We measured tissue stable nitrogen (~s15N) and carbon (~s13C) values to investigate the extent of seasonal and age-related variation in the foraging ecology of Atlantic puffins. For adults, there was ...considerable seasonal variation in the foraging niche. A generalized, lower trophic level (TL) diet during the winter moult was replaced by a highly specialized, higher TL diet during summer when birds were rearing chicks. The seasonal δ 15N enrichment of 2.36 ppt is consistent with an increase of 0.65 TL. Output from a 2-source single isotope (~s15N) mixing model suggested that adult diets were composed largely of zooplankton during winter with a switch to capelin (or other higher TL prey) in summer. A concurrent decrease in ~s15N variability suggests that adult diets are more varied in winter. Trophic position of first-year birds was similar across summer and fall, as they went from being provisioned by parents at the colony to feeding independently. Both isotope mixing model and stomach contents analysis suggested that first-year birds relied largely (>85%) on capelin (or other higher TL fish) in fall. In summer, the trophic position of adults was significantly higher than that of nestlings; however, greater ~s15N variability suggested that nestling diet was mixed overall. Shipboard surveys indicated an offshore movement of puffins post-breeding; however, this distributional shift was not reflected in ~s13C signatures of adults. The dietary shift and increased TL of adult Atlantic puffins from winter to summer is consistent with reports for puffin species in the Pacific, suggesting that puffins may undergo the most extensive seasonal trophic shift among the auk species.
The diving behaviour of the Shy Albatross Diomedea cauta was investigated using archival time-depth recorders (TDRs) and maximum depth gauges (MDGs). Data from birds carrying multiple devices and ...from diving simulations indicated that the degree of correspondence between TDRs and MDGs varied with the dive depth, duration and frequency, as well as with body placement. The MDGs were the most reliable when the diving depth was greater than 0.5 m, when the diving frequency was low and when gauges were placed on the birds' backs. The TDRs were used during late incubation and early chick rearing in 1994. Fifty-two dives (0.4 m) were recorded during 20 foraging trips of 15 individuals. The majority of dives were within the upper 3 m of the water column and lasted for less than 6 s. However, dives to 7.4 m and others lasting 19 s were recorded. The albatrosses dived between 07.00 h and 22.00 h, with peaks in their diving activity near midday and twilight. Mean diving depth varied throughout the day. with the deepest dives occurring between 10.00 h and 12.00 h. Two dive types were identified on the basis of the relationship between dive depth and descent rate. Plunge dives were short (5 s), and the birds reached a maximum depth of 2.9 m. Swimming dives were both longer and deeper. The characteristics of Shy Albatross plunge dives were similar to those of gannets Morus spp., which are known to be proficient plunge divers. Swimming dives suggest that Shy Albatrosses actively pursue prey underwater.
To examine seasonal and inter-annual shifts in the energy requirements of captive harp seals (Phoca groenlandica), metabolic rate and body temperature were repeatedly measured over the annual cycle. ...Seasonal shifts were evident in both parameters, with spring and summer (April to September) peaks decreasing throughout fall and winter (October to March). Seasonal changes in oxygen consumption concur with earlier published reports and data presented here validate these trends inter-annually. The standard metabolic rates (SMRs) of all seals were lower than predicted during fall/winter, but were indistinguishable from expected rates during spring/summer. Although individual variation in metabolic rate was largely independent of changes in both total body mass and predicted total body fat over the year, such variation was more closely related to changes in predicted lean body mass. Both deep rectal and core body temperatures co-varied with metabolic rate, perhaps indicating a metabolic defense of fat for thermoregulation. The implications of these shifting basal requirements are considered in the light of calculating the impact of the harp seal herd on fisheries resources in the Northwest Atlantic.PUBLICATION ABSTRACT
We used electronic weighing platforms inside artificial nests to remotely study chick provisioning and growth in Shy Albatrosses (Thalassarche cauta) at Albatross Island, Tasmania, from 1996 to 1998. ...Pairs of birds concurrently carried radio-transmitters, allowing each meal to be attributed to an individual parent. Chicks received relatively small meals (372 g) once every 22 hr, and were provisioned at 392 g day−1 from the end of the brooding period to fledging. Meal size increased with chick age while the feeding frequency decreased, such that chicks were provisioned at a relatively constant rate until reaching peak mass (5.5 kg at 109 days). Provisioning subsequently declined and chicks lost mass, leaving the nest after 127 days weighing 5.0 kg. Male chicks were fed for 10 days longer than females, they received 27% more food, grew faster, and attained higher peak and fledging masses. Between hatching and fledging, overall food consumption by chicks was estimated at 44.9 kg. Rates of chick provisioning and growth were constant between years. Overall, adult males and females provisioned chicks equally. However, large imbalances were often observed within pairs, and in some cases one parent adjusted its provisioning schedule to compensate for its mate. Adults generally decreased provisioning rates when chicks were well fed, but only some elevated their feeding frequency when faced with greater demands. The ability to increase provisioning to hungry chicks contrasts with expectations from studies of other neritic species. Alimentación y Tasa de Crecimiento de Pichones de Thalassarche cauta en la Isla Albatros Resumen. Utilizamos balanzas electrónicas ubicadas dentro de nidos artificiales para estudiar a distancia la alimentación y el crecimiento de polluelos de Thalassarche cauta entre 1996 y 1998 en la Isla Albatros, Tasmania. Acoplamos radio transmisores a parejas de aves de manera que cada episodio de alimentación en el nido podría ser atribuido a uno de los padres. Los pichones recibieron comidas relativamente pequeñas (372 g) una vez cada 22 horas y recibieron 392 g de alimento por día desde el final del período en que las aves empollan hasta el abandono del nido. Mientras que el tamaño de las comidas aumentó con la edad de los pichones, la frecuencia de alimentación disminuyó. Al principio los pichones fueron alimentados a una tasa relativamente constante hasta alcanzar un pico en su peso (5.5 kg a los 109 días). Después de esto, la tasa de alimentación se redujo, generando una disminución en el peso hasta llegar a 5.0 kg al momento de abandonar el nido después de 127 días. Los polluelos machos fueron alimentados durante 10 días más que las hembras, recibieron 27% más alimento, crecieron más rápidamente y alcanzaron pesos superiores en el momento pico y al salir del nido. Desde la eclosión hasta el abandono del nido, el consumo total estimado de alimento por parte de los pichones fue de 44.9 kg. Las tasas de alimentación y crecimiento de los polluelos fueron constantes entre años. En general, los machos y hembras adultos alimentaron por igual a los pichones. Sin embargo, se observaron grandes desbalances entre los miembros de algunas parejas. En algunos casos, uno de los padres ajustó su tasa de alimentación al polluelo para compensar la de su pareja. Los adultos generalmente disminuyeron las tasas de suministro de alimento cuando los pichones estaban bien alimentados pero sólo algunos de ellos aumentaron la frecuencia de alimentación cuando recibieron demandas superiores. La capacidad de incrementar la tasa de alimentación de polluelos hambrientos contrasta con lo esperado a partir de estudios en otras especies neríticas.
Abstract
UK social care policy recognises the importance of short breaks for sustaining care-giving relationships; however, there is limited understanding of how unpaid carers’ break needs evolve in ...response to the degenerative course of dementia and how these are supported. Using narrative analysis, the stories of thirteen spousal carers for people living with dementia were used to construct an experiential description of the care-giving career, in which spousal carers evolving break needs, experience of accessing breaks and desired break outcomes were explored. The care-giving career was marked by the continual adaptation and acceptance of acute and gradual changes to the care-giving relationship which influenced breaks needs. Irrespective of when in the care-giving career, the process of deciding upon a meaningful break was relational and emotive, emphasising the relevance of relational support to aid transitions to breaks of mutual value. With the deepening cognitive impairment of the person living with dementia, spousal carers encountered difficulties in achieving breaks due to relational and service factors. The conceptualisation of care-giving as a series of shifting configurations underlines the necessity for ongoing and skilful practitioner engagement to help unpaid carers consider ‘what matters’ to them, and proactively respond to changes in ‘what matters’.
Caring for a spouse or partner living with dementia can be challenging. Short breaks from care-giving routines and responsibilities can make a positive difference to unpaid carers’ health and well-being and increase satisfaction with the care-giving role. There is little research exploring unpaid carers’ changing needs for breaks and how these are supported. Based on the stories of thirteen spousal carers, we explored how spousal carers experienced breaks as their partners’ dementia progressed. Breaks were important to sustain or strengthen care-giving relationships, however, as the needs of the person living with dementia grew more complex, the process of finding a meaningful break took time and involved compromise. Our findings highlight the importance of knowledgeable practitioners who can skilfully support unpaid carers to reflect on and define ‘what matters’ to them; this can help promote unpaid carers self-awareness to make effective choice of break(s). Reflecting the diversity of preferences and interests of spousal carers and their partner with dementia, having choice of flexible breaks options, including the option to experience breaks ‘together’, were important to deliver meaningful outcomes. As break needs change, relational support to enable transitions to different types of breaks was important to ease associated anxieties.
The importance of supporting unpaid carers for people living with dementia (PLWD) is recognised in adult social care policy both nationally and internationally. In the UK, social care legislation ...emphasises care and support should help people achieve the outcomes that matter to them in their life; this includes the opportunity to take a break from caring routines and responsibilities. Accordingly, there is growing policy and practice interest in short breaks provision to address the diversity of carer break needs and preferences and deliver meaningful outcomes for carers and those they support. This paper reports findings from qualitative staff interviews that offered strategic and operational insights into short breaks provision. It presents a dynamic model of the short break landscape in a region of Wales, describing factors shaping local and regional decision‐making. The model identifies key challenges (barriers) and opportunities (enablers) that shape the planning, commissioning and delivery of bespoke short breaks for spousal carers and their partner living with dementia. Through highlighting the interplay between complex context‐specific processes and contingences, the model informs initial theory development in short breaks provision.
The Patagonian Shelf Large Marine Ecosystem supports high levels of biodiversity and endemism and is one of the most productive marine ecosystems in the world. Despite the important role marine ...predators play in structuring the ecosystems, areas of high diversity where multiple predators congregate remains poorly known on the Patagonian Shelf. Here, we used biotelemetry and biologging tags to track the movements of six seabird species and three pinniped species breeding at the Falkland Islands. Using Generalized Additive Models, we then modelled these animals' use of space as functions of dynamic and static environmental indices that described their habitat. Based on these models, we mapped the predicted distribution of animals from both sampled and unsampled colonies and thereby identified areas where multiple species were likely to overlap at sea. Maximum foraging trip distance ranged from 79 to 1,325 km. However, most of the 1,891 foraging trips by 686 animals were restricted to the Patagonian Shelf and shelf slope, which highlighted a preference for these habitats. Of the seven candidate explanatory covariates used to predict distribution, distance from the colony was retained in models for all species and negatively affected the probability of occurrence. Predicted overlap among species was highest on the Patagonian Shelf around the Falkland Islands and the Burdwood Bank. The predicted area of overlap is consistent with areas that are also important habitat for marine predators migrating from distant breeding locations. Our findings provide comprehensive multi-species predictions for some of the largest marine predator populations on the Patagonian Shelf, which will contribute to future marine spatial planning initiatives. Crucially, our findings highlight that spatially explicit conservation measures are likely to benefit multiple species, while threats are likely to impact multiple species.
Visual predators tend not to hunt during periods when efficiency is compromised by low light levels. Yet common murres, a species considered a diurnal visual predator, frequently dive at night. To ...study foraging of murres under different light conditions, we used a combination of archival tagging methods and astronomical models to assess relationships between diving behaviour and light availability. During diurnal and crepuscular periods, murres used a wide range of the water column (2-177 m), foraging across light intensities that spanned several orders of magnitude (10(3)-10(-10) Wm(-2)). Through these periods, they readily dived under conditions equivalent to ambient moonlight (~10(-4) Wm(-2)) but rarely under conditions equivalent to starlight (~10(-8) Wm(-2)). At night, murres readily foraged during both moonlit and starlit periods, and diving depth and efficiency increased with nocturnal light intensity, suggesting that night diving is at least partially visually guided. Whether visually guided foraging is possible during starlit periods is less clear. Given the dense prey landscape available, random-walk simulations suggest that murres could benefit from random prey encounters. We hypothesise that murres foraging through starlit periods rely either on close-range visual or possibly nonvisual cues to acquire randomly encountered prey. This research highlights the flexibility of breeding common murres and raises questions about the strategies and mechanisms birds use to find prey under very low light conditions.
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