project the consequences of changes in agricultural policy on ring-necked pheasant populations.

Declining ring-necked pheasants in the Klamath Basin, California: I. Insecticide exposure

A study of organophosphorus (OP) insecticide exposure was conducted on a declining population of ring-necked pheasants (Phasianus colchicus) associated with agricultural lands at Tule Lake National Wildlife Refuge (TLNWR) during the summers of 1990–92. Findings at TLNWR were compared with a nearby pheasant population at Lower Klamath National Wildlife Refuge (LKNWR) not subjected to intensive farming or OP insecticide applications. Direct toxicity of anticholinesterase (antiChE) compounds (in this case methamidophos) killed 2 young pheasants (91 and 92% brain acetylcholinesterase [AChE] inhibition), but no deaths of adult radio-equipped hens were ascribed to direct insecticide intoxication. However, within 20 days postspray of OP insecticides, 68% (28 of 41) of the adult pheasants collected at TLNWR were exposed to antiChE insecticides, and exhibited brain AChE inhibition of 19–62%, with 15% (6 of 41) showing >55% brain AChE inhibition. The lack of radio-equipped hens dying was unexpected because >50% brain AChE inhibition has been frequently used as a ‘diagnostic tool’ for evaluating cause of death from antiChE insecticides. No young were radio-equipped, so the extent of the effects of insecticide exposure on the survivorship of young was unknown. It is concluded that insecticide exposure was not the major factor impacting the pheasant population (see Grove et al., in press), although some young were acutely intoxicated. However, the loss of insects killed by insecticide use may have contributed to food shortages of young pheasants, indirectly influencing survival.

Evaluation of Pheasant Crowing Rates as a Population Index

Assumptions of many call-count indexes remain untested. One assumption of the pheasant crowing count index is that crowing rates are similar among populations. We measured crowing rates of ring-necked (Phasianus colchicus torquatus), Sichuan (P. c. strauchi), and hybrid rooster pheasants from 1 hour before until 1 hour after sunrise, 1992-93. We tested hypotheses that crowing rates were unrelated to subspecies, age, year, and weather variables. A model predicting crowing rates included subspecies and time from sunrise as significant effects (R 2 = 0.41). This model described a parabola where crowing rates reach maximum at 9 minutes after sunrise, regardless of subspecies. Temperature, wind velocity, and cloud cover were not significant in explaining crowing rate variation. Recommendations for improving the crowing count survey include: conducting surveys from 30 minutes before to 30 minutes after sunrise, increasing the listening period length from 2 to 4 minutes for ring-necked pheasant populations, and adjusting for subspecific differences in crowing rates.

Ring-Necked Pheasant Population Genetic Structure

We investigated genetic variability in 34 ring-necked pheasants (Phasianus colchicus) from northeastern Iowa using randomly amplified polymorphic DNA (RAPD). We collected pheasants from 5 Conservation Reserve Program (CRP) habitats or longer-standing patches of overwintering and breeding habitats. Each habitat patch was separated from the others by 5-30 km of unsuitable breeding habitat. Significant genetic differentiation was found in 9 of the 10 possible inter-patch comparisons, the exception being 2 sites that were separated by only 5 km. This high level of genetic subdivision among closely neighboring patches suggests that populations are highly fragmented.

Habitat Use and Movements of Female Ring-Necked Pheasants during Fall and Winter

We studied diurnal habitat use and movements of 56 female ring-necked pheasants (Phasianus colchicus) on private and public lands in southern Wisconsin from September through April 1968-71 using radio telemetry. Habitat use of female pheasants was a function of month, year, female age, and snow cover depth, but not female survival through April. Females preferred food patches and brush, and avoided pastures and active croplands in all 7 months. Shrub-carr wetlands were preferred by females in all months except October, and marshes were preferred in all months except January and February. Retired croplands were preferred from October to December, but avoided in January. Upland hardwoods were avoided in most months except for periods of deep snow cover. Monthly home-range sizes averaged 32 ha. Home-range size during 10-day periods peaked in late October through early November, and declined to a low in early January through early February. Juveniles had larger ranges than adults, and preyed-upon females had larger ranges than surviving females. Home-range size was positively related to corn harvesting and pheasant hunting pressure, and negatively related to snow cover depth. Females began a directional move (f = 1,150 m) to winter cover in late September. Distance to winter cover was also a function of female age, female fate, corn harvest, and snow cover depth. Heavy hunting pressure appeared to temporarily suppress the use of food patches and strip cover, and accelerate the final move to winter cover, but did not cause females to move off public lands. Females remained in winter cover from early November through early February, using a variety of areas and habitats. The abundance of wetland cover in winter may have been responsible for a lack of winter concentration and independent moves between adults and juveniles. J. WILDL. MANAGE. 53(2):462-475 Habitat management has been advocated to reverse the decline of ring-necked pheasant populations in the midwestern United States (Farris et al. 1977, Edwards 1985). An understanding of the movement and habitat use of pheasants is basic to prescribing habitat management. The pheasant has adopted different patterns of habitat use and movements in response to local habitat conditions (Olsen 1977), so that regional data on pheasant behavior are not universally applicable. There have been several general descriptions of pheasant habitat use and movements during fall and winter, mostly of winter concentrations (Olsen 1977), but few with data on habitat preference or home-range size. Gates and Hale (1974) documented habitat preferences in Wisconsin during winter and described fall and winter movements through visual observations of marked birds, but could not detail home range dynamics during these seasons. Recent workers have used radio telemetry to study the details of habitat use and movements in pheasants (Hanson and Progulske 1973, Warner 1979), but their data extended only into early fall. Wooley and Rybarczyk (1981) documented female pheasant habitat preferences and movements throughout the year with telemetry in southern Iowa. Penrod and Hill (1985) related female pheasant habitat preferences and home range sizes to female age, fate, and winter severity using telemetry in western New York. Dumke and Pils (1973) used radio telemetry to document the dynamics of pheasant survival centered on public land in Wisconsin. We present data on pheasants during the fall and winter from the same study area. Our objectives were to describe female pheasant habitat use, preference, and movements during fall and winter in Wisconsin, and show how they related to age, fate, hunting pressure, crop harvesting, and weather. Additionally, we tested 4 hypotheses advanced by Gates and Hale (1974): 1) movements in early fall and those to winter cover are separate, 2) females return to fall sites during spring, 3) movements of juvenile females to winter cover are not independent of adult movements, and 4) adults from the same fall sites move to winter cover in the same direction. H. H. Miller, of the University of Wisconsin' Present address: Wisconsin Department of Natural Resources, Box 7921, Madison, WI 53707.

Responses of Illinois Ring-Necked Pheasant Populations to Block Roadside Management

Ring-necked pheasant (Phasianus colchicus) nesting and population trends were studied from 1967 through 1984 on a block roadside management area in Illinois, the 5,182-ha Ford County Management Unit (FCMU). Vegetation was developed as breeding habitat on roadsides, and mowing voluntarily was delayed by farmers to minimize nest destruction. Compared with a nearby reference area, pheasant abundance on the FCMU was numerically low prior to management (1967-69) and was 2-3 x greater beginning in 1970. The juxtaposition of other key habitats in the land mosaic influenced the use of roadsides by nesting hens. Under a diverse farming situation, undisturbed roadside cover and other landscape features had a synergistic effect on local pheasant abundance. The effects of roadside management were such that the boom phase in regional pheasant trends were amplified, and subsequent declines related to land use and severe winters were moderated. J. WILDL. MANAGE. 50(4):525-532 Numerous disturbance factors interact with breeding populations of pheasants ultimately affecting reproduction, as well as survival, during this critical season (Warner and Etter 1985). Over the intensively row cropped Midwest, however, there have been few long-term experimental attempts to control disturbances and to gauge the effects of management strategies on pheasant demography. Seeded, undisturbed roadside vegetation in Illinois is attractive to nesting pheasants. Warner et al. (unpubl. data) reported that nest densities in managed roadsides generally were higher than in other cover types and that, from 1963 through 1972, 29% of 806 nests on roadsides on the Sibley Study Area (SSA), Illinois, were successful. Variations in the frequency of nesting on roadsides were, in part, related to site specific characteristics of the tracts (Warner et al., unpubl. data). Because mowing of experimental roadsides on the SSA was controlled by research staff with only a few managed tracts (Joselyn et al. 1968), the FCMU was established to evaluate more of a regional scheme of development (a block of 4.5 x 4.5 general land office [GLO] sections, each GLO section = 259 ha); nearly all road rights-of-way were seeded and left unmowed through 1 August. The objective of this study was to consider the long-term impact of block roadside management on pheasant abundance. In addition to population trends, the ecology of pheasant nesting was studied in relation to some key properties of the land mosaic. We acknowledge the following staff of the Ill. Nat. Hist. Surv. (INHS): G. C. Sanderson, W. R. Edwards, and S. L. Etter for technical and editorial support and R. L. Westemeier and E. Steger for editorial support. L. M. David and J. A. Moak, Ill. Dep. Conserv. (IDC), also provided technical support. This work is a contribution of Fed. Aid Wildl. Restor. Proj. W-66-R, the IDC, U.S. Fish and Wildl. Serv. (USFWS), and INHS cooperating. The IDC and USFWS have no responsibility for the form and content of the data in this report or for the conclusions reached.

Habitat, Survival, Productivity, and Abundance of Pheasants in Western Oregon, 1947-1975

Indices of survival, productivity, and density were derived from annual censuses of ringnecked pheasants (Phasianus colchicus) in the Willamette Valley from 1947 to 1975. Abundance of pheasants in spring was moderate and variable in the late 1940's and early 1950's (10-20 birds/40.5 ha), increased in the early 1960's (35-40/40.5 ha), and decreased in the early 1970's (3-8/40.5 ha). Amount of land in soil bank was closely correlated to abundance of pheasants in spring. Reproductive performance remained relatively constant from 1949 to 1975. Survival of adult females during summer and during winter were significantly correlated (r = 0.89) to annual percent change in total density of pheasants in spring. About 25 to 30 percent of the pheasant habitat in the Willamette Valley was lost between 1945 and 1970. Survival of adult females was the most important factor affecting long term trends in population size. J. WILDL. MANAGE. 42(4):866-874 Populations of ring-necked pheasants have undergone many changes since the introduction of the species in the Willamette Valley, Oregon, in 1881 (Gabrielson and Jewett 1970:226). Of particular interest is the recent (-10 years) decline in abundance experienced by many populations of pheasants (Leite 1971, Tripp 1971, Nish 1973, Snyder 1973, Weigand 1973, Labisky 1975). The pheasant population in the Willamette Valley was no exception, declining to very low levels in the early 1970's. Most of the declines were attributed to changes in quantity and quality of habitat but the relationships between habitat and population dynamics were not specified. The interest of wildlife managers in predicting fall population levels generated many investigations of the causes of annual changes in population levels. Some of the factors reported to influence fall population levels included weather in spring and winter, number of young produced, number of females in spring, survival of females, and behavior of chicks and nesting females (Green 1938, Allen 1950, Kozicky and Hendrickson 1951, Stokes 1954, Linder and Agee 1965, Wagner et al. 1965, Stokes 1968, Wagner and Stokes 1968, Gates and Hale 1975). However, none of these factors fully explains long-term changes in abundance of pheasants. Our objectives were to determine the relative importance of survival and recruitment to long-term changes in abundance of pheasants and to relate changes in quantity and quality of habitat to recruitment, survival, and abundance. W. L. Allen, Benton County Office, Agricultural Stabilization and Conservation Service assisted in obtaining aerial photographs, and F. Ives, Oregon Department of Fish and Wildlife, provided data and field notes of pheasant censuses. E. C. Meslow and J. A. Crawford reviewed the manuscript.

Pecking as a Mortality Factor in Penned Ring-Necked Pheasant Chicks

Pecking of chicks by adult hen pheasants ( Phasisnus colchicus) accounted for a known mortality of 2 to 14 percent of chicks hatched in pens 0.82S to 40 acres in size in a series of studies on pheasant reproduction conducted in Ohio from 1951 through l954. Repeated observations of pecking as a cause of mortality of confined juvenile pheasants raise questions as to the possible occurrence of pecking in wild populations. The purpose of this paper is to report observations of pecking of juveniles by adult hens as a cause of mortality in confined populations of ring-necked pheasants. These observations resulted from four studies of the behavior and productivity of confined pheasants, conducted from 1951 to 1954 by graduate students of ie Ohio Cooperative Wildlife Research Unit, The Ohio State University, Columbus, in cooperation wii the Ohio Division of Wildlife. Results of this work are available only in theses. The observations on which this report is based were made by R. J. Smith, F. W. Kessler, W. L. Muhlbach, and V. D. Semones. I thank Helen C. Schultz and Dr. G. C. Sanderson for editorial assistance.

Tolerances of Two Populations of Ring-Necked Pheasants to DDT

Tolerance to DDT of a population of ring-necked pheasants (Phasianus colchicus) occupying an area to which DDT was applied for 8 years, and of a population inhabiting a nearby area with no history of insecticide use was investigated during 1966-68. Median lethal concentrations (LC5o) of technical DDT in diets of week-old chicks indicated that progeny from the unexposed population were sig- nificantly more tolerant to DDT than progeny from the exposed population (P < 0.025). Levels of tol- erance could not be explained on the basis of amounts of DDT residues passed to young through eggs, lengths of time that parents were in captivity, or to the number of generations in captivity. If DDT acted as a selective force on the population of pheasants occupying the area treated with DDT, differ- ences in tolerance of the two populations must have been greater prior to use of DDT on the treated area. Abstract: Tolerance to DDT of a population of ring-necked pheasants (Phasianus colchicus) occupying an area to which DDT was applied for 8 years, and of a population inhabiting a nearby area with no history of insecticide use was investigated during 1966-68. Median lethal concentrations (LC5o) of technical DDT in diets of week-old chicks indicated that progeny from the unexposed population were sig- nificantly more tolerant to DDT than progeny from the exposed population (P < 0.025). Levels of tol- erance could not be explained on the basis of amounts of DDT residues passed to young through eggs, lengths of time that parents were in captivity, or to the number of generations in captivity. If DDT acted as a selective force on the population of pheasants occupying the area treated with DDT, differ- ences in tolerance of the two populations must have been greater prior to use of DDT on the treated area. This is a report on levels of tolerance to DDT (nomenclature for chemical insecti- cides is that of Kenaga and Allison 1969) exhibited by two populations of ring-necked pheasants. One population inhabited an area to which technical DDT was applied annually for 8 years; the other inhabited an area which had no history of agricultural applications of chlorinated hydrocarbon in- secticides.

Weather and Pheasant Populations in Southwestern North Dakota

High productivity and survival of ring-necked pheasants (Phasianus colchicus) were correlated with high rainfall and cool temperatures in May and June during an 8-year period in southwestern North Dakota. These findings differed markedly from those of several earlier studies in the less arid midwestern United States where cool, wet weather in the spring generally affected pheasant populations adversely. General trends in the pheasant population could be explained on the basis of precipitation in May and June. The population was relatively high during the mid-1950's when wet and dry May and June periods occurred in alternate years but declined markedly after 2 consecutive years of spring and summer drought. The population remained at a static low during 1960 through 1963 when wet and dry spring and summer periods again occurred alternately. This paper presents the results of a study on the relation of weather to ring-necked pheasant population fluctuations in southwestern North Dakota. The study was initiated after pheasants decreased markedly throughout southwestern North Dakota in conjunction with a period of drought. We surmised that poor reproductive success, caused by the drought, was responsible for the population decline, and we set out to test this possibility by examining weather records and data on pheasant productivity. During the work it became apparent that annual survival was important in the population fluctuations and also appeared to have been affected by weather. Much has been published on the effects of weather on pheasant populations but the results of most studies have differed from ours. Biologists in eastern and midwestern portions of pheasant range have generally concluded that high precipitation and cool temperatures in the spring and summer have adverse effects on productivity (Perry 1946, Allen 1947, Dustman 1950, Kozicky et al. 1955). However, Wandell (1949:374376) cautioned that this is not always true and cited findings in Illinois and Montana where adverse weather and excessive rainfall did not result in decreased pheasant populations. The present study was done in a region of limited precipitation and the results suggest that drought, rather than excessive rainfall, was the factor that limited the pheasant population. We wish to thank the many biologists and game wardens of the North Dakota Game and Fish Department for collecting data, Jack Samuelson and Lloyd Oldenburg for suggestions relating to the analysis, A. D. Geis, A. J. Godin, and R. I. Smith for reviewing the manuscript, and A. J. Godin for preparing the figures. DESCRIPTION OF THE REGION Primary pheasant range in western North Dakota is south and west of the Missouri River (Fig. 1) with highest densities of pheasants in the south-central part of the region. This region is within the Missouri Plateau section of the Great Plains and is locally called the Area. Glaciation (Iowan stage) barely extended south and west of the present Missouri River. The topography of the Slope Area is almost wholly the result of erosion, with much of 1 This paper is a North Dakota Game and Fish Department contribution supported by funds from Federal Aid Project W-67-R-2. 2 Present address: Migratory Bird Populations Station, Laurel, Maryland.

Effectiveness of Two Flushing Devices Used in Hay Mowing

Biologists at the Rose Lake Wildlife Experiment Station tested two devices designed to reduce wildlife losses during hay mowing. We ran the tests on the farm area of the station near Lansing, Michigan, from 1950 through 1955. During four of these years we tested the Ohio flushing bar (Warvel, 1949) using four-pound cast-iron sash weights suspended from cables, and during three years we used the extension of the exhaust pipe of a tractor as a flushing device. Flexible metal tubing was attached to the exhaust pipe and supported by the bar used for the Ohio flushing device. This arrangement directed the noise and blast of the unmuffled exhaust into the hay about 13 feet in front of the cutter bar and in the middle of the swath. We found both devices to be mechanically satisfactory, requiring little maintenance. Our tests had the advantage of being closely observed but the disadvantage of dealing with a small population of ring-necked pheasants. Game flushed or killed was tallied by a biologist riding on the mowing machine. We mounted a seat on the caster wheel of a John Deere No. 5 Power Mower so that the observer could get a clear view of the cutter bar and the effects of the flushing device. Because of low pheasant numbers, biologists had to observe the cutting of over 900 acres of hay in order to get approximately 100 pheasant flushes from both of the devices and the control. Spring pheasant numbers on the experiment station varied between six and eight birds per 100 acres during the study period, and hayfield losses were not a serious mortality factor. There was approximately one nest per 30 acres of hay during the 6-year period. While the low pheasant population was not ideal for the test, I feel we did flush enough pheasants to establish the relative effectiveness of the two devices under Rose Lake conditions. In the cutting of 936 acres of hay, 304 pheasant and 101 rabbit flushes were observed, and 13 adult hen and 47 juvenile pheasants and 15 rabbits were killed. We used a John Deere Model B tractor operating at between four and five miles per hour. The hay was secondand third-year alfalfa mixed with smooth brome grass (Bromus inermis). Figures given in this paper are for the first cutting only. The first cutting usually began at or just before the peak of pheasant hatching so that most of the fields were actually cut just after the hatching peak had passed. Between 15 and 20 individual hayfields were involved each year, and a total of 35 different fields were cut during the 6-year period. For the first three years we cut half the total hay acreage with the Ohio bar and half as a control. The fourth year we cut a third with the Ohio bar, a third with the exhaust, and a third as a control. For the last two years we cut half the acreage with the exhaust and half as a control. Each individual field was cut entirely by one method. We attempted to cut adjoining fields by different methods, and during the test period all fields were at some time cut by each method. Our tests failed to show that either the Ohio bar or use of the exhaust blast reduced hayfield mortalities (Table 1). We were disappointed with the results, since investigators in other states have reported greatly reduced pheasant losses when using the Ohio-type flushing bar (Wisconsin-Bell, 1954; Iowa-Boehnke, 1954, and Klonglan, 1955; North Dakota-Fisher, 1954; Ohio-Warvel, 1949, and Swagler, 1951). The failure of the exhaust blast was not surprising, in view of the experimental findings of Stewart and Dustman (1955) regarding the response of incubating pheasants' auditory stimuli.

Variations in Two Spring Indices of Male Ring-Necked Pheasant Populations

Variations in Two Spring Indices of Male Ring-Necked Pheasant Populations