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An Eastern Kingbird Tyrannus tyrannus was found on Barra, Outer Hebrides, on 29th September 2016 and remained until the following day. What is believed to have been the same individual was relocated at Bornish, South Uist, on 2nd October. This is the firs t British and the third European record, following sightings in Co. Galway in 2012 and 2013. [ABSTRACT FROM AUTHOR]

The first documented records of Eastern Kingbird, Tyrannus tyrannus (Aves: Tyrannidae), for Uruguay are reported. The species was recorded 4 times between 1993 and 2016 in southeastern Uruguay. Due to the few records of isolated individuals we propose that the species is a vagrant in Uruguay. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Field Ornithology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nest placement presumably reflects selection for secure sites to minimize failure. Most tests of this hypothesis, however, have failed to support it. We used artificial nests (ARTs) to experimentally evaluate nest-site-choice behavior by an open-cup-nesting bird, the Eastern Kingbird (Tyrannus tyrannus). In 2010 and 2011, we placed ARTs in trees in the riparian zone at Malheur National Wildlife Refuge, Oregon, USA, to test whether (1) characteristics describing the physical location in trees of used and unused ARTs differed, (2) used ART sites more closely resembled naturally chosen sites, (3) successful natural nests (NATs) and successful ARTs were similarly located along the major axis describing nest placement, and (4) unused ARTs resembled failed NATs. Used and unused ART sites differed, but unused ART sites were more similar to NAT sites. The latter unexpected result occurred because (1) unused ARTs were located at sites between more heavily used higher and lower locations and (2) most kingbirds nesting at lower locations used ARTs instead of building their own nest. In both ARTs and NATs, differences between successful and failed nests exhibited the same pattern for most nest-site variables, and the major gradient describing nest location was the same; successful nests tended to be placed on more vertically oriented branches that were placed closer to the top of the tree. Kingbird nest placement was thus selective. However, extensive overlap in the locations in trees of failed NATs and both successful and unused ARTs suggests that other factors, such as macrohabitat characteristics or prior experience of individual birds with particular nest sites, may have influenced success and/or decisions to use or reject nests in particular locations. Thus, consideration of phenomena beyond the nest site itself may be required to fully understand the process of nest-site choice in birds. [ABSTRACT FROM AUTHOR]

Reuse of open cup nests is rare among passerine birds despite possible savings of time and/or energy that might yield reproductive advantages. Anecdotal observations of the open-cup-nesting eastern kingbird, Tyrannus tyrannus, at Malheur National Wildlife Refuge (MNWR), OR, U.S.A., showed that 10% of females reuse old nests of mainly American robins, Turdus migratorius. We therefore deployed artificial nests in 2010 and 2011 at MNWR to provide female kingbirds with the opportunity to reuse nests to test predictions of the time/energy saving hypothesis. We also used a flood that submerged nest sites in 2011 as a natural experiment to test the nest site shortage hypothesis' prediction that nest reuse by kingbirds should increase when the availability of nest sites is reduced. Female kingbirds used artificial nests heavily in both years, and, contrary to the time/energy saving hypothesis, they did so more in the year of earlier breeding. We also rejected three other predictions of the time/energy saving hypothesis, namely that, within seasons, females nesting in artificial nests (1) breed earlier, (2) produce larger clutches and eggs and (3) fledge more young. The only prediction of the time/energy saving hypothesis that we failed to reject was that time to lay replacement clutches following nest failure tended to be earlier in females that used artificial nests. Nest reuse was significantly more frequent in the flood year. Given this result, and our rejection of most predictions of the time/energy saving hypothesis, we conclude that frequent nest reuse by kingbirds at MNWR is likely the result of a shortage of quality nest sites. [ABSTRACT FROM AUTHOR]

Descriptions of intra- and interspecific variation in migratory patterns of closely related species are rare yet valuable because they can help assess how differences in ecology and life-history strategies drive the evolution of migration. We report data on timing and location of migration routes and wintering areas, and on migratory speed and phenology, of Eastern Kingbirds (Tyrannus tyrannus) from Nebraska and Oklahoma and of Western Kingbirds (T. verticalis) and Scissor-tailed Flycatchers (T. forficatus) from Oklahoma. Eastern Kingbirds primarily departed the breeding site in September, migrating to the Amazon Basin (Bolivia and Brazil), >6,400 km from their breeding site, then used a second wintering site in northwestern South America (Colombia, Ecuador, and Peru) before returning to the breeding site in April. Western Kingbirds left Oklahoma in late July, migrating >1,400 km to northwestern Mexico, then to central Mexico and finally to Central America before returning to Oklahoma in April. Scissor-tailed Flycatchers departed Oklahoma mainly in mid-October, migrating to Central America (El Salvador, Guatemala, Honduras, and Nicaragua), -2,600 km from the breeding site, remaining there until early April before returning to Oklahoma. Timing of migration appears to be tightly linked to molt. Early departure of Western Kingbirds from the breeding site appears to be timed so that they molt in the Sonoran Desert region during the monsoon, whereas Scissor-tailed Flycatchers remain at their breeding site to complete molt in late summer, when insect prey are abundant. Eastern Kingbirds delay molt until reaching South America where, possibly, abundant fruit supports molt. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Field Ornithology is the property of Resilience Alliance and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article offers information on birds that breed in or migrate through Florida but are rarely encountered during the winter season. It describes seven species of Neotropical migrants recorded during winter for the first time, including the Swallow-tailed Kite or Elanoides forficatus, Eastern Kingbird or Tyranus tyranus, and Blue-winged Warbler or Vermivora cyanoptera. The first winter records of three other Neotropical species are not yet described in detail including Chimney Swift or Chaetura pelagica, Yellow-bellied Flycatcher or Empidonax flaviventris, and Scarlet Tanager or Piranga olivacea.

This article presents a mark-recapture analysis of the banding and bleeding data on Eastern Kingbirds. Research methods including site study, data preparation, and model structure and hypotheses are presented. The results on transition probability, recapture probability, and survival probability are discussed. It explains that the researchers found little to no evidence that blood sampling adversely affected Kingbirds. Three tables showing recapture and survival probabilities are presented.

Harsh weather in spring presents energetic challenges to birds during migration and upon reaching the breeding grounds, and yet, birds often arrive well before breeding begins. We studied a population of Eastern Kingbirds in eastern Oregon from 2004 through 2007. Early arriving kingbirds faced the poorest weather conditions, and therefore we predicted that benefits of early arrival must exist to balance the presumed costs. Early-arriving kingbirds were more likely to both acquire a high-quality territory and to replace nests after failure. Early-arriving birds also bred early, and early breeding led to larger clutches and greater production of young. Early-arriving males also sired more extra-pair young than later arrivers. Our data suggest that arrival date is in part influenced by individual quality, and that arrival date has reproductive consequences, with the primary benefits of early arrival being the acquisition of a high-quality territory, early breeding, and increased probability of replacing failed initial nests. [ABSTRACT FROM AUTHOR]

The article reviews the 2013 issue of the periodical "Florida Field Naturalist."

Sex allocation theory predicts that if variance in reproductive success differs between the sexes, females who are able to produce high-quality young should bias offspring sex ratio towards the sex with the higher potential reproductive success. We tested the hypothesis that high-quality (i.e., heavy) female eastern kingbirds ( Tyrannus tyrannus) that bred early in the breeding season would produce male-biased clutches. A significant opportunity for sexual selection also exists in this socially monogamous but cryptically polygamous species, and we predicted that successful extra-pair (EP) sires would be associated with an excess of male offspring. Although population brood sex ratio did not differ from parity, it increased significantly with female body mass and declined with female breeding date, but was independent of the morphology and display (song) behavior (correlates of reproductive success) of social males and EP sires. Male offspring were significantly heavier than female offspring at fledging. Moreover, the probability that male offspring were resighted in subsequent years declined with breeding date, and was greater in replacement clutches, but lower when clutch size was large. Probability of resighting female offspring varied annually, but was independent of all other variables. Given that variance in reproductive success of male kingbirds is much greater than that of females, and that male offspring are more expensive to produce and have a higher probability of recruitment if fledged early in the season, our results support predictions of sex allocation theory: high-quality (heavy) females breeding when conditions were optimal for male recruitment produced an excess of sons. [ABSTRACT FROM AUTHOR]

Nest defense represents a parental strategy to maximize fitness by enhancing prospects of offspring survival. We used a taxidermic mount of a nest predator to measure nest defense of Eastern Kingbirds (Tyrannus tyrannus) at Malheur National Wildlife Refuge in southeastern Oregon in 2003 and 2004 to test the hypotheses that intensity of nest defense (1) was individually repeatable, (2) differed between males and females, and (3) predicted nest success. We also predicted that (4) intensity of defense would increase with age and number of young, but decline over the breeding season. Intensity of nest defense was significantly repeatable for male kingbirds. Male response was twice as strong as female response during incubation and the nestling period, but nest success was independent of defense scores of males and females. Simple paired comparisons suggested female responses did not change between incubation and the nestling period, whereas males tended to defend nestlings more vigorously than eggs. Multivariate analyses demonstrated strong individual differences were the main source of variation in nest defense. Intensity of nest defense by males and females increased with age of young, declined seasonally, but was not related to number of young. Kingbird nest defense is a repeatable behavior that differs between males and females and, as predicted by parental investment theory, nests of the greatest value (older young and earlier broods) were defended most aggressively. Received 13 November 2007. Accepted 4 May 2008. [ABSTRACT FROM AUTHOR]

Theory predicts that maximal fitness is obtained by individuals who begin to breed immediately upon reaching sexual maturity. However, delayed breeding occurs regularly in some taxa, and in birds and mammals is most often associated with long lifespan and/or limited access to suitable habitats. Delayed breeding is not expected among relatively short-lived species such as migratory passerine birds, but this assumption remains untested in many species. Here we quantify age at first reproduction in an eastern kingbird Tyrannus tyrannus population breeding in an ecological island, and through both observational and experimental approaches, investigate the potential causes for the high frequency of delayed breeding that occurs in this population. Nearly half of the fledged nestlings that returned to the breeding grounds did not breed in their first potential breeding season. Some non-breeders occupied territories, for at least some period, but most remained as non-territorial ‘floaters’. Parentage analysis failed to show any reproductive success for female floaters, and only limited success for male floaters, indicating that floating was not a successful reproductive tactic. On the other hand, a strong negative relationship existed between population size and the proportion of young birds that bred in their first year, and non-territorial birds of both sexes quickly filled territory vacancies created by experimental adult removals. Limited breeding habitat and territorial behavior of older birds thus appear to be the main causes of delayed breeding in kingbirds. The frequency of delayed breeding in most species is unknown but of potential significance because failure to incorporate accurate estimates of age at first reproduction in population models may lead to flawed population projections. [ABSTRACT FROM AUTHOR]

The study of breeding habitat selection has focused mainly on physical characteristics of the environment such as nest sites and food abundance, both of which are required for successful reproduction. However, individuals may have limited time to make settlement decisions, and thus, their knowledge of resource availability may be incomplete. Furthermore, food abundance during settlement may not reflect levels later in the breeding season. An alternative perspective is that the most direct measure of habitat suitability is derived from social information such as the presence of conspecifics (conspecific attraction) or their reproductive performance (habitat copying). We tested resource and socially based hypotheses of habitat selection in a population of eastern kingbirds, Tyrannus tyrannus, at Malheur National Wildlife Refuge in southeastern Oregon, U.S.A. Kingbirds nested in areas with a greater proportion of suitable nest trees than what was generally available, but many areas with suitable numbers of trees went unused. Kingbirds also settled in areas of relatively high insect abundance, but only in years when overall abundance was low. We also found support for the socially based hypotheses. Relative to where they nested previously, kingbirds tended to settle in areas of higher conspecific density. But, we found stronger evidence in favour of habitat copying, suggesting that dispersing individuals settled in areas that produced more fledglings in the previous year. Kingbirds thus appeared to select breeding habitat based, in part, on resource availability, but dispersal decisions may be influenced by social information, primarily past reproductive success of conspecifics. [Copyright &y& Elsevier]

To be used as honest signals of quality, phenotypic traits must vary markedly within populations and show repeatable differences between individuals. Eastern kingbirds, Tyrannus tyrannus, sing a distinctive dawn song in the predawn darkness, and one hypothesis for its function is that it serves as an honest signal of male quality that females use during choice of within-pair or extrapair mates. Over a 2-year period, we quantified dawn songs of males to measure between- and within-season repeatability of the timing (start and end time) and length of song bouts, and song rate. We also measured morphological characters to measure repeatability and describe individual differences in body size and plumage quality. All song traits varied considerably among males, start time and song rates were repeatable between years, and all song rates were repeatable within both years. All morphological characters were significantly repeatable between years. Moreover, early singing males were larger and had relatively long flight feathers, and males that sang at high rates had relatively long flight feathers. Early singing males were also paired to the earliest breeding females, and in one year, male song rate was positively correlated with their social mate''s clutch size. Relatively long flight feathers in other species are typical of older males and individuals of higher body condition, suggesting that, despite being suboscine passerines with relatively simple and innate songs, eastern kingbirds use song performance as an honest signal of male quality that females may use during mate choice. [Copyright &y& Elsevier]

Effects of alternate mating strategies on the opportunity for sexual selection are widely debated, and recent studies have concluded that the effects of extrapair (EP) paternity on the opportunity for sexual selection may have been overstated due to 1) methodological limitations of empirical studies and 2) the potential for males to gain from additional within-pair (WP) reproductive opportunities. We therefore examined the impact of EP paternity on the opportunity for sexual selection in the socially monogamous and single-brooded eastern kingbird (Tyrannus tyrannus). EP paternity was common in all 3 years of our study (61% of 89 broods, 47% of nestlings) and realized reproductive success (EP + WP young) ranged from 0 to 9 young/male/year. A total of 31% of males lost all WP paternity (24% sired neither WP nor EP young, whereas 7% sired EP but not WP young), and variance in male realized reproductive success was more than 9 times greater than that of apparent reproductive success. Nearly half of EP mates were not nearest neighbors, and many were separated by 3 or more territories (>1000 m). EP success was independent of nest defense behavior, but early singing males and males with high song rates were most successful at both a population level and when cuckolders and cuckoldees were compared. EP paternity contributed significantly to the opportunity for sexual selection in kingbirds, and we suggest that this is probably due to the low potential for WP variation in reproductive success, apparent long-distance movements of one or both sexes, and consequent absence of reciprocal cuckoldry. [ABSTRACT FROM PUBLISHER]

I report on the lifetime reproductive success (LRS) of female Eastern Kingbirds (Tyrannus tyrannus) in central New York. I investigated the major correlates of LRS and specifically tested the hypothesis that small body size yields reproductive benefits. Lifetime reproductive success varied widely: 15-20% of females failed to fledge young over their life, whereas 50% of young were fledged by 20% of females. Female lifespan varied between one and eight years, and females that died after one breeding season tended to be smaller-bodied than long-lived females (≥2 seasons). I therefore conducted analyses of LRS for the entire sample and for longer-lived females separately. As in other species, lifespan was the strongest predictor of LRS, followed by the proportion of eggs laid that resulted in fledged young (P). Lifetime reproductive success varied positively with clutch size and, as predicted, inversely with body size (i.e., tarsus length) of females. However, variance partitioning indicated that most variation in LRS was attributable to the effects of lifespan and P, but that a substantial negative covariance existed between lifespan and R The latter result was consistent with experimental evidence of a cost of reproduction in Eastern Kingbirds. Analysis of the correlates of lifespan, P, and clutch size showed that over a female's lifetime, (1) the longest-lived birds fledged an intermediate proportion of the eggs that they laid, (2) the most productive birds were of intermediate wing length, and (3) females with small tarsi produced the largest clutches and lost the fewest nests to predators. Hence, although lifespan was the dominant influence on LRS, negative effects of large female size appeared to be expressed through the influence of body size on other demographic parameters that contribute to LRS. [ABSTRACT FROM AUTHOR]

The reuse of old nests by open-cup nesting passerines is a seemingly rare but potentially adaptive behavior if, as a consequence, females begin to breed earlier, lay larger clutches, or fledge more young. We report an unusually high rate of nest reuse (~10% of 341 nests) for Eastern Kingbirds (Tyrannus tyrannus) breeding at Malheur National Wildlife Refuge, Oregon. We found no difference in availability of nesting habitat or food abundance in territories in which nests were and were not reused. We also found no support for the hypotheses that kingbirds benefited from nest reuse by breeding earlier, laying larger clutches, or fledging more young, and, contrary to expectations, females that reused nests laid significantly smaller eggs than females who built their own nests. Nest reuse was independent of age: a roughly equal number of females for which we had multiple years of data both reused nests and built new nests, but at different points in their lives. Competition for nest sites seems high at Malheur National Wildlife Refuge because many open-cup nesting species utilize similar nest sites in the limited zone of riparian vegetation. A shortage of high-quality nest sites, coupled with interspecific competition, may underlie the high frequency of nest reuse in this kingbird population. [ABSTRACT FROM AUTHOR]

Among socially monogamous birds, standard metrics suggest that males are only ∼5% larger than females. An untested assumption is that, with the exception of reproductive systems, males and females are scaled mirror images of one another. I used external morphological and skeletal data, and information on muscle mass and organ size, to test this assumption in a population of breeding Eastern Kingbirds (Tyrannus tyrannus). Male and female Eastern Kingbirds exhibited no differences in body mass or standard measures of size, except in a longer (∼6%) wing chord and tail in males. However, keel length, a character rarely measured in the field, was 9.7% larger in males. In principal component analysis, overall body size (PCI) failed to differ between the sexes unless keel length was included. Analysis of 16 skeletal characters also showed that only the bones associated with flight were larger in males. However, the most significant differences between the sexes was that lean dry pectoral muscle mass (LDPMM) was nearly 30% greater in males, whereas the alimentary tract was 27.5% heavier in females. Females also carried more fat. In both sexes, LDPMM scaled in a positive allometric manner with body mass (i.e., slope > 1.0), but the significantly higher slope of males suggested especially strong selection for large muscle mass and, presumably, greater power generation during flight. Eastern Kingbirds thus exhibit pronounced cryptic sexual size dimorphism, but it is not clear whether natural or sexual selection is responsible. These data call for a broader perspective for measuring and a re-evaluation of sexual size dimorphism in other socially monogamous species. [ABSTRACT FROM AUTHOR]

I used data from a 13-year study of eastern kingbirds Tyrannus tyrannus from central New York, USA, to evaluate the relative impact of female age and body size on reproduction. I also calculated repeatabilities of reproductive traits for both females and the sites where they bred in an attempt to evaluate the relative contribution of each to intrapopulation variation in reproduction. Female age had a strong influence on timing of breeding (breeding date advanced by one day for each year of life), but was not a significant source of variation for clutch size, egg mass, number of young to hatch or fledge, or total seasonal production. Repeatabilities of breeding date for females and sites were both significant (0.284 and 0.181, respectively), but the only other significant repeatabilities were for female clutch size (0.282) and female egg mass (0.746). Among-year repeatabilities of breeding date for females who bred at two or more sites over their lifetime were as high as those for females that were site faithful. Thus, breeding date was probably affected independently by the female and site. No measure of productivity exhibited a repeatable pattern in comparisons made among females or sites. All reproductive traits were entered as dependent variables in a series of stepwise multiple regression analyses in an attempt to identify female properties (size, lifespan and condition) that might be linked proximately to differences in breeding statistics. I found that (a) large birds tended to breed the earliest, (b) clutch size was independent of female size, condition and lifespan, (c) female body size and egg size were correlated positively, but (d) production of young was independent of all measured female properties. Reproduction appears to be linked more closely to the female than to the site. Body size accounts for a portion of the repeatable portion of breeding date and egg mass, but most of the intrapopulation variation in these and other traits remained unexplained. [ABSTRACT FROM AUTHOR]

Presents information on a study which examined the genetic parentage in the socially monogamous and territorial Eastern Kingbird in a central New York population by multilocus DNA fingerprinting. Methodology; Results and discussion.

Abstract: I developed a demographic model for species inhabiting a mosaic of habitats of varying quality and among which dispersal was limited only by territorial behavior. I used the model to describe an ongoing decline of an Eastern Kingbird ( Tyrannus tyrannus) population breeding in the Charlotte Valley of central New York and to explore the possibility that the population utilized a network of source-sink habitats. Population size declined in upland and floodplain habitats between 1989 and 1999, but remained stable along a riparian zone (the “creek”). Population size after 10 years was predicted accurately when I used the empirically observed, habitat-specific rates of adult survival, productivity, and adult dispersal among habitats, and assumed a 5% rate of immigration into the upland. Simulation of the effect of density-dependent variation in reproductive success or a small increase in adult survival in all habitats failed to improve the model's predictive ability. The model indicated that none of the subpopulations was self-sustaining over 50 years and that population decline was driven by declining adult survival. Further analyses, however, showed that small increases in adult survival along the creek changed the creek habitat into a source and reversed population trends. Simulation of realistic rates of habitat loss as a result of forest maturation did not affect predicted population size at 50 years, but, assuming that the area of pasture and grazed lands continues to decline at current rates, the kingbird population is predicted to become extinct locally within 40 years. Riparian zones appear to be source habitats for kingbirds and should be targeted for protection. Sink habitats were also important because in every year most of the kingbird population bred on the floodplain or in the upland and many floodplain birds later dispersed to the creek. Preservation of open space is thus critical for maintenance of kingbird populations in... [ABSTRACT FROM AUTHOR]

Examines the impact of habitat heterogeneity and adult dispersal and survival on the population dynamics of eastern kingbirds, Tyrannus tyrannus, based on a study of creek, floodplain and upland habitats in Charlotte Valley, central New York. Comparison of habitat suitability of creek and floodplains; Variation of adult dispersal and survival with habitat.

Studies the evolution of clutch size in the eastern kingbird in central New York. Comparison of the annual variation in the relationship between productivity and brood size; Impact of experimental increases in brood size on production.

Examines sex roles, parental experience and reproductive success of eastern kingbirds called Tyrannus tyrannus. Parental behavior during incubation and nestling periods; Impact of previous breeding experience on behavior and reproductive success; Performance of all incubation by females; Nest guarding behavior by males; Provisioning rates.

The article discusses the behavior, status and distribution of bird species in the Naugatuck River Greenway in Connecticut. The author had seen Baltimore Orioles, Yellow Warblers, Eastern Kingbirds and Warbling Vireos nesting at the Housatonic River side of the trail. Red-breasted Merganser, Hooded Mergansers and Common Mergansers migrate in the greenway in the dead of the winter. The greenway has become an oasis where people and wildlife can learn to live together.

The article reports on the 2009 bird banding at Kelleys Island in Ohio. A total of 520 birds of 63 species were banded at the island. The highlights of the season include the banding of a clay-colored sparrow in Long Point on May 16, 2009. Some of the unusual birds that were banded during the year include the Arcadian flycatchers, eastern kingbird, wood thrush, northern parula and song sparrow. During the past 14 years, the station has banded a total of 4,126 birds of 102 species.