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Juvenile survival in birds is difficult to estimate, but this vital rate can be an important consideration for management decisions. We estimated juvenile survival of cooperatively breeding Florida Scrub-Jays (Aphelocoma coerulescens) in a landscape degraded by fire suppression and fragmentation using data from marked (n = 325) and unmarked juveniles (n = 1,306) with an integrated hierarchical Bayesian model. To assess the combined analyses, we also analyzed these datasets separately, with a Cormack-Jolly-Seber model (marked) and young model (unmarked). Our data consisted of monthly censuses of territorial family groups from Florida Scrub-Jay populations in East Central Florida collected over a 22-year period. Juvenile survival was estimated from July when young Florida Scrub-Jays begin developing independence to March when they become first-year individuals and grouped according to the habitat quality class of their natal territory that were based on shrub height (with intermediate shrub heights being optimal and short and tall shrub heights being suboptimal) and the presence of sandy openings (the preferred open having many sandy openings; closed not having enough). Parameter estimates in the combined analysis were intermediate to the separate analyses. Notable differences among the separate analyses were that suboptimal habitat survival was lower in the unmarked analysis, the unmarked analysis showed a linear effect of time not seen in the marked analysis, and there was an effect of male breeder death in the marked but not unmarked analysis. The combined data analysis provided more inference than did either dataset analyzed separately including juveniles in optimal-closed territories unexpectedly had higher survival than those in optimal-open, survival increased through time, and male breeder death had a negative effect on survival. This study suggests that optimal-closed habitat may play an important role in juvenile Florida Scrub-Jay survival perhaps by providing better cover from predators and warrants further investigation for management implications. [ABSTRACT FROM AUTHOR]

In the first comprehensive assessment of the reproductive rates of critically endangered California Condors (Gymnogyps californianus) recovering from complete extirpation in the wild, we analyzed 20 years (1999-2018) of data from condor flocks in southern and central California. We found that several anthropogenic threats affected reproductive rates: (1) coastal space use by female condors was associated with lower hatch probability, presumably due to foraging on marine mammals and associated DDE exposure; (2) trash ingestion by chicks decreased fledging probability prior to implementation of trash management in 2007; and (3) all parent deaths during rearing resulted in chick or early fledgling deaths, and most parental deaths were due to lead poisoning. We also detected several effects on reproductive rates from the complex individual-based management of condors, which involves ongoing releases of captive-bred individuals and health interventions including treatment of lead poisoning. Recruitment rates were lower for new release sites, which we attribute to a lack of individual- and flock-level experience. In addition, the number of free-flying days in the wild in the year before first breeding and in the 8 weeks before subsequent breeding was positively associated with female and male recruitment and with female rebreeding probabilities, respectively, indicating that removing individuals from the wild may reduce their breeding success. Finally, probabilities of recruitment, rebreeding, and fledging all increased with age, and given the age distribution skew of the recovering flocks toward younger individuals, overall reproductive success was lower than would be expected at the stable age distribution. Thus, reproductive rates should increase over time as the mean age of California Condors increases if current and emerging threats to reproduction, including the loss of breeders due to lead poisoning, can be addressed. [ABSTRACT FROM AUTHOR]

Short-toed Eagle Circaetus gallicus is the only snake eagle that nests in the Palearctic. Its diet has been studied in several European countries and it is essentially based on reptiles. The aims of this work were to characterise the feeding habits of Short-toed Eagle breeding in the Tolfa Mountains (Central Italy) including a comparison of the diet with that of other populations. Moreover, we assessed changes in the diet of the former population using published data collected more than 35 years ago. We monitored five nests and three roosts between 2020 and 2021. Using camera traps and the collection and analysis of feeding remains, a total of 247 prey items were identified. The diet of the sampled nests/individuals was clearly snake-based (93.5% of prey spectrum). We found no significant differences between the diet of nestlings and adult individuals. The main prey was the Western Whip Snake Hierophis viridiflavus (83% of snakes captured), probably due to its high availability in the environment and its average size, which is positively selected by the Short-toed Eagle. Long-term comparison with previous data shows an over time contraction of the diet breadth with a relative increase of Western Whip Snake compared to other prey. The same pattern is observed in long-term studies on the snake community of our study area and is probably linked to both local anthropogenic impacts and global warming, which tend to favour thermophilic and generalist snake species During the reproductive period our population showed a narrower diet breadth when compared to the diet of other Mediterranean sites, but a similar overall structure, with a comparable frequency of snakes. The populations with the wider diet breadth are those located in areas with a greater abundance of thermophilic snake species of medium to large size, such as France, Spain and Greece. [ABSTRACT FROM AUTHOR]

In 2008, we investigated the relationships between the hatching success of the Little Grebe Tachybaptus ruficollis with egg laying onset, nest diameter, as a proxy of nest size, and egg weight, as a proxy of egg size, in an artificial wetland in Mazandaran Province, northern Iran. The first egg was laid on April 23 and the last chick hatched on July 27. From 118 eggs on 25 nests, we recorded a total of 72 hatchlings (hatching rate: 61%). A generalized linear model (GLM) revealed that while egg size and nest diameter were not significant factors predicting hatching success, egg laying onset predicted significantly the hatching success as early breeders were likely to produce less hatchlings than late breeders. Further studies will be necessary to elucidate the underlying mechanisms of such results. [ABSTRACT FROM AUTHOR]

Abstract Background Bird fanciers’ lung (BFL) is a very famous type of hypersensitivity pneumonitis (HP) produced by airborne exposure to avian antigens. Immunological response and duration of exposure to the avian protein increase the risk of developing BFL. The current study investigates the risk factors and the clinical characteristics of BFL in pigeon breeders. This study aimed to determine the risk factors and clinical characteristics of HP in pigeon breeders. Results This cross-sectional observational study included 67 hypersensitivity pneumonitis patients with a history of pigeon breeding. Patients were subjected to history taking (age, smoking history and duration, and type of exposure to birds), clinical examination, chest X-ray, high-resolution computed tomography (HRCT), oxygen saturation, and spirometry. Most of BFL patients were females (83.6%) and non-smokers (86.6%). Breathlessness, cough, fever, and crackles were the most common findings. Sweeping for birds was associated with more reduction of forced vital capacity (FVC) (p value 0.02). Patients who were exposed in closed places had a rapid onset of symptoms (p value 0.01). Conclusion In this study, most of the patients with BFL are females and non-smokers. Sweeping for birds and exposure in closed areas are important risk factors of HP in BFL.

Background: Knowledge on migration patterns and flyways is a key for understanding the dynamics of migratory populations and evolution of migratory behaviour. Bird migration is usually considered to be movements between breeding and wintering areas, while less attention has been paid to other long-distance movements such as moult migration. Methods: We use high-resolution satellite-tracking data from 58 taiga bean geese Anser fabalis fabalis from the years 2019–2020, to study their moult migration during breeding season. We show the moulting sites, estimate the migratory connectivity between the breeding and the moulting sites, and estimate the utilization distributions during moult. We reveal migration routes and compare the length and timing of migration between moult migrants and successful breeders. Results: All satellite-tracked non-breeding and unsuccessfully breeding taiga bean geese migrated annually to the island of Novaya Zemlya in the high Arctic for wing moult, meaning that a large part of the population gathers at the moulting sites outside the breeding range annually for approximately three months. Migratory connectivity between breeding and moulting sites was very low (rm = − 0.001, 95% CI − 0.1562–0.2897), indicating that individuals from different breeding grounds mix with each other on the moulting sites. Moult migrants began fall migration later in autumn than successful breeders, and their overall annual migration distance was over twofold compared to the successful breeders. Conclusions: Regular moult migration makes the Arctic an equally relevant habitat for the taiga bean goose population as their boreal breeding and temperate wintering grounds, and links ecological communities in these biomes. Moult migration plays an important role in the movement patterns and spatio-temporal distribution of the population. Low migratory connectivity between breeding and moulting sites can potentially contribute to the gene flow within the population. Moult migration to the high Arctic exposes the population to the rapid impacts of global warming to Arctic ecosystems. Additionally, Novaya Zemlya holds radioactive contaminants from various sources, which might still pose a threat to moult migrants. Generally, these results show that moult migration may essentially contribute to the way we should consider bird migration and migratory flyways. [ABSTRACT FROM AUTHOR]

Assortative mating by telomere lengths has been observed in several bird species, and in some cases may increase fitness of individuals. Here we examined the relationship between telomere lengths of Blue-footed Booby (Sula nebouxii) mates, long-lived colonial seabirds with high annual divorce rates. We tested the hypothesis that interactions between maternal and paternal telomere lengths affect offspring and parental survival. We found that relative telomere lengths (RTL) were strongly positively correlated between members of a breeding pair. In addition, RTL of both parents interacted to predict fledgling recruitment, although fledglings with two very long-RTL parents performed only averagely. Telomere lengths also predicted adult survival: birds with long telomeres were more likely to survive, but birds whose mate had long telomeres were less likely to survive. Thus, having long telomeres benefits survival, while choosing a mate with long telomeres benefits reproductive output while penalizing survival. These patterns demonstrate that while a breeder's RTL predicts offspring quality, assortative mating by RTL does not enhance fitness, and a trade-off between different components of fitness may govern patterns of assortative mating by telomere length. They also illustrate how testing the adaptive value of only one parent's telomere length on either survival or reproductive success alone may provide equivocal results. [ABSTRACT FROM AUTHOR]

The ubiquitous fungi belonging to the genus Aspergillus are able to proliferate in a large number of environments on organic substrates. The spores of these opportunistic pathogens, when inhaled, can cause serious and often fatal infections in a wide variety of captive and free-roaming wild birds. The relative importance of innate immunity and the level of exposure in the development of the disease can vary considerably between avian species and epidemiological situations. Given the low efficacy of therapeutic treatments, it is essential that breeders or avian practitioners know the conditions that favor the emergence of Aspergillosis in order to put adequate preventive measures in place. [ABSTRACT FROM AUTHOR]

This short report proposes to integrate the recent checklist of the bird species of Italy with an alien species breeding in Italy since 2011, the Alexandrine parakeet Psittacula eupatria. Two reproductive populations are currently present, one in Reggio Emilia with about 20 individuals and the other one in Rome, with 3-4 birds. Records of single free–ranging individuals of this species of Indian origin occurred in other locations of northern-central Italy, in one case recorded for several consecutive years and then disappeared. If this report will be accepted by the COI, the Italian checklist reaches a total of 20 naturalised and not yet naturalised alien birds, i.e. the 3.6% of listed species. [ABSTRACT FROM AUTHOR]

Natal dispersal and local recruitment are affected by factors both intrinsic and extrinsic to juveniles and may affect fitness. Understanding the relationship between dispersal and population density in birds has been hindered by a lack of long-term studies and a focus on resident species has neglected the role of weather operating at large spatial scales. I studied local recruitment and the reproductive consequences of natal dispersal distance within a population of Northern Flickers (Colaptes auratus), a migratory woodpecker. During a field study spanning 16 yr in British Columbia, 8,272 fledglings were banded and 138 males and 105 females recruited locally. The average annual local recruitment rate for males (3.36%) was greater than that for females (2.55%) and the propensity to recruit locally was positively correlated with an early hatch date and high body condition. Annual local recruitment was not associated with population density in the year of hatch but was positively correlated with population density in the year of settlement. Local recruitment was also positively correlated with warmer springs during migration, consistent with the phenology hypothesis that the location of settlement is affected by weather along the route. Among local recruits, natal dispersal distance was independent of the presence of parents and so dispersal was not a behavior to prevent inbreeding. However, settling closer to the natal site led to reproductive benefits in terms of earlier laying dates and better nest success. Therefore, juveniles may gain useful information about the location of nesting substrates, predation risk, and patchy food resources by exploring the landscape around their natal site during the post-fledging period and then settling in the familiar area after returning from migration. [ABSTRACT FROM AUTHOR]

A total of one hundred and twenty ducklings (i. e. 60 Muscovy and 60 Mallard) were used for the study to evaluate the breeds effect on growth performance and prediction of body weight using linear body measurements of two breeds of ducks with the aid of General Linear Model and stepwise regression procedure of SPSS. Data on individual body weight (BW), body height (BH), body length (BL) breast circumference (BC), thigh length (TL), bill length (BIL), wing length (WL)and shank length (SL) of 120 ducks were collected on Muscovy and Mallard ducks and used to predict body weight at 4 and 8 weeks. The results showed that Muscovy (56.6t ± 6.7 - 1037.5 ± 30.29g) was significantly superior (P<0.05) to Mallard (51.8 ± 1.66 - 875.44 ± 70.30g) in body weight and in all the linear body measurements from day old to week 10. Individual body weight and linear body measurements was predicted at various ages (4 and 8 weeks) by genetic groups. The values of the coefficient of determination (R²) ranged from (88.6 - 97%) and (81.8 - 90.3%) in Muscovy and Mallard respectively at week 4. While, (R²) ranged from (58.7 - 92%) and 80.1 - 86.9%) in Muscovy and Mallard respectively at week 8. Since linear body measurements that can readily predict body weight without ducks being slaughtered, it is therefore, highly desirable as it will ensure the selection of animals that will reach market weight and size at relatively faster rate. This will also serve as a tool for breeders in selecting animals destined for use as breeding stock. These Muscovy and Mallard can be improved by exploiting the principle of phenotypic plasticity to obtain strains to complement other breeds of duck. Muscovy can also be used to upgrade some other indigenous ducks for better performance in a systematic breeding program. [ABSTRACT FROM AUTHOR]

The article offers information on the current northernmost breeding pair of the california gnatcatcher. Topics include, northernmost pair of the california gnatcatcher previously reported to the U.S. Fish and Wildlife Service (USFWS); surveying of bird habitat during breeding season; and observing bird's nesting status.

In the San Francisco Bay area, California, the Double-crested Cormorant Phalacrocorax auritus population has recovered from significant declines to reach breeding population sizes comparable to those from the late 19th century, when only one colony offshore at the South Farallon Islands (SFI) was known. The recent replacement of the bridge hosting one of the current largest colonies prompted a comprehensive assessment of Bay Area breeding population trends through 2017. Since the early 1970s, the Bay Area population has expanded from < 50 pairs at one site, SFI, to nearly 3 500 pairs at > 20 colonies, with breeding documented at 31 different locations. However, missing counts at many colonies before 2003 prevented calculation of precise, long-term growth rates. Expansion has been facilitated by cormorant adaptations to the urbanized estuary, including nesting on bridges, electrical towers, non-native trees, and managed pond levees. Breeding colonies that formed by 1984 on the San Francisco-Oakland Bay Bridge (SFOBB) and Richmond-San Rafael Bridge (RSRB) grew quickly, and in several different years totaled more than 1 000 nests. From 2003 to 2017, when construction of a new east span of the SFOBB (and demolition of the old span) was underway and when substantial maintenance of the RSRB occurred, the colonies on the bridges declined by 71 % and the overall Bay Area population declined by 39 %. The decline was likely due to reduced prey availability, although construction disturbance may have driven some birds from the bridges to colonies outside the region. On the Outer Coast, the colony at Hog Island was formed in 2001 and has become the largest in the study area since 2011. Nesting on artificial platforms installed on the new SFOBB east span in 2017 occurred only after demolition of the old span was complete, despite social attractions being in place since 2011. [ABSTRACT FROM AUTHOR]

Abstract Striking uniformity exists in humans' preference to conceal sexual activity from conspecifics' view. Yet, little is known about the selective pressures acting upon its evolution. To investigate this question, we studied the cooperatively breeding Arabian babbler (Turdoides squamiceps), which has been suggested being the only other species where dominant individuals conceal sex regularly. We examined whether birds indeed conceal sex and tested different hypotheses postulating that sex concealment functions to avoid predators, signal dominance status, or to avoid social interference. The results showed that the birds concealed sex in all observed cases of copulation, did not prefer to copulate under shelters and concealed mating solicitations from adult conspecifics. In addition, subordinates did not attack dominants who courted the respective female. Hence, none of the tested hypotheses explains these results satisfactorily. We postulate that dominant Arabian babblers conceal sex to maintain cooperation with those helpers they prevent from mating. Empirical desiderata for testing this 'Cooperation-Maintenance' hypothesis are discussed. [ABSTRACT FROM AUTHOR]

Reproductive activities can incur various costs to breeding individuals in birds. One cost is that reproduction decreases survival probabilities of attendant individuals, which may have a major effect on population demography. During brood rearing, adults of precocial species usually make extensive movements to lead their young to sites with adequate food resources and dense cover. However, few studies have evaluated the effects of brood movement on attendant precocial adults. In this study, we tracked female Chinese Grouse during brood-rearing periods using radiotelemetry at Lianhuashan Nature Reserve, Gansu, China, during 2010-2012, to evaluate the effects of brood rearing and movement distances on females’ survival probabilities using known fate models in program MARK. All 41 females attempted to breed, and 30 females successfully hatched at least one chick; 11 failed during the incubation period. Although females with broods moved more extensively than females without broods, movement distances did not influence survival probabilities of attendant females. Seven females with broods were killed by predators, resulting in a lower survival probability (0.958 ± 0.016 weekly survival and 0.679 ± 0.099 through the 9-weeks brood-rearing periods) than for females without broods, which all survived the brood-rearing periods. Our results agree with the prediction of life history theory, which assumes that cost must correlate with reproduction. The extensive movement patterns found in this study might reflect a lack of suitable brood-rearing habitat near nest sites, which might be detrimental to chick survival and influence the persistence of this population. [ABSTRACT FROM AUTHOR]

Body weight (BW) and rearing photoperiod are important factors affecting sexual maturation rate and reproductive performance in broiler breeders. The current experiment used a 2 × 3 factorial arrangement of treatments to study the interaction between BW and rearing photoperiod on reproductive performance in group housed broiler breeder hens, while minimizing variation in BW. Hens (n = 180) were fed with a precision feeding system to allocate feed individually to achieve the breeder-recommended target curve (Standard) or to a target curve that reached the 21 wk BW at 18 wk (High). Hens were on 8L:16D, 10L:14D, or 12L:12D photoschedules during rearing and were photostimulated at 21 wk with a 16L:8D photoschedule. Sexual maturity (defined as age at first egg) and individual egg production to 55 wk were recorded. At 55 wk, proportional weights of individual body components were determined by dissection. Differences were reported as significant at P ≤ 0.05. A significant interaction between BW and rearing photoschedule affected age at sexual maturity and egg production. In the High BW treatment, age at sexual maturity did not differ between hens under the 8L:16D and 10L:14D photoschedules (173 vs. 172 d, respectively). In the Standard BW treatment, the 12L:12D rearing photoperiod delayed sexual maturity compared with the 8L:16D rearing photoperiod (266 vs. 180 d, respectively). All hens on the High BW treatment laid at least 1 egg before the end of the experiment. Conversely, 3.3, 18.1, and 37.6% of Standard BW hens on the 8L:16D, 10L:14D, and 12L:12D photoschedules, respectively, never commenced egg production. At the end of the experiment, proportional breast weight was higher and proportional fatpad weight was lower in Standard compared to High BW hens (25.8 vs. 27.5% and 2.4 vs. 1.5% of BW, respectively). We conclude that increased BW partially counters the effect of longer photoschedules on sexual maturity in broiler breeders and that dissipation of the photorefractory state depends on BW. [ABSTRACT FROM AUTHOR]

Life history theory assumes a trade-off between reproduction and survival. Investigations of this trade-off in birds have focused primarily on costs of rearing altricial young, because such costs are assumed to be low in species with precocial young. We experimentally manipulated nest success to test for a trade-off between (1) raising offspring for up to 1 yr after successfully nesting and (2) survival in female Ross's Geese (Chen rossii), a species with self-feeding, precocial young. We used multistate capture-resighting analysis that also incorporated recoveries of dead birds for inference about survival. We detected a general negative effect of successful nesting on survival, whereby point estimates of annual survival for successfully nesting females were consistently lower than those for failed nesters. Failed nesters had a greater proportion of mortality attributable to hunting, judging from their higher rates of reported mortality by hunters compared to successful nesters; thus, a cost of breeding associated with successful nesting likely resulted from natural mortality factors during incubation and brood rearing, and not from exploitation by humans. [ABSTRACT FROM AUTHOR]

In contrast to theoretical predictions of even adult sex ratios, males are dominating in many bird populations. Such bias among adults may be critical to population growth and viability. Nevertheless, demographic mechanisms for biased adult sex ratios are still poorly understood. Here, we examined potential demographic mechanisms for the recent dramatic shift from a slight female bias among adult eider ducks (Somateria mollissima) to a male bias (about 65% males) in the Baltic Sea, where the species is currently declining. We analysed a nine-year dataset on offspring sex ratio at hatching based on molecularly sexed ducklings of individually known mothers. Moreover, using demographic data from long-term individual-based capture-recapture records, we investigated how sex-specific survival at different ages after fledgling can modify the adult sex ratio. More specifically, we constructed a stochastic two-sex matrix population model and simulated scenarios of different survival probabilities for males and females. We found that sex ratio at hatching was slightly female-biased (52.8%) and therefore unlikely to explain the observed male bias among adult birds. Our stochastic simulations with higher survival for males than for females revealed that despite a slight female bias at hatching, study populations shifted to a male-biased adult sex ratio (> 60% males) in a few decades. This shift was driven by prime reproductive-age individuals (≥5-year-old), with sex-specific survival of younger age classes playing a minor role. Hence, different age classes contributed disproportionally to population dynamics. We argue that an alternative explanation for the observed male dominance among adults–sex-biased dispersal–can be considered redundant and is unlikely, given the ecology of the species. The present study highlights the importance of considering population structure and age-specific vital rates when assessing population dynamics and management targets. [ABSTRACT FROM AUTHOR]

Over a 47-year period, 1970-2016, a breeding population of Purple Finches (Haemorhous purpureus) was studied at an Adirondack mountain, New York state, location leading to the banding o f13,256 finches and 3240 return captures in subsequent years of these birds (16,494 total captures, not including thousands of same-season repeat captures). Purple Finches were abundant breeders between 1971-1990, but declined abruptly from 1991-1995 through 2011-2015 by 52.1%. This decline coincides with a shift in the National Temperature Index anomaly going from negative to positive by +2.08° F during the Apr-Sep breeding season from 1971-1975 to 2011-2015. Average spring arrival dates were earlier by eight days from 16 Apr to 8 Apr and banding dates for newly fledged immatures were also earlier by eight days from 9 Jul to I Jul. Adult males (3309 banded, 51.9%) outnumbered adult females (3063 banded, 48.1%) but included 814 brown-plumaged adults early in the season of unknown sex; 6017 hatching-year birds were banded. Returning adult males more greatly outnumbered adult females by 61.5% to 38.5%; while hatching-year birds that returned at a time when their sex could be determined were 58.9% male, 41.1% female. The oldest recaptured finches by their respective sexes were two males at II yr-01 mo and a female at 10yr-0 mo. [ABSTRACT FROM AUTHOR]

Animal migration is receiving increasing research attention through ever more sophisticated tracking technologies, but the difficulty of trapping nonbreeding floaters has prevented comprehensive tracking studies of how migration varies in young breeders and floaters and whether this has consequences for recruitment (i.e. the transition from floating to breeding). To fill this gap, we satellite-GPS tracked young black kites, Milvus migrans , which start to breed when 1–7 years old. In the prebreeding migration, floaters departed and arrived later than breeders, travelled faster with fewer days at stopovers, as if in a hurry, and suffered more from cross-winds. Survival, recruitment, the territory quality and offspring production of the first reproductive attempt, as well as eventual longevity, declined rapidly with small departure delays. The high payoffs for small gains in timing set young kites on a race for early arrival: individuals improved their departure through early life and late migrants were progressively removed from the population or lingered as old floaters. As a result, individual improvements and selective mortality caused each cohort to progressively split after 3 years of age between a vanishing tail of late floaters and a body of early travelling individuals that then shaped the migratory traits of the adult population. Thus, migration in early life acted as a demographic bottleneck that filtered the transition to the next stage of the life cycle through a carryover effect that linked events operating on different continents. [ABSTRACT FROM AUTHOR]

The present study was carried out to find the effect of different levels of aflatoxin BI (AFB1) on egg production of breeder Japanese quails (Colurnix columix japonica). One hundred and sixty quail breeders at six weeks of age were distributed in completely randomized experimental design with five treatments and four replicates of eight birds each (3:1 female to male ratio). The five treatments diets containing <5 (control), 20, 40, 60 and 80 ppb AFB1 were applied during 7 to 26 weeks of age. The egg production was significantly (P<0.05) lower in all the treatment groups compared to control. Results suggested that long time exposure to aflatoxin BI at 20 ppb level or more adversely affected the egg production. [ABSTRACT FROM AUTHOR]

Background: Most birds exhibit bi-parental care with both sexes providing food for their young. Nestling signal food needs through begging. However, for some species, males rarely visit the nest, so have limited opportunity for gaining information directly from the chicks. Instead, females beg when males deliver food. We tested whether this calling signalled nutritional need and specifically the needs of the female (Breeder Need hypothesis) or that of their chicks (Offspring Need hypothesis). Results: We observed begging and provisioning rates at 42 nests of hen harrier (Circus cyaneus) in Scotland, explored the factors associated with variation in begging rate and the relationship between begging and provisioning. We also tested the impact of food on begging and provisioning through a feeding experiment. Female begging rate increased up to a chick age of 3 weeks and then tailed off. In addition, begging increased when broods were large. Conclusions: Our data provided support for the Offspring Need hypothesis. At nests where adlib food was provided females reduced their begging rate. These patterns suggested that female begging was an honest signal of need. However, begging continued even with adlib food and was only weakly associated with greater provisioning by males, suggesting that these calls may also play an additional role, possibly reflecting sexual or parent-offspring conflict. [ABSTRACT FROM AUTHOR]

Harris's Hawks ( Parabuteo unicinctus) are cooperative breeders, and groups of more than a pair have been reported from Arizona (49% to 83%) and New Mexico (51%). However, two studies (Griffin 1976, Brannon 1980) suggested that they breed in groups infrequently in Texas (5% and 13%). During a banding study from 2004-2014, I occasionally captured three or more adults at the same time and place, and I regularly observed groups of three or more adults. I undertook a study to determine sizes of breeding groups in south Texas in 2014 and 2015 in a mix of breeding habitats, primarily thorn scrub forest, but also parks, agriculture with forest and grassy plots, industrial areas, and urban areas. I determined that more than half (56%) of the 73 breeding groups I observed in south Texas were composed of three or more individuals, contrary to the results of the two earlier Texas studies, which may have underestimated group size because of fewer short visits compared to longer visits spent determining group size in this study. [ABSTRACT FROM AUTHOR]

For cooperatively breeding birds, it has been proposed that breeders should reduce their investment in eggs when they count on helpers, because this can be compensated for by helpers provisioning of nestlings. Data from some species have supported this prediction, but this is not the case in others. It has also been proposed that mothers should not reduce but rather increase investment if the presence of helpers enhances the reproductive value of offspring, a pattern that might also influence egg production as long as helpers are predictable for laying females. Here, we studied maternal expenditure in eggs and clutches in the Iberian magpie, to see whether mothers reduce their expenditure at the egg stage in the presence of helpers. Our results show that investment in clutches varied depending on the year, date in the season and age of the mother, but there were no reductions in maternal expenditure per individual egg when they counted on helpers. On the contrary, a pattern emerged in the opposite direction of more investment in eggs associated with the future presence of helpers at the nestling stage. Our data suggest that the predictability of helpers, along with the type of benefits accrued from the contribution of helpers, may be crucial to understanding the reaction of mothers at egg production. [ABSTRACT FROM AUTHOR]

During 2016 I carried out a yearlong avian survey at Lair o' the Bear Park in Jefferson County, Colorado. Abundance and breeding status of the species identified were noted, as were their various habitat affiliations during different seasons. To gain a more accurate estimate of species richness and the breeding status of the birds at the site, I used two other sets of records that provided overlapping data for the previous ten years. Between 2007 and 2016 the three sources found 143 species. Sixty-three were confirmed breeders, 22 probable, and 25 possible. The other 33 showed no breeding behavior at the site. [ABSTRACT FROM AUTHOR]

Periodic weighing of seabird chicks is labour-intensive and repeated handling can cause high levels of disturbance to chicks. Although automatic weighing systems using a fibreglass nest have been designed for albatross species with a pedestal nest made of mud, this approach is inappropriate for great albatross species (genus Diomedea) whose nests consist of a low mound of soil and vegetation. We developed an automatic weighing technique, using a digital scale beneath a natural nest, to remotely measure meal size in great albatrosses. To illustrate the system's capability when used coupled with time-lapse cameras, we present sample data by comparing meal sizes fed to chicks by male and female parents of northern royal albatross (Diomedea sanfordi). Our weighing system is not only applicable to other great albatross species, but can also be modified to allow automatic weighing of other terrestrial breeders. [ABSTRACT FROM AUTHOR]

The ringing data on Common Rosefinch obtained during thirteen field seasons (2002-2014) at the National Park 'Russky Sever' (Vologda region) are analyzed. Birds were trapped in two sites 59 km apart. The age of the birds (yearlings or first breeders and adults) was determined according to the plumage color in every male captured with mist nets. The apparent survival rate of adult individuals was determined using two methods: according to the ratio of males' age and the CJS model (Lebreton et al., 1992; Bursky, 2011). A total of 713 captures of 657 individuals were analyzed. The ratios of ages in the males from the sites studied did not differ; yearlings amounted to 56% of all males. The rate of survival in the males based on the age ratios was estimated at 44 ± 2%. The apparent survival rate obtained using the CJS model was significantly higher (61 ± 6%). The survival rate of adult rosefinches in two sites did not differ and did not depend on sex. Literature materials on the age ratio and survival of rosefinches in local populations are analyzed. There is a suggestion that the mismatch of the survival rates obtained by two methods and the high proportion of yearling males in the banding captures can be explained by the fact that the majority of individuals of that age category did not participate in nesting. [ABSTRACT FROM AUTHOR]

Birds are one of the animals most widely used by humans and are highly valued as pets. The present work reports the use of wild birds as pets in the city of Campina Grande, Paraíba State (PB), Brazil. The owners' choice and perceptions of the species ecology was assessed as well. The methodology employed included unstructured and semi-structured interviews, guided tours and direct observations. A total of 26 bird species distributed among ten families and four orders were identified. The most frequently encountered order was Passeriformes (76.9%), with a predominance of the family Emberizidae (34.6%). The specimens kept as pets were principally obtained in public markets or between the breeders themselves. The popularity of birds as pets, compounded by the inefficiency of official controls over the commerce of wild animals has stimulated the illegal capture and breeding of wild birds in Campina Grande.As aves destacam-se entre os animais mais utilizados pelas populações humanas. Em geral são bastante apreciadas como animais de estimação. Este estudo visou inventariar as aves silvestres utilizadas como animais de estimação na cidade de Campina Grande-PB Brasil, buscando informações sobre o motivo da sua escolha e sobre o conhecimento dos criadores acerca do comportamento e biologia das espécies criadas. A metodologia empregada envolveu entrevistas livres, entrevistas semiestruturadas, turnês guiadas e observação direta. Foram identificadas 26 espécies de aves, distribuídas em dez famílias e quatro ordens. A ordem encontrada com maior frequência foi a Passeriformes (76,9%), com predominância de aves da família Emberizidae (34,6%). Os espécimes são obtidos, principalmente, através do comércio em feiras livres ou entre os próprios criadores. Esse cenário, associado à popularidade das aves como animais de estimação e a ineficiência da fiscalização tem fomentado o crescimento do comércio e criação ilegal de aves em Campina Grande.

Despite its importance for the evolution of cooperative breeding, it has proven difficult to determine whether helpers improve their recipients' fitness. Helpers affect fitness in multiple ways, both positive and negative, but their effects can also be concealed through reduced maternal investment. Furthermore, determining the direction of causation is difficult, as helper presence may indicate a productive territory, rather than high productivity indicating an effect of help. In cooperatively breeding red-winged fairy-wrens (Malurus elegans) groups reduce care when they have male helpers, but groups with female helpers do not, so nestlings receive more food. Thus our predictions vary with helper sex rather than helper number, and by studying within-group changes with regard to group composition we separate phenotypically plastic responses from among-group correlations. Females did not reduce egg size in response to an increasing number of female helpers. However, more male or female helpers allowed females to lay larger clutches and more female helpers reduced re-nesting intervals. There was mixed support for a benefit of load lightening: Helpers, but not breeders, gained survival benefits with increasing number of male helpers. However, helper survival decreased with the number of female helpers, suggesting that increased competition counterbalanced these male helper benefits. We also found consistent among-group differences, which would have erroneously been interpreted as helper effects had we not disentangled the within-group changes with regard to group composition. This study highlights the importance of assessing carers' benefits in relation to both group composition and size, and of investigating the within-individual plastic response of helper effects. [ABSTRACT FROM AUTHOR]

Divorce can be an important behavioral strategy to improve fitness. This is particularly relevant for species that are territorial year-round with continuous partnerships, where individuals face constraints on partner choice due to limited vacancies and dispersal opportunities. We tested several hypotheses for divorce in such a species, the cooperatively breeding bird Malurus coronatus. Based on 9 years of detailed information on dispersal and survival of 317 breeding pairs, we tested whether divorce is driven by inbreeding avoidance, by a better partner or territory, or by social variables (number of subordinates and fidelity of partners). We found that divorce is important to escape incest: incestuous pairs were substantially more likely to divorce (64%) than non-incestuous pairs (14%). However, incestuous pair bonds lasted up to a year, highlighting constraints on breeder dispersal. Non-incestuous pairs also divorced, but here the only predictor for divorce was the presence of extrapair offspring in a previous brood. Although reproductive failure did not trigger divorce, and reproductive success did not improve in the year following divorce, females that dispersed after divorce obtained higher quality territories, unlike females that dispersed after their partner died. Thus, divorce may be a strategy to improve long-term benefits associated with better territories. Some divorces appeared to be forced evictions by older females, although direct evidence for this is limited. Taken together, our findings demonstrate the complexity of factors that affect the occurrence of divorce when partner choice is constrained. [ABSTRACT FROM AUTHOR]

Personality is an intriguing phenomenon in populations because it constrains behavioral flexibility. One theory suggests that personality could be generated and maintained if dependent on asset protection. It is predicted that trade-offs with fitness expectations and survival probability encourage consistent behavioral differences among individuals (personality). Although not mutually exclusive, the social niche specialization hypothesis suggests that a group of individuals that repeatedly interact will develop personality to avoid costly social conflict. The point at which behavioral consistency originates in the social niche hypothesis is still unclear, with predictions for development after a change in social status. In the facultative cooperatively breeding Seychelles warbler (Acrocephalus sechellensis), residing on Cousin Island, breeding vacancies are limited and this forces individuals into different social roles. We used this system to test whether reproductive and social state predicted among-individual differences in exploration. We had 2 predictions. First, that an individual's start in life can predict personality, whereby young individuals with a good start to life (associated with early age reproduction and earlier onset survival senescence) are fast explorers, suggesting reproductive state-dependence. Second, that an individual's social status can predict personality, whereby dominant individuals will be fast explorers, suggesting that the behavior is social state-dependent. Neither of the behaviors was associated with social state and social state did not affect behavioral consistency. However, novel object exploration was associated with a proxy of reproductive state. Our results provide further support for state being a mechanism for generating individual differences in behavior. [ABSTRACT FROM AUTHOR]

Among cooperatively breeding species, helpers are hypothesised to increase the survival of breeders by reducing breeder workload in offspring care and increased group vigilance against predators. Furthermore, parental nepotism or other benefits of group living may provide a survival benefit to young that delay dispersal to help. We tested these hypotheses in the Karoo Scrub-robin (Cercotrichas coryphaeus), a long-lived, and facultative cooperatively breeding species in which male helpers make substantial contributions to the care of young. We found that annual breeder survival in the presence of helpers did not differ detectably from breeders without helpers or breeders that lost helpers. Furthermore, helpers did not gain a survival benefit from deferred breeding; apparent survival did not differ detectably between male helpers and male breeders followed from one year old. These results are consistent with other studies suggesting a lack of adult survival benefits among species where breeders do not substantially reduce workloads when helpers are present. They are also consistent with the hypothesis that males that delay dispersal make the 'best of a bad job' by helping on their natal territory to gain indirect fitness benefits when they are unable to obtain a territory vacancy nearby. [ABSTRACT FROM AUTHOR]

In recent years, long-term studies based on movement monitoring tools have improved our knowledge about spatial ecology and home range behaviour of endangered species. In order to study individual spatial-temporal variations in size, use and fidelity of home ranges and other spatial parameters (kernel at different levels), and determine the influence of sex and different annual periods in these variations, 17 adult breeders (of both sexes) of an endangered territorial raptor, Bonelli's Eagle ( Aquila fasciata), were equipped with GPS satellite transmitters and tracked over a 7-year period in Aragón (northeast Spain). The home range (kernel 95 %) of these eagles showed high individual variations as well as other spatial parameters (kernels 75, 50 and 5 %). No interannual variations for the same individual were found. Females changed home range size and use during the year, it being different in the breeding season. Home range fidelity was high for all individuals (overlap 76.18 %) over the three annual periods in all years. Nevertheless, fidelity to nesting areas was low (only 30 %) during the same periods. This work highlights the importance of long-term monitoring studies to elicit information on home range behaviour for developing accurate conservation guidelines. Maintenance of home range size and fidelity across years assures that the adoption of any conservation management plan would have a lasting impact over time. In addition, protection zones should be increased to critical areas (kernel 75 %) and restriction of specific activities causing disturbance during the breeding season should be implemented. [ABSTRACT FROM AUTHOR]

Individuals within animal groups may differ in personality and degree of familiarity raising the question of how this influences their social interactions. In Iberian magpies Cyanopica cooki , a portion of first-year males engage in cooperative behaviours and dispersal, allowing addressing this question. In this study, we first investigate the relationship between colony familiarity (native versus foreign) and reproductive status (breeding versus helping) of males during 21 years. Secondly, we measure the exploratory behaviour and monitor reproductive status of a sample of individuals with different colony familiarity during 2 years. Long-term monitoring revealed that foreign individuals were more likely breeders. The analysis on the subset of individuals in which exploratory behaviour was measured revealed a mediatory effect of exploratory behaviour in the association between colony familiarity and helping behaviour. Specifically, among foreign individuals, higher explorative males were more frequently involved in helping behaviour than lower explorative ones. Conversely, among native males, breeders were more explorative than helpers. Our results suggest that aspects of personality may mediate the value of familiarity in reproductive tasks in social species. [ABSTRACT FROM AUTHOR]

Genetic selection that has been carried out for several dozen years has led to significant progress in poultry production by improving productive traits and increasing the profitability of broiler breeder and layer hen production. After hatching, broilers and layers differ mainly in feed intake, growth rate, efficiency of nutrient utilization, and development of muscles and adipose tissue. A key role can be played by hormonal mechanisms of appetite control in broilers and layers. The paper discusses the consequences of different growth rates resulting from longterm genetic selection on feed intake, efficiency of nutrient utilization, and development of muscles and adipose tissue, with particular consideration of the hormonal mechanisms of appetite control in broilers and layers. The information presented in this review paper shows that it would be worth comparing these issues in a meta-analysis. [ABSTRACT FROM AUTHOR]

This study evaluated the effects of dietary canthaxanthin (CX) and 25- hydroxycholecalciferol (25-OH-D3) supplementation on the antioxidant status and tibia quality of duck breeders and newly hatched ducklings. In total, 780 female and 156 male duck breeders were randomly allotted to 2 treatments. Duck breeders were fed either a commercial diet (containing 3,000 IU/kg vitamin D3) or the same diet plus a mixture of CX (6 mg/kg) and 25-OH-D3 (0.069 mg/kg) for 40 wk. The antioxidant status of duck breeders, egg yolk, and ducklings; tibia quality of duck breeders and ducklings; and shell quality of breeder eggs were investigated. The total antioxidant capacity of breeder female liver (P = 0.028), breeder male testis (P = 0.049), egg yolk (P = 0.032), one-day-old duckling liver (P = 0.024), and one-day-old duckling yolk sac (P = 0.012) were increased by dietary supplementation of the mixture of CX and 25-OH-D3. The inclusion of CX and 25-OH-D3 decreased liver protein carbonyl of breeder females (P = 0.030), and liver malonaldehyde (P = 0.050) and protein carbonyl (P = 0.030) of breeder males. Yolk (P < 0.001), shank (P < 0.001), and yolk sac pigmentation (P < 0.001) of one-day-old ducklings were increased by the supplementation of the CX and 25-OH-D3 mixture. No differences (P > 0.05) were observed in tibia quality or eggshell quality between treatments. In conclusion, the inclusion of the mixture of CX and 25-OH-D3 in a diet sufficient in vitamin D3 increased antioxidant status but not tibia quality of duck breeders and newly hatched ducklings. [ABSTRACT FROM AUTHOR]

Individuals that retain their former partners often perform better than conspecifics that switch partners. This may be due to high-quality individuals being more faithful to their partners and more productive. Investigations of the fitness benefits of mate retention that also control for potential confounding effects of individuals are scarce. We studied the influence of mate retention and breeding experience on breeding performance of the hair-crested drongo (Dicrurus hottentottus) by carrying out both cross-sectional and longitudinal analyses. Pairs with longer pair-bond duration did not fledge more young or fledglings of better body condition nor did they produce more or better fledglings than newly formed pairs consisting of at least 1 experienced breeder, that is, individuals that had bred before. Individuals produced fewer fledglings when they were paired with an inexperienced breeder, especially when females were paired with inexperienced males. Although clutch size was not affected by mate retention or breeding experience, pairs consisting of inexperienced breeder(s) had a relatively higher predation rate of eggs and/or nestlings because they may be less effective in nest defense. The onset of breeding was advanced in the year following mate retention, but not in the second year thereafter, when pairs still remained together. Furthermore, only the breeding experience of the male determined the onset of breeding: Pairs consisting of inexperienced males bred later in the season. Our results suggest that breeding experience, and particularly the breeding experience of the male, but not mate retention, is important in determining the breeding performance of hair-crested drongos. [ABSTRACT FROM AUTHOR]

The present study was executed to compare breeder performance parameters (feed intake, Age at 1st egg, egg weight, hen day & hen house production %, FCR /kg and/dozen eggs) in mass selected (MS), pedigree based selected (PS) and random bred controls (RBC), in three consecutive generations of Japanese quail. In generationl (G1), 11000 quail chicks were randomly distributed into 22 sub-groups. After 3 weeks, birds were weighed and sexed; the higher body weight birds were selected as the parents of next generation. Out of 22 groups, first group was maintained with fully pedigree record, in second group birds were picked randomly without following any selection procedure, rest 20 groups were subjected to mass selection. Pedigree selection significantly improved egg weight, egg mass and FCR/ kg egg mass in higher body weight selected birds with the advancement in generations. Hence, it can be concluded that short term selection for higher 3-week body weight in quails exhibited little or no deterioration, rather improved subsequent production performance with the advancement of generations. [ABSTRACT FROM AUTHOR]

The effects of Zinc Oxide (ZnO) and E. Coli-derived 6-phytase supplemented-diet on the reproductive performance in aged broiler breeder hens and on immune responses of their progeny chicks were studied. In a 2 4 factorial arrangement, 2 inclusion levels (0 or 300 U kg-1 diet) of E. coli-derived phytase and 4 inclusion levels (30, 60, 90, and 120 mg kg-1 diet) of ZnO were provided from 62 throughout 72 weeks of age. A total of 128 hens were randomly assigned into 8 dietary treatments with 4 replicates of 4 hens each. During 66 to 71 weeks of age, egg production and egg weights were daily recorded. Results showed that ZnO and ZnO phytase interaction affected the egg weight and fertility rate (P< 0.01). Adding ZnO and phytase to diet increased the relative weight of bursa of Fabricius and liver in the hatchlings. Also, the interactive effect of ZnO and phytase on the relative weight of heart was significantly affected by the hatchlings (P< 0.01). In conclusion, dietary supplementation of ZnO and E. coli-derived 6-phytase profoundly improved the fertility rate in aged broilers breeder hens, although the effects on immunity of their progeny were negligible. [ABSTRACT FROM AUTHOR]

This study was executed to test the effect of low crude protein (12% CP), probiotics (Protexin®), vitamins (C and E) and combination of these treatments on serum mineral profile, cell mediated and humoral immunity of molted White Leghorn breeder males. Birds of 59 weeks age (n=270) were maintained at animal house of Faculty of Veterinary Science, University of Agriculture, Faisalabad, for this study. Normal breeder diet containing crude protein (CP) 16% (140 g/bird/day) was provided with fresh drinking water (ad libitum) and daily lighting schedule of 16 hours was fixed. After one week acclimatization, all the birds were forced molted by dietary ZnO (3g/Kg diet) until desired body weight reduction. These birds were divided into six groups (45 birds/group), post molting. Group A served as a control (normal diet). Other Groups were supplemented with diet containing vitamin C (500 mg/Kg), vitamin E (90 mg/Kg), probiotics (0.05 g/Kg), 12% CP and a combination of the aforementioned supplementations, respectively. Serum samples were collected for five consecutive weeks at one week interval after the start of semen production. Significant (P≤0.05) increase in serum concentrations of sodium, magnesium and calcium were found in vitamin E supplemented group. Macrophage engulfment percentage was also higher in both opsonized and unopsonized conditions (60 and 90 min) in vitamin E supplemented group. Moreover, serum antibody titers against ND (heamagglutination inhibition) and IB (indirect ELISA) were improved. In conclusion, vitamin E may be the best option for improving health and immunity against these diseases, during post molt period. [ABSTRACT FROM AUTHOR]

Poultry and poultry products are commonly considered as the major vehicle of Campylobacter infection in humans worldwide. To reduce the number of human cases, the epidemiology of Campylobacter in poultry must be better understood. Therefore, the objective of the present study was to determine the distribution and genetic relatedness of Campylobacter in the Thai chicken production industry. During June to October 2012, entire broiler production processes (i.e., breeder flock, hatchery, broiler farm and slaughterhouse) of five broiler production chains were investigated chronologically. Representative isolates of C. jejuni from each production stage were characterized by flaA SVR sequencing and multilocus sequence typing (MLST). Amongst 311 selected isolates, 29 flaA SVR alleles and 17 sequence types (STs) were identified. The common clonal complexes (CCs) found in this study were CC-45, CC-353, CC-354 and CC-574. C. jejuni isolated from breeders were distantly related to those isolated from broilers and chicken carcasses, while C. jejuni isolates from the slaughterhouse environment and meat products were similar to those isolated from broiler flocks. Genotypic identification of C. jejuni in slaughterhouses indicated that broilers were the main source of Campylobacter contamination of chicken meat during processing. To effectively reduce Campylobacter in poultry meat products, control and prevention strategies should be aimed at both farm and slaughterhouse levels. [ABSTRACT FROM AUTHOR]

In the present research, we evaluated the supportive effects of different dietary supplements including vitamin E, vitamin C, probiotics, 12% crude protein diet and combination of all these treatments on lipid profile, hormonal status and serum proteins level of post-molt White Leghorn male breeders. For this purpose 270 commercially available male layer breeders at the age of 59 weeks were procured and introduced to Zn-induced molting after which supplemented feed was given. Serum samples were collected to assess the lipid profile including triglycerides, total cholesterol, HDL-cholesterol, LDL-cholesterol; hormonal status including triiodothyronine (T3), thyroxin (T4), thyroid stimulating hormone (TSH), cortisol and serum proteins level including albumin, globulin and total protein to evaluate the effect of supplements on general health status of post molt birds. Results showed that as a whole, vitamin C and probiotic treatments helped in improvement of lipid profile and vitamin E helped in improving thyroid hormones level. Vitamin C helped in a better way in declining corticosterone level as compared to other groups. Probiotics and combination treatments helped in improving serum proteins level. To the best of our knowledge, this is the first time that effect of these treatments is evaluated in molted male layer breeders. [ABSTRACT FROM AUTHOR]