Plastic Leg Bands Research Articles

Determinants of growth rates and mass of Canada geese goslings

ABSTRACTFledgling mass is an important determinant of first‐year survival and recruitment into the breeding population for many Arctic‐nesting goose species. In turn, fledgling mass of these geese is influenced by hatch date and forage quality and quantity in the brood‐rearing area. Less is known about the determinants of growth rates and fledgling mass in temperate‐nesting geese. For 25 years, we examined near‐fledging mass, hatch dates, and growth rates of Canada geese (Branta canadensis) nesting in Connecticut, USA by tracking individually marked geese that wore neck collars or large plastic leg bands. Fledgling mass was influenced by sex (males were heavier), gosling age when weighed, and family type (fledglings raised in 2‐parent families were heavier than those raised in gang broods). Paternal nesting experience (years of prior nesting) influenced fledgling mass, probably because goslings with experienced fathers hatched earlier than goslings with inexperienced fathers. Among fledglings raised in gang broods, fledgling mass was positively correlated with the number of parents attending the brood and negatively correlated with the number of goslings within the brood. Gosling growth rates (daily gain in mass) were higher for males than females; goslings in 2‐parent families grew 2 g/day faster than those in gang broods. Late‐hatched goslings grew faster than goslings that hatched earlier. In gang broods, growth rates were positively correlated with the ratio of parents to goslings. Assessing goose sex ratios, Julian hatching dates, family types, and brood sizes will allow waterfowl managers in temperate regions to refine their goose population models. This, in turn, will allow waterfowl managers to determine more accurately what proportion of the populations can be safely harvested or how best to manage nuisance goose populations. © 2018 The Wildlife Society.

Interference from long-tailed finches constrains reproduction in the endangered Gouldian finch

1. Interspecific interference competition for nest-sites among cavity-nesting birds can have important effects on reproductive fitness and the distribution of competing species. 2. We observed interference at nest-sites in free-living populations of the endangered Gouldian finch (Erythrura gouldiae) and sympatric long-tailed finch (Poephila acuticauda), and also experimentally tested the relative strength and effect of interference at nest-sites in captive populations. 3. Levels of competitive interference at nest-sites in the wild were high for Gouldian, but not long-tailed finches, and interference frequency was inversely related to Gouldian finch reproductive success. High levels of interference conferred reduced fledging success but did not affect offspring condition. 4. Captive experiments corroborated the field data, also demonstrating fitness costs of interspecific competition, and that long-tailed finches dominated resources under standardized conditions. 5. Such asymmetrical competition dynamics are likely to constrain reproduction in Gouldian finch populations, potentially affecting recruitment and hindering the recovery of remaining populations of this endangered species.

Return Rates of Aluminum Versus Plastic Leg Bands from Electrocuted Harris's Hawks (Parabuteo unicinctus)

Resumen En estudios de aves rapaces, la habilidad para identificar individuos correctamente es facilitada por la utilizacion de anillas de aluminio. Debido a que las aves rapaces generalmente descansan sobre lineas electricas, las anillas de aluminio pueden contribuir al riesgo de electrocucion, o pueden servir como indicadoras de electrocucion en cadaveres intactos. Para comprobar estas posibilidades, marcamos 89 individuos de Parabuteo unicintus en Tucson, Arizona, U.S.A. con anillas de aluminio o de plastico y comparamos las heridas y causas de muerte en 23 individuos recogidos. No encontramos diferencia en la tasa de electrocucion en 41 individuos marcados con anillas de aluminio y 38 individuos marcados con anillas de plastico, y no encontramos quemaduras en las anillas o en las patas alrededor de las anillas. En general, las hembras y los adultos fueron mas propensos a ser encontrados muertos por electrocucion. Nuestros datos no apoyan la hipotesis de que las anillas de aluminio aumentan el riesgo d...

Plastic Color Bands Have No Detectable Short-Term Effects on White-Breasted Nuthatch Behavior

We examined whether plastic leg bands had short-term effects on foraging behavior in White-breasted Nuthatches (Sitta carolinensis), a species which, because of their very short legs and unusual habit of hanging upside-down on bark, may be particularly susceptible to deleterious effects of plastic bands. Ten nuthatches were outfitted with varying numbers of colored plastic bands and observed foraging in an aviary after two days of habituation. Wearing up to five plastic bands caused no detectable change in any of the variables measured: number of flights, body position, choice of foraging substrate, seed caching, seed hammering, and seed retrieval.

Patterns of common loon (Gavia immer) mercury exposure, reproduction, and survival in wisconsin, USA

AbstractA long‐term study was initiated in 1992 to investigate whether elevated Hg exposure measured in Wisconsin common loons was associated with reduced reproductive performance or survival. Adults loons (n = 99) and chicks (n = 56) were captured on 45 lakes during 1992 and 1993, each was individually color‐marked with plastic leg bands, and blood and feathers were collected for Hg analysis. Adult return rates and reproductive outcome were then recorded for the 45 lakes from 1993 to 1996. A significant linear relationship was observed between lake pH and log‐transformed adult blood Hg (r2 = 0.22, p < 0.01) and chick blood Hg (r2 = 0.56, p < 0.001) concentrations. Egg Hg concentrations (mean = 0.9 ± 0.3 μg Hg/g fresh weight) were within the range associated with reduced hatching success or reduced survival of embryos or hatchlings in other sensitive avian species. Chick production was lower at lakes where chick blood Hg concentrations were elevated. However, no relationship was observed between levels of adult Hg exposure and reproductive performance or annual adult return rates (an index of survival). Establishing a cause‐and‐effect relationship between Hg exposure and loon fitness is complicated by the negative correlation between lake pH and Hg exposure and potential confounding with other influences on productivity that may also be related to lake pH.

Effects of colour bands on male competition and sexual attractiveness in zebra finches (Poephila guttata)

Recent work suggests that coloured plastic leg bands may alter the sexual attractiveness and reproductive success of zebra finches (Poephila guttata). For example, males wearing red bands are more attractive to females and have enhanced reproductive success compared with males that have light green bands. Colour bands have been widely used in studies of avian behaviour and therefore could introduce bias if they regularly have a significant impact on social interactions among individuals. We carried out an experiment to assess the proximate effects of colour bands on zebra finch behaviour. Male zebra finches maintained in a large indoor aviary were given either red or light green bands and then scored for their ability to compete for a limited number of nest boxes and to attract females. The same males were randomly reassigned either red or light green bands and tested for their ability to regain boxes and attract new females. We found no correlation between band colour and a male's ability to gain either a nest or female. However, there was an association between male activity level and success. Also, those males that attracted a female in the first part of the experiment were more likely to do so in the second part of the experiment. We conclude that any immediate advantages conferred by attractive band colours may be masked under conditions of strong intermale competition for nests and mates.

Influence of colour-banding on the conspecific preferences of zebra finches

Male and female zebra finches are affected by the colour of plastic leg bands worn by opposite-sex conspecifics. They find certain colours more attractive, and others less attractive, than the natural unbanded condition. Females prefer red-banded males over unbanded ones, and avoid light-blue and light-green banded males. Males prefer black and pink banded females and avoid those wearing light-blue or light-green bands. These findings may have utility for the study of mate choice in monogramous species; they also raise important questions about a widely used experimental technique.

Sex Ratio Manipulation and Selection for Attractiveness

Laboratory experiments performed on a monogamous estrildid, the zebra finch (Poephila guttata), indicate that sex ratio of offspring is affected by non-genetic markers (colored plastic leg bands) that vary in attractiveness to birds. Results suggest that natural selection favors individuals that produce offspring of the sex of the more attractive parent within a breeding pair.

Sleeping Behavior of Purple Martins

-I studied the behavior of Purple Martins (Progne subis) at nightfall and the birds' sleeping arrangements, each night, from spring arrival until premigratory flocking began. Martins slept in martin houses until about 15 June, after which they commonly slept in trees. Birds that were firmly established on a territory slept in a room of that territory. Some pairs of birds slept together in the same room and others did not. This behavior was determined by the males. Pairs that occupied their territories for a week or longer often slept together. While building nests, pairs began to prefer certain rooms for sleeping. During egg laying and incubation, all females slept in the nest. They slept with the young and probably brooded them at night until the nestlings were 1315 days old. Some females ceased sleeping with the nestlings after two weeks, and these females either slept in a tree or resumed sleeping with their mates. Many vagrant martins slept in martin houses, often on occupied territories. Martins frequently called from 03:00 until daybreak. I hypothesize that Purple Martins copulate in martin house rooms at night, probably in the early morning. Pairs' sleeping together facilitates mating. Nocturnal copulation benefits males by minimizing cuckoldry and neighbor interference. Females benefit by being less vulnerable to gang rapes. Pairs also may sleep together to conserve heat on cool spring nights. Despite recent studies of Purple Martins (Progne subis), primarily by Finlay (1971, 1976), Niles (1972), Brown (1978a-e, 1979), and E. J. Bitterbaum (pers. comm.), and earlier work by Allen and Nice (1952), Johnston and Hardy (1962) and Johnston (1966), little attention has been paid to sleeping behavior of martins after spring arrival and before premigratory flocking. In fact, sleeping behavior has not been well studied in any North American swallow. A consideration of sleeping patterns in Purple Martins is important for three reasons. First, since martins are thought to copulate within the nesting cavity (Brown 1978a), any sleeping arrangement that uses this chamber could facilitate copulation. Copulation within the cavity may, among other functions, minimize male cuckoldry. Second, sleeping patterns are reliable indicators of an individual's colony residency, and thus are useful in censuses of Purple Martins. Third, additional knowledge of behavior in the genus Progne may be helpful in defining phylogenetic relationships among member species. I present here an investigation of sleeping behavior in Purple Martins. STUDY SITE AND METHODS I made all observations at a Purple Martin colony in Sherman, Grayson Co., north Texas, each year from 1968 to 1976. The colony grew from 2 pairs in 1968, to 3 in 1969-1970, 8 in 1971-1972, 19 in 1973, 20 in 1974, 25 in 1975, and 35 in 1976. A total of 123 pairs (246 individuals) was observed. Although some birds returned year after year, to simplify procedures I treated all birds each year as different individuals; thus the reported total is slightly inflated. All individuals were recognized either by painted aluminum bands, colored plastic leg bands, behavior characteristics, or plumage features. Approximately half of the birds each year were banded or colormarked, and I could also recognize some individuals by their slight habits which became evident after careful observation. These traits included establishing ownership of certain perches on which no other birds were allowed, specific routes to and from the nesting houses, unusually strong aggression toward other martins in the colony and toward other species that came near, and individual patterns of the Claiming-Reclaiming (Johnston and Hardy 1962) display which, for many males early in the season, were uniquely characteristic. Plumage differences were useful in identifying firstyear males because the purple mottling on the head, breast, and belly is variable. Most females were also recognizable by the shading and patterning of gray on the head, breast, and belly. My techniques for capturing adults had a low yield and I could not capture all birds for banding. Only those that were individually recognizable were included in the study. After the martins arrived and became established at the colony, I observed each pair daily and recorded sleeping behavior throughout the season. Toward the end of the season as the colony grew (especially in 1975-1976), it became difficult to observe the behavior of each pair every evening, but all birds were observed at least every other evening. During 1968-76, I noted sleeping behavior on 1,392 nights (24,324 bird-nights). By month, there were 60 nights in February, 262 in March, 253 in April, 242 in May, 270 in June, 265 in July, and 40 in August. I distinguished five major stages during the nesting

Reproductive Habits in the Snow Goose: The Influence of Female Age

Parental age influences reproductive performance in several avian species. Clutch size increases and nesting becomes earlier after the first year of breeding in certain species (e.g., Great Tit (Parus major), Kluijver 1951; Blacklegged Kittiwake (Ra Canada Goose (Bruntu cunudensis muxha), Brakhage 1965). Other species show no effect of female age and, in a few instances, clutch size declines with age (see Klomp 1970). The correlation of parental age with hatching and fledging success shows similar variability among species. In many colonial nesting species, young birds establish territories in peripheral or marginal habitats (e.g. Coulson 1971) either because of their inferior competitive ability in acquisition of central nest sites (Coach 1958, WynneEdwards 1962) or because adults, nesting earlier, establish central territories by precedence ( Coulson 1971). The Lesser Snow Goose ( Anser cuerulescens caerulescens; Delacour 1954) has been under study at a small nesting colony (3,000 pairs) at La P&rouse Bay, Manitoba (58”24’ N 94”24’ W) since 1968. Many of the birds of this colony are individually identifiable through coded plastic leg bands. In this paper, we examine the age of females as a factor affecting the spatial distribution of nests in the colony, reproductive success and the timing of nesting. Annual differences in the proportion of young birds that nest are also examined. Male geese that hatch at La P&rouse Bay seldom return to the colony after reaching reproductive maturity (Cooke et al. 1975). We have, therefore, been unable to establish a population of banded males of known age and to examine the influence of male age on reproduction.

An Improvement in Fabrication of Large Plastic Leg Bands

An Improvement in Fabrication of Large Plastic Leg Bands

Further Studies of Bob-White Mobility in Central Missouri

Because of differing results of mobility studies conducted at widely separated points in the bob-white's (Colinus virginianus) range, and because of lack of specific information on this subject under Missouri conditions, a series of investigations on mobility of wild bobwhites was initiated by the Missouri Cooperative Wildlife Research Unit. First results of this study were reported by Murphy and Baskett (1952). (Bobwhite mobility in central Missouri, Jour. Wildl. Mgt. 16: 498-510, 1952). The investigation reported here, the second of the series, was designed to supplement the first. The studies were made on and in the vicinity of the Ashland Wildlife Research Area in Boone County, central Missouri. This area comprises 2,240 acres of abandoned farm land and second growth oak-hickory woodland; approximately one-third of the acreage consists of abandoned fields along ridges, and other openings which are frequented by quail and are widely distributed through the area. Quail densities on the entire Ashland Area averaged about one bird per nine acres in late winter. The open north-central portion carried somewhat higher densities, as did neighboring farmland to the north and west, where most off-area trapping was conducted. The land south and east of the Ashland Area is mostly wooded, and supported fewer quail. Data were secured by trapping and banding wild bob-whites. Materials used in the two studies were similar: cock-and-hen traps baited with grain in fall and winter, and furnished with decoy females in spring and summer. Quail were banded with numbered aluminum bands, but colored plastic leg bands and neck markers were used as supplementary marking systems. Procedures were also similar, but in the present study, the Ashland Area was trapped somewhat less intensively, and the surroundings more intensively, than in the previous investigation. The studies had in common an inadequate measure of egress. For detailed description of the area, of materials and procedures, and for a review of pertinent literature, the reader is referred to the paper by Murphy and Baskett (op. cit.). 'Contribution from the Missouri Cooperative Wildlife Research Unit: U. S. Fish and Wildlife Service, Wildlife Management Institute, Missouri Conservation Commission, Edward K. Love Foundation, and University of Missouri cooperating. The writer is indebted to T. S. Baskett who directed the research, and to D. A. Murphy, W. H. Elder, T. G. Scott, and P. C. Smith for advice and assistance.