Nondomestic Birds Research Articles

Helminths Fauna in the Gastrointestinal Tract of Some Domesticated and Non-Domesticated Birds of District Karak, Khyber Pakhtunkhwa, Pakistan

This study aimed with the spotting and evaluation of the current status of gastrointestinal tract (GIT) helminths of domesticated and non-domesticated birds of district Karak different localities. For this purpose we captured/collected 120 birds of 10 selected species. Overall helminths prevalence was recorded 68% (82/120), highest in wild crows 83% (10/12) followed by wild quails 75% (09/12) while lowest recorded in night-angle 50% (06/12). The identified species of parasites belonging to nematodes were, namely, Heterakis gallinae 64% (53/82), Strongyloides avium 57% (47/82), Gongylonema ingluvicola 51% (42/82), Ascaridia galli 47% (39/82), Trichius trichiura (whipworm) 86% (71/82), Enterobius vermicularis (pinworm) 89% (73/82), the cestodes were, namely, Raillietina echinobothrida 59% (49/82), Raillietina cesticillus 57% (47/82) , Raillietina tetragona 46% (38/82), Hymenolepis carioca 39% (32/82) and the trematodes were, namely, Ascocotyle 51% (42/82), Cercarioides 62% (51/82) Echinostoma trivolvus 63% (52/82). Present study demonstrated that feeding behaviour and gender of birds play a vital role in the prevalence and infection of avi-fauna of District Karak.

Primordial germ cells isolated from individual embryos of red junglefowl and indigenous pheasants of Thailand

Interspecific germline chimerism mediated by transplantation of primordial germ cells (PGCs) of wild species to domestic hosts promises the conservation of wild birds. Cryopreservation of avian eggs and embryos is impracticable, and currently only frozen PGCs enable conservation of both the male and female descendants. Purebred offspring have been obtained from germline chimeras of wild avian species, proving the feasibility of such technology. In vitro propagation has been optimized for avian PGCs of domestic species; however, evidence is rather limited for successful isolation as well as long-term culture from a single embryo of wild species. With accelerating biodiversity loss, we have committed to preserving current genetic resources by freezing PGCs isolated from individual embryos in addition to their genetic material. We have devised a reliable protocol for the isolation and proliferation of PGCs from wild fowls in the family Phasianidae that are conserved in captive breeding (red junglefowl, bar-tailed pheasant, kalij pheasant, Siamese fireback pheasant, and silver pheasant). We obtained individual isolates of cultured circulating PGCs (49.7%, 79/155) as well as tissue PGCs (92.9%, 144/155). The specific co-culture conditions of autologous embryonic cells, without additional growth factors, facilitated the proliferation of so-called tissue PGCs (the remaining PGCs in embryonic tissue following blood aspiration). Only circulating PGCs left in blood vessels and of PGCs migrating to developing gonads have been previously reported. However, the present study is the first to report on the harvest of ectopic PGCs. The defined conditions sustained continuous proliferation of tissue PGCs for at least six months and maintained PGC identity following cryopreservation. Cultured tissue PGCs of these wild species were extensively characterized for their expression of the germ cell-specific proteins, chicken vasa homolog (CVH) and deleted in azoospermia-like (DAZL), as well as the ability to colonize chicken embryonic gonads. The novel protocol is practical for generating enough PGCs for cryopreservation, transplantation, and additionally, it enables isolation of PGCs from both blood circulation and embryonic tissue simultaneously. For conservation purposes, this approach is potentially applicable more widely to other non-domestic birds than those in the family Phasianidae that were investigated in the present study.

Prenatal Transfer of Gut Bacteria in Rock Pigeon.

Vertebrates evolved in concert with bacteria and have developed essential mutualistic relationships. Gut bacteria are vital for the postnatal development of most organs and the immune and metabolic systems and may likewise play a role during prenatal development. Prenatal transfer of gut bacteria is shown in four mammalian species, including humans. For the 92% of the vertebrates that are oviparous, prenatal transfer is debated, but it has been demonstrated in domestic chicken. We hypothesize that also non-domestic birds can prenatally transmit gut bacteria. We investigated this in medium-sized Rock pigeon (Columba livia), ensuring neonates producing fair-sized first faeces. The first faeces of 21 neonate rock pigeons hatched in an incubator, contained a microbiome (bacterial community) the composition of which resembled the cloacal microbiome of females sampled from the same population (N = 5) as indicated by multiple shared phyla, orders, families, and genera. Neonates and females shared 16.1% of the total number of OTUs present (2881), and neonates shared 45.5% of their core microbiome with females. In contrast, the five females shared only 0.3% of the 1030 female OTUs present. These findings suggest that prenatal gut bacterial transfer may occur in birds. Our results support the hypothesis that gut bacteria may be important for prenatal development and present a heritability pathway of gut bacteria in vertebrates.

Catbirds are the New Chickens: High Sensitivity to a Dioxin-like Compound in a Wildlife Species.

Dioxins and dioxin-like compounds (DLCs) are highly toxic and persistent global pollutants with extremely large differences in sensitivity across taxonomic groups. The chicken has long been considered uniquely sensitive to DLCs among avian species; but DLC toxicity in nondomesticated birds is largely untested, and the relevance of the chicken as an ecological model is uncertain. New approaches that use genotyping of the AHR1 ligand binding domain to screen for DLC sensitivity among avian species predicted that the gray catbird, a relevant wildlife species, is also highly sensitive. We tested this prediction using egg injections of a dioxin-like PCB (PCB-126) and found that the catbird is at least as sensitive as the chicken to DLCs, based on both embryotoxicity and mRNA induction of phase I metabolizing enzymes (CYP1A4/5). This study is the first to confirm that there are wildlife species as sensitive as the chicken and demonstrates how using predictive genotyping methods and targeted bioassays can focus toxicity assessments on ecologically relevant species.

Great Tits Build Shallower Nests than Blue Tits in an Insular Oak-Dominated Habitat Mosaic

Longitudinal multi-plot studies of nest architecture in non-domesticated birds are rare. Here we report the results of an 18-year multi-plot study that compared heights of fresh female-built nests in Corsican Great Tits ( Parus major) and Blue Tits ( Cyanistes caeruleus ogliastrae). Boxes with relatively small nest-chambers were erected in a landscape with habitat patches that were either dominated by food-rich broad-leaved deciduous oaks ( Quercus humilis) or food-poor evergreen oaks ( Quercus ilex). Nest height tended to change with oak habitat type in a species-specific manner. Great Tits built shallower nests than Blue Tits supporting the published findings from other geographic regions (Poland, UK, southern mainland France). Potential impacts of local climate factors and risks related to nest predation on the species-specific expression of the size of nests are discussed.

Gizzard Mass Dynamics of Nestling Rooks Corvus Frugilegus

Developmental changes of the gizzard have rarely been studied in nestlings of non-domesticated birds or under natural conditions. Because nestlings would have variable amounts of stomach contents, we wanted to discover whether in natural conditions gizzard developmental changes are dependent on digesta mass. We examined the mass of gizzard and digesta in 56 nestling Rooks Corvus frugilegus aged between 1 and 13 days old. We found that gizzard mass increased nearly nine-fold, from an average of 1.25 g to 10.85 g. Gizzard mass expressed as a proportion of body weight significantly decreased with the age of nestlings. In hatchlings, the median ratio of gizzard mass to body weight was 18.4%; in 13-day old nestlings this value was only 5.8%. Tarsus length, a poor predictor of gizzard mass, explained 61% of its total variance. Nestlings (regardless of their age) without digesta or with small volumes of digesta had statistically significantly smaller gizzards (expressed as ratio of gizzard mass to body weight) than did nestlings with full gizzards, which suggest a rapid response of gizzard volume and musculature to variable food intake during post-hatch development.

Rapid sexing of selected Galliformes by polymerase chain reaction

Vent sexing of one-day-old chicks in commercial hatcheries has long been common practice and can be highly accurate. However, there are circumstances when this technique is not applicable such as smaller breeds, non-domestic birds, or where is the necessity of precise sexing. In this study we present a simple and reliable method for fast gender determination in selected Galliformes for which phenotypic determination of sex is difficult until maturity. Four species were tested: two commercial species – chicken (Gallus gallus) and turkey (Meleagris gallopavo), and two game birds – common pheasant (Phasianus colchicus) and wood grouse (Tetraro urogallus). DNA was tested with universal single-pair primers polymerase chain reaction (PCR) detecting W chromosome specific sequence yielding a single band of length specific for each species. The method was developed with regards to time consumption and cost-effectiveness giving results in less than two hours. The method may also be used for early sexing in commercial chicken and turkey flocks as well as sexing of smaller game birds flocks or for research laboratories when rapid sexing of selected Galliformes cells is required.  

Two Cases of Neoplasia of Basal Cell Origin Affecting the Axillary Region in Anseriform Species

Neoplasms of the skin are occasionally seen in domestic birds but are uncommon in nondomestic birds. An 8-year-old male hooded merganser (Lophodytes cucullatus) was presented with bilateral axillary ulcerative lesions that improved but did not resolve with empiric antibiotic and antifungal therapy. Skin biopsies were taken, and bilateral feather folliculomas were diagnosed on histopathologic examination. The duck was euthanatized because of the poor prognosis. A 9-year-old Indian runner duck (Anas platyrhynchos) was presented with an ulcerative lesion, with pseudomembrane and serocellular crust affecting the axillary region. This mass was diagnosed as a basosquamous carcinoma. The mass was surgically excised, and no recurrence was observed. Feather folliculomas are usually considered benign neoplasms in domestic birds and may be primarily ulcerative, exudative, bilateral, and symmetric in location. Basosquamous carcinoma may have a similar gross appearance. It is unknown if the axillary region may be an area with increased incidence of neoplasia in birds. This appears to be the first report of feather folliculoma and basosquamous carcinoma in Anseriforme species. Feather folliculomas and other neoplasms, such as basosquamous carcinoma, should be considered as a differential diagnosis in ulcerative or proliferative skin lesions in birds.

The Design, Construction, and Operation of a Whole-Body Inhalation Chamber for Use in Avian Toxicity Studies

Environmental risk assessments are broadening to include evaluations of avian species exposed to gaseous and particulate materials (; ; ). Since the avian respiratory tract is fundamentally different from the respiratory tract of rodents, the effects of gaseous materials on birds cannot validly be extrapolated from data derived from rodent exposure studies (; ). To address the lack of avian-specific lowest observable effect levels used to calculate reference concentrations for airborne pollutants, a system was designed to facilitate research on inhalation toxicology in small birds. Birds have long been used as early indicators of poor air quality (), and various chambers have been designed for head only exposures of larger birds (). Smaller birds with short tracheal lengths and hooked beaks however require less restrictive exposure apparatus, thus warranting the proposed design. The chamber described in this article was designed to accommodate a small falcon, the American kestrel, a species frequently used in toxicological risk assessments (Wiemeyer & Lincer, 1987a; ; ; ). To accomplish this, a 41-L closed inhalation system capable of exposing 12 adult American kestrels was constructed primarily of galvanized steel, polyvinyl chloride, and copper tubing. Humidified air was passed over the birds and subsequently decontaminated by an activated carbon filter and released to a HEPA filtration system. The proposed inhalation chamber was successfully used in 2005 and 2006 to expose a total of 55 male American kestrels to benzene and toluene. Measurements of various biochemical endpoints associated with benzene and toluene toxicity allowed us to study the effects of airborne pollutants on small nondomesticated birds in a controlled laboratory setting.

Comparative immunoecology in birds: hypotheses and tests

In this review, I focus on three key questions in avian comparative immunoecology: variation in immune responses in relation to sex; latitude (and pace-of-life); and the annual cycle. I present hypotheses and evaluate the so far rather scanty and heterogenic data to test them. Sex differences in immune responses have been hypothesized to be caused by inferior immune responses in the heterogametic sex (females in birds), sexual selection (males invest more in mate acquisition and less in immune function compared to females under polygyny, whereas the sexes invest equally in immune function under monogamy), or body size differences. Available data refute the heterogametic sex hypothesis, but tentatively support the sexual selection hypothesis. Latitudinal patterns of immune responses have been hypothesized to be adjusted to parasite pressure, pace-of-life or breeding season stress. In passerine birds, species breeding closer to the equator (where parasites presumably are more abundant) tended to show stronger humoral but not cell-mediated immune responses. Annual patterns of immune responses could be related to melatonin levels or adjusted to seasonal differences in parasite exposure (high exposure in tropical migrants in winter and in temperate breeding birds in summer). The results from studies of immune responses over the annual cycle in birds show no clear pattern over the annual cycle and there is little consistency between different components of the immune system. Clearly, to facilitate further testing of these intriguing ideas in comparative immunoecology, more studies on non-domesticated birds are needed.

Semen Collection, Spermatozoa Cryopreservation, and Artificial Insemination in Nondomestic Birds

Semen collection and artificial insemination have made important contributions to the breeding of avian species in captivity. These techniques have been successfully used primarily in breeding programs of rare and endangered species and in the production of hybrid falcons for the sport of falconry. Semen samples are collected from nondomestic birds by using the cooperative, massage, and electroejaculation methods. After semen collection, insemination is done by the simple process of transferring semen samples directly into the oviduct of the hen. Freshly collected semen samples also can be diluted to obtain the desired spermatozoa concentration for multiple inseminations or for short-term and long-term storage. This paper reviews the different methods used for semen collection, techniques for semen dilution and preservation, and use of artificial insemination in nondomestic birds.

Individual variation in plasma estradiol-17β and androgen levels during egg formation in the European starling Sturnus vulgaris: implications for regulation of yolk steroids

While it is clear that maternal transfer of steroids to egg yolk can have significant effects on offspring phenotype, an unresolved question is whether females can facultatively adjust yolk hormone levels independently of their own plasma levels or whether yolk steroid levels are simply a direct consequence of temporal variation in the female’s hormonal status. In part, this is because we lack detailed information about the day-to-day pattern of changes in plasma hormone levels during the laying cycle for non-domesticated birds. Here, we describe changes in plasma estradiol-17β (E2) and androgens, throughout laying in relation to specific stages of ovarian follicular development in the European starling ( Sturnus vulgaris). Plasma E2 levels increased rapidly from the onset of rapid yolk development (RYD) to reach maximum levels in birds with a complete follicle hierarchy (⩾4 yolky follicles). However, levels decreased linearly throughout the later stages of follicle development returning to pre-breeding values before the final yolky follicle was ovulated. In females with ⩾4 yolky follicles there was 10-fold variation in plasma E2 levels among individual females, but this was not related to plasma levels of the main yolk precursor vitellogenin or to the total mass of yolky follicles developing at the time of blood sampling. In contrast to E2, plasma androgen levels showed only a very gradual linear decline throughout the laying cycle from pre-RYD to clutch completion. Furthermore, androgen levels showed less individual variability: 4-fold variation among females with ⩾4 yolky follicles, although this was also independent of our measures of reproductive function. Data on inter- and intra-individual variation in female hormone levels are important to set-up a priori predictions for, and interpretation of, studies of yolk hormone levels.

A current view of veterinary flock health management: Developing “growing pains”

At the present time, avicultural medicine as the term is generally applied in clinical settings lacks a systematic means with which to evaluate and examine the nondomestic bird flock. These systematic evaluations are a key to developing a true flock health program. Without a proper physical examination of the flock, it is virtually impossible to make complete and balanced managerial recommendations for the individual patient as well as in the overall flock. The breeding collection of nondomestic birds in the private avicultural sector is in many ways the most important and most neglected patient in avian medicine today. Properly executed complete flock evaluation techniques will lead to sound flock management with proven value, resulting in documentation of optimal flock health management programs and techniques for future reference. Incompletely performed, flock medical intervention can become harmful if not devastating. This report will review the basics of proper flock evaluation techniques and itemize some of the more common specific errors encountered in flock diagnoses and veterinary intervention.

Time course and reversibility of changes in the gizzards of red knots alternately eating hard and soft food.

The ability to change organ size reversibly can be advantageous to birds that perform long migrations. During winter, red knots (Calidris canutus) feed on shellfish and carry a muscular gizzard that weighs 10% of their body mass. Gizzard size decreases when these birds eat soft foods, e.g. while breeding in the tundra. We studied the reversibility and time course of such changes using ultrasonography. Two groups of shellfish-adapted knots (N=9 and N=10) were fed alternately a hard and a soft food type. Diet switches elicited rapid reversible changes. Switches from hard to soft food induced decreases to 60% of initial gizzard mass within 8.5 days, while switches to hard food induced increases in gizzard mass to 147% within 6.2 days. A third group of knots (N=11), adapted to soft food for more than 1 year, initially had very small gizzards (25% of the mass of shellfish-adapted gizzards), but showed a similar capacity to increase gizzard size when fed shellfish. This is the first non-invasive study showing rapid digestive organ adjustments in non-domesticated birds.

Storage of poultry semen

Methods of semen collection and artificial insemination (AI) in poultry, requirement for diluents, methods of liquid and frozen storage of avian semen and evaluation of spermatozoa after storage for fertilizing ability are reviewed. Frozen storage of semen from non-domestic birds is also briefly discussed.

Genetic relatedness of Salmonella isolates from nondomestic birds in Southeastern United States.

Salmonella infections have been implicated in large-scale die-offs of wild birds in the United States. Although we know quite a bit about the epidemiology of Salmonella infection among domestic fowl, we know little about the incidence, epidemiology, and genetic relatedness of salmonellae in nondomestic birds. To gain further insight into salmonellae in these hosts, 22 Salmonella isolates from diseased nondomestic birds were screened for the presence of virulence and antibiotic resistance-associated genes and compared genetically using pulsed-field gel electrophoresis (PFGE) and random amplified polymorphic DNA analysis. Of the 22 Salmonella isolates examined, 15 were positive for the invasion gene invA and the virulence plasmid-associated genes spvC and pef. Most (15 of 22) were generally sensitive to antibiotics. However, two Salmonella isolates from pet birds were identified as Salmonella enterica serovar Typhimurium DT104. Despite the general susceptibility of these Salmonella isolates to most antimicrobial agents, antibiotic resistance-associated genes intI1, merA, and aadA1 were identified in a number of these isolates. Five distinct XbaI and nine distinct BlnI DNA patterns were observed for the 22 Salmonella isolates typed by PFGE. PFGE analysis determined that Salmonella isolates from passerines in Georgia and Wyoming were genetically related.

Timing of the Calcium Intake and Effect of Calcium Deficiency on Behaviour and Egg Laying in Captive Great Tits, Parus major

The calcium demand of egg-laying birds is much higher than in other vertebrates during reproduction. We showed elsewhere that a low level of calcium availability can greatly affect the eggshell quality and reproduction of free-living passerines. However, there are few data on calcium demand and calcium intake in relation to egg laying and behaviour and egg-laying performance under conditions of calcium shortage in nondomesticated birds. We examined these aspects in an experiment with captive great tits, Parus major, on a diet deficient in calcium, with or without snail shells as an additional calcium source. More than 90% of the calcium intake for egg production took place during the egg-laying period. Females ingested about 1.7 times as much calcium as they deposited in eggshells. Removing the snail shells after the first egg resulted in eggshell defects and interruptions of laying after 1-3 d. Females without snail shells doubled their searching effort and started to burrow in the soil and to eat sand, small stones, and their own eggs. Most calcium was consumed in the evening, probably to supplement the calcium available from the medullary bone with an additional calcium source in the gut during eggshell formation. The results demonstrated that eggshell formation requires accurate timing of the calcium intake and that obtaining sufficient calcium is time-consuming, even in calcium-rich environments. These factors pertaining to calcium intake greatly affect the ability of birds to collect sufficient calcium for eggshell formation in calcium-poor areas.

Adaptive differences in the timing of egg laying between different populations of birds result from variation in photoresponsiveness

Although intraspecific variation in reproductive photoresponsiveness has been demonstrated in many bird species, it has never been examined in conjunction with comparative long-term field studies which accurately identified key factors governing local adaptation of life history traits, and rarely in combination with studies of non-domesticated birds that breed in captivity. Furthermore, it is generally assumed that, within species, adaptive differences in photoresponsiveness mainly occur across populations breeding at different latitudes, and that at similar latitudes, interpopulation variations in timing of breeding is mainly caused by proximate responses to variations in micro-climate or food. Considering results of breeding experiments in laboratory conditions in the framework of long-term comparative studies of natural populations, we here provide the first evidence in a bird that adaptive differences in the onset of first clutches between populations breeding at similar latitudes proximately mainly results from variation in responses to daylength.

Crane reproductive physiology and conservation

AbstractSome unique features of crane reproduction, management, and conservation are described. Because cranes are sexually monomorphic, sexing is difficult and must be accomplished using behavior, laparoscopy, cloacal examination, genetic techniques, or fecal steroid analysis. Although husbandry techniques for cranes are similar to those used with other nondomestic birds, a number of basic characteristics, such as extreme aggressiveness, imprinting by the crane chick on man, a delayed molt in the immature crane, delayed sexual maturity, and infertility, pose special problems for the propagator. Artificial insemination is a practical solution to crane infertility. Vigorous captive management and propagation efforts must become increasingly important if several endangered crane species are to survive the continuing decline in wild populations. The ultimate goal is the restoration of suitable habitat and sustainable native populations.

Disorders of the avian female reproductive system

An analysis is provided of reproductive disorders encountered at necropsy of 1666 adult, female birds excluding poultry. The results are compared with other accounts of these disorders in non-domesticated species and poultry. At least 650 different species were examined, belonging to 24 of the 27 avian orders. All were non-domesticated birds, with the exception of 133 budgerigars, 48 canaries and 4 pigeons. Reproductive disorders were found in 148 (8.9%) representing 88 different species in six orders. There was no conclusive evidence of species susceptibility. Some individuals were affected with more than one type of disorder, the most prevalent being obstruction of the oviduct and ectopic ovulation; in each case 28.6% of 161 disorders. Less common disorders were oophoropathies (16.8%), salpingitis without apparent obstruction (10.6%), neoplasia (4.3%), ruptured oviduct (3.1%) and miscellaneous disorders (8.0%). Domestic poultry bred for egg production are probably more susceptible to reproductive disorders than non-domesticated species. In the latter birds predisposing causes include senility and bacterial infections, but many more are probably involved.