Feeding Areas Research Articles

Diet of hawksbill turtles (Eretmochelys imbricata) in the Gulf of California, Mexico

Abstract Hawksbill turtles (n = 56) in a foraging ground around Isla San Jose, Gulf of California, Mexico, were caught, measured, and their skin and scutes sampled. Tissue samples from putative prey species were collected from observed hawksbill feeding areas in the foraging ground. Measurements of each turtle's straight carapace length were used to estimate the average life stage of the population. Tissue samples were processed for stable carbon and nitrogen isotope analysis to estimate foraging habits of turtles in this location. The majority (96.4%) of measured individuals' straight carapace length fell in the size range considered to be juveniles. A Bayesian mixing model analysis of the δ13C and δ15N values of hawksbill skin and potential prey indicated that hawksbills consume primarily invertebrates and algae, with lesser contributions from seagrass and mangrove material. There was a positive linear relationship between turtle size and the δ13C values from scute samples, and an increase in the δ13C values of five individuals recaptured in subsequent years suggested a potential location shift from a pelagic habitat in the turtles' post‐hatching, earliest juvenile years to the nearshore foraging area around Isla San Jose in their later juvenile years.

Potential Impact of Climate Change on Salmonid Smolt Ecology

The migratory life history of anadromous salmonids requires successful migration between nursery, feeding, and spawning habitats. Smolting is the major transformation anadromous salmonids undergo before migration to feeding areas. It prepares juvenile fish for downstream migration and their entry to seawater. We reviewed the effects of climate change on smolt ecology from the growth of juveniles in fresh water to early post-smolts in the sea to identify the potential effects of climate change on migratory salmonid populations during this period in their life history. The focus was especially on Atlantic salmon. The shift in suitable thermal conditions caused by climate change results in Atlantic salmon expanding their range northward, while at the southern edge of their distribution, populations struggle with high temperatures and occasional droughts. Climatic conditions, particularly warmer temperatures, affect growth during the freshwater river phase. Better growth in northern latitudes leads to earlier smolting. Thermal refuges, the areas of cooler water in the river, are important for salmonids impacted by climate change. Restoring and maintaining connectivity and a suitably diverse mosaic habitat in rivers are important for survival and growth throughout the range. The start of the smolt migration has shifted earlier as a response to rising water temperatures, which has led to concerns about a mismatch with optimal conditions for post-smolts in the sea, decreasing their survival. A wide smolt window allowing all migrating phenotypes from early to late migrants’ safe access to the sea is important in changing environmental conditions. This is also true for regulated rivers, where flow regulation practices cause selection pressures on migrating salmonid phenotypes. The freshwater life history also affects marine survival, and better collaboration across life stages and habitats is necessary among researchers and managers to boost smolt production in rivers. Proactive measures are recommended against population declines, including sustainable land use in the catchment, maintaining a diverse mosaic of habitats for salmonids, restoring flow and connectivity, and conserving key habitats.

Macrophyte habitat selection by moulting mute swans and the effect of recreational disturbance in the largest Baltic Sea lagoon

Moult, the process of replacing old feathers with new, is a critical event in the annual cycle of all bird species. In the Curonian Lagoon, situated in the south-eastern Baltic Sea, recreational activities and shipping lanes occur in close proximity to the staging areas of waterfowl. Knowledge on the habitat use of these birds however is scant. In this study, we combined visual observations, satellite telemetry and the distribution of macrophytes to study habitat use by moulting herbivorous mute swans (Cygnus olor) and analysed how the localities of the swans depended on the distribution of macrophyte habitats and anthropogenic activities. Our data highlighted the most important swan staging areas within the Lithuanian part of the Curonian Lagoon, this specifically being mostly shallow areas (<1-metre depth) with diverse and high-density coverage of submerged vegetation dominated by charophytes and pondweeds. The submerged macrophyte habitats in water depths of 1–2 m and stands of clasping-leaf pondweeds were considered less important for swans. Our results showed that mute swans exploited only half the most suitable habitat areas for feeding. Based on indirect assessment of the relationship between the abundance of swans and disturbance by kitesurfing and boating, we discuss possible impacts on their moulting grounds. Knowledge on both selection of moulting grounds and habitat use by waterbirds is necessary for effective management and biodiversity conservation.

Ornamental Fish Diversity of some Wetlands in Nimati, Jorhat, Assam

The main sources of air-breathing and attractive fish species in the Brahmaputra basin are the wetland or the floodplain lakes. A significant number of riverine species are transported in the wetland areas by the flood impulse of the Brahmaputra and its tributaries. Various types of ornamental fish can be found in the marshes of Assam. There are numerous wetlands nearby Brahmaputra River in the Nimati Ghat of the Jorhat district of Assam. Many riverine species use wetlands as breeding and feeding areas. Unfortunately, the fish population in wetland areas is declining as a result of habitat destruction. The present communication deals with the ornamental fish diversity in some wetlands nearby Nimati, Jorhat. The study was conducted in three important wetlands of Nimati, Jorhat District namely Borsola, Sarala and Gohain beel during monsoon season. A total of 56 ornamental fish species from different genus has been recorded from the wetlands. The fish found in these wetlands are a source of livelihood to the local population. Some fish are utilized for therapeutic purposes as well.

Numerical and experimental investigations on internal humidifying designs for proton exchange membrane fuel cell stack

For an automotive proton exchange membrane fuel cell engine, the efficient water content management is critical to its overall efficiency and lifetime. The fuel cell stack designed with internal humidifying effect is a promising solution for enhanced performance and compact system integration. In this work, a novel internal humidifying fuel cell stack design is proposed which utilizes the water and heat transfer through membrane in the triangular gas feed areas. Validated by the experimental test, a coupled three-dimensional model is developed to compare the fuel cell performance with three different feed area functions. The active feed area design performs the worst with the lowest reaction uniformity, while the humidifying feed area design presents the best performance with greatly improved water content distributions. The internal humidifying stack design is suitable for operations under dry reactants inflow conditions with more performance improvement and more evenly distributed reaction, which is beneficial for the compact fuel cell system integration without external humidifiers. To further improve the internal humidification effects of the stack, the asymmetric inlet/outlet feed areas with specific flow channels will be studied in future work.

Comparing microplastics ingested by the bogue Boops boops (Teleostei: Sparidae) to those available in its feeding areas: A case study on the Portuguese west coast

Understanding the exposure of wild marine fish to microplastics (MPs) has been frequently assessed through the quantification and characterization of MPs found in stomachal contents. However, whether such particles mirror the MPs available in the environment or suggest a selectivity ability in the species, it has been scarcely analyzed. Here, in addition to investigating temporal patterns in the abundance and diversity of MPs ingested by Boops boops (Linnaeus, 1758) caught in coastal waters between Setúbal and Sesimbra (Portugal), we also aimed at comparing them with the patterns of MPs occurring locally, namely where the bogue feeds: at both surface water and seabed sediments. A total of 200 fish, 50 per month, were supplied at the local fish first sale concurrently with the water and sediments sampling (from October 2018 to January 2019). Fibers accounted for 93% of all MPs ingested and were also the main type of MPs extracted from sediments. Both food intake (inferred by fish gastrointestinal tract) and abundance of MPs per fish (1.80 ± 1.26; mean ± SD, n = 102) significantly decreased during the 4 month-period analyzed. Such decreasing tendency is potentially related to this species reproduction season. Despite the distinct fluctuations observed in the abundance of MPs found in both feeding areas of the bogue, it was possible to detect similarities between fish and sediments regarding the predominance of fibers, namely those belonging to the smaller size class. Yet, the prevailing colors differed, suggesting a selection capability of the bogue. Further studies taking place in spring/summer months (out of the reproduction season) are thus needed to clarify how MPs ingestion will vary in this species and consequently interfere with its ability to mirror the MP pollution patterns in this coastal region.

The Danube Delta: The Achilles Heel of Danube River–Danube Delta–Black Sea Region Fish Diversity under a Black Sea Impact Scenario Due to Sea Level Rise—A Prospective Review

The Danube Delta is one of Earth’s biodiversity hotspots and includes many endemic, rare, and important species of both major conservation and economic value. This unique complex of ecosystems also plays a key role for Danube River and Black Sea fish fauna through its role as a natural safe buffer, shelter, feeding, reproduction, and smooth transitional area for a large number of fish species. Climate change is inducing a progressive sea level rise in the Black Sea, a fact that is expected to impact the delta’s key complex and dynamic habitats, biocoenoses, and associated biota, and last but not least the key taxonomic group, namely, fish. Around one-third of the fish species of this delta will be greatly affected, sometimes negatively, by this climate change scenario, another one-third to a lesser extent, and the final one-third not at all. The ecological positive feedback of fish can stimulate environmental change and is expected to be responsible for changes within Danube Delta ecosystems, and also for the near Danube River and Black Sea diverse matrix of aquatic and semi-aquatic ecosystems. Sea level rise in the Black Sea is considered to have been one of the main stress factors of the Danube Delta fish fauna in the past, and is likely to be the case in the future. In this spatio-temporal dynamic context, for the fish species under threat and risk, in situ-adapted management measures are highly required. The current work brings for the first time such a prospective knowledge about the potential impact on Danube River–Danube Delta–Black Sea coast fish diversity in the potential climate change–sea level rise scenario.

Comparative Study of Camel Milk from Different Areas of Xinjiang Province in China.

Xinjiang province is the main camel feeding area in China with a large square, and camel milk from different areas have different qualities. By now, there are few reports about the quality of camel milk from different areas of Xinjiang province in China. In this study, seven batches of camel milk and one batch of cow milk were collected, and the contents of fat, protein, lactose, total solid, and nonfat milk solid of these milk samples were determined, as well as the contents of lysozyme and vitamin C. All samples were scored and compared by principal component analysis score and comprehensive weighted multi-index score. As the results, camel milk from different areas showed different contents of fat (4.62%-7.02%), protein (3.34%-3.95%), lactose (3.85%-4.79%), total solid (13.59%-17.00%), nonfat milk solid (8.55%-9.73%), vitamin C (12.10-41.25 μg/mL), and lysozyme (8.70-22.80 μg/mL), as well as different qualities. This variation would help people to know more about quanlity of camel milk in Xinjiang province. Camel milk from Jeminay showed the best quality, and then followed by camel milk from Fukang, Changji, and Fuhai, while cow milk showed the lowest score. Therefore, Jeminay is the most suitable place for grazing camels. Our findings show the different qualities of camel milk in different distribution areas of Xinjiang province, and provide an insight for the evaluation of camel milk. In the present study, only seven components in camel milk were determined, many other factors, such as cfu, mineral, and other vitamins, have not been considered.

Tidewater glaciers as “climate refugia” for zooplankton-dependent food web in Kongsfjorden, Svalbard

With climate warming, many tidewater glaciers are retreating. Fresh, sediment-rich sub-glacial meltwater is discharged at the glacier grounding line, where it mixes with deep marine water resulting in an upwelling of a plume visible in front of the glacial wall. Zooplankton may suffer increased mortality within the plume due to osmotic shock when brought in contact with the rising meltwater. The constant replenishment of zooplankton and juvenile fish to the surface areas attracts surface-foraging seabirds. Because access to other feeding areas, such as the marginal ice zone, has become energetically costly due to reduced sea-ice extent, glacial plumes may become increasingly important as “climate refugia” providing enhanced prey availability. Here, we investigated zooplankton concentrations within the plume and adjacent waters of four tidewater glaciers in Kongsfjorden, Svalbard, in early August 2016 and late July 2017. Our aim was to compare the zooplankton composition, abundance, and isotopic signatures within the plumes to those in adjacent fjord and shelf waters. Our hypothesis was that the plumes resulted in increased zooplankton mortality through osmotic shock and increased prey availability to predators. The mortality due to osmotic shock in the glacial plume was low (&amp;lt;5% dead organisms in samples), although slightly higher than in surrounding waters. This indicates that plumes are inefficient “death traps” for zooplankton. However, the high abundance and biomass of zooplankton within plume areas suggest that the “elevator effect” of rising glacial water supplies zooplankton to the sea surface, thereby enhancing prey availability for surface-feeding seabirds. Thus, our study provides evidence that glacial plumes are important as “climate refugia” for foraging seabirds. Stable isotope signatures showed that the glacial bay zooplankton and fish community represent a distinct isotopic niche. Additionally, zooplankton mortality associated with the plume estimated over 100-days of melt season supports a flux of 12.8 tonnes of organic carbon to benthic communities in the glacial bays. Benthic scavengers, such as Onisimus caricus and Anonyx nugax, were abundant in the glacial bay, where they feed on sinking organic matter.

The results of the initial introduction of &lt;i&gt;Bupleurum aureum&lt;/i&gt; Fisch. ex Hoffm. in the middle taiga subzone of the Komi Republic

The paper summarizes the results of a long-term introduction study of plants of golden boletus in the collection of medicinal plants of the Botanical Garden of the Institute of Biology of the Komi Scientific Center of the Ural Branch of the Russian Academy of Sciences. The primary introduction of the species into new growing conditions became possible only by transferring living plants to cultivation from the places of natural growth of the Tomsk Region, followed by propagation of plants from seeds of their own reproductions. The optimal methods of seed propagation of this species in the conditions of the North were revealed: winter sowing with freshly harvested seeds and self-sowing of seeds with further transplantation of emerging seedlings to a new plot with a feeding area of 30 30 cm golden is distinguished by high survival rate, winter hardiness and stability in the coenosis. The mass transition of plants into the generative period occurred in the second third year of life. The phenology and dynamics of plant growth have been studied. The rhythm of the seasonal development of plants in. golden in culture in the North corresponds to the new soil and climatic conditions of cultivation. The growing season is 96100 days. Golden boletus regularly forms full-fledged seeds, which, after undergoing natural stratification under snow cover, germinate in the spring and give a large self-sowing. Real seed productivity (the number of mature full-fledged seeds) in plants c. golden of different ages varies over the years from 420 to 570 seeds per shoot. The morphobiological signs of the generative shoot were studied in culture and the amplitude of their variability was determined. High and very high levels of individual variability of signs of the floral zone of the shoot indicate the possibility of targeted selection of more productive individuals within the population. For the first time, data on the content of proteins and its amino acid composition in plants are presented. The mass fraction of nitrogen (in terms of crude protein) in the aboveground phytomass was 1,51,8%. In proteins from aboveground phytomass, 17 amino acids were identified, including 7 essential ones (threonine, valine, methionine, isoleucine, leucine, phenylalanine, lysine). The proportion of essential amino acids averaged 39% of the total. The highest rates were noted for amino acids: glutamic, aspartic, leucine, lysine, alanine and valine 13,1, 10,7, 9,2, 8,1, 6,7 and 6,2% respectively.

Speech-Language Pathologists and Disaster Management: Team Roles

Purpose: Disaster management is a topic that is multi-faceted and intricately maintained by professionals who volunteer their expertise and time to assist those who have been affected by an unforeseen disaster. Creating a well-rounded and effective team is of immense importance during disaster situations. Speech-language pathologists can provide vital skills in the realm of communication, feeding, and other areas. However, the role of speech language pathologists within the disaster management team is not well documented in the literature. The purpose of the study was to identify awareness, involvement, and training of speech language pathologists in disaster management stages through exploration of their self-reported knowledge, skills, and roles to better understand their likelihood of response and potential collaborative roles within a disaster management team. Method: To gather data on self-reported awareness, knowledge, skills, participation, training, and perceptions of speech language pathologists as part of the disaster management stage, a cross-sectional survey study was designed. The study specifically targeted licensed speech language pathologists within the state of Florida. Results: There were 216 viable survey responses to analyze. Descriptive and correlational analyses were conducted to examine how speech-language professionals perceive their fit in the arena of disaster management. Speech language pathologists who responded to this survey were primarily white, 40–49-year-old females who had experienced some form of disaster. Most respondents reported receiving no training in disaster management; however, they indicated that speech language pathologists and other healthcare professionals have unique skills that could contribute to disaster management stages. Although there was reportedly limited training and guidance available and minimal professional experience with disaster, speech language pathologists who reported having professional experience with disaster stages, indicated an increased likelihood of participating in future disaster management. Conclusions: Similar to interdisciplinary teams found in clinical practice, healthcare professionals need training and education about their roles to form teams to address the needs of individuals in all disaster management stages. Analyses indicated that speech language pathologists perceive themselves, and other healthcare professionals, could provide meaningful contributions to the disaster management team; however, they have not had adequate professional experience or training.

Infestation of white mustard agrocenosis, depending on agricultural practices in the conditions of the forest-steppe of the Middle Volga region

To obtain environmentally friendly products, in the technology of cultivating agricultural crops, the basis of modern weed control should be agricultural practices. In this regard, the purpose of the research is to select the optimal seeding rate and sowing method for white mustard, which increase the self-regulation of the number of weeds in the agrocenosis to obtain the highest seed yield. The experiment was carried out in 2020–2022 on the meadow-chernozem soil of the experimental plot of the Federal State Budgetary Educational Institution of Higher Education Penza State Agrarian University. The weather conditions during the years of research were different, but they met the requirements for the growth and development of white mustard. The growing season of mustard in the first and third years passed under conditions of sufficient moisture at the optimum temperature regime (HTC 1.3 and 1.0, respectively). In the second year of research, drier conditions developed, when the hydrothermal coefficient was 0.87. On average, the minimum infestation of mustard crops before harvesting was traced with an ordinary sowing method of 36-51 pcs/m2 with a wet weight of weeds of 75.8-106.0 g/m2, while with a wide-row method their number was 43-62 pcs/m2 with a mass of 91.0-129.2 g/m2, where the feeding area increased not only for cultivated, but also for weeds. Moreover, the agrocenosis was the cleanest with the maximum seeding rate (3 million germinating seeds/ha) and mustard sowing with a row spacing of 15 cm, where the vegetative mass actively suppressed weeds. The highest infestation in terms of quantity and weight of the weed component was established at a rate of 1.5 million and mustard sowing with a row spacing of 30 cm. Plants with row sowing with a seeding rate of 2.0-2.5 million germinating seeds/ha were more competitive, while providing a maximum oilseed yield of 2.46-2.58 t/ha.

Poleward spawning of Atlantic mackerel (Scomber scombrus) is facilitated by ocean warming but triggered by energetic constraints

Abstract The Northeast Atlantic mackerel is an income breeder with indeterminate fecundity, spawning in multiple batches at optimal temperatures around 11°C in the upper water column during February–July along the continental shelf from 36–62°N. Based on macroscopic staging of gonads (N ∼62000) collected in 2004–2021, we detected an on-going extension of spawning activities into the Norwegian Sea feeding area (62–75°N), reaching stable levels around 2012 onwards. This poleward expansion increased as more fish entered the area, whilst the maximum proportions of spawners concurrently dropped from about 75 to 15% from May to July. Detailed histological examinations in 2018 confirmed the macroscopic results but clarified that 38% of the spawning-capable females in July terminated their spawning by atresia. We suggest that increased access to suitable spawning areas (≥10°C), following ocean warming from 2002 onwards, functions as a proximate cause behind the noticed expansion, whereas the ultimate trigger was the historic drop in body growth and condition about 10 years later. Driven by these energetic constraints, mackerel likely spawn in the direction of high prey concentrations to rebuild body resources and secure the future rather than current reproduction success. The ambient temperature that far north is considered suboptimal for egg and larval survival.

Environmental impact of water exchange blocking in a strait – a multidisciplinary study in the Baltic Sea

In this study, we report the environmental impact of water exchange blocking by a 3 km road dam built in 1896 in the shallow Väike Strait, north-eastern Baltic Sea. Using a multidisciplinary measurement campaign and numerical simulations, we show ecological conditions in the strait have considerably altered; the previously free-flowing strait now comprises two bays with separate circulation systems. Water exchange in the area close to the dam has decreased 10–12-fold. Since advection is weakened, exchange with the atmosphere and sediments has a relatively greater role in shaping water characteristics. Consequently, occasional very high sea surface temperature, salinity, and total nitrogen, and strong diurnal cycles in water temperature (>4°C) and dissolved oxygen (>4 mg l−1) were observed near the dam in summer. Oxygen levels are continuously below saturation in winter and concentration occasionally drops to hypoxic levels with ice cover. Nitrogen content in sediments near the dam is 3–4 times higher than in neighboring areas. The dam also modifies sea level, wind wave and suspended matter patterns in the strait. Sediments near the dam show elevated content of hazardous substances likely associated with traffic on the dam road. The phytobenthos community near the dam is dominated by annual green algae, which massively decompose during winter. The dam likely impedes fish migration between suitable feeding and spawning areas, also there have been fish kills caused by rapid fluctuations in sea levels, amplified by dam. The construction of new openings would alleviate negative impacts of the dam.

Design of a Highly Compatible Underwater Wireless Power Transfer Station for Seafloor Observation Equipment

Conventional cabled seafloor observatories (CSOs) power in-situ instruments via wet-mated or dry-mated direct electrical contact (DEC) connectors to achieve long-term and real-time observation. However, the DEC connectors have high risks of water leakage and short circuits in power feeding, especially under high water pressure. This paper proposes a highly compatible underwater station based on inductive wireless power transfer (IPT) technology to address the above reliability issue. A novel energy transmitter with runway-structure coils is applied to the proposed underwater station to cover a sufficient power feeding area so that various in-situ equipment can be powered with desirable misalignment tolerance. The magnetic field distribution is analyzed by both derivation and finite element analysis (FEA) methods, and the principal parameters of the transmitter are further optimized and compared with both the mixed-integer sequential quadratic programming (MISQP) algorithm and the evolutionary algorithm (EA) for better performance. The same results show a reliable optimization process. The WPT circuit characteristics are also investigated to power different loads and improve the power transmission efficiency. The output power decreases, and the transmission efficiency rises and then decreases as the load increases. In addition, receivers with higher mutual inductance have better transmission performance. A prototype of the underwater station has been tested both in air and in water, and the experimental results have proven it can power multiple seafloor observation instruments stably and achieve compatibility requirements. The maximum output power of the station prototype for testing is 100 W, and the maximum overall transmission efficiency is 61%.

The current state of Japanese mackerel Scomber japonicus and the peculiarities of its nutrition in feeding areas

During a period of high stock levels chub mackerel migrates to Russian waters for feeding and become available for domestic fisheries. In 2016, the domestic mackerel fishery was organized after a long break. Mackerel catches increased until 2018, followed by a slight decline. Based on the materials of the autumn survey conducted in Russian waters of the Northwest Pacific Ocean in 2020, the size and age composition, biological condition and nutrition of chub mackerel during feeding in the South Kuril zone is given.

Seasonal migration, site fidelity, and population structure of European seabass (Dicentrarchus labrax)

Abstract Large-scale electronic tagging is a very powerful tool to study how fish movements and migrations shape the internal dynamics of populations. This knowledge, crucial for improving fishery management, was still limited for the European seabass, whose stocks in the Northeast Atlantic have declined drastically over the last decade. To better understand the species ecology and the spatio-temporal structure of the population, we tagged seabass in the North Sea, the English Channel, and the Bay of Biscay, from 2014 to 2016. Out of 1220 deployed DSTs, 482 have been recovered by November 2022. Approximately half of them included a period of potential spawning migration. Reconstructed trajectories confirmed seabass to be a partial migratory species, as individuals exhibited either long-distance migrations or residence. Most migrants exhibited fidelity to summer feeding areas and winter spawning areas. Our dataset enriches the knowledge of seabass biological traits (e.g. temperature and depth ranges, vulnerability to predation and fishing). Our results suggest a spatial structure of the Atlantic population that differs from the stock structure currently considered for assessment and management. The consequences should be explored at both the European level and by regional managers involved in conservation outcomes.

Drastic reduction of the population distribution of White Storks predicted in absence of landfills

AbstractOrganic waste production has greatly increased following human sprawl and led to the development of landfills in recent decades. This abundant and reliable anthropogenic food source has favored several species, some of which consequently became overabundant. Landfills present hazards to wildlife, which may suffocate on plastic materials, tangle on cords, and get exposed to pollutants and pathogens. In response to environmental and public health concerns over the maintenance of landfills, the European Commission proposed to close the landfills. Our objective was to determine the impact of Landfill European Directive on the White Stork (Ciconia ciconia) whose population recovery and growth was linked to landfill exploitation. We implemented species distribution models to project future distribution in the absence of landfills in the Community of Madrid (Spain). Habitat suitability was estimated based on nest occurrence and we included data from land cover types, human population density, and two different climate change scenarios (i.e. emissions in low and high shared socioeconomic pathways). Given that protection measures, particularly implemented in protected areas, were associated with population recovery, we also evaluated the overlapping degree between protected areas and projected distribution. Our models predicted a sharp decline in breeding population distribution with landfill closure, reaching values similar to the 1984 breeding census when the species was categorized as threatened. Our results also suggest a decrease in maximum habitat suitability. Climate change also contributed to a reduction in breeding population distribution given model predictions for the extreme emission pathway (ssp5). Measures such as gradual change in landfill management, continuous monitoring of breeding populations, and evaluation of the White Stork use of natural feeding areas before and after landfill closure, should be considered.

Fibre-based feed supplements – fermentation and moisture characteristics, edibility and particle size influence cage-reared laying hens’ preference based on feed consumption and time at the feeder

ABSTRACT 1. Past studies have shown that fibre-based feed supplements, such as silage, are well accepted by laying hens and can reduce feather pecking and cannibalism. What is uncertain is whether fermentation and moisture characteristics, edibility or particle size influence the hen’s choice for a fibre-based feed supplement or if there are more preferred materials. 2. The study included three experiments on fermentation and moisture characteristics (Experiment 1), edibility (consumable; Experiment 2) and particle size (Experiment 3) on laying hen preference for different supplements. 3. Experiments were conducted in conventional cages, where two cages formed one replication (six replicates per treatment) and each feeding area was subdivided into a trough (basal diet) and a supplement insert (supplements). Since the hens had a free choice between the basal diet and the supplements, feed consumption and the percentage of time hens spent at the supplement insert indicated the strength of preference. The basal diet dry matter (DM) consumption was assessed for all experiments and the supplement and total DM consumption was documented for Experiments 1 and 3. In addition, the percentage of the observed time hens spent at the trough or supplement insert was observed for Experiments 2 and 3. 4. There was an increase in the supplement DM consumption for non-fermented and moist supplements (P < 0.05) and, in some cases, a smaller particle size (P < 0.05). Furthermore, hens spent more time with edible (P < 0.05) and small-sized (P < 0.05) supplements. It was concluded that a preferred material in addition to the basal diet could increase the time hens spend at the feeder by up to 1 hour per photoperiod.

Effect of kelp gull harassment on southern right whale calf survival: a long-term capture-recapture analysis.

Kelp gulls (Larus dominicanus) commonly feed on the skin and blubber of surfacing southern right whales (SRW, Eubalaena australis) in the near shore waters of Península Valdés (PV), Argentina. Mothers and especially calves respond to gull attacks by changing their swimming speeds, resting postures and overall behaviour. Gull-inflicted wounds per calf have increased markedly since the mid-1990s. Unusually high mortality of young calves occurred locally after 2003, and increasing evidence points to gull harassment as a factor contributing to the excess deaths. After leaving PV, calves undertake a long migration with their mothers to summer feeding areas; their health during this strenuous exertion is likely to affect their probabilities of first-year survival. To explore the effects of gull-inflicted wounds on calf survival, we analysed 44 capture-recapture observations between 1974 and 2017, for 597 whales photo-identified in their years of birth between 1974 and 2011. We found a marked decrease in first-year survival associated with an increase in wound severity over time. Our analysis supports recent studies indicating that gull harassment at PV may impact SRW population dynamics.