The extent of intertidal flats in the Yellow Sea region has declined significantly in the past few decades, resulting in severe population declines in several waterbird species. The Yellow Sea region holds the primary stopover sites for many shorebirds during their migration to and from northern breeding grounds. However, the functional roles of these sites in shorebirds’ stopover ecology remain poorly understood. Through field surveys between July and November 2015, we investigated the stopover and moult schedules of migratory shorebirds along the southern Jiangsu coast, eastern China during their southbound migration, with a focus on the ‘Critically Endangered’ Spoon-billed Sandpiper Calidris pygmaea and ‘Endangered’ Nordmann’s Greenshank Tringa guttifer. Long-term count data indicate that both species regularly occur in globally important number in southern Jiangsu coast, constituting 16.67–49.34% and 64.0–80.67% of their global population estimates respectively, and it is highly likely that most adults undergo their primary moult during this southbound migration stopover. Our results show that Spoon-billed Sandpiper and Nordmann’s Greenshank staged for an extended period of time (66 and 84 days, respectively) to complete their primary moult. On average, Spoon-billed Sandpipers and Nordmann’s Greenshanks started moulting primary feathers on 8 August ± 4.52 and 27 July ± 1.56 days respectively, and their moult durations were 72.58 ± 9.08 and 65.09 ± 2.40 days. In addition, some individuals of several other shorebird species including the ‘Endangered’ Great Knot Calidris tenuirostris, ‘Near Threatened’ Bar-tailed Godwit Limosa lapponica, ‘Near Threatened’ Eurasian Curlew Numenius arquata and Greater Sand Plover Charadrius leschenaultii also underwent primary moult. Our work highlights the importance of the southern Jiangsu region as the primary moulting ground for these species, reinforcing that conservation of shorebird habitat including both intertidal flats and supratidal roosting sites in this region is critical to safeguard the future of some highly threatened shorebird species.

The blue crab Callinectes sapidus is an important ecological and commercial species. It plays a fundamental role in the structure and function of coastal benthic food webs, with global catches of ~74,357 tons. This is the most exploited portunid species in Brazil. However, few studies about the ecology and population dynamics of C. sapidus have been published. This study aimed to analyse the preferred areas for the spatial distribution of juveniles and moulting individuals of C. sapidus in shallow areas of the Patos Lagoon estuary and the adjacent marine reproductive area, and their relation to water and sediment characteristics. Juveniles and moulting individuals preferred the embayment of the upper estuary, where the sediments are finer, with higher contents of organic matter and the presence of submerged vegetation. There was also a temporal variability in the abundance of juvenile size classes, with two marked increments of smaller individuals: (1) in late spring and summer and (2) in winter, indicating two recruitment peaks. Unusual environmental conditions in the summer of the first year, with an increase of fine sediments and organic matter, combined with low salinities in the adjacent marine area, allowed recruitment of individuals there. We suggest better attention to the embayment around the Marinheiros Island (considered here as upper estuary) for management and protection measures due to the overlapping of recruitment preferences of the blue crab, pink shrimp and fish species in this area.

We analysed the morphological variations through geometric morphometric approaches of the dorsal and ventral views of growing male and female Callinectes danae Smith 1869, based on the hypothesis that swimming crabs present polymorphism during growth. Our research identified six instars for females, seven instars for males and one instar for unsexed individuals (young). The sixth instar of females and the seventh instar of males were composed of adults. We identified 20 landmarks from the dorsal view, and 16 landmarks from the ventral view. Based on canonical analysis and Procrustes distance, we observed the formation of clearly separated instars (both views), indicating a significant change during ontogeny, not only in the pubertal moult. The most prevalent changes occurred in the abdomen, with males thinning and females broadening the abdomen during growth. In the dorsal view, we observed a displacement of anterolateral spines to the posterior region throughout the growth period and that the anterolateral and frontal teeth of juveniles were more ornate than those of adults. The ontogenetic trajectories for males and females have similar origins and follow different directions over the instars, with maximum distance after the pubertal moult (P < 0.05).

Physically weighing large marine mammals sequentially over time has presented researchers with a logistical challenge and has severely limited sample sizes. Using a well-established photogrammetry method we developed a simple mathematical method to calculate accurate mass measurements at specific stages in the life cycle of a top marine predator. Female southern elephant seals (n = 23) at Marion Island were sampled sequentially using photogrammetry and three-dimensional models (based on each photogrammetry project) were built for estimation of body mass. Simple equations were applied to obtain mass at critical instances in their life cycle. Marion Island elephant seal mass data was compared to data obtained from physically weighed elephant seals from King George, South Georgia and Macquarie islands. Females from Marion Island are smaller, but their percentage lactation mass loss is similar to females from these other populations. The similarity of percentage mass loss during lactation between different female populations illustrates the accuracy and practicality of the photogrammetric method over a temporal scale. Photogrammetric mass estimation can be used alongside datasets of physically weighed animals and can greatly benefit ecology and life history studies.

The application of stable-hydrogen isotope (δD) measurements to the study of animal movement, resource use and physiology depends on understanding factors driving variation in δD in animal tissues. The source of micro-scale variation in δD is poorly known, yet understanding micro-scale patterns of δD could shed light on important ecological processes and improve our abilities to track animal movements. Using linear and additive models, we explored the influence of micro-scale habitat use, moisture and diet on tissue δD values of Nicaraguan cloud-forest birds. Using mist nets, we captured 211 individuals of 22 resident Neotropical species at 500–1390 m asl and collected feather and claw samples. Based on three years of data from year-round sampling, our results suggest that microhabitat, seasonal shifts in moisture δD, and diet all influence bird tissue δD values. Our model results reveal a previously undescribed microgeographical effect on δD, where foraging level (understorey versus overstorey) and foraging location (forest interior versus adjacent coffee plantation) were significant predictors of δD values in bird claws and feathers. Mean claw and feather δD values among species varied from −83‰ to −19‰. Top models for claws and feathers explained 57% and 52% of variation in δD respectively. Direct comparisons of understorey (mean ± SD of −30‰ ± 15‰) versus overstorey (−50‰ ± 15‰) claw values suggest that δD may be useful in tracking vertical, micro-scale movement. Higher δD values in forest understorey birds reveal a heavy reliance upon recycled, fog moisture. Fragmentation and climate change may result in increasingly desiccated cloud forest that may exert a more negative influence on the food webs of understorey species that seem to be supported by recycled sources of moisture in the dry season.

Morphometric and gonad maturity of Libinia spinosa on the coast of Mar del Plata, Argentina, were assessed. In both sexes various morphometric features were measured to determine the morphometric maturity, and through macroscopic inspection of gonads and analysis of its content, different stages of gonad maturity were described and the physiological maturity was estimated. In females, the carapace width ranged from 8 to 56.5 mm while in males from 4.6 to 81.97 mm. The size at which 50% of females were morphometrically mature was calculated at 40.6 mm. Based on the allometric growth of the abdomen, two morphometric groups of females were recognized as juvenile and adult phases. In males, results of principal component analysis showed that the most suitable variables that efficiently represent the size and sexual differentiation factor were the carapace width and cheliped length respectively. The size at which 50% of males were morphometrically mature was estimated at 58.9 mm. Based on the allometry of the cheliped growth, two morphometric groups were recognized as immature and mature phases. Males maintained under laboratory conditions moulted and growth was related to regular and terminal moults. Males reached their terminal moult at a wide size-range, from 48.5 mm to 61.4 mm of carapace width. This terminal moult coincided with the size of morphometric maturity. In both sexes four stages of gonad development were described, two corresponded to immature phases and two to mature phases. The size at which 50% of females and males reached gonad maturity was LC50 = 40.33 mm and LC50 = 33.6 mm, respectively. In females, both morphometric and gonad maturity occurred at a similar size. In males, gonad maturity is acquired prior to morphometric maturity, thus three different types of males were characterized: (1) those with small carapace width and cheliped, without spermatophores in their vas deferens; (2) those with large carapace width and small cheliped, bearing spermatophores in their vas deferens; and (3) those with large carapace width and cheliped, bearing spermatophores in their vas deferens.

During the unusually extended breeding season of 1984/85 in Tsavo-East National Park, Kenya, Quelea quelea were sampled and moult patterns recorded. Particular attention was paid to individuals with an interrupted moult pattern. These were further classified as either having their moult arrested or suspended. Apparently, post-nuptial moult begins earlier in males than in females. Although the majority of quelea bred and moulted sequentially, these activities overlapped in many individuals and moulting suspended after the replacement of a few feathers. The initiation of post-nuptial moult before the cessation of breeding, followed by moult interruption, is evidence for the physio-ecological drive in quelea to complete their moult as soon as possible to prepare for the next breeding opportunity.

The aim of this study was to evaluate secondary fibre shedding in relation to seasonal hormonal changes in young cashmere-bearing goats reared in southern Italy. We used 14 cashmere-bearing kids, seven males and seven females, of a Scottish breed-population of goats specialized in cashmere production. Monthly, a hair patch of 4 cm2 was clipped from both left and right mid sides alternately and cashmere length and its yield were determined. Blood samples were taken every 2 weeks and plasma was assayed for prolactin (PRL), growth hormone (GH), tri-iodothyronine (T3), thyroxine (T4), progesterone and testosterone. With the same frequency, animals were monitored for onset of moult. Our data indicate that in young cashmere goats at their first moult, secondary fibre shedding is a seasonal event that is strictly related to changes in photoperiod and that PRL has a pivotal rôle in regulating this phenomenon. This corresponds with findings in adults. The observation that both thyroid hormones and sex steroids varied seasonally suggests that they are involved in the regulation of the moult cycle, but their precise rôle remains to be elucidated. Our data also indicate that GH seems to be implicated in the control of the moult cycle. The finding that maximal fibre shedding occurred earlier in males than females could be ascribed to differences in GH levels and to the earlier increase in plasma concentration of PRL observed in males.

Moult and pre-migratory fuelling are energy-demanding processes in birds, usually showing a limited degree of temporal overlap. The barn swallow Hirundo rustica, a strictly aerial insectivorous, long-distance passerine migrant (15–20 g), accumulates conspicuous energy stores (up to 30–40% of lean body mass) before embarking on the autumn migratory flight between western European breeding areas and African sub-Saharan winter quarters. During the pre-migratory fattening period (September–October), both adult and juvenile birds replace body (contour) feathers. The seasonal overlap between moult and energy storing was studied in barn swallows in Italy. Data from 23 000 birds, measured during eight study seasons, were analysed to investigate whether the simultaneous replacement of body feathers and fuelling was associated with reduced energy stores. Among all age and sex-classes, non-moulting individuals showed a relatively greater level of energy stores compared to moulting birds. This was particularly evident during the last phase of the pre-migratory fuelling period, when birds were building up energy stores at maximum rate. The proportion of moulting birds was greater among adults as compared to juveniles, and adult males moulted faster/earlier than females. The frequency of individuals with growing feathers among the innermost primary feathers was greater among birds replacing body feathers. The presence of moulting wing feathers in adult birds only marginally affected energy stores, as compared to the replacement of body feathers. Hence, our data show a negative association between replacement of contour feathers and energy stores in a long-distance migratory bird, suggesting that a physiological trade-off between these two energy-demanding processes may occur, and that a late moult may ultimately have a negative effect on the successful termination of the migratory journey.

The effect of plane of nutrition on the timing of the moult in cashmere goats was investigated. Three groups of mature does were individually offered food to supply 0·8 (L, no. = 14), 1·2 (M, no. = 14) or 20 (H, no. = 13) times their estimated maintenance energy requirements from mid December until mid May. Two other groups of goats which were shorn in mid January, were offered 1·2 times maintenance requirements from mid December until mid March when food levels were increased to either 1·6 M (SL, no. = 6) or ad libitum (SAL, no. = 6). In mid May mean live weights for treatments L, M, H, SL and SAL were 36·0, 41·5, 46·9, 33·0 and 43·1 kg (average s.e.d. = 2·27, P < 0·001).

The pattern of moult was described by changes in a subjectively assessed moult score, the proportion of follicles with brushes and staple length. The loss of brushes, indicating the start of the moult, began from the primary follicles on days 143, 131, 76, 150 and 129 (average s.e.d. = 13·5, P < 0001), and from the secondary follicles on days 141, 128, 104, 144 and 125 (average s.e.d. = 14·1, P = 0·053) for treatments L, M, H, SL and SAL respectively. The loss of brushes from primary and secondary follicles was completed on average, by days 194 and 206 of the experiment respectively, and there were no differences between treatments. Moult score and staple length data confirmed the conclusion that lowering the plane of nutrition delayed the start of the moult. No additional effect of fleece removal in the shorn treatments was observed.

Changes in circulating levels of plasma prolactin, thyroxine, tri-iodothyronine, insulin, insulin-like growth factor-1 and growth hormone were related to seasonal changes in daylength and plane of nutrition. Their rôle in the control of the moult is discussed.

Manipulation of the nutrition of cashmere goats in early spring has the potential to delay and increase the synchrony of fibre moult and to improve the efficiency of cashmere harvesting.

The development and moulting of the birth and first adult coat of two genotypes of cashmere-bearing goats, a highyielding Siberian (S) and low-yielding Icelandic × Scottish feral (IF), were examined. Samples of fibre from the neck, mid side, belly and rear-leg areas and of mid-side skin were obtained monthly from five male and five female kids of each genotype from birth to 13 months of age. Guard hair and undercoat length, secondary/primary (S/P) skin follicle ratio and the proportion of skin follicles containing a non-growing fibre with a brush end were recorded. S/P ratio reached an asymptote between 4 and 5 months of age and was higher fP < 0·01) in S (10·7) than in IF (6·7) kids. In both genotypes peaks of brush formation in primary follicles occurred between 2 and 4 months and again between 8 and 11 months of age. In contrast to primary follicles, secondary follicles had only a single peak of brush formation occurring at 10 and 8 months of age for S and IF kids respectively. Guard hair moulted from the birthcoat, but there was no loss of undercoat prior to 12 months of age and harvesting of cashmere prior to this time is unnecessary.

The secondary follicles of S kids had a longer growing period and fibre length increased at a greater rate than that of IF kids, resulting in more than a two-fold difference in the maximum undercoat length. Assessments to estimate the final weight and proportion of cashmere, made prior to completion of growth of the fleece, are likely to underestimate these parameters for high-yielding goats in comparison with their low-yielding counterparts. However, it is unlikely to alter the ranking, and hence the selection, of animals for retention in the breeding herd.