Non-invasive assessment of positive affective state using infra-red thermography in rats.

With recent increased focus on positive welfare in animal welfare science, there is demand for objective positive welfare indicators. It is unclear whether changes in body surface temperature can be used to non-invasively identify and quantify positive states in mammals. We recorded continuous measurements of tail surface temperature using infra-red thermography (IRT) and concurrent behavioural observations in male and female Wistar rats ().

HPAIV outbreak triggers short-term colony connectivity in a seabird metapopulation.

Disease outbreaks can drastically disturb the environment of surviving animals, but the behavioural, ecological, and epidemiological consequences of disease-driven disturbance are poorly understood. Here, we show that an outbreak of High Pathogenicity Avian Influenza Virus (HPAIV) coincided with unprecedented short-term behavioural changes in Northern gannets (Morus bassanus). Breeding gannets show characteristically strong fidelity to their nest sites and foraging areas (2015-2019; n = 120), but during the 2022 HPAIV outbreak, GPS-tagged gannets instigated long-distance movements beyond well-documented previous ranges and the first ever recorded visits of GPS-tagged adults to other gannet breeding colonies.

Body surface temperature of rats reveals both magnitude and sex differences in the acute stress response.

Understanding how biological markers of stress relate to stressor magnitude is much needed and can be used in welfare assessment. Changes in body surface temperature can be measured using infrared thermography (IRT) as a marker of a physiological response to acute stress. While an avian study has shown that changes in body surface temperature can reflect the intensity of acute stress, little is known about surface temperature responses to stressors of different magnitudes and its sex-specificity in mammals, and how they correlate with hormonal and behavioural responses.

The prevalence and source of plastic incorporated into nests of five seabird species on a small offshore island.

There is little evidence documenting the prevalence of plastic nest incorporation for different seabird species and populations, and even less detailing the source of such debris as nesting material. This study presents a baseline dataset on the presence of plastic in the nests of five seabird species on Lady Isle, Scotland using a novel and repeatable methodology for quantifying plastic incorporated into nests. Plastic was found in 24.

Eye region surface temperature dynamics during acute stress relate to baseline glucocorticoids independently of environmental conditions.

Reactions to acute stressors are critical for survival. Yet, the challenges of assessing underlying physiological processes in the field limit our understanding of how variation in the acute stress response relates to fitness in free-living animals. Glucocorticoid secretion during acute stress can be measured from blood plasma concentrations, but each blood sample can only provide information for one point in time.

Effects of interspecific coexistence on laying date and clutch size in two closely related species of hole-nesting birds.

Coexistence between great tits Parus major and blue tits Cyanistes caeruleus, but also other hole-nesting taxa, constitutes a classic example of species co-occurrence resulting in potential interference and exploitation competition for food and for breeding and roosting sites. However, the spatial and temporal variations in coexistence and its consequences for competition remain poorly understood. We used an extensive database on reproduction in nest boxes by great and blue tits based on 87 study plots across Europe and Northern Africa during 1957-2012 for a total of 19,075 great tit and 16,729 blue tit clutches to assess correlative evidence for a relationship between laying date and clutch size, respectively, and density consistent with effects of intraspecific and interspecific competition.

Tritrophic phenological match-mismatch in space and time.

Increasing temperatures associated with climate change may generate phenological mismatches that disrupt previously synchronous trophic interactions. Most work on mismatch has focused on temporal trends, whereas spatial variation in the degree of trophic synchrony has largely been neglected, even though the degree to which mismatch varies in space has implications for meso-scale population dynamics and evolution. Here we quantify latitudinal trends in phenological mismatch, using phenological data on an oak-caterpillar-bird system from across the UK.

Surface temperature elevated by chronic and intermittent stress.

Stress in homeothermic animals is associated with raised body core temperature and altered patterns of peripheral blood flow. During acute stress, peripheral vasoconstriction causes a short-lived drop in surface temperature that can be detected non-invasively using infrared thermography (IRT). Whether and how skin temperature changes under chronic stress, and hence the potential of IRT in chronic stress detection, is unknown.

Eye region surface temperature reflects both energy reserves and circulating glucocorticoids in a wild bird.

Body temperature of endotherms shows substantial within- and between-individual variation, but the sources of this variation are not fully understood in wild animals. Variation in body temperature can indicate how individuals cope with their environment via metabolic or stress-induced effects, both of which may relate to depletion of energy reserves. Body condition can reflect heat production through changes to metabolic rate made to protect energy reserves.

Interspecific variation in the relationship between clutch size, laying date and intensity of urbanization in four species of hole-nesting birds.

The increase in size of human populations in urban and agricultural areas has resulted in considerable habitat conversion globally. Such anthropogenic areas have specific environmental characteristics, which influence the physiology, life history, and population dynamics of plants and animals. For example, the date of bud burst is advanced in urban compared to nearby natural areas.

Legacy Pollutants are Declining in Great Skuas (Stercorarius skua) but Remain Higher in Faroe Islands than in Scotland.

To monitor environmental pollutants in Faroese biota, samples from a top predator were analysed and put into a spatial and temporal context. Analysis of 20 Great Skua eggs sampled in 2012 from the Faroe Islands showed >70 % lower concentrations of legacy persistent organic pollutants (POPs) than in samples analysed in 1977. The 2012 Faroese eggs showed higher concentrations than for eggs in Shetland from about the same period (2008).

Meta-analysis indicates that oxidative stress is both a constraint on and a cost of growth.

Oxidative stress (OS) as a proximate mechanism for life-history trade-offs is widespread in the literature. One such resource allocation trade-off involves growth rate, and theory suggests that OS might act as both a constraint on and a cost of growth, yet studies investigating this have produced conflicting results. Here, we use meta-analysis to investigate whether increased OS levels impact on growth (OS as a constraint on growth) and whether greater growth rates can increase OS (OS as a cost of growth).

Plastic debris in great skua (Stercorarius skua) pellets corresponds to seabird prey species.

Plastic is a common item in marine environments. Studies assessing seabird ingestion of plastics have focused on species that ingest plastics mistaken for prey items. Few studies have examined a scavenger and predatory species that are likely to ingest plastics indirectly through their prey items, such as the great skua (Stercorarius skua).

Thermal Imaging to Study Stress Non-invasively in Unrestrained Birds.

Stress, a central concept in biology, describes a suite of emergency responses to challenges. Among other responses, stress leads to a change in blood flow that results in a net influx of blood to key organs and an increase in core temperature. This stress-induced hyperthermia is used to assess stress.

Skin temperature reveals the intensity of acute stress.

Acute stress triggers peripheral vasoconstriction, causing a rapid, short-term drop in skin temperature in homeotherms. We tested, for the first time, whether this response has the potential to quantify stress, by exhibiting proportionality with stressor intensity. We used established behavioural and hormonal markers: activity level and corticosterone level, to validate a mild and more severe form of an acute restraint stressor in hens (Gallus gallus domesticus).

Female but not male zebra finches adjust heat output in response to increased incubation demand.

In many incubating birds, heat transfer from parent to egg is facilitated by the brood patch, an area of ventral abdominal skin that becomes highly vascularised, swells and loses its down feathers around the time of laying. Only the female develops a brood patch in most passerine species, but males of some species can incubate and maintain the eggs at similar temperatures to females even without a brood patch. Here we used a novel application of infrared thermography to examine sex differences in parental care from a physiological perspective.

State dependent effects of elevated hormone: nest site quality, corticosterone levels and reproductive performance in the common eider.

Nest shelter in incubating birds is of major importance in providing protection against unfavourable conditions such as harshness of the environment and exposure to predators. We examined the link between nest shelter, baseline corticosterone (CORT) levels and hatching success in common eiders (Somateria mollissima) incubating at nest sites with different levels of shelter. Since more sheltered nest sites could be occupied by better-quality females, we also used an experimental manipulation of nest shelter to separate the effects of the physical attributes of the nest site from those of individual quality.

The effect of maternal state on the steroid and macronutrient content of lesser black-backed gull eggs.

It has been proposed that female birds can influence the phenotype of their offspring by provisioning eggs with variable amounts of nutrients and maternal hormones. Egg quality is strongly influenced by maternal body reserves and the amount of food available at the time of egg formation. This study investigated the effects of maternal state and food availability on the capacity of female lesser black-backed gulls Larus fuscus to provision their eggs with macronutrients and steroid hormones.

Field-scale dispersal of Aphodius dung beetles (Coleoptera: Scarabaeidae) in response to avermectin treatments on pastured cattle.

Very few studies have examined, at the field scale, the potential for faecal residues in the dung of avermectin-treated cattle to affect dung-breeding insects. The current study examined populations of dung beetles (Scarabaeidae: Aphodius) using pitfall traps baited with dung from untreated cattle on 26 fields across eight farms in southwest Scotland. The fields were grazed either by untreated cattle or by cattle treated with an avermectin product, i.

Inbreeding and loss of genetic variation in a reintroduced population of Mauritius Kestrel.

Many populations have recovered from severe bottlenecks either naturally or through intensive conservation management. In the past, however, few conservation programs have monitored the genetic health of recovering populations. We conducted a conservation genetic assessment of a small, reintroduced population of Mauritius Kestrel (Falco punctatus) to determine whether genetic deterioration has occurred since its reintroduction.

Effects of avermectin residues in cattle dung on yellow dung fly Scathophaga stercoraria (Diptera: Scathophagidae) populations in grazed pastures.

The effects of avermectin exposure on natural populations of the yellow dung fly, Scathophaga stercoraria Linnaeus, were investigated at the field scale on farms in south-west Scotland. Pastures forming the focus of the study were grazed with either untreated cattle or cattle receiving standard, manufacturer-recommended treatment regimes of an avermectin product. Flies were sampled between April and July in 2002 and 2003 using dung-baited pitfall traps.

The perils and prospects of using phytohaemagglutinin in evolutionary ecology.

Several techniques are available for quantifying the vertebrate immune response, information that is particularly useful for understanding the contribution of immunity to the evolution of life-history strategies. The most widely used is the phytohaemagglutinin (PHA) skin-swelling technique, which is usually regarded as an index of acquired immunity. However, our understanding of the effects of PHA in skin is poor, despite the fact that it has implications for what the test can tell us about immune activity.

Compensatory growth impairs adult cognitive performance.

Several studies have demonstrated that poor early nutrition, followed by growth compensation, can have negative consequences later in life. However, it remains unclear whether this is attributable to the nutritional deficit itself or a cost of compensatory growth. This distinction is important to our understanding both of the proximate and ultimate factors that shape growth trajectories and of how best to manage growth in our own and other species following low birth weight.