Primary Feather Growth Research Articles

Trypanosomiasis: An emerging disease in Alpine swift (Tachymarptis melba) nestlings in Switzerland?

Alpine swifts (Tachymarptis melba) are sub-Saharan migratory birds, which, in Switzerland, nest in colonies that have been continuously monitored for over 40 years. In the summer of 2022, despite favourable environmental conditions, an unexpectedly high number of sudden mortalities (30–80%) occurred in 20 to 45-day-old nestlings from several nesting sites, of which 3 were monitored in detail. Nestlings submitted for post-mortem analysis (n = 5) were in good body condition but exhibited extensive subcutaneous haematomas (n = 5), myocardial petechiae (n = 2) and stunted growth of primary feathers (n = 1). In all birds, 4–5 μm large, amastigote-like protozoans were identified in skeletal and cardiac muscle sections. These tissues tested positive in a PCR targeting the 18S-rRNA gene of Trypanosoma spp. Amplified sequences showed 99.63% identity with sequences of Trypanosoma corvi (JN006854 and AY461665) and Trypanosoma sp. (AJ620557, JN006841). 72 blood smears of 45-day-old nestlings from two colonies were assessed, of which 20 contained trypomastigote forms, some with high parasitaemia (highest average of 56.4 in 10 high power fields, 400x magnification). Trypomastigote morphometrics (n = 36; mean total length = 30.0 μm; length of free flagellum = 5.8 μm) were consistent with those of T. bouffardi. These findings suggest that an avian trypanosomiasis causing mass nestling mortality could be an emerging disease in Swiss Alpine swift populations.

Genome-wide association analysis of the primary feather growth traits of duck: identification of potential Loci for growth regulation

The feather is an important epidermal appendage, plays an important role in the life activities of avian specie, and has important economic value. Revealing the molecular regulation mechanism of feather growth has a significant meaning in studying adaptive evolution, physiology, and mating of avian species and also provides a theoretical reference for poultry breeding. In this study, the genome-wide association analysis (GWAS) of 358 ducks was based on primary feather length phenotypic data (28-60 d), length growth rates (LGRs), and maturity scores (60 d) to explore the genetic basis affecting feather growth and maturation. The results showed that, among the primary feather 1 to 5 in ducks, the mean LGR of primary feather 2 was the fastest, with the longest length. The primary feathers in males grew and matured slightly faster than in females. The mean maturity scores of primary feather 10∼7 were higher than primary feather 1 to 3 in ducks. GWAS further showed 116 SNPs associated with feather length traits. In addition, 2 candidate regions (Chr1: 127,407,230-127,524,879 bp and Chr21: 182,061,707-183,616,298 bp) were associated with LGR, which contain total 13 candidate genes (The extremely significant SNPs were mainly located in 2 genes: Chr1: REPS2 and Chr21: PTPRT). Four candidate regions (Chr1: 29,113,036-28,675,018 bp, Chr2: 18,253,612-149,111,290 bp, Chr15: 6,489,774 to 12,138,221 bp and Chr21: 6,578,021-8,472,904 bp) were associated with feather maturity, which contain total 24 candidate genes (The extremely significant SNPs were mainly located in 4 genes: Chr1: IMMP2L, DOCK4 and DDX10, Chr2: LDLRAD4). In conclusion, sex factors influence feather growth and maturity, and the genetic basis of the growth /maturity trait between different feathers is similar. REPS2, PTPRT genes, and IMMP2L, DOCK4, DDX10, and LDLRAD4 are important candidate genes that influence feather growth and maturity, respectively.

Avoidance, tolerance, and resistance to ectoparasites in nestling and adult tree swallows

We examined avoidance, tolerance, and resistance strategies of nestling and adult tree swallows Tachycineta bicolor in response to ectoparasitic blowflies Protocalliphora sialia. Tree swallows avoided settling in north‐facing nest boxes early in the breeding season. These boxes were more likely to be parasitized later in the season, suggesting that box selection may facilitate blowfly avoidance. After experimentally manipulating blowfly intensity, we found that nestlings were generally tolerant of parasitism. Parasites significantly reduced nestling blood hemoglobin but had no effect on nestling body mass, primary feather growth, age at fledging, or fledging success. Parents of parasitized nestlings did not increase their food provisioning rate to promote nestling tolerance. Adult female tree swallows demonstrated both tolerance and resistance: blowfly parasitism had no effect on adult hemoglobin and body mass, and those with higher P. sialia‐binding antibody levels had fewer blowfly larvae in their nests. Nestling antibodies were unrelated to blowfly intensity. Despite considerable variation among years, our results suggest that the costs of blowfly parasitism to nestling and adult tree swallows are modest, and limited to blood loss in nestlings. Future work should examine the effects of reduced blood hemoglobin on fledgling survival and the importance of parasite‐specific antibodies.

Replacement and growth of primary feathers in captive rock pigeons, Columba livia (Aves: Columbidae)

The replacement and growth of 311 primary feathers of eight captive male rock pigeons, Columba livia Gmelin, 1789 were monitored daily. Feather replacement was recorded in all months, but the primaries 1 to 5 (innermost primaries) were replaced mostly from September to December, whereas the primaries 6 to 10 (outermost primaries) were more frequently replaced from January to August. Each primary was held in plumage from six to fifteen months, but the lifetime of the outer feathers was longer than that of the inner feathers. A new primary emerges two or three days after its predecessor has been dropped, but the primaries replacing the feathers accidentally lost during bird handling emerge only after about eight days. The average growth period of a primary ranged from 21 to 37 days, with the larger and outermost feathers exhibiting a longer growth period. A constant average growth rate of 4 to 5 mm/day was found for all primaries until the last two days of growth, when the growth rate of the feathers became progressively slower. Bilateral symmetry in the primary replacement, when the same feather is replaced simultaneously in both wings, was not significant (22.2%) in the birds monitored in this study.

Use of Laser Ablation and Cryosurgery to Prevent Primary Feather Growth in a Pigeon (Columba livia) Model

Many species of birds kept in captivity must be rendered flightless to prevent escape from open enclosures. In this study, we evaluated the use of diode laser and cryosurgery as methods of ablating primary feather follicles in domestic pigeons (Columba livia). In group 1 birds (n = 6), primary feather 10 of both wings was treated with the diode laser (10 W, 2 seconds) and primary feather 6 was treated with the cryoprobe (5 seconds, 3 cycles). In group 2 birds (n = 6), primary feathers 10 and 6 were treated with the cryoprobe for 20 and 30 seconds, respectively, for 3 cycles. In all birds, primary feather 8 on both wings was manually pulled as the control follicle. Results showed that in group 1 birds, diode laser ablation prevented feather regrowth in 83% of follicles, however, freezing with the cryoprobe for 5 seconds did not prevent feather regrowth. In group 2 birds, treatment with the cryoprobe prevented feather regrowth at 100% and 42% of the treated sites (treatment times of 20 and 30 seconds, respectively). Significant tissue swelling and edema were observed in all group 2 birds. On histologic examination, follicle damage was most severe at the laser-treated sites in group 1 birds and at the 20-second freezing sites in group 2 birds, which correlated with the prevention of feather regrowth. The control follicles and follicles adjacent to treated areas in both groups were histologically normal. Feather follicle ablation with both the diode laser and the cryoprobe are effective in preventing feather regrowth; however, success with the cryoprobe depends on the ability of the probe to directly contact the feather follicle. Diode laser is a superior technique because it is faster, easier to perform, and causes minimal tissue damage.

Growth and Allocation in Captive Common Murre (Uria Aalge) Chicks

AbstractIn birds, relative growth rates of morphological characters change in response to restricted food intake during development. Differential allocation of limited resources is hypothesized to reflect functional priorities for developing chicks. Body mass, wing, and flight feathers have been identified as potential priorities for seabird chicks. We used allometry to examine allocation in captive Common Murre chicks fed within a range of natural provisioning. During days 10–45 post-hatch, chicks were fed one of four diets that varied in biomass, energy content, and composition. Energy intake had a more profound effect on growth and development than diet composition; it significantly reduced absolute growth of body mass, manus, and tarsus. Between day 15 and day 20, allocation changed in all treatments: growth of manus was maintained at the expense of body mass. Chicks in more restricted treatments shifted allocation to manus at a lower body mass than those in less restricted groups, but subsequently allocated similarly. Wing loading was higher for chicks than for adult alcids, but scaled similarly. Growth of primary feathers was the most sensitive to small differences in diet composition. Our data also suggest that some changes in allocation may be ontogenetically determined rather than part of an adaptive response to reduced food intake.Croissance et Allocation chez des Oisillons Uria aalge

Control of fledging age in Leach's Storm‐Petrel, Oceanodroma leucorhoa: chick development and prefledging mass loss

Summary Leach's Storm‐Petrel (Oceanodroma leucorhoa) chicks accumulate fat through most of the nestling period, near the end of which they typically weigh 50–100% more than their parents. Much of this excess mass is lost abruptly prior to leaving the nest and fledging itself marks the termination of parental care. In this study, we evaluated the hypothesis that the onset of the prefledging mass loss period coincides with the end of the development period and the completion of structural growth. We characterized the pattern of prefledging mass loss and the timing of fledging with respect to a point (T), based on wing growth, at which structural development stops. Variation in T suggested that development rate is partially influenced by parental food provisioning, particularly early in the nestling period (age 16–20 days) just prior to the onset of rapid primary feather growth. The timing of mass loss and fledging in relation to T suggested that prefledging mass loss begins upon completion of wing growth and that fledging occurs after chicks have reached a mass compatible with sustained flight. Thus, the time to fledging is positively correlated with nestling mass at the end of the development period. The prefledging period of mass loss is a unique phase of anorexia placed between parental feeding and self‐feeding in the life of the young petrel.

The effects of delaying the start of moult on the duration of moult, primary feather growth rates and feather mass in Common Starlings Sturnus vulgaris

In many species of birds there is a close relationship between the end of breeding and the start of moult. Late‐breeding birds therefore often start to moult late, but then moult more rapidly. This is an adaptive mechanism mediated by decreasing day lengths that allows late‐breeding birds to complete moult in time. This study asked how these birds complete moult of the primary feathers more rapidly, and the consequences of this on the mass of primary feathers. Common Starlings Sturnus vulgaris were induced to moult rapidly in one of two ways. In the first experiment, one group was exposed to artificially decreasing photoperiods from the start of moult, whereas the control group remained on a constant long photoperiod. The second experiment was a more realistic simulation. Two groups were allowed to moult in an outdoor aviary. One group started to moult at the normal time. In the other, the start of moult was delayed by 3 weeks with an implant of testosterone. The duration of moult was significantly reduced in both the group experiencing artificially decreasing photoperiods and the group in which the start of moult was delayed. The faster moult rate was achieved by moulting more feathers concurrently. The rate of increase in length of each of the primary feathers, and their final length, did not differ between groups. The rate at which total new primary feather mass was accumulated was greater in more rapidly moulting birds, but this was insufficient to compensate for the greater numbers of feathers being grown concurrently. Consequently, the rate of increase in mass of individual feathers, and the final feather mass, were less in the rapidly moulting birds. A 3‐week delay in the start of moult is not an unrealistic scenario. That this caused a measurable decrease in feather mass suggests that late‐breeding birds are indeed likely to suffer a real decrease in the quality of plumage grown during the subsequent moult.

Diet quality during pre‐laying and nestling periods influences growth and survival of Florida scrub‐jay (Aphelocoma coerulescens) chicks

AbstractFood availability is one of the most important determinants of successful reproduction in birds. In a previous study, it was shown that Florida scrub‐jays Aphelocoma coerulescens maintained a third egg mass when supplemented with a high fat and high protein diet during pre‐breeding, as opposed to birds that were not supplemented that laid third eggs markedly lighter in mass than first‐ and second‐laid eggs. Increases in egg quality promote chick growth and survival in many avian species. In this study, scrub‐jays were provided with supplements throughout the pre‐laying and nestling periods of 2001 and 2002 to investigate whether diet quality influenced growth and survival of chicks. Fledging success and survival to independence of unsupplemented chicks were higher for 2002 compared with 2001 indicating that breeding conditions (e.g. natural food availability) for jays were probably improved in the former year. Consistent growth patterns were found during the first 11 days post‐hatch between chicks on supplemented and those on unsupplemented territories. Of the three growth measures, only seventh primary feather growth tended to be greater for third‐hatched chicks on supplemented territories compared with third‐hatched chicks on control territories. Food supplementation influenced survival of chicks. Compared with chicks hatching on unsupplemented territories, fledging success of chicks hatching from second‐laid eggs was significantly greater in 2001, but not in 2002. Chicks from third‐laid eggs on supplemented territories also tended to survive better in 2001 compared with chicks from unsupplemented territories, but, again, no such effect was found in 2002. We conclude that food supplementation in the pre‐laying and nestling periods results in little measurable improvement in chick growth. However, improvements were found in survival of chicks that may be mediated through improvements in egg quality, but also may be the result of changes in foraging strategies of provisioning birds on supplemented territories. Chicks on supplemented territories might be in better body condition than those on unsupplemented ones. Methods other than morphometrics may be required to detect elevations in body condition of chicks raised on supplemented territories.

Stable Isotope Analysis of Temporal Variation in the Diets of Pre-Fledged Laughing Gulls

Abstract The δ13C, δ15N, and δ34S stable isotopic values of feathers from pre-fledged Laughing Gulls (Larus atricilla) in coastal Virginia and Jamaica Bay, New York were used to examine dietary variation during the nestling period. The tip portions of the feathers were used to indicate diet during the initiation of primary feather growth, whereas the base portions indicated diet during the period immediately prior to fledging. The results indicate that diets of the nestlings in Virginia moved to a higher trophic level during the period prior to fledging, however the New York nestlings did not appear to undergo any appreciable dietary change during this period. Overall, nestlings from both colonies consumed proportionately more foods of marine origin than freshwater or terrestrial. Therefore, the results do not support those of earlier studies that suggested that partially developed salt glands in young gulls might restrict the diet to more terrestrial or freshwater prey in the early stages of nestling growth.

Effects of Summer Feeding Area on Gosling Growth in Snow Geese

Relative growth of body parts (wing, culmen, tarsus) in young Snow Geese differed among years and among summer feeding areas only a few kilometers apart in the vicinity of the McConnell River, Northwest Territories, Canada. Gosling age was unknown at time of capture, so we expressed all differences in measured characteristics as a function of culmen length. This procedure may underestimate the magnitude of differences in growth with respect to age. Year and summer feeding area had large, independent effects on relative growth. Growth of primary feathers showed the greatest variation of measurable variables among feeding areas. We argue that the cause of most differences in relative growth was nutritional variation of vegetation. If goslings with retarded growth do not entirely catch up on fall staging areas, there may be lasting demographic effects.

Rates of Primary-Feather Growth in Nestling Birds

Rates of primary-feather growth with respect to increase in length and increase in feather mass were estimated for nestlings of a range of bird species. The relationships between primary feather growth-rate constants and adult primary-feather length, primary-feather mass and adult body mass for these species are described. As adult body size increases, flight-feather growth is completed in a shorter proportion of the post-hatching growth period. The rate of deposition of primary-feather mass scales to final (asymptotic) primary-feather mass with a similar scaling exponent as that relating rates of overall growth in body mass to adult weight.

Breeding biology of tree swallows in relation to wetland acidity

We examined aspects of the breeding biology of tree swallows (Tachycineta bicolor) in relation to the pH, presence or absence of fish, and dissolved organic carbon concentration in 51 wetlands adjacent to nest boxes northeast of Sudbury, Ontario. Wetland pH was positively related to swallow clutch size, the total volume of eggs in a clutch (clutch volume), the number of fledglings per successful nest, and several measures of nestling size and growth. Swallows breeding near wetlands where fish were present laid earlier, but had smaller eggs and clutch volumes and slower growth of primary feathers than swallows breeding near fishless wetlands. Organic carbon concentrations were poorly related to the reproduction of swallows. These results are discussed in relation to possible mechanisms for the effects of wetland acidity on avian reproduction.

Age Determination of Juvenile Spruce Grouse in Eastern Canada

Primary lengths of juvenile spruce grouse (Dendragapus canadensis) in New Brunswick and Ontario were measured to evaluate a method for determining juvenile age (McCourt and Keppie 1975). The Alberta growth curve for juvenal primary 7 (J7) is accurate for New Brunswick and Ontario but the Alberta growth curves for juvenal primary 9 (J9) and postjuvenal primary 7 (PJ7) are not accurate for those regions. A new growth curve for J9 is presented that can be used for birds in New Brunswick and Ontario. J. WILDL. MANAGE. 52(1):113-115 A method for determining the age of juvenile spruce grouse was developed by McCourt and Keppie (1975). Their graphs of primary feather growth have been used to estimate ages of juveniles in Michigan (Robinson 1980), New Brunswick (Quinn and Keppie 1981), Alberta (Smyth and Boag 1984), and Ontario (Szuba and Bendell 1984). Only Robinson (1980) is known to have tested the validity of the Alberta growth curves for his area. Measurements from chicks of known age in New Brunswick and Ontario are examined here to evaluate whether biologists are justified in the use of growth relationships derived in Alberta over wide geographical regions. Thanks are extended to D. M. Keppie for reviewing several manuscript drafts and providing financial support through a grant from the Natural Sciences and Engineering Research Council of Canada.

Effect of Lighting Program and Nutrition on Feather Replacement of Molted Single Comb White Leghorn Hens ,

This experiment concerned the induced molt of 320 60-wk old Single Comb White Leghorn hens placed two per cage in two adjoining sections of a light-tight, fan-ventilated poultry building. Treatments compared were: 1) lighting program: Washington (WSU) vs. North Carolina (NCSU). The WSU program used 8 h light/day for 28 days beginning 7 days before fast. The NCSU program used continuous light for 7 days prior to fast, followed by 12 h light/day for 21 days. The light portion of the photoperiod was then increased in steps in both treatments to 16 h. 2) Molt diet: cracked corn (CC) vs. 16% protein molt ration (MR) for 14 days. 3) Laying diet. A 14% protein mash calculated to contain .60% or .65% total sulfur amino acids (TSAA) or ascorbic acid (AA) at 0 or 50 ppm added to the laying mash. Day 1 was designated as the first day of photoperiod modification.Primary and secondary feather loss and subsequent primary feather growth were all significantly increased by the WSU light program at 56, 84, and 112 days. Total and average growth of new primaries was significantly increased by MR at 56 days and total primary feather growth by .65% TSAA at 112 days. No effects due to AA were observed. Photoperiod had the greatest effect on molt per se, with MR and .65% TSAA increasing early and late growth, respectively.

An analysis of weight changes in the Mute SwanCygnus olor

The weights of Mute Swans contain useful information on individuals' prospects for survival and breeding but to interpret them one needs to know what 'typical' weights would be. This paper uses multiple linear regression to predict such 'typical' weights: 1968 zveighings of 957 Mute Swans, from south Staffordshire, England, are analysed with respect to sex, age, moultstage, month of capture and breeding status. Because of marked sexual dimorphism, knowing a swan's sex is fundamental to interpreting its weight; age from hatching and stage of primary feather growth affect cygnets' weights near fledging; weights of young swans change with age during their first years of life; primary feather moult significantly depresses the weights of first year males but not, in this study area, of older males or females; monthly, seasonal changes are generally small; breeding adults are significantly heavier. The results and their biological implications agree well with other, less comprehensive, analyses. The method desc...

Nestling house wrens: weight and feather growth

Six models were tested for weight and feather growth of nestling house wrens (Troglodytes aedon). For weight growth, the logistic model with an asymptote A of 10.4 g and a growth-rate constant K of 0.52 day−1 was best. Curves for weight growth of individuals varied, and some birds had pronounced weight recession. Growth of primary feather 10 followed the Gompertz model with A and K equal to 18.8 mm and 0.32 day−1, respectively. Growth of rectrix feather 6 could best be described by the von Bertalanffy model with a forced A value of 32.5 mm and K equal to 0.12 day−1. Fitting of the models to rectrix feather length was complicated because fledging occurred when growth was only 37% complete as opposed to 84% complete for primary feather growth. The variation among broods of growth parameters and nestling time ranged up to 54.5%. First and second broods did not differ significantly in these parameters and brood size could not account for much of the observed variability. Weight growth and primary feather growth were linked, but this was not the case for weight and rectrix, or for primary and rectrix feather growth. Some birds that failed to fledge had depressed growth. Weight growth and recession are particularly well suited for investigating natural and man-made environmental stresses such as gamma radiation.

GROWTH AND DEVELOPMENT OF NESTLING HEN HARRIERS

SUMMARYNestling Hen Harriers Circus cyaneus in Orkney were weighed and measured during two nesting seasons.The 501 weights and 390 longest primary measurements produce a composite record of growth for this species. The general shape of both weight and primary growth curves is sigmoid.The primary feather growth can be measured at age seven and eight days after hatching and is less variable as an index of growth than is weight. The nestling period varies usually from 30 to 36 days, and age at first flight depends on the ratio of primary length to weight. Males usually fly before their heavier female siblings.The asynchronous hatching produces a size‐rank between nestling Hen Harriers. The significance of the size‐rank to growth and mortality is discussed.Sexual dimorphism develops at the nestling stage. Weights and measurements of males and females at different ages are tabulated.Asynchronous hatching, and the influence of latitude differences on growth rate are briefly discussed.