Lina Roth - Academia.edu (original) (raw)

Papers by Lina Roth

Applied Animal Behaviour Science

Scientific Reports, Apr 21, 2021

Previously, we found that dogs belonging to the herding breed group, selected for human cooperati... more Previously, we found that dogs belonging to the herding breed group, selected for human cooperation, synchronise their long-term stress levels with their owners. The aim of the current study was to investigate features that could influence long-term stress levels in ancient dog breeds, genetically closer to wolves, and dogs specifically selected to work independently of their owner. Twenty-four ancient breed dogs and 18 solitary hunting dogs were recruited and hair samples were obtained from both dogs and owners from which hair cortisol concentration (HCC) was analysed. Additionally, the owners completed lifestyle surveys, the Monash Dog Owner Relationship Scale (MDORS) on human-dog relationship, and both dog and owner personality questionnaires (Dog Personality questionnaire and Big Five Inventory survey). The results from the MDORS indicate that the subscale Perceived cost correlated to the dog HCC of tested breed groups: solitary hunting breeds (χ 2 = 4.95, P = 0.026, β = 0.055), ancient breeds (χ 2 = 2.74, P = 0.098, β = 0.027), and herding dogs included from a previous study (χ 2 = 6.82, P = 0.009, β = − 0.061). The HCC of the solitary hunting dogs was also related to the owner personality traits Agreeableness (χ 2 = 12.30, P < 0.001, β = − 0.060) and Openness (χ 2 = 9.56, P = 0.002, β = 0.048) suggesting a more substantial influence of the owner on the solitary hunting dog's HCC compared to the ancient breeds. No effect of owner HCC on dog HCC was found in either ancient or in solitary hunting breeds. Hence, the long-term stress synchronisation is likely to be a trait in breeds selected for human cooperation. In conclusion, dog HCC is often related to the owners' personality, but is primarily influenced by the owner-dog relationship. In a previous study we found that dogs mirror the long-term stress levels of their owners 1. The HCC of the dog was shown to synchronise with the HCC of the owner and was in addition more associated to the owner's personality compared to its own. Emotional contagion has earlier been shown through both short-term physiological, endocrine, and behavioural responses between dogs and humans 2-4 and could be a result of the domestication of the dog and sharing everyday life. It might, however, also be affected by the recent breed selection and the working task of the breed. Both border collies and Shetland sheepdogs revealed a strong long-term stress synchronisation with their owners 1. However, both belong to the herding breed group, specifically selected to cooperate with humans, and this might have contributed to the stress synchronisation with the owner. Recent selection of breeds, and even breed lines within breeds 5 , has been shown to affect the behaviour of dogs 6 , and this might also have an effect on the interspecies emotional contagion. In contrast to herding dogs, the ancient breeds are thought to be closer genetically to wolves 7 and have not been selected specifically for human cooperation. Also, there are those breeds that are selected for hunting independently, visually separated from the owner, and that have been shown to differ in both their attention as well as behaviour towards humans 8,9. During hunting seasons in Sweden, there is a tradition of releasing hunting dogs into the forest to let them work on their own. The dog will search the terrain, find targeted animals and drive them forward or, alternatively, make them stationary and gain the hunter's attention through barking. Hence, these dogs are not specifically bred to cooperate with humans but instead bred for their natural hunting skills. In a recent study 10 the degree of selection of coopertiveness with humans was shown to affect stress-related behaviours during owner separation. Therefore, we aimed in this study to assess long-term stress levels in hair samples from dogs and their owners, from both solitary hunting dogs as well as ancient dog breeds, and compare the results to our previous study on herding dogs 1 .

Applied Animal Behaviour Science, 2020

Humans have shared a long history with horses and today we mainly consider horses as companions f... more Humans have shared a long history with horses and today we mainly consider horses as companions for sports and leisure activities. Previously, the human perspective of the human-horse relationship has been investigated but there has been little focus on the horse's perspective. This study aimed to reveal whether horses show attachment-related behaviour towards the owner compared to a stranger in a modified Strange Situation Procedure (SSP) consisting of a walking phase, a standing still phase, separation from the owner/stranger and lastly a reuinon. We tested 26 privately owned horses in an indoor experimental area of 20 × 14 m. In addition to testing, the owners were asked questions about their training methods. Based on these questionnaire results, owners were divided into groups depending on whether they mainly used negative reinforcement, positive reinforcement or a combination of both methods during training. They also completed a horse personality questionnaire. The results showed that the horses spent more time in door proximity when separated from the owner and the stranger (owner: Z = − 3.46, P = 0.001; stranger: Z = 3.40, P = 0.001) compared to the reunion phase, and they sought human proximity during reunion. The horses' heart rates were higher during the separation compared to the reunion with both the owner (Z = − 3.44, P = 0.001) and the stranger (Z = − 2.40, P = 0.016). These results are examples of attachment-related features and suggest that horses consider both the owner and the stranger as a safe haven. However, the results are not clear as to whether or not horses perceive their owners as a secure base since their exploratory behaviour during owner reunion was similar to that during stranger reunion. Interestingly, horses trained with positive reinforcement spent most time in door proximity during separation from the stranger (χ 2 (2) = 6.18, P = 0.045) and similarly there was a tendency also during owner separation (χ 2 (2) = 5.20, P = 0.074). The same group of horses also spent more time in stranger proximity (χ 2 (2) = 6.16, P = 0.046) and in physical contact with stranger (χ 2 (2) = 8.62, P = 0.013) than the other two training style groups during reunion. When correlating scores from the horse personality questionnaire with behaviours during owner reunion, we found few significant associations, but the trait Inquisitive correlated with both proximity to owner and ears forward (rs = 0.41, P = 0.035 and rs = 0.49, P = 0.011, respectively), and ears forward also correlated with the trait Excitability (rs = 0.39, P = 0.047) and Dominance (rs = 0.46, P = 0.019). Hence, this study revealed attachment-related behaviours of horses towards humans even though the results cannot resolve whether these fulfil all criteria for an attachment-bond.

Journal of Experimental Biology, 2007

SUMMARY Most mammals have dichromatic colour vision based on two different types of cones: a shor... more SUMMARY Most mammals have dichromatic colour vision based on two different types of cones: a short-wavelength-sensitive cone and a long-wavelength-sensitive cone. Comparing the signal from two cone types gives rise to a one-dimensional chromatic space when brightness is excluded. The so-called `neutral point'refers to the wavelength that the animal cannot distinguish from achromatic light such as white or grey because it stimulates both cone types equally. The question is: how do dichromats perceive their chromatic space? Do they experience a continuous scale of colours or does the neutral point divide their chromatic space into two colour categories, i.e. into colours of either short or long wavelengths? We trained horses to different colour combinations in a two-choice behavioural experiment and tested their responses to the training and test colours. The horses chose colours according to their similarity/relationship to rewarded and unrewarded training colours. There was no e...

Journal of Experimental Biology, 2006

SUMMARY The dual retina of humans and most vertebrates consists of multiple types of cone for col... more SUMMARY The dual retina of humans and most vertebrates consists of multiple types of cone for colour vision in bright light and one single type of rod, leaving these animals colour-blind at night. Instead of comparing the signals from different spectral types of photoreceptors, they use one highly sensitive receptor, thus improving the signal-to-noise ratio. However, nocturnal moths and geckos can discriminate colours at extremely dim light intensities when humans are colour-blind, by sacrificing spatial and temporal rather than spectral resolution. The advantages of colour vision are just as obvious at night as they are during the day. Colour vision is much more reliable than achromatic contrast, not only under changing light intensities, but also under the colour changes occurring during dusk and dawn. It can be expected that nocturnal animals other than moths and geckos make use of the highly reliable colour signals in dim light.

Proceedings of the Royal Society of London. Series B: Biological Sciences, 2004

Nocturnal animals are said to sacrifice colour vision in favour of increased absolute sensitivity... more Nocturnal animals are said to sacrifice colour vision in favour of increased absolute sensitivity. This is true for most vertebrates that possess a dual retina with a single type of rod for colour-blind night vision and multiple types of cone for diurnal colour vision. However, among the nocturnal vertebrates, geckos are unusual because they have no rods but three cone types. Here, we show that geckos use their cones for colour vision in dim light. Two specimens of the nocturnal helmet gecko Tarentola (formerly Geckonia) chazaliae were able to discriminate blue from grey patterns by colour alone. Experiments were performed at 0.002 cd m À2 , a light intensity similar to dim moonlight. We conclude that nocturnal geckos can use cone-based colour vision at very dim light levels when humans rely on colour-blind rod vision.

Journal of Vision, 2009

The nocturnal helmet gecko, Tarentola chazaliae, discriminates colors in dim moonlight when human... more The nocturnal helmet gecko, Tarentola chazaliae, discriminates colors in dim moonlight when humans are color blind. The sensitivity of the helmet gecko eye has been calculated to be 350 times higher than human cone vision at the color vision threshold. The optics and the large cones of the gecko are important reasons why they can use color vision at low light intensities. Using photorefractometry and an adapted laboratory Hartmann-Shack wavefront sensor of high resolution, we also show that the optical system of the helmet gecko has distinct concentric zones of different refractive powers, a so-called multifocal optical system. The intraspecific variation is large but in most of the individuals studied the zones differed by 15 diopters. This is of the same magnitude as needed to focus light of the wavelength range to which gecko photoreceptors are most sensitive. We compare the optical system of the helmet gecko to that of the diurnal day gecko, Phelsuma madagascariensis grandis. The optical system of the day gecko shows no signs of distinct concentric zones and is thereby monofocal.

The eye is oriented so that the nasal region is upwards and the temporal region downward... more The eye is oriented so that the nasal region is upwards and the temporal region downwards in the image. The measured structures and distances are enhanced by white lines and indicated as; a.l. – axial length, c – cornea, e.d. – equatorial diameter, l.a. – lens anterior surface, l.p. – lens posterior surface, r – receptor layer. Anterior chamber depth is the distance between c and l.a., lens thickness is the distance between l.a. and l.p. and back vertex distance is the distance between l.p. and r. The scale bar is 5 mm.</p

Two males (A, squares) and two females (B, circles) were tested in each breed. Each poin... more Two males (A, squares) and two females (B, circles) were tested in each breed. Each point represents the average of six measurements in two individuals and error bars indicate the standard deviation. Stars indicate a significant difference between breeds (two sample t-test, p<0.05, two-tailed).</p

Animal Cognition, 2021

The communicating skills of dogs are well documented and especially their contact-seeking behavio... more The communicating skills of dogs are well documented and especially their contact-seeking behaviours towards humans. The aim of this study was to use the unsolvable problem paradigm to investigate differences between breed groups in their contact-seeking behaviours towards their owner and a stranger. Twenty-four dogs of ancient breeds, 58 herding dogs, and 17 solitary hunting dogs were included in the study, and their behaviour when presented with an unsolvable problem task (UPT) was recorded for 3 min. All breed groups interacted with the test apparatus the same amount of time, but the herding dogs showed a longer gaze duration towards their owner compared to the other groups and they also preferred to interact with their owner instead of a stranger. Interestingly, the solitary hunting dogs were more in stranger proximity than the other groups, and they also showed a preference to make contact with a stranger instead of their owner. Hence, we found differences in contact-seeking be...

Scientific Reports, 2021

Scientific Reports, 2020

An amendment to this paper has been published and can be accessed via a link at the top of the pa... more An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Journal of Veterinary Behavior, 2020

Hair cortisol is a promising biomarker to measure long-term stress since cortisol is incorporated... more Hair cortisol is a promising biomarker to measure long-term stress since cortisol is incorporated into the hair shaft as it grows. However, few studies have previously assessed hair cortisol concentrations (HCC) in horses. In this study, HCC was evaluated in both mane hair from the neck and body hair from the withers in 153 horses of different breeds, from seven different stables with three different management regimes (Free-roaming horses, Riding school horses, Trotter horses). In addition, 4 hours of behavioural observations were performed at each stable, and for 43 of the horses, a personality survey was completed. Mane and withers HCC correlated moderately, but significantly (rs=0.48, p<0.001). Differences between the stables were found for both mane and withers hair (both p<0.01) and the stable with lowest HCC also showed highest occurrences of positive social and resting behaviours (both p<0.01). There were no significant differences in HCC between the management regimes even though Free-roaming horses showed less negative social behaviours compared to Riding school horses (p=0.041) and Trotter horses (p=0.055). The personality traits Dominance, Anxiousness, and Excitability revealed weak to moderate correlations with mane HCC (rs=-0.34, p=0.027; rs=-0.46, p=0.002; rs=-0.31, p=0.043 respectively) which might suggest that personality could also be related to long-term stress levels in horses.