SEASONAL, HABITAT AND SEX-SPECIFIC PATTERNS OF FOOD UTILIZATION BY RED-WINGED BLACKBIRDS (Agelaius phoeniceous) IN EASTERN ONTARIO AND THEIR ECONOMIC IMPORTANCE

Crop depredation by red-winged blackbirds (Agelaius phoeniceus) causes serious economic losses to agricultural crops each year in both Canada and the United States. The concentration of vulnerable, monocultural crops, particularly corn, during periods when large flocks of blackbirds congregate in roosting areas prior to migration has invariably led to heavy feeding pressure (Stone et al., 1972; Wiens and Dyer, 1975; Tyler et al., 1978). Efforts to reduce damage levels by mechanical and chemical dispersal agents have been largely unsuccessful, at least in terms of a long-term solution to the problem. Recently, the lethal control of blackbird populations using surfactants has been proposed. However, the potential repercussions of the removal of substantial numbers of birds from northern breeding areas are virtually unknown (Robertson et al., 1978). Much of the research dealing with the feeding ecology of red-winged blackbirds has been limited to fall and winter periods when large aggregations of birds are actively involved in crop depredation (Goddad, 1969; Williams, 1976; Dolbeer et al., 1978) or pose a potential health hazard (Monroe and Cronholm, 1976). However, what is not known is the degree to which the removal of deleterious weed seed and insect pests cited in several studies (Bird and Smith, 1964; Mott et al., 1972; Robertson et al., 1978) might be of potential value to agriculture. The issue of whether the benefits derived from redwing foraging compensate for the negative aspects associated with crop depredation and health hazards remains largely unresolved. The present study attempted to evaluate the pest status of this species using diet information derived from food habits analysis conducted during the residency of red- winged blackbirds in a northern breeding area. By determining how the feeding ecology of red-winged blackbirds varies on a seasonal basis, among different breeding habitats and between sexes, we hoped to determine more realistically which segments of the population might be responsible for the greatest benefits or detriments and, thereby, more accurately evaluate the economic impact of the species as a whole. To achieve this aim, the study provides an accurate description of the common insects and weed pests utilized by redwings. By determining the relative proportions of those items known to be detrimental, we hoped to illustrate, at least qualitatively, the degree to which redwing foraging is comprised of both beneficial and harmful components.

Effect of crude protein levels and organic selenium supplementation in the diets fed during the breeding season on reproductive parameters of red-winged tinamous (Rhynchotus rufescens)

There is little information on the nutrition of red-winged tinamous (Rhynchotus rufescens) reared in captivity, and their nutritional requirements still need to be determined. This study aimed at determining dietary crude protein requirements and testing four organic selenium supplementation levels in the diet of red-winged tinamous during the breeding season. Birds were housed in a conventional broiler house divided in 16 boxes with one male and three females each. Iso-energy (2800kcal ME/kg) pelleted feeds, based on corn and soybean meal, were supplied in tube feeders. In the first experiment, treatments consisted of four different diets containing different crude protein (CP) contents (15, 18, 21, or 24%) and in the second experiment, the four diets contained equal protein level (22.5%) and four different organic selenium levels (0, 0.2, 0.4, or 0.8ppm). Data were analyzed by the least square method. The best egg weight and eggshell thickness were obtained with 22.5% dietary CP. Organic selenium did not influence the studied reproductive traits of red-winged tinamous (Rhynchotus rufescens) males or females.

Reproductive and behavioral aspects of red-winged tinamous (Rhynchotus rufescens) in groups with different sex ratios

The aim of this research study was to evaluate the reproductive performance of tinamous submitted to five different male:female ratios. The study was carried out with 72 birds in a randomized experimental design with 4 replications. Tinamous were housed in cages, using the ratios of one (1:1), two (2:1), three (3:1) and four (4:1) females per male, and also one male was housed with three females individually (3R:1), in a rotational system. Reproductive records of the breeding season from September 2004 to March 2005 were used. The reproductive traits studied were: number of eggs laid, fertility, and percentage of eggs damaged and cracked by pecking. Nonparametric analyses of these traits were performed using Kruskal-Wallis test. Two replications of treatments 1:1 and 4:1, and one of treatment 2:1 were video-taped for three days, 12 hours/day. The videotapes were sampled according to the scan method to fit an ethogram. Birds were also watched for one hour per day to study dominance and agonistic behavior. None of the reproductive traits was affected by mating sex ratio (p<0.05). Female dominance could be related to displacement behavior (r=1.00), and male sitting in immobility plus sitting in activity behaviors were related to lower number of damaged eggs (r=-0.90). Social dominance was indirectly determined by displacement behavior in the study situation. A large number of damaged eggs occurred in all treatments, thereby not allowing a clear conclusion on the best male:female ratio.

Isolation and characterization of ten novel microsatellite loci in the red-winged tinamou (Rhynchotus rufescens, Tinamiformes, Aves) and cross-amplification in other tinamous

We describe the isolation and characterization of ten microsatellite loci from the red-winged tinamou (Rhynchotus rufescens) and also evaluated the cross-amplification of these loci and other ten loci previously developed for the great tinamou (Tinamus major) in other tinamous. Genetic variability was assessed using 24 individuals. Six loci were polymorphic with moderate to high number of alleles per locus (2-12 alleles) and showed expected heterozygosity (HE) ranging from 0.267 to 0.860. All loci conformed to the Hardy-Weinberg expectation and linkage disequilibrium was not significant for any pair of loci. This battery of polymorphic loci showed high paternity exclusion probability (0.986) and low genetic identity probability (4.95 x 10(-5)), proving to be helpful for parentage tests and population analyses in the red-winged tinamou. The cross-amplification was moderate where of the 160 locus/taxon combinations, 46 (28.75%) successfully amplified.

Estimation of (co)variance components and genetic parameters for weights of red-winged tinamou using random regression models

Com este trabalho objetivou-se determinar parâmetros genéticos para peso corporal de perdizes em cativeiro. Foram utilizados modelos de regressão aleatória na análise dos dados considerando os efeitos genéticos aditivos diretos (AD) e de ambiente permanente de animal (AP) como aleatórios. As variâncias residuais foram modeladas utilizando-se funções de variância de ordem 5. A curva média da população foi ajustada por polinômios ortogonais de Legendre de ordem 6. Os efeitos genéticos aditivos diretos e de ambiente permanente de animal foram modelados utilizando-se polinômios de Legendre de segunda a nona ordem. Os melhores resultados foram obtidos pelos modelos de ordem 6 de ajuste para os efeitos genéticos aditivos diretos e de ordem 3 para os de ambiente permanente pelo Critério de Informação de Akaike e ordem 3 para ambos os efeitos pelos Critério de Informação Bayesiano de Schwartz e Teste de Razão de Verossimilhança. As herdabilidades estimadas variaram de 0,02 a 0,57. O primeiro autovalor respondeu por 94 e 90% da variação decorrente de efeitos aditivos diretos e de ambiente permanente, respectivamente. A seleção de perdizes para peso corporal é mais efetiva a partir de 112 dias de idade.

Effects of Incubation Temperature and Relative Humidity on Embryonic Development in Eggs of Red-Winged Tinamou (Rhynchotus rufescens).

This study was conducted to assess the effects of incubation temperature (34 C, 36[degree]C and 38[degree]C) and relative humidity (RH, 50% and 60%) on egg weight loss, embryo mortality, hatchability, incubation time and chick weight in eggs from red-winged tinamou. The eggs were placed in incubators that were operated at 34[degree]C, 36[degree]C, or 38[degree]C and 50% or 60% RH (mean wet bulb temperatures of 28[degree]C and 30[degree]C, respectively) from day 1 to hatching. Each treatment had two replicate groups of 30 eggs each. Hatchability varied with incubation temperature and RH and was highest for eggs incubated at 36[degree]C and 60% RH and lowest for eggs incubated at 38[degree]C. Early, intermediate and late embryo mortality were highest at 38[degree]C, 38[degree]C/50% RH, and 50% RH, respectively. Incubation period was longest at 34[degree]C and shortest at 38[degree]C/50% RH. Present results show the highest hatchability of red-winged tinamou eggs after incubation at 36[degree]C and 60% RH; highest embryo sensitivity to high temperature in the early period of incubation (1 to 7 days), to high temperature and low RH in the second period of incubation (8-14 days) and to low RH in the late period of incubation (after 15 days) and shortest incubation period with increasing temperature and RH.

Meat and carcass traits of the red-winged tinamou (Rhynchotus rufescens)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Variable assessment of wing colouration in aerial contests of the red-winged damselfly Mnesarete pudica (Zygoptera, Calopterygidae)

Wing pigmentation is a trait that predicts the outcome of male contests in some damselflies. Thus, it is reasonable to suppose that males would have the ability to assess wing pigmentation and adjust investment in a fight according to the costs that the rival may potentially impose. Males of the damselfly Mnesarete pudica exhibit red-coloured wings and complex courtship behaviour and engage in striking male– male fights. In this study, we investigated male assessment behaviour during aerial contests. Theory suggests that the relationship between male resource-holding potential (RHP) and contest duration describes the kind of assessment adopted by males: self-assessment, opponent-only assessment or mutual assessment. A recent theory also suggests that weak and strong males exhibit variations in the assessment strategies adopted. We estimated male RHP through male body size and wing colouration (i.e. pigmentation, wing reflectance spectra and transmission spectra) and studied the relationship between male RHP and contest duration from videodocumented behavioural observations of naturally occurring individual contests in the field. The results showed that males with more opaque wings and larger red spots were more likely to win contests. The relationships between RHP and contest durations partly supported the self-assessment and the mutual assessment models. We then experimentally augmented the pigmented area of the wings, in order to evaluate whether strong and weak males assess rivals’ RHP through wing pigmentation. Our experimental manipulation, however, clearly demonstrated that strong males assess rivals’ wing pigmentation. We finally suggest that there is a variation in the assessment strategy adopted by males

Variable assessment of wing colouration in aerial contests of the red-winged damselfly Mnesarete pudica (Zygoptera, Calopterygidae)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

THE EFFECTS OF ORNITROL ON WILD POPULATIONS OF RED-WINGED BLACKBIRDS AND GRACKLES

For the past three years the New Jersey Department of Agriculture, in coop¬eration with the New Jersey Agricultural Experiment Station, has conducted field evaluations on the effects of reproductive suppressants on wild populations of red-winged blackbirds. These studies have been performed in conjunction with the North East 49 (a Federally sponsored regional project which presently has nine states in the North East and Ohio cooperating to develop means to combat bird damage to agricultural crops) regional project on control of bird depredations. Field evaluations in 1968 and 1969 centered around the effects of TEM (tri-ethylene melamine) on the reproductive rates of red-winged blackbirds. At the close of the 1969 season further field testing of the chemical was discontinued because of the material's apparent lack of effectiveness as a reproductive inhibitor. In 1970 the field evaluations were conducted to determine the effects of Orni-trol (20, 25-diazocholesterol dihydrochloride, supplied by G. D. Searle and Company, Chicago, Illinois) on the reproductive rates of red-winged blackbirds. A small colony of common grackles was also studied during this same investigation.

BLACKBIRD DAMAGE AND CONTROL--AN INFORMAL SEMINAR

The object is to hash over a few problems as we see them on this red-winged blackbird situation. I'm Mel Dyer, University of Guelph, Guelph, Ontario. Around the table are Tom Stockdale, Extension Wildlife Specialist, Ohio Cooperative Extension Service, Columbus; Maurice Giltz, Ohio Agriculture Research and Development Center, Wooster, Ohio; Joe Halusky, U.S. Fish and Wildlife Service, Columbus, Ohio; Daniel Stiles, U.S. Fish and Wildlife Service, Washington, D.C.; Paul Rodeheffer, U.S. Fish and Wildlife Service, Columbus, Ohio; Brian Hall, Blackbird Research Project, University of Guelph, Guelph, Ontario; George Cornwell, Virginia Polytechnic Insti¬tute, Blacksburg, Va.; Dick Warren, Peavey Grain Company, Minneapolis, Minn.; Bob Fringer, N.J. Department of Agriculture, Trenton, N.J.; Charles Stone, U.S. Fish and Wildlife Service, Columbus, Ohio; Larry Holcomb, Ohio Agricultural Research and Development Center, Wooster, Ohio; Doug Slack, Ohio Agricultural Research and Development Center, Wooster, Ohio; Charles Wagg, N.J. Department of Agriculture, Trenton, N.J.; Dick Smith, U.S. Fish and Wildlife Service, Columbus, Ohio; and Jim Caslick, U.S. Fish and Wildlife Service, Gainesville, Fla. As I see the situation, as a director of a red-winged blackbird research project, we have a problem which has been defined in human terms concerning a natural animal population.

Agnes Ethelwyn Wetherald fonds

An accomplished poet, writer and journalist, Ethelwyn Wetherald’s works were present in all Ontario readers for school children. Among her most notable works are; The Indigo Bird, The Red-Winged Blackbird, and The Pasture Field. The above poem Legacies is one of her most famous works and appears on her gravestone. Wetherald was born in 1857 as the sixth child out of an eventual eleven. Although born in Rockwood Ontario, she spent most of her life in Fenwick (Pelham Township), Ontario, where she died in 1940. Wetherald used her surroundings as her inspiration and focused on nature. She has been coined a nature poet and journalist. Wetherald received her education at both the Friends boarding school in Union Springs, N.Y. and at Pickering College in Pickering Ontario. After her schooling she wrote numerous articles for the Toronto Globe under the pen name Bel Thistelwaite, derived from her Grandmother’s name. These articles lead to a position as Women’s editor of the Globe and later she was part of the Advertiser’s editorial staff in London Ontario. Wetherald continued writing after she was finished with the papers and published six volumes of poetry between 1895 and 1931. Her work was not only known amongst school children, but also attracted the attention of Earl Grey, Governor-General of Canada in 1907 and Sir Wilfred Laurier, Prime Minster of Canada in 1911. In 1921 she published a book entitled Tree Top Morning, which she dedicated to her daughter Dorothy Rungeling who also became an author. Recently Rungeling published Life and works of Ethelwyn Wetherald 1857-1940 : with a selection of her poems and articles about her mother. Rungeling, Dorothy W., Life and works of Ethelwyn Wetherald

POPULATION ESTIMATES

In dealing with population estimates, we need to determine first the reason for estimating the population. If we are dealing with a local situation, are we concerned with a local estimate? If we are dealing with a regional problem, are we concerned with a regional estimate? The blackbird problem is chiefly a regional problem, but we need to look at broader horizons than just local or regional situations. Are we dealing with a national problem? Is this problem a year-round one or is it a seasonal problem? We may want to know just purely the number of birds we are dealing with. Another reason for doing population estimates might be to determine the effectiveness of some lethal control method that has been employed. Fortunately, those species with which we are most concerned are those not on the endangered species list at the present time. Many Ohio farmers would like to see the Red-winged Blackbird on the endangered species list, I think, but it is not there. My particular interest in population estimates is to determine if we can develop an early warning system for the agriculturists, so that they can better anticipate the time they can expect damage from birds. A lot of methods have been tried in the past.

BIRD DEPREDATION ON RICE AND OTHER GRAINS IN ARKANSAS

In Arkansas, blackbirds are responsible for appreciable damage to rice, grain sorghum, oats, wheat, rye, and corn. By far, the greatest damage is to rice. As is shown in the following table, the losses to rice producers amounted to an estimated $3,049,055 in 1968, the last year that a survey was made. Nearly two-thirds (63%) of this loss was to standing rice destroyed and to the cost of bird control measure in standing rice. The remaining losses ($2,140,320 ) are to seeding or to efforts to control bird depredations to new seeding, (see Table 1). Blackbird damage to grain sorghum and corn was mostly to standing grain; that to oats, wheat and rye, to seeding, although there is occasional damage to standing grain. Additional problems are caused by blackbirds in feed lots. The total losses to Arkansas agricultural producers due to blackbirds in 1968 was about $3,500,000. Bird damage in a specific locality and on specific crops seems to vary in intensity from year to year. However, surveys during the past ten years suggest a fairly consistent level of total damage state-wide. The damage in 1968-and I believe in 1969—was somewhat lighter than we have come to expect from past exper¬ience. (See table 2.) On a per acre basis the damage in 1968 showed a considerable decline when compared to previous years. A part of this decline is probably a temporary situation. Some of the decline in losses to rice and grain sorghum, however, are due to changes in varieties, such as development of bird-resistant milo, and to changes in cultural methods. Further appreciable reductions due to changes in these factors seem unlikely, (see table 3.) Since rice producers sustain the greatest losses to birds, they have generated the greatest demand for bird control programs. Three species are responsible for most of the damage to rice. They are the red-winged blackbird, common grackle and brown-headed cowbird. These birds have created problems for rice producers since the first successful rice crop was grown near Lonoke, Arkansas, in 1904.

Color variation in museum specimens of birds: effects of stress, pigmentation, and duration of storage

Animal coloration often serves as a signal to others that may communicate traits about the individual such as toxicity, status, or quality. Colorful ornaments in many animals are often honest signals of quality assessed by mates, and different colors may beproduced by different biochemical pigments. Investigations of the mechanisms responsible for variation in color expression among birds are best when including a geographically and temporally broad sample. In order to obtain such a sample, studies such as this often use museum specimens; however, in order for museum specimens toserve as an accurate replacement, they must accurately represent living birds, or we must understand the ways in which they differ. In this thesis, I investigated the link between feather corticosterone, a hormone secreted in response to stress, and carotenoid-basedcoloration in the Red-winged Blackbird (Agelaius phoeniceus) in order to explore a mechanistic link between physiological state and color expression. Male Red-winged Blackbirds with lower feather corticosterone had significantly brighter red epaulets than birds with higher feather corticosterone, while I found no significant changes in red chroma. I also performed a methodological comparison of color change in museum specimens among different pigment types (carotenoid and psittacofulvin) and pigments in different locations in the body (feather and bill carotenoids) in order to quantify colorchange over time. Carotenoids and psittacofulvins showed significant reductions in red brightness and chroma over time in the collection, and carotenoid color changed significantly faster than psittacofulvin color. Both bill and feather carotenoids showed significant reductions in red brightness and red chroma over time, but change of both red chroma and red brightness occurred at a similar rate in feathers and bills. In order to use museum specimens of ecological research on bird coloration specimen age must be accounted for before the data can be used; however, once this is accomplished, museum- based color data may be used to draw conclusions about wild populations.