The chemical composition of the uropygial gland secretion of rock dove Columba livia

The uropygial gland is a holocrine secretory gland of birds. The lipid and the waxy sebum that the gland secretes is coated on the beak and transferred to the plumage in preening. The composition of the gland secretions from birds of different species has been determined, but little is known about the lipids of the secretion of the gland of the rock dove Columba livia. The amount of secretion, the total lipid content and the fatty acids composition of the secretion of C. livia captured in the nonbreeding season was reported. The mean amount of the secretion within the gland was 30 mg; the mean lipid content of the secretion was 0.385 mg/mg of secretion, which was equivalent to approximately 38% of the secretion. The weight of the secretion relative to gland weight was 32%. If we assume that the amount of the gland secretion constitutes a valid parameter to determine the degree of the gland development, our results indicate that the physiological role of the gland does not depend upon gland mass (GW); the rock dove in particular has a small gland, but its secretion represented 32% of the gland's mass. The composition of the lipids extracted from the gland secretion consisted of C14 to C20 fatty acids, most of them were unsaturated. The secretion of the gland contained approximately 59% of unsaturated fatty acids with a prevalence of oleic acid (37%) and a low content of linoleic (6%) and arachidonic acids (7%). The saturated long chain fatty acids were mainly 14:0, 16:0 and 18:0 in a percentage of approximately 34%. No sexual differences were found in any of the evaluated parameters.     

Zur Mauser der Ringeltaube(Columba palumbus)

Zusammenfassung Die Handschwingenmauser alter Ringeltauben aus Westdeutschland beginnt sehr einheitlich im letzten Aprildrittel mit H1 und endet Anfang Dezember mit H10.Junge Ringeltauben aus späten Bruten unterbrechen ihre deszendente Mauser der Handschwingen im Winter, spätestens Anfang Januar, und fahren damit erst im April dort fort, wo sie sie zuvor unterbrochen hatten. Ein Teil der Jungen reiht sich schon Ende April in den dann beginnenden H-Mauser-Zyklus der Alten ein, indem mit H1 bereits die 2. gegen die 3. H-Generation vertauscht wird. Junge, bei denen die erste Handschwingen-Generation dann noch nicht vollständig erneuert ist, werden (stets?) zu Staffelmauserern.Der Wechsel der Armschwingen ist konvergent auf A6 zu. Der Armfittich wird jedoch oft nur unvollständig vermausert, und dies hat große Unregelmäßigkeiten, auch in der zeitlichen Abstimmung mit der Handschwingenmauser, zur Folge.Die Mauser der Steuerfedern beginnt bei jungen Ringeltauben in der Regel mit S1 und nicht vor dem Ausfall von H6. Die weitere Reihenfolge läßt keine exakte Ordnung erkennen.Ein Einfluß der Brut auf die Mauser ist nicht ersichtlich. Junge Ringeltauben beginnen mit der Handschwingenmauser schon wieder, wenn sie noch auf dem Heimzuge sind. Dagegen scheint starker Frost zu Beginn des Winters ihre H-Mauser zu hemmen und eine Mauserpause von rund 3 Monaten zu bewirken.

---

Summary The paper describes the molt of the remiges and rectrices in Ring Doves,Columba palumbus, and contains some remarks on the body plumage.Primaries. Adult birds, from the latter third of April until early December, molt their primaries in a descending order from P₁ to P₁₀.Juveniles from late clutches interrupt the descending molt of their primaries latest by early January and continue the sequence in April. Some of them begin a new molting sequence already by the end of April (in synchrony with the molt in adults), shedding the 2nd generation P₁ for the 3rd generation P₁. Unless the 1st generation molt is completed by this time, the molt of the immatures is telescoped with a plumage at one time composed of three generations of feathers.Secondaries. The secondaries are shed convergently from the outer- and innermost feather toward S₆. However this molt is frequently incomplete and leads to considerable irregularities in the timing and state of the cycle.Rectrices. In young Ring Doves the molt of the rectrices starts with the innermost R₁, commonly after P₆ is shed. The sequence is very irregular and follows no specific pattern.There appears to be no correlation between molt and reproduction. Immature Ring Doves initiate another molt of their primaries while still on their northward migration. Low temperatures at the onset of winter block the shedding of the primaries and may cause a three-month delay.

     

Nest survival of Woodpigeons (Columba palumbus) in North African forests

Capsule The nesting success of the Woodpigeon Columba palumbus in oak forests in Morocco is affected by human disturbance and nest-site characteristics.

Aims To determine factors affecting the nesting success of Woodpigeons subject to two levels of disturbance in a holm oak Middle Atlas forest.

Methods Woodpigeon nests were monitored in highly disturbed (n?=?30) and less-disturbed sites (n?=?60) over two years (2010–11). Logistic-exposure models were used to estimate daily nest-survival rate and evaluate mechanisms (altitude, temporal factors, nest location, nest-site habitat and degree of human influence) affecting nest survival.

Results Daily nest-survival rate was higher in less-disturbed sites (0.987; 95% CL: 0.980–0.991) than in high-disturbance sites (0.967; 95% CL: 0.949–0.978). Increasing density of trees surrounding nest sites and distance from the nest tree to the closest track increased daily nest-survival rate.

Conclusions Less-disturbed sites confer better nesting conditions than highly disturbed ones. Management measures should control the access of vehicles, especially trucks, in the forest of the Middle Atlas and introduce a grazing regime that will allow the forest regeneration, which would improve Woodpigeon nesting success by increasing the density of holm oak trees.     

The effects of changing agricultural practice upon Woodpigeon Columba palumbus numbers

The Woodpigeon Columba palumbus population in a 1070 ha study area in East Anglia was studied from 1961 to 1986. This paper relates variations in Woodpigeon numbers to changes in the areas and types of crops grown. In the early 1960s the mean Woodpigeon population fluctuated between 60 and 112 birds per 50 ha during the winter months. Subsequently there was a steady decline until the population levelled out in the early 1970s at around 30 birds per 50 ha. From a very low point in 1977, the numbers of birds increased reaching in 1986 a mean of 55 birds per 50 ha. Marked changes occurred in the types of cereals grown in the area. In the 1960s spring-sown barley was the major crop with winter-sown wheat occupying most of the remaining area. Throughout the 1970s winter wheat was increasingly grown and winter-sown barley replaced the spring-sown variety. Although the area of permanent pasture did not change significantly, the area of clover ley was reduced markedly in the late 1960s. In the mid 1970s silage and oilseed rape were introduced and the cultivation of peas was expanded. On the basis of the crop types grown, the study period was divided into two 11-year blocks 1961–1971 and 1975–1985. Crop preferences of Woodpigeons were calculated for each month within each of these 11-year periods. A series of stepwise regressions was then conducted on both of the 11-year periods in order to see how well the areas of preferred crops in a particular month could account for the mean population size of that month. In the winters 1961/62 to 1971/72 the winter Woodpigeon population size was influenced by two crops. The area of cereal sowings largely determined how many birds remained in the area in December. The availability of clover ley, which depended upon both the area of clover ley and the amount of snow cover, controlled the population size in January and February. In the winters 1975/76 to 1985/86 the population size was again affected by two crops. In November the amount of grain on both stubbles and sowings influenced how many young birds stayed in the area. The area of oilseed rape in December then set the population size which changed very little throughout the rest of the winter. The change in the pattern of population regulation has profound implications for the likely success of shooting Woodpigeons in winter as a means of reducing local numbers.     

The chemical composition of uropygial gland secretions from ralliformes

The uropygial gland wax from rails contains ester waxes, triester waxes and triglycerides. The ester waxes are composed of mainly methyl-substituted fatty acids with predominantly n-alkanols. Methyl-branched alcohols are only found in minor amounts. The occurrence of 2,6,10- and 4,8,12-trimethyl-substituted acids can be used as chemotaxonomie markers. The triester waxes contain n-fatty acids, n-alkanols and alkyl-hydroxymalonic acids.     

Melatonin and the phagocytic process of heterophils from the ring dove (Streptopelia risoria)

A functional connection between the pineal gland and the immune system in mammals and birds has been established. This study investigates the effect of melatonin upon the non-specific immunity of heterophils isolated from the ring dove. The different stages of the phagocytic process: adherence to nylon fiber, spontaneous and induced mobility, ingestion of latex beads and digestion were evaluated for heterophils incubated in the presence of 5, 25, 50, 75, or 100 \sgmaelig;M of melatonin. In addition, the chemoattractant power of the hormone for heterophils was studied. The 100 \sgmaelig;M melatonin dose possessed a significant chemoattractant ability for heterophils whilst ingestion of latex particles was enhanced at all doses studied. The superoxide anion level, as measured by the free radicals produced during the metabolic burst, is decreased after incubation with 100 \sgmaelig;M of melatonin.     

The ecology and economics of damage to Brassicae by wood-pigeons Columba palumbus

Damage caused by wood-pigeons, Columba palumbus, to spring cabbage and Brussels sprouts was measured during three winters in two areas in the Vale of Evesham, Worcestershire. In one area (experimental) special attempts were made to reduce pigeon damage in addition to the normal efforts of the growers. In the other (control) area no such additional measures were taken. There was slightly more damage in 1969-70, but low market prices made it less important than in 1968-9 or 1970-1. There was no significant difference in any season between the damage in the control and experimental areas. No damage was caused to Brussels-sprout buttons as the birds ate only the tops of the plants; they preferred Brussels sprouts to cabbages and it is likely that the presence of the former helped to reduce the amount of damage to nearby cabbage fields. The amount of damage was not correlated with the amount spent on crop protection; actual damage was not correlated with the grower's estimates in the control area. In the second season a very intensive shooting campaign in the experimental area did not result in less damage, but the movements of local inhabitants and farm workers near a village did afford protection. The significance of the damage in the Vale and elsewhere is assessed in relation to the economics of crop production, the cropping pattern for cabbages and the behaviour and ecology of the wood-pigeon.     

The Host-Restriction of Haemoproteus sp. indet. of the Wood-Pigeon Columba p. palumbus

SYNOPSIS. Earlier experiments suggested that the species of Haemoproteus which infects English wood-pigeons ( Columba p. palumbus ) and is transmitted by the hippoboscid dipteran fly Ornithomya avicularia , was unable to infect Columba livia domestica , a host of H. columbae . This has now been confirmed by the injection of sporozoites into two pairs of pigeons, one of each species; in both experiments the C. palubus developed parasitemia while the C. livia did not. It has also been shown that this species of Haemoproteus can complete sporogony in a small proportion (2/73) of Pseudolynchla canariensis , the vector of H. columbae .     

Haemoproteus palumbis sp. nov. (Sporozoa, Haemosporina) of the English Wood-Pigeon Columba p. palumbus

SYNOPSIS. Haemoproteus palumbis sp. nov. is described from the English wood-pigeon, Columba p. palumbus. Its pigmented gametocytes inhabit erythrocytes and resemble those of H. columbae (in C. livia ) but may be slightly longer and narrower. It is characterized by having oval or slightly lobed, not elongate, schizonts in endothelial cells of lung and heart, a prepatent period of 14 days, and a sporogonic cycle in the hippoboscid fly Ornithomya avicularia lasting 6 1/2–7 days. H. palumbis sp. nov. cannot infect C. livia but can infect a small proportion of individuals of Pseudolynchia canariensis , the vector of H. columbae.     

Melatonin, lipid peroxidation, and age in heterophils from the ring dove (Streptopelia risoria)

Numerous recent studies have shown the ability of physiological as well as all pharmacological concentrations of melatonin to prevent oxidative stress. We have found that incubating avian heterophils from young birds with a pharmacological concentration of 100 μM (23 × 10⁶ pg/ml) melatonin reduced superoxide anion levels by modulating the activity of superoxide dismutase while also enhancing phagocytosis. There was also a decline in lipid peroxidation levels with both physiological and pharmacological concentrations of this indolamine.

In the present work, we evaluated malonaldehyde (MDA) levels as an indicator of lipid peroxidation (both basal and antigen-induced) in young and old animals (ring doves) at different times of day (16:00 and 00:00) and with two incubation times (15 and 60 min). The lipid peroxidation was also measured in heterophils from old animals, incubated with the physiological concentrations of melatonin measured in young animals (50 and 300 pg/ml, diurnal and nocturnal, respectively). The results, expressed as nmol MDA/mg protein, show that MDA levels were higher in heterophils of old animals than in the young birds in all the experimental groups studied at both 16:00 and 00:00 (00:00 is the time at which the lowest peroxidation levels were obtained). Incubation with melatonin was found to reduce MDA levels, with the maximum reduction being after the 60 min incubation time and the nocturnal melatonin concentration. At both concentrations (diurnal and nocturnal), melatonin also counteracted the enhancement of MDA levels caused by latex beads, with the effect being greater at the longer incubation time. In conclusion, the results are further evidence of the antioxidant effect of melatonin even at physiological concentrations, and suggest its utility as a therapeutic agent in some pathological processes associated with age.     

Cytological differentiation in the uropygial gland.

Ultrastructural changes were studied in the cells undergoing secretory differentiation in zone I of the tubules of the uropygial gland of White Plymouth Rock chickens. A layer of basal cells and four secretory stages are recognized as the cells migrate from the periphery to the lumen of tubules and progressively elaborate a secretion product. Basal cells, containing rough endoplasmic reticulum and free ribosomes, rest on the basement membrane and are the source from which secretory cells arise. Dilated perinuclear cisternae and the proliferation of smooth endoplasmic reticulum in the form of vesicles, invaginated sacs and cusp-shaped cisternae indicate the onset of lipgenesis in stage I cells. The perinuclear cisternae are more dilated and the endoplasmic reticulum is composed on saccules and cisternae in stage II cells. Stage III cells are characterized by concentric lamellae of endoplasmic reticulum surrounding secretory droplets. Dilated cisternae of endoplasmic reticulum and secretory droplets both contain a reticular substance. The perinuclear cisternae of stage III cells have returned to normal dimensions. Large mature lucent secretory droplets, lined with electron-dense material, fill the cytoplasm ostage IV cells which degenerate and release their secretory product into the tubule lumen. Spherical membrane-bound compartments containing a mottled substance of moderate electron density occur in basal cells and all subsequent secretory stages. These mottled bodies are surrounded by saccules of endoplasmic reticulum in stage II cells and are intimately associated with secretory droplets in stage III cells, but there is no evidence that they give rise to secretory droplets and their role in secretory differentiation is unknown.     

The uropygial gland secretions of birds of the family sylviidae

The preen gland secretions from eight species of the genera Acrocephalus and Sylvia (Sylviidae, Passeriformes) mainly consist of monoester waxes. The fatty acids and alcohols are methyl-substituted at even numbered positions only. One of the methyl groups of the fatty acids is always located in the 2-position. Two patterns of methyl substitution are found for the alkanols: $\text{2-}\text{mono-}$, $\text{2,6-di-}$, and $\text{2,6,x-}\text{trimethyl}$ on the one hand, and 4-mono-, 4,8-di-, and 4,8,$\text{y-}\text{trimethyl}$ on the other. There is, however, no doubt in the uniformity of the family Sylviidae from the chemotaxonomical point of view; the waxes of the species investigated can be arranged in a gradual succession of substitution patterns. The monoester waxes of Sylviidae are similar to those found for the closely related family Turdidae.     

Hydrocarbon and multibranched ester waxes from the uropygial gland secretion of grebes (Podicipediformes).

The uropygial gland secretion of some grebes (Podicipediformes) had been shown to contain saturated and unsaturated aliphatic hydrocarbons and monoester waxes. While ester waxes are common constituents of preen gland secretions, nonisoprenoid hydrocarbons have not been detected hitherto. The wax constituents are very complex, belonging to several multibranched homologous series, including unusual acids with ethyl branches. The waxes were identified by gas-liquid chromatography-mass spectrometry and equivalent chain length comparisons. A method for the prediction of equivalent chain length values of unknown methyl esters is offered. The results are discussed from a chemotaxonomic viewpoint.