Growth of nestling Hamerkops Scopus umbretta in central Mali

Data on growth of nestling Hamerkops Scopus umbretto were analysed with respect to year and season of hatching and to hatch sequence. Quantitative growth characters included weight, culmen, tarsus, tail, third outermost primary quill, standard wing-length and wing span. The growth constant K of weight was 0.179 and time t₁₀-t₉₀ was 21.8 days. Least-squares analyses showed differences in weight gain, culmenlength and tarsus-length related to year and month but not to sequence of hatching. Predictive equations for character against age are provided for all linear measurements. Characters which attained apparent asymptotes before fledging were weight and culmen and tarsus-length whilst other characters varied between 80 and 90% of reported adult size. Qualitative indications of growth discussed are crest development, colouration and the disappearance of the egg-tooth. The rainy and post-rains seasons appear to offer the Hamerkop the best chances of successful breeding and maximum growth rates.     

Growth of nestling Hamerkops Scopus umbretta in central Mali

Data on growth of nestling Hamerkops Scopus umbretta were analysed with respect to year and season of hatching and to hatch sequence. Quantitative growth characters included weight, culmen, tarsus, tail, third outermost primary quill, standard wing-length and wing span. The growth constant K of weight was 0·179 and time t₁₀–t₉₀ was 21·8 days. Least-squares analyses showed differences in weight gain, culmen-length and tarsus-length related to year and month but not to sequence of hatching. Predictive equations for character against age are provided for all linear measurements. Characters which attained apparent asymptotes before fledging were weight and culmen and tarsus-length whilst other characters varied between 80 and 90% of reported adult size. Qualitative indications of growth discussed are crest development, colouration and the disappearance of the egg-tooth. The rainy and post-rains seasons appear to offer the Hamerkop the best chances of successful breeding and maximum growth rates.     

The breeding biology of the white-chinned petrel Procellaria aequinoctialis at South Georgia

Aspects of the breeding biology of the whitc-chinned petrel Procellaria aequinoctialis were studied at South Georgia. Laying, hatching and fledging dates, together with egg and adult measurements, rate of weight loss of eggs and incubating adults and data on the duration of incubation shifts were recorded. Chick growth in weight, tarsus length, culmen length and wing length from hatching to fledging was followed in detail and breeding success and causes of mortality documented. Comparisons are made with other populations of the species, other members of the genus Procellaria and other Procellariiformes. Despite being the largest burrow-nesting petrel in the world, P. aequinoctialis conforms well to the overall relationships between body weight and breeding parameters for Procellariiformes in general.     

Growth of nestling black kites Milvus migrans: effects of hatching order, weather and season

The growth of black kites Milvus migrans was studied in 1981, 1982 and 1984 at the Doñana Biological Reserve (south-west Spain). Fifteen variables were submitted to a principal component analysis in order to characterize the growth pattern of the young. In general, in the nestlings that fledged, rapid weight gain corresponded to rapid growth of the tarsus and feathers. For nestlings that starved, tarsus growth took priority over weight gain. Within the same brood, the last-hatched sibling grew more slowly than its older sibling and the differences between them increased in proportion to the hatching asynchrony. Brood size did not affect growth as clearly as hatching order and hatching asynchrony. Increased rainfall and lower maximum temperature, factors that seem to make the search for food more difficult, had negative effects on the youngest sibling in a multiple brood and on single nestlings. The only environmental variable that had an effect on all of the nestlings was the hatching date.     

Variations in growth of Cape petrel Daption capense chicks

This study reports on the growth of Cape petrel chicks at Nelson Island, South Shetland Islands, Antarctica, during the breeding seasons 1990/91 and 1991/92. Parameters of logistic growth model fitted to mass, wing, culmen and tarsus measurements were compared between available composite data sets. Differential growth rate of morphometric characters and their proportional development at hatching and fledging conform to the pattern observed in other fulmarine petrels, overall growth rate being among the fastest found in Procellariiformes. Composite growth curves varied significantly between populations, but few annual, seasonal, and intercolony differences were found within the Nelson Island population. As the differences between chicks from equally disturbed colonies were less marked than in comparison with the control colony, regular handling most probably reduced the growth in this study. Larger eggs produced heavier rather than structurally larger hatchlings, which attained higher peak and fledging mass and size. Strength of the relationship between egg-size and chick measurements initially declined with chick age but, in contrast with results of earlier studies, increased again after around the middle of the chick-rearing period. This suggests that pre-hatching maternal factors probably influenced initial and fledging (peak) size and mass of chicks via egg-size, while intermediate stages of growth were less affected. A difference in mass between chicks from small and large eggs was maintained until fledging and increased gradually until peak mass was reached.     

Reproduction of the Mottled Piculet in southern Brazil

ABSTRACT.   On 28 October 1996, I found a Mottled Piculet ( Picumnus nebulosus ) nest on Anhangava Mountain in southern Brazil. The nest cavity (10.6 cm × 5.6 cm) was in the trunk of a dead tree at a height of 85 cm. The circumference of the trunk at cavity height was 37 cm and the cavity entrance (diameter = 2.46 cm) was located near the top of the chamber. The nest was lined with wood fragments and contained four eggs. On average, eggs were 16.3-mm long and 13.0-mm wide and weighed 1.38 g. The parents spent 17 d incubating the eggs. Hatchlings had closed eyes and no feathers. By 20 d posthatching, nestlings were active and had plumage similar to that of adult females. Young fledging 22–25 d after hatching. Nestling weight gain and tarsus growth were fastest at the beginning of the nestling period, while wing, tail, and culmen growth had a linear relationship with nestling age. Both the adult male and female provided parental care during the nestling period. Although, the nesting behavior of Mottled Piculets was similar to that reported for other members of the genus, information on the reproductive biology of species in the genus Picumnus is still limited.     

陕西汉中野生朱鹮雏鸟的生长发育特征

2014年和2015年监测朱鹮保护区野生朱鹮(Nipponia nippon)15只雏鸟的生长发育,拟合其生长发育数据的生长曲线和相对生长公式,与1989年研究结果进行对比。结果显示,野生朱鹮雏鸟的生长发育不受孵化顺序的影响,雄性体长的生长速度快于雌性。目前朱鹮雏鸟体重、体长、翅长、嘴峰长、跗跖长和中趾长的生长均符合逻辑斯谛生长曲线,雏鸟体重生长率在13日龄左右达到最大。与1989年的研究结果比较发现,目前野生朱鹮幼鸟总体生长发育有所放缓。这可能与近年野生朱鹮种群的增长和扩散导致的环境压力加大以及繁殖期食物资源不足有关。     

Nestling growth in the African fish eagle in Uganda

Nestling African fish eagles Haliaeetus vocifer (Daudin, 1858) in Queen Elizabeth National Park (QEP), Uganda, attained and exceeded the adult body weights of their respective sexes by fledging time. The growth curves conformed with the sigmoid form of most animal species. The overall growth rate, K (g/day), was low, averaging 0.077 ± 0.017 g/day and the time t_10–90 required to complete growth from 10 to 90% of the asymptotic weight was c. 42 days. Brood size and hatching order did not significantly influence growth rates but the sex of the young did. The tarsus, femur and humerus reached adult sizes by fledging time but the standard wing did not.     

The effects of hatching asynchrony on growth and mortality patterns in Eurasian Hoopoe Upupa epops nestlings

Growth is a fundamental life history trait in all organisms and is closely related to individual fitness. In altricial birds, growth of many traits is restricted to the short period between hatching and fledging and strongly depends on the amount of food that parents deliver and the extent of hatching asynchrony. However, empirical studies of energy allocation to growth of different body size traits as a function of hatching asynchrony are scarce. We studied growth and mortality of Eurasian Hoopoe Upupa epops, a species with a long breeding season and high brood size variance, whose nestlings show pronounced hatching asynchrony, in order to test how hatching asynchrony affects different growth traits in the context of territory quality, season and brood size. The growth of five body traits (body mass, and lengths of tarsus, third primary, bill and longest crest feather) was investigated to understand how it was affected by brood size, hatching date and order, and territory quality. In total, 241 nestlings from 39 nests were measured every 4 days in 2014 in south‐western Switzerland. Brood size, hatching date and hatching order had the strongest influence on growth trajectories, although tarsus growth was only marginally affected by these variables. Nestlings that hatched earlier than their siblings were heavier and had longer third primaries, bills and crest feathers compared with later‐hatched siblings. In territories of high quality, hatching order differences disappeared for body mass growth, but persisted for lengths of third primary, bill and crest feathers. Brood size was inversely associated with third primary, bill and crest feather lengths, but positively associated with body mass. Nestling mortality was higher in later‐hatched nestlings and in broods that were raised in territories of lower quality. Our study shows that in nestlings, energy was allocated differentially between body traits and this allocation interacted with hatching order and territory quality. Rapid mass gain by nestlings was prioritized in order to increase competitive ability. Our results provide support for the brood reduction hypothesis as an explanation of hatching asynchrony in Hoopoes.     

Morphometry, diet and habitat in the kingfishers (Aves: Alcedinidae)

Factor analysis of the linear dimensions of 92 species of kingfisher indicated that morphological differences were associated with four diet categories (aquatic, littoral, terrestrial and fossorial animals). Analysis of covariance confirmed the significance of these differences for culmen, tarsus and tail length but not for wing length. Habitat factors resulted in some significant differences but these were less easy to interpret. One case of intraspecific variation showed similar trends for culmen length.     

Adaptive benefits of differential post-fledging development patterns in the Lesser Flamingo (Phoenicopterus minor)

Measurements of five morphological components (mass, skull length, culmen, flattened wing and tarsus) and blood samples were taken from 154 fledged wild Lesser Flamingos Phoenicopterus minor captured during 2001 and 2002 at Lake Bogoria, Kenya (0°11'–20'N, 036°06'E). The sample included adults (>3 years old), immature birds (2–3 years old) and first-year juvenile birds of both sexes. The sex of each bird was determined by PCR amplification of the CHD-Z and CHD-W genes, using DNA extracted from blood samples. Within each gender, there were significant differences in mass and tarsus length amongst the three age groups, indicating that the skeletal size and mass of Lesser Flamingos continue to increase between fledging and attainment of adult plumage at three to four years of age. The different morphological components increased in size at different rates, although the same components appeared to increase at similar rates in both males and females. Skull and culmen lengths had reached adult size in juvenile birds, while juvenile wing length, tarsus length and mass were approximately 95%, 85% and 75% of adult size, respectively. The adaptive significance of these findings is discussed.     

Hatching asynchrony and growth trade‐offs within domesticated and wild zebra finch,Taeniopygia guttata,broods

The Australian zebra finch, Taeniopygia guttata, is a widely used model organism, yet few studies have compared domesticated and wild birds with the aim of examining its relevance as an evolutionary model species. Domestic and wild broods hatch over approximately 4 and 2 days, respectively, which is important given that nestlings can fledge after as little as 12 days, although 16–18 days is common. We aimed to evaluate the extent to which the greater hatching asynchrony in domestic stock may effect reproductive success through greater variance in size hierarchies, variance in within‐brood growth rates, and partial brood mortality. Therefore, by simultaneously controlling brood sizes and experimentally manipulating hatching intervals in both domesticated and wild birds, we investigated the consequences of hatching intervals for fledging success and nestling growth patterns, as well as trade‐offs. Fledging success was similarly high in domestic and wild broods of either hatching pattern. Nonetheless, between‐brood analyses revealed that domestic nestlings had significantly higher masses, larger skeletal characters, and longer wings than their wild counterparts, although wild nestlings had comparable wing lengths at the pre‐fledging stage. Moreover, within‐brood analyses revealed only negligible differences between domestic and wild nestlings, and larger effects of hatching order and hatching pattern. Therefore, despite significant differences in the hatching intervals, and the ultimate size achieved by nestlings, the domestication process does not appear to have significantly altered nestling growth trade‐offs. The present study provides reassuring evidence that studies involving domesticated zebra finches, or other domesticated model organisms, may provide reasonable adaptive explanations in behavioural and evolutionary ecology. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100 , 763–773.     

Morphometric variability on a microgeographical scale in two inshore seabirds

The range of morphometric variation among two inshore seabirds, the Kerguelen cormorant Phalacrocorax atriceps verrucosus and the gentoo penguin Pygoscelis papua was investigated on the Kerguelen and Crozet archipelagos. Four measurements (weight, culmen, flipper and body length for gentoos; weight, culmen, wing and tarsus length for cormorants) were compared in the same seven localities on Kerguelen. In addition, culmen and wing length were compared in four localities on Crozet for gentoo penguins. The two species exhibited similar trends in variation within Kerguelen although the range of variation was greater in cormorants. Compared to the largest cormorants and gentoo of Kerguelen, the smallest stocks were 60 and 36% of the weights, respectively. There is little evidence elsewhere of similar broad morphometric variability in seabirds on a microgeographical scale. The variation observed did not follow a regular cline and appeared to be less related to physical factors (sea temperatures) than to the local biological factors during the breeding season.     

Ectoparasites cause increased bilateral asymmetry of naturally selected traits in a colonial bird

Abstract Parasitism has been shown to correlate with levels of bilateral symmetry in some organisms, with more asymmetric individuals often having more parasites. However, few studies have shown experimentally that parasitism directly causes increased asymmetry. By fumigating some cliff swallow (Petrochelidon pyrrhonota) colonies and leaving others untreated, we investigated experimentally whether ectoparasitism by the cimicid swallow bug led to higher levels of asymmetry in length of wings, outer tail feathers, and tarsus among juvenile and adult birds. Juveniles from fumigated colonies measured soon after fledging had significantly less asymmetry in wing and outer tail length than juveniles from nonfumigated colonies; asymmetry in tarsus length was unaffected by parasitism. Adults that had undergone one or more post‐juvenal molts on the wintering grounds showed no differences in asymmetry between those reared in fumigated vs. nonfumigated colonies. These results show that ectoparasitism directly leads to increased feather asymmetry in cliff swallows, probably through parasite‐induced nutritional stress. Because wing and tail asymmetry impair flight performance and reduce foraging efficiency, the increased asymmetry caused by parasites represents a fitness cost to cliff swallows. This is among the few experimental studies to show an effect of parasites on asymmetry of naturally selected characters.     

Optimal brood size and its limiting factors in the Rufous Turtle DoveStreptopelia orientalis

Optimal brood size and its limiting factors of the Rufous Turtle Dove,Streptopelia orientalis, were studied at the campus of the University of Tsukuba, Japan, during the breeding season in 1990–92. The dove usually lays two eggs in a nest. I made nests of a brood size of one and three by transferring a hatchling from one nest to the other, and compared their fledging success, factors of breeding failure, weight and tarsus length at fledging, growth rate and nestling period with those of a brood of two. The index of fitness (fledgling weight multiplied by average number of fledglings per nest) was almost the same in broods of two and three. However, the highest variation in fledging weight within the brood and the extension of nestling period were observed in broods of three, which caused the extension of inter-brood interval and consequently the smaller number of broods in the total breeding season. Therefore, broods of three would not have an advantage in producing more offspring than broods of two. Crop milk production had an effect on the growth of nestlings in the early phase of the nestling period, but the rapid growth in the granivorous phase compensated for the growth delay of the smallest nestling in broods of three. Small brood size and a large number of broods in a season would also be more effective under high predation pressure.     

树麻雀表型的环境适应进化

树麻雀(Passer montanus)分布范围广、海拔梯度大,也是人类活动的伴随物种。对中国837个样本的10个形态特征与温度、日照、海拔和风速等4个主要环境因子进行相关分析,结果显示:树麻雀的体重、嘴裂、翅长、尾长、跗跖长、脑骨宽、眼间距与日照因子显著相关(P0.05),体重、体长、翅长、尾长、跗跖长与海拔因子显著相关(P0.05),体重、嘴峰、翅长、脑骨长与温度因子显著相关(P0.05),表明树麻雀的形态指标易随环境因子的变化而变化。通过控制经度和海拔两个变量,对形态指标与纬度的偏相关分析表明,体重、翅长、脑骨长和脑骨宽与纬度呈显著正相关(P0.05),体表突出部分嘴峰、嘴裂与纬度呈显著负相关(P0.05),即随着纬度的升高,树麻雀身体逐渐变大,符合贝格曼规律;体表突出部分嘴峰和嘴裂随纬度升高变短,符合阿伦规律。飞行能力与海拔因子呈极显著正相关(n=92,r=0.217,P=0.038),表明树麻雀在高海拔地区具有更强的飞行能力,这也许是它成为广布种的重要原因。     

Genetic and environmental components of growth in nestling blue tits (Parus caeruleus)

We investigated the effect of brood‐size mediated food availability on the genetic and environmental components of nestling growth in the blue tit (Parus caeruleus), using a cross‐fostering technique. We found genetic variation for body size at most nestling ages, and for duration of mass increase, but not of tarsus growth. Hence, nestling growth in our study population seems to have the potential to evolve further. Furthermore, significant genotype–environment interactions indicated heritable variation in reaction norms of growth rates and growth periods, i.e. that our study population had a heritable plasticity in the growth response to environmental conditions. The decreasing phenotypic variance with nestling age indicated compensatory growth in all body traits. Furthermore, the period of weight increase was longer for nestlings growing up in enlarged broods, while there was no difference to reduced broods in the period of tarsus growth. At fledging, birds in enlarged broods had shorter tarsi and lower weights than birds in reduced broods, but there was no difference in wing length or body condition between the two experimental groups. The observed flexibility in nestling growth suggests that growing nestlings are able to respond adaptively to food constraint by protecting the growth of ecologically important traits.     

Gender determination by body weight and linear measurements in American and Chilean flamingos,previously surgically sexed: Within-sex comparison to greater flamingo measurements

Gender was determined by laparoscopic visualization of the gonads for 38 adult American flamingos (Phoenicopterus ruber ruber L.) and 36 adult Chilean flamingos (P. chilensis L.). Concomitant body weight (kg) and linear measurements (mm) of the culmen (bill), tarsus (tarsometatarsus), middle toe, and wing were taken. Statistical comparisons of body weight and linear measurements for male vs. female were made for each species. Also, the same-sex statistical comparisons were made between these two species, and between each of these two species and with data for greater flamingos (P. r. roseas L.) from a previous publication. As previously published for greater flamingos, an overlap between sexes existed in all measurements with males on average larger than females for both American and Chilean flamingos. However, Students' t-test indicated a significant sexual difference for all measurements between males and females of each species except for culmen length in Chilean flamingos. Students' t-test also indicated a significant difference when species were compared (Chilean vs. greater, and American vs. Chilean) and subspecies (American vs. greater) were compared for most of the 5 measurements. Thus, despite limitations imposed by between-sex overlap, weights and linear measurements, especially tarsus, middle toe, and wing length, appear to be useful in determining an individual's gender when species or subspecies identification is considered.     

SEXUAL SELECTION IN THE BARN SWALLOW (HIRUNDO RUSTICA). IV. PATTERNS OF FLUCTUATING ASYMMETRY AND SELECTION AGAINST ASYMMETRY

The patterns of variation in fluctuating asymmetry were studied in four morphological characters of the barn swallow Hirundo rustica. The level of absolute and relative asymmetry was larger in the secondary sexual character “outer tail length” than in three nonsexual morphological traits (wing, central tail, and tarsus length). The extent of individual asymmetry in outer tail length was negatively correlated with tail-ornament size, whereas the relationship between asymmetry of all other morphological characters and their size was flat or U-shaped. Asymmetry in outer tail length was unrelated to asymmetry in other morphological characters, whereas asymmetries in the length of wing, central tail, and tarsus were positively correlated. Male bam swallows exhibited larger asymmetry in outer tail length than females. Asymmetry of most morphological traits exhibited intermediate repeatabilities between years, with the exception of male and female outer tail length, which were highly repeatable. Tail asymmetry of offspring weakly, though significantly, resembled that of their parents. Asymmetry in wing and outer tail length was also significantly related to several fitness components. Male barn swallows that acquired a mate were less asymmetric in wing and outer tail length than unmated males. Females with more asymmetrical tails laid eggs significantly later. Annual reproductive success was unrelated to fluctuating asymmetry. Male barn swallows that survived were less asymmetric in wing and outer tail length than nonsurvivors, whereas female survivors were less asymmetric in outer tail length than nonsurvivors. These results suggest that levels of fluctuating asymmetry in barn swallows are associated with differences in fitness.     

Sexing greater flamingos by weight and linear measurements

The sex of 59 adult Greater Flamingos (Phoenicopterus ruber roseus L.) was determined by laparoscopic exam of the gonads. Concomitant body weight (kg) and linear measurements (mm) of the culmen (bill), tarsus, middle toe, and wing were taken and compared for males vs. females. Although an overlap between sexes existed in all measurements, males on average were larger than females. Student's t-test indicated significant sexual differences for all five measurements. Thus, weights and linear measurements—especially tarsus, middle toe, and wing length—appear to be a useful parameter in determining an individual's sex in lieu of laparoscopic, feather pulp, blood chromosome, or fecal steroid analysis.