Molting Period Research Articles

Non‐breeding distribution and at‐sea activity patterns of the smallest European seabird, the European Storm Petrel (Hydrobates pelagicus)

Determining the non‐breeding distribution and activity patterns of migratory animals is essential to understand the trade‐offs across breeding, moulting and migratory periods and to evaluate the differential levels of exposure of these animals to threats throughout the year. By taking advantage of the current miniaturization of geolocators, during the breeding season of 2019, we deployed geolocators on 10 European Storm PetrelsHydrobates pelagicusbreeding on Benidorm Island, Western Mediterranean, to determine the distribution and activity patterns of this small seabird species. Of the eight individuals that were recaptured with usable geolocation data, all individuals migrated to the North Atlantic Ocean, ranging between the Canary Islands and south of Iceland. They possibly take advantage of the more productive waters in the North Atlantic areas explored during the non‐breeding period compared with the Western Mediterranean areas explored during the breeding period. This migratory pattern contrasted with the partial migration described for individuals breeding in the Central Mediterranean. Tracked individuals were more synchronous in their prenuptial than in their postnuptial migratory phenology, probably due to a higher probability of breeding success related to earlier arrival to the breeding area. At‐sea activity data indicated that individuals spent more time on the water at night (and especially on those nights around the new moon) during the first half of the non‐breeding period (matching the dates of the moulting period of the species). Although birds may begin to moult their feathers while breeding, some seemed to overlap the moulting period with the postnuptial migration. Our results show that multi‐colony studies are needed to understand the drivers of distinct migratory patterns at intra‐ and inter‐population levels and how small migratory species trade‐off the overlap of moult with other energetically demanding activities such as breeding or migrating.

Effect of biogas sludge meal supplement in feed on growth performance molting period and production cost of giant freshwater prawn culture

The worldwide prawn industry strives for better production and environmental sustainability. Shrimp feed is one of the most expensive aquaculture inputs; therefore, it must be cost-effective and environmentally safe. Fish meals in aquaculture are becoming unsustainable due to the cost and environmental concerns. The effects of a biogas sludge meal supplement in feed on freshwater prawn productivity were studied. This study aimed to examine the growth, survival rate, yield, feed conversion ratio, and molting period of giant freshwater prawns (Macrobrachium rosenbergii) fed with and without biogas sludge a low-cost resource. The four treatments were T1 (0% biogas sludge), T2 (10% biogas sludge), T3 (20% biogas sludge), and T4 (30% biogas sludge). Protein content ranged from 26.7 to 27.4% in the experimental diets. The experiment was conducted in 3 × 3x1.5 m cages in an earthen pond for 80 days. The data shows that freshwater prawn growth performance did not differ significantly across treatments (P > 0.05). Biogas sludge has been demonstrated to be a low-cost feed component for freshwater prawns. Regarding survival, productivity, and feed conversion ratio, T2 (10% biogas sludge) outperformed the other two. As a result of the research, it was determined that 10% of biogas sludge might be used as a low-cost freshwater prawn feed option. The molting period of freshwater prawns fed biogas-containing feed was investigated at various levels. Freshwater prawns grown in baskets in a pond at 32.2 °C for a trial period of 90 days were molted differently (P > 0.05). The molting periods for Tl, T2, T3, and T4 were 19, 18, 19.8, and 20.8, respectively. In addition, the research suggests efficient and long-term methods for supplying nutrient-dense prawn feed to aquaculture production systems.

Molt patterns and age and sex determination criteria for selected landbirds in an urban area of the Peruvian Central Coast

Despite molting is an important and expensive activity in the life cycle of birds, this process is poorly known for neotropical species and even less so for species inhabiting urban zones. We studied molt patterns, aging and sexing criteria, and morphometrics for seven common resident species in an urban area of ​​Lima city, Peru. All species evidenced complete prebasic molts. Partial to eccentric incomplete preformative molts were evidenced for six species (Camptostoma obsoletum, Pyrocephalus rubinus, Catamenia analis, Poospiza hispaniolensis, Coereba flaveola, and Thraupis episcopus); whereas Columbina cruziana exhibited a complete molt. All thraupid species exhibited partial prealternate molts. Preformative and prebasic molts were recorded mostly during the dry season, and the few records of prealternate molts might suggest its occurrence soon after the wet season. Our species also exhibited low molt synchrony, with some of them (C. cruziana, P. rubinus, and C. flaveola) exhibiting extensive molt periods likely explained by its potential to reproduce throughout the year and/or the existence of suspended/ protracted molts. Morphometric analysis evidenced significant differences according to sex for C. cruziana, P. rubinus, and C. analis, with the wing chord being the most common characteristic for distinguishing between sexes. Our study covers an important gap in the knowledge of the natural history of urban birds and provides information to test hypotheses of molt pattern variation on species with widespread distribution throughout the Americas.

Kittlitz’s Murrelet Seasonal Distribution and Post-breeding Migration from the Gulf of Alaska to the Arctic Ocean

Kittlitz’s Murrelets (Brachyramphus brevirostris) nest during summer in glaciated or recently deglaciated (post-Wisconsin) landscapes. They forage in adjacent marine waters, especially those influenced by glacial meltwater. Little is known of their movements and distribution outside the breeding season. To identify post-breeding migrations of murrelets, we attached satellite transmitters to birds (n = 47) captured at sea in the Gulf of Alaska and Aleutian Islands during May – July 2009 – 15 and tracked 27 birds that migrated from capture areas. Post-breeding murrelets migrated toward the Bering Sea, with short periods of movement (median 2 d) separated by short stopovers (median 1 d). Travel speeds averaged 79.4 km d-1 (83.5 SD, 449.1 maximum). Five Kittlitz’s Murrelets tagged in Prince William Sound in May migrated to the Bering Sea by August and four continued north to the Arctic Ocean, logging 2500 – 4000 km of travel. Many birds spent 2‒3 weeks with little movement along coasts of the Alaska Peninsula or eastern Bering Sea during late August through September, also the pre-basic molt period. Ship-based surveys, many of which were conducted concurrently with our telemetry studies, confirmed that substantial numbers of Kittlitz’s Murrelets migrate into the Arctic Ocean during autumn. They also revealed that some birds spend winter and spring in the Bering Sea in association with ice-edge, polynya, or marginal ice zone habitats before returning to summer breeding grounds. We conclude that this species is best characterized as a sub-Arctic and Arctic species, which has implications for future risk assessments and threat mitigation.

Вселение байкальской нерпы (Pusa sibirica Gm.) в озеро Байкал и современные угрозы популяции в связи с изменением климата (обзор). Сообщение 2. Палеоусловия эволюции байкальской нерпы в оз. Байкал и современные угрозы в связи с потеплением климата

Message 2 gives the possible timing of the introduction of the Baikal seal into Lake Baikal. Baikal in terms of geological history and paleoclimatic conditions. Based on the analysis of peleoclimatic reconstructions, as well as molecular genetic studies of fish, the following statements were put forward: 1. An ancestor of the Baikal seal settled in deep-water and already cold-water Baikal with an established thermohaline type of circulation. 2. Prior to introduction, the ancestral form lived in polar conditions and was to some extent adapted to ice conditions. 3. The development and consolidation of structural-functional and other adaptations to the specific conditions of the settlement reservoir, probably, quickly formed a new species. 4. By the time of settlement, the lake had an ichthyofauna capable of meeting the trophic needs of a large fish-eating mammal. 5. The evolution of golomyankas (Comephorus) – the main food of the Baikal seal - and the formation of the Baikal seal as a species, could take place in parallel. For this reason, the behavior of golomyankas and the diving strategy of seals turned out to be strictly coordinated. 6. The invasion of the ancestral form occurred at the end of the late Pleistocene, possibly in the Zyryansk time, through dammed glacial lake systems and the Yenisei-Angara rivers. Changes in the behavior of the Baikal seal, which are already occurring in response to warming and changes in living conditions, are described. In particular, the shortening of the ice period has already led to a change in the behavior of animals (due to the lengthening of the molting period). The potential threats to the seal population, which may arise if the negative forecasts of climatologists begin to come true, are also assessed. In particular, if the duration of the ice period is reduced to two months, this will certainly have a negative impact on the reproduction of the population, and, as a result, on its demography. There is a high probability of a change in the habitat of seals during the birth and rearing of puppies. The population will decrease, but the rest of the animals will adapt, perhaps be better provided with food, and the population will continue to exist at a different level (in terms of numbers). On the whole, an alarming, but not tragic picture of the immediate future of this species of seals emerges.

A pheromone bouquet controls the reproductive behaviour of the male shore crab, Carcinus maenas

The reproduction of many brachyuran crustaceans involves the formation of mating pairs often around the time of the female moult with attraction of a sexual partner and mating behaviour controlled by sex pheromones. In shore crabs, Carcinus maenas, females produce sex pheromones that are released in the urine. High Performance Liquid Chromatography analysis (HPLC) of female urine shows that the pheromone, identified as the nucleotide uridine diphosphate (UDP), elutes as an unresolved peak with structurally related nucleotides. We examined female urine samples over the moult cycle and detected UDP as well as uridine triphosphate (UTP). Bioassays were conducted to establish the possibility of a blend of nucleotides forming a sex pheromone bouquet in C. maenas. Whilst UDP induced the male mate guarding behaviour (cradling), a mixture of the two nucleotides at a ratio of 4:1 UDP:UTP elicited an even stronger mating response than either UDP or UTP individually. The urine concentration and composition of these nucleotides changes over the moult period pre and post ecdysis, providing evidence that a pheromone bouquet composition is not always constant. The change of the bouquet is related to the physiological state of the sender, here the moult cycle. Our study unravels the functionality of reaction-specific molecules in a pheromone bouquet. Whilst UDP is the mating signal, UTP acts as an attractant and combined they maximise the reproductive response. The use of bouquets provides species-specificity, potentially enabling reproductive isolation of sympatric species, and contains valuable information on the physiological state of the sender.

Індекс біологічної цінності м’яса курчат-бройлерів за експериментального випоювання антибіотику Даноксан-50

Індекс біологічної цінності м’яса курчат-бройлерів за експериментального випоювання антибіотику Даноксан-50

Long-term decline and geographical variation in the numbers of moulting Common Eiders Somateria mollissima in Shetland

ABSTRACT Capsule Numbers of moulting Common Eiders Somateria mollissima counted in Shetland during surveys from 1977 to 2019 decreased from approximately 14,500 to an estimated 3600 individuals, a 75% population decline. Aims To report results of extensive surveys of Eiders across Shetland during the annual complete moult period, review historical surveys, and evaluate long-term population changes and the possible underlying causes for change. Methods Extensive areas of coastal Shetland were surveyed for Eiders during the annual moult period from July to September, every one to five years from 1977 to 2019. Spatial sampling was variable between surveys from 1977 to 1993 but more systematic and standardised during all surveys from 1996 to 2019. Overall population change, changes in numbers of birds within areas categorised as either exposed or sheltered coast, and change in the proportion of adult males to females/juveniles were assessed. Results Surveys from 1977 to 1993 indicated a 55% decrease, from approximately 14,500–6500 individuals, and surveys from 1996 to 2019 showed a 45% decrease, from an estimated 6700–3600 individuals, indicating an overall population decrease of approximately 75% from 1977 to 2019. From 1996 to 2019, Eider numbers decreased in areas of exposed coast by approximately 90% but increased by at least 70% in the more sparsely populated sheltered areas, and the overall proportion of adult males to females/juveniles reduced by one-third. Conclusion From 1977 to 2019, a substantial decline of approximately 75% occurred in the Shetland Eider population at the time of moult. Shetland Eiders are not S. m. mollissima but morphologically and genetically akin to S. m. faeroeensis, the Faroese subspecies, the rarest subspecies worldwide, so this decline is of high conservation concern. Causes of the decline largely remain unknown, but ecological datasets on Shetland Eiders are few and detailed studies, including remote tracking of individuals’ movements throughout the year, would be worthwhile.

Temporal and scalar variations affect resource use of northern bobwhite broods.

Disparate resource use originating from phenology of biotic resources, abiotic conditions, and life cycles of exploiting organisms underscores the importance of research across time and space to guide management practices. Our goal was to evaluate resource use of northern bobwhite (Colinus virginianus; bobwhite) at two spatial scales and across three age classes, from hatching through a period of the postjuvenile molt. Our study was conducted at Tall Timbers Research Station, Tallahassee, FL, USA—situated in a landscape subjected to small scale (<20 ha) prescribed fires on a 2‐year fire rotation. We predicted prescribed fire, disking, and supplemental feeding would dictate resource use, but effects would depend on time since fire, brood age, and time of day. We predicted vegetation and temperature would govern roost use by broods, but these effects would also depend on age. We radio‐tracked 62 broods 21–35 times / week during May–October 2018 and 2019. Broods were less likely to use areas with large proportions of hardwood drains but favored sites with greater proportions of burned uplands, regardless of the time of day. Broods were less likely to use areas at greater distances from supplemental feed; this relationship had no interaction with age but was stronger later in the nesting season (>July 15). Broods were more likely to use areas with greater proportions of fallow fields during the day than for roosting. Broods used roosts with more woody cover and visual obscurity than at available sites. Roosts consisted of less grass and bare ground. However, these effects interacted with age; broods used sparser cover at older ages. Neonate broods were more likely to use cooler roosts with greater thermal stability, but this effect was reversed for juveniles. Broods may alter resource use with changes in vulnerabilities to threats such as thermal risks and predation.

Breeding biology and biometrics of Myiozetetes c. cayanensis (Aves: Tyrannidae) in southwest Brazilian Amazonia with breeding season in Brazil

Our study provides information on the breeding and biometrics of Rusty-Margined Flycatcher Myiozetetes cayanensis in southwest Brazilian Amazonia. Myiozetetes cayanensis is distributed from Central America until north of South America. We made observations on reproduction and captures of this species in a terra firme forest fragment in the state of Acre, between 1999 and 2020 and we evaluated the breeding season in Brazil through citizen science data. We monitored nine nests between 2012 and 2020, built at a mean height of 1.8 m above ground. Clutch size was two, three or four eggs, incubated for 15 days. We monitored the development of six nestlings: minimum hatch weight was 2 g and young fledged with a mean mass of ca. 25.5 g. The constant growth rate (K) of nestlings was 0.18 with a growth asymptote of 22.8 g. Daily survival rate was 90% and 100% during the incubation and nestling periods, respectively. The Mayfield success in the incubation and nestling periods was 20 and 100%, respectively. Apparent nesting success in the incubation and nestling periods was 46 and 100%, respectively. We recorded a minimum longevity of 2 years, nine months and 26 days. The subspecies M. c. cayanensis start to nest mainly between the dry and rainy season in Brazil, overlapping with the molt period in southwest Amazonia.

First nest records, nestling growth and morphometrics of Dendroplex picus peruvianus (Aves: Dendrocolaptidae) in southwestern Brazilian Amazon

We reported the first data on the breeding and growth in Dendroplex picus peruvianus from a forest fragment in southwestern Amazonia. We observed and netted this species between 1999 and 2019. We found two active nests in 2012 and 2013, but we monitored only one. Clutch size was two eggs, incubated for 16 days. The constant growth rate (K) of nestlings was 0.31 with a growth asymptote of 46.3 g. We recorded a longest minimum longevity of eight years. Our records showed that D. p. peruvianus breeds mainly in the rainy season (September–March) overlapping with the molt period.

Transcriptome Analysis of Hormone-and Cuticle-Related Genes in the Development Process of Deutonymph in Tetranychus urticae.

Simple SummaryThe two-spotted spider mite, Tetranychus urticae, is an important agricultural pest. Gene expression dynamics during different development time points of deutonymphal development process in T. urticae were investigated. The transcriptome sequencing aims to identify hormone- and cuticle-related genes that regulated the development process of spider mite. Moreover, this comprehensive transcriptome will provide a foundation for further research of development process in T. urticae.Tetranychus urticae is an important agricultural pest that feeds on more than 1100 plant species. To investigate gene expression network in development process of deutonymph, a comprehensive transcriptome analysis of different developmental time points of deutonymph in T. urticae was performed. Comparing with expression profile of 7 h, 309, 876, 2736, and 3432 differential expression genes were detected at time points 14 h, 21 h, 28 h, and 35 h, respectively. The expression dynamic analysis indicated that genes in hormone- (ecdysteroid and juvenile hormone) and cuticle- (chitin and cuticle proteins) related pathways were indispensable for development process in deutonymph. Among hormone related pathway genes, the ecdysteroid biosynthesis pathway genes were highly expressed at the growth period of development process, which is opposite to the expression patterns of juvenile hormone biosynthesis pathway genes. For cuticle related pathway genes, 13 chitinase genes were identified in the genome of T. urticae, and 8 chitinase genes were highly expressed in different time points of developmental process in the deutonymph of T. urticae. Additionally, 59 cuticle protein genes were identified from genome, and most of the cuticle protein genes were expressed in the molting period of developmental process in deutonymph. This study reveals critical genes involved in the development process of deutonymph and also provides comprehensive development transcriptome information for finding more molecular targets to control this pest.

Experimental corticosterone manipulation increases mature feather corticosterone content: implications for inferring avian stress history from feather analyses

Feathers incorporate circulating steroids during development. It is therefore assumed that the corticosterone (CORT) content of feathers (CORTf) represents an integrated measure of plasma CORT over the moult period. We tested this assumption by quantifying CORTf in feathers of House Sparrows (Passer domesticus (Linnaeus, 1758)) that were plucked before and after experimental manipulation of circulating CORT. Two of the seven flight feathers collected from each bird were fully grown throughout the CORT-manipulation period. We found that CORTf of all seven feathers corresponded with plasma CORT levels of non-moulting reference House Sparrows given the same implants. Surprisingly, the CORTf of the two mature feathers was 4- to 10-fold higher than values measured in the new replacement feathers. Our results show that CORTf of mature feathers may be affected by circulating CORT outside the moulting period. The most plausible explanation for our results is that CORT was transferred onto feather surfaces externally, but the mechanisms involved remain to be identified. Researchers are encouraged to establish effective procedures, in terms of both solvent and duration, for removing surface residues without extracting CORT from within the feather. This will increase confidence when inferring moult-related stress status from feather analyses in future ecological studies.

The Potential Uses of Curcumin and PMSG Hormones to Increase Egg Production of Muscovy Ducks through Increasing Estradiol Concentrations and Shortening Laying Rest Period

The aim of this research was to study the effects of curcumin administration, injection of PMSG hormone, and the combination of curcumin supplementation and PMSG injection on the physiological parameters and performance of female Muscovy ducks. The objects of this research were 40 young female Muscovy ducks, aged 24 weeks, subjected to treatments: control (P1), curcumin supplementation at a dose of 24 mg/100 g feed (P2), intramuscular injection of PMSG hormone at a dose of 0.015 mL/hen (P3), and the combination of curcumin and PMSG (P4). The results showed that the treatment gave nonsignificant improvements in Muscovy duck performances, including feed consumption, egg production, and the day of laying period and molting period. Treatment gave a significant increase in serum estradiol concentration at molting period after treatment. This study concluded that the treatment provides no significant improvement in the performance of female Muscovy ducks because the genetic diversity of Indonesian ducks remains high.

Temperature effects on the non-parasitic phase of Amblyomma parvum (Acari: Ixodidae)

The tick Amblyomma parvum has a wide distribution in the Central and South America. Therefore, throughout its distribution range, populations of this tick are exposed to different abiotic factors (e.g., Temperature and humidity). Here, we assess the effect of five temperatures, 18°C, 21°C, 24°C, 27°C, 32°C and 80 ± 10% RH on non-parasitic phases of A. parvum under controlled conditions of laboratory. Our results show that temperature affects all parameters of the non-parasitic phases of A. parvum. Mean periods of premolt and molting of immatures, and mean periods of pre-oviposition, oviposition and incubation of females decreases as temperature increases from 18 °C to at 32 °C. Conversely, the molting success of larvae increased from 18 °C to 32 °C but the percentages were statistically non-significant under 21°C, 24°C and 27°C. The molting success of nymphs was higher than 95% under all temperatures. Mean percentages of egg mass and EPE increases as temperature increase from 18 °C to 27°C, then both decrease at 32 °C. The mean percentage of egg hatching was higher than 90% from 21 to 32 °C. The total non-parasitic phase of A. parvum was completed in an average of 223.4, 150.9, 114.7, 90.2 and 69.0 days, respectively, under temperatures of 18°C, 21°C, 24°C, 27°C and 32°C. The effect of five temperatures studied in this experiment suggest that populations of A.parvum can exhibit different biological and ecological behaviors throughout its distribution range, as expected to occur in ticks with wide range distribution.

English

Fall armyworm, Spodoptera frugiperda (Diptera:Lepidoptera) is a destructive pest of agricultural crops especially maize in many countries including Pakistan. The environmental factors like temperature play significant role in the growth and development of insect pests. It is very important to know the proper knowledge about effect of temperature on the development of Spodoptera frugiperda before managing this pest. For this purpose, the current study was conducted to check the effect of temperature (20 and 26◦C) on the life cycle of S. frugiperda under laboratory conditions. The results showed that the developmental times of all stages (eggs, larvae and pupae) were inversely related to temperature. The incubation period of eggs was 4.01±0.00b and 2.00±0.00b at 20 and 26◦C, respectively. The development time of first, second, third, fourth, fifth and sixth larval instar was 3.51±0.10b, 3.04±0.15b, 2.33±0.10b, 2.97±0.14b, 3.45±0.19b and 4.99± 0.22b, respectively at 20◦C while 2.77±0.13c, 2.89±0.20bc, 2.09±0.12bc, 2.22±0.17bc, 2.90±0.23c and 3.56±0.19b, respectively at 26◦C. The time of growth and development was increased at low temperature while reduced at high temperature. The food consumption rate and molting period of larvae can increase at high temperature for complete their growth and development. The current study concluded that environmental factors like temperature are highly effect the insect pests morphology and biology.

A Comparison Of Soft-shell Crab Production Methods: Autotomy, Herbal Extract and Natural Rearing

The world market demand for soft-shell crabs is increasing due to their delicate taste and ease of eating. However, the current production methods of soft-shell crabs (mutilation / limb autotomy) is either considered unethical or the waiting period for molting is too long. Thus, this research assessed the effect of mutilation (removal of all appendages except swimming legs), using herbal extract (Vitomolt TM ) as a stimulant for moulting, and without stimulation (control) on growth (body size and weight increment), molting period, molting percentage and survival. It was observed that mutilation method stimulated faster molting in crabs compared using herbal extracts and naturals, however, with a significantly lower increase in body size and weight. Molting rate was highest in crabs subjected to mutilation (92%), followed by those injected with than Vitomolt TM (73%) and control (52%). The survival rate of crabs subjected to Vitomolt TM was the highest (94.8%) compared to mutilation group (91.7%) and control (89.6%). Based on these results, mutilation is not recommended for soft-shell crab production due to their lower body size and weight increment (lesser profit for farmers). The use of herbal extract (Vitomolt TM ) has huge potential as a stimulant for molting in soft-shell crab production as its usage increased survival and molting rate in S. olivacea .

Hard to Manage? Dynamics of Soft-Shell Crab in the Newfoundland and Labrador Snow Crab Fishery

Capture of recently molted soft-shell crab in the Newfoundland and Labrador (NL) snow crab (Chionoecetes opilio) fishery is undesirable due to resource wastage associated with low meat yield and supposed high mortality rates upon discard. This study is intended to formalize best-practice management advice for avoidance of soft-shell crab in the fishery. The study investigates factors affecting soft-shell incidence in the catch across a large geographic stock range encompassing dynamic habitat and contrasting harvest rate strategies. The results demonstrate an interaction between seasonality and harvest rate in governing soft-shell crab levels in the fishery. Greatest potential for high soft-shell incidence occurs in late-spring or summer (June–July) fisheries in warm water populations subjected to heavy fishing pressure, with warm water populations shown to be associated with earlier molting periods. The study concludes that the optimal time to harvest snow crab is during winter or early spring, and advises that wherever winter or early spring fisheries are not possible, a best-practice management strategy is to minimize wastage by maintaining a strong residual biomass of large hard-shell males in the population at all times. This strategy is easily enabled by consistent application of low exploitation rates.

Harbor Seals as Sentinels of Ice Dynamics in Tidewater Glacier Fjords

Tidewater glaciers calve icebergs into the marine environment which serve as pupping, molting, and resting habitat for some of the largest seasonal aggregations of harbor seals (Phoca vitulina richardii) in the world. Although they are naturally dynamic, advancing and retreating in response to local climatic and fjord conditions, most tidewater glaciers around the world are thinning and retreating. Climate change models predict continued loss of land-based ice with unknown impacts to organisms such as harbor seals that rely on glacier ice as habitat for critical life history events. To understand the impacts of changing ice availability on harbor seals, we quantified seasonal and annual changes in ice habitat in Johns Hopkins Inlet, a tidewater glacier fjord in Glacier Bay National Park in southeastern Alaska. We conducted systematic aerial photographic surveys (n = 55) of seals and ice during the pupping (June; n = 30) and molting (August; n = 25) periods from 2007 to 2014. Object-based image analysis was used to quantify the availability and spatial distribution of floating ice in the fjord. Multivariate spatial models were developed for jointly modeling stage-structured seal location data and ice habitat. Across all years, there was consistently more ice in the fjord during the pupping season in June than during the molting season in August, which was likely driven by seasonal variation in physical processes that influence the calving dynamics of tidewater glaciers. Non-pup harbor seals and ice were correlated during the pupping season, but this correlation was reduced during the molting season suggesting that harbor seals may respond to changes in habitat differently depending upon trade-offs associated with life history events, such as pupping and molting, and energetic costs and constraints associated with the events.

Urban links to molt schedule, body condition and carotenoid‐based coloration in the house finch Haemorhous mexicanus

Animals in urban environments are exposed to novel conditions, such as habitat and dietary alterations, and night‐time light pollution, that can shift the timing and expression of life‐history traits. Birds are popular urban‐ecological study subjects, and in these feathered animals regular plumage molt is a critical process for maintenance of feather quality and their associated functions (e.g. thermoregulation, aerodynamics and communicative coloration). We hypothesized that environmental changes associated with urbanization might affect the timing and progression of molt. As molt is energetically and nutritionally costly, we also tested whether putative urban–rural molt differences might be explained by indirect effects of urban environments on aspects of health (i.e. body condition, sexually selected plumage color). We tracked body molt intensity during molt onset, peak and completion in both sexes of urban and rural house finches Haemorhous mexicanus, and related this to body condition and sexually selected carotenoid‐based plumage coloration. We found that urban birds began molting earlier, peaked at a lower molt intensity and ended molt later than rural conspecifics. We also find that both body condition and plumage hue in males explain variation in body molt intensity differently for urban and rural populations at various points during the molting period. Overall, we demonstrate that songbird molt patterns and the development of carotenoid‐based sexual ornaments can be altered in urban environments, and that rapid urbanization may have broader implications for molt dynamics, annual life‐history traits and sexual selection.