| 1. |
- Debeffe, L., et al.
(författare)
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Short- and long-term repeatability of docility in the roe deer: sex and age matter
- 2015
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 109, s. 53-63
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Tidskriftsartikel (refereegranskat)abstract
- Behavioural consistency is a key assumption when evaluating how between-individual differences in behaviour influence life history tactics. Hence, understanding how and why variation in behavioural repeatability occurs is crucial. While analyses of behavioural repeatability are common, few studies of wild populations have investigated variation in repeatability in relation to individual status (e.g. sex, age, condition) and over different timescales. Here, we aimed to fill this gap by assessing within-population variation in the repeatability of docility, as assessed by the individual’s response to human handling, in a free-ranging population of European roe deer, Capreolus capreolus. Docility was an equally repeatable behaviour at both short- and long-term timescales, suggesting that this behavioural trait is stable across time. Repeatability did not differ markedly between age and sex categories but tended to be higher in juvenile males than in juvenile females. Finally, contrary to expectation, individual variation in the repeatability of docility was not correlated with individual body mass. Further studies are required to assess the life history consequences of the individual variation in docility we report here.
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| 2. |
- Andersson, Anastasia, et al.
(författare)
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Two shades of boldness : novel object and anti-predator behavior reflect different personality dimensions in domestic rabbits
- 2014
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Ingår i: Journal of ethology. - : Springer Science and Business Media LLC. - 0289-0771 .- 1439-5444. ; 32:3, s. 123-136
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Tidskriftsartikel (refereegranskat)abstract
- It is increasingly common to quantify and describe behavioral variation in domestic and wild animals in terms of personality. Correlating behavioral traits are referred to as personality dimensions or factors and different dimensions have been reported in different species. Boldness is a well-described personality dimension in several species, although some issues remain unclear. Previous models of boldness include both novelty and risk taking, but recent studies indicate that these types of behaviors may reflect separate personality dimensions. In this study, we developed a behavioral test battery for domestic rabbits, and recorded behaviors of 61 individuals in four different situations (novel object, novel arena, social, and predator interactions). We used domestic rabbits as a model because behavioral variation in rabbits has rarely been quantified in terms of personality dimensions, although rabbit behavior is described. We also wanted to investigate behavioral variation in a Swedish rabbit breed of conservation concern - the Gotland rabbit. Factor analysis of the behavioral test measures suggested three personality dimensions: exploration, boldness, and anxiety. Novel object scores clustered in the exploration and boldness factors, whereas scores associated with predator interactions were explained by anxiety, indicating that novel object and anti-predator behavior reflect different personality dimensions in rabbits.
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| 3. |
- Bergvall, Ulrika A, et al.
(författare)
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A test of simultaneous and successive negative contrast in fallow deer foraging behaviour
- 2007
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Ingår i: Animal Behaviour. - : Elsevier BV. - 0003-3472 .- 1095-8282. ; 74:3, s. 395-402
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Tidskriftsartikel (refereegranskat)abstract
- The study of contrast investigates how rewards influence behaviour when animals are exposed to two or more levels of rewards compared to when they experience only a single level. The appearance of an exaggerated response to a shift in reward is referred to as a contrast effect and is an empirically well-established phenomenon. Although contrast effects could be important in foraging behaviour, no direct experimental tests of contrast effects in foraging by mammalian herbivores exist. During foraging, mammalian herbivores can encounter a range of plants that vary in the amount of nutrients and toxins. They may thus compare food items by taste, which in turn can give rise to contrast effects. In feeding experiments with fallow deer, Dama dama, we investigated the presence of simultaneous negative contrast. We found that the deer consumed less from a bowl of pellets containing 1% tannin when they shifted to it from a bowl with pellets containing only 0.25% tannin than when they shifted from another bowl with pellets containing 1% tannin. We estimated a fourfold difference between treatments in test food consumption at the highest levels of preloading, but none at the lowest levels. We found no support for successive negative contrast in experiments where the deer approached food in a runway, comparing a current reward with the memory of a previous reward. We suggest that simultaneous negative contrast can influence foraging decisions in mammalian herbivores.
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| 4. |
- Bergvall, Ulrika A., et al.
(författare)
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Anti-browsing effects of birch bark extract on fallow deer
- 2013
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Ingår i: European Journal of Forest Research. - : Springer Science and Business Media LLC. - 1612-4669 .- 1612-4677. ; 132:5-6, s. 717-725
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Tidskriftsartikel (refereegranskat)abstract
- A major problem within forest industry is unwanted browsing on seedlings from mammalian herbivores. The aim of this study was to evaluate the effects of birch bark extracts as repellents towards fallow deer. Birch bark was extracted in a conventional way with ethanol as solvent at ambient temperature and with a new method, liquid CO2 extraction. An analysis of the ethanol-extracted birch bark showed that it contained large amounts of terpenoids, of which the most abundant was betulin. In seven different treatment trials, we used 15 individually handled fallow deer. To investigate the binary taste preferences, birch bark extract was added to food and presented in two bowls in typical two-choice tests. We found that the amount of a food type consumed during a trial and the number of shifts between food bowls were dependent on the amount of the birch extract the food contained. Concentrations of above 1 % by dry weight of birch extract acted as a repellent. In addition, such concentrations produced shorter feeding bouts by a greater willingness to change bowls. Therefore, our conclusion is that birch bark extract acts as a repellent towards fallow deer and is therefore likely to act as a repellent against other deer species. In addition, we show that birch bark extract produced by the new and more environmentally sustainable method employing liquid CO2 mixed with ethanol has the same repellent effect as the traditional ethanol extraction.
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| 5. |
- Bergvall, Ulrika A, et al.
(författare)
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Associational effects of plant defences in relation to within- and between-patch food choice by a mammalian herbivore : neighbour contrast susceptibility and defence
- 2006
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Ingår i: Oecologia. - : Springer Science and Business Media LLC. - 0029-8549 .- 1432-1939. ; 147:2, s. 253-60
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Tidskriftsartikel (refereegranskat)abstract
- A basic idea of plant defences is that a plant should gain protection from its own defence. In addition, there is evidence that defence traits of the neighbouring plants can influence the degree of protection of an individual plant. These associational effects depend in part on the spatial scale of herbivore selectivity. A strong between-patch selectivity together with a weak within-patch selectivity leads to a situation where a palatable plant could avoid being grazed by growing in a patch with unpalatable plants, which is referred to as associational defence. Quite different associational effects will come about if the herbivore instead is unselective between patches and selective within a patch. We studied these effects in a manipulative experiment where we followed the food choice of fallow deer when they encountered two patches of overall different quality. One of the two patches consisted of pellets with low-tannin concentration in seven out of eight buckets and with high concentration in the remaining bucket. The other patch instead had seven high- and one low-tannin bucket. We performed the experiment both with individuals one at a time and with a group of 16-17 deer. We found that the deer were unselective between patches, but selective within a patch, and that the single low-tannin bucket among seven high-tannin buckets was used more than a low-tannin bucket among other low-tannin buckets. This corresponds to a situation where a palatable plant that grows among unpalatable plants is attacked more than if it was growing among its own kind, and for this effect we suggest the term neighbour contrast susceptibility, which is the opposite of associational defence. We also found that the high-tannin bucket in the less defended patch was less used than the high-tannin buckets in the other patch, which corresponds to neighbour contrast defence. The neighbour contrast susceptibility was present both for individual and group foraging, but the strength of the effect was somewhat weaker for groups due to weaker within-patch selectivity.
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| 6. |
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| 7. |
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| 8. |
- Bergvall, Ulrika A., 1970-, et al.
(författare)
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Chemical Immobilization of Free-ranging Fallow Deer (Dama dama) : Effect of Needle Length on Induction Time
- 2015
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Ingår i: Journal of Wildlife Diseases. - : Wildlife Disease Association. - 0090-3558 .- 1943-3700. ; 51:2, s. 484-487
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Tidskriftsartikel (refereegranskat)abstract
- We evaluated impact of the needle length, sex, and body condition on chemical immobilization induction time in 50 (29 males and 21 females) free-ranging fallow deer (Dama dama) in Sweden, 2006-11. Induction time is probably the single most important factor when immobilizing free-ranging wildlife with the use of a remote drug-delivery system. Induction times should be short to minimize stress and risk of injury, and to ensure that immobilized animals can be found and clinically monitored as soon as possible. We measured the distance between the darting location and where we recovered the immobilized animal and also the time occurring between the two events. We used two types of needles: 2.0 × 30- or 2.0 × 40-mm barbed needles with side ports. The most important result is that a 10-mm-longer dart needle can reduce the retrieval time substantially (>20 min) until an animal is under monitoring. On average after the darting, the retrieval time decreased from 51 to 29 min and the distance decreased from 519 m from the darting location to 294 m. We suggest that a needle length of 40 mm is preferable for immobilization of wild fallow deer, especially for animals in over-average-to-fat body condition.
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| 9. |
- Bergvall, Ulrika A, 1970-
(författare)
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Development of feeding selectivity and consistency in food choice over5 years in fallow deer
- 2009
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Ingår i: Behavioural Processes. - : elsevier. - 0376-6357 .- 1872-8308. ; 80, s. 140-146
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Tidskriftsartikel (refereegranskat)abstract
- In order to better understand the development and maintenance of feeding selectivity, several feedingexperimentswere performed with fallowdeer (Damadama L.). In experiments performed when the fawnswere between tenand 27 days old, itwas found that all fawnsshowedpreferences for sucrose but aversionstowards tannic acid and ascorbic acid.However, differences in selectivity towards tannic acidwere presentalready before the fawns became functional ruminants and these individual differences lasted 5 years.Moreover, individuals that ingested overall less tannic acid, searched more thoroughly between foodsources. When the foraging behaviour was compared with age (11–41 days old and 65–97 days old), itwas found that the time a fawn spent eating, increased with age, and the time spent on exploration,smelling and tasting plants decreased with age. Furthermore, the fawns increased their intake of grassand herbs, while the intake of soil and dead plant material decreased with age.
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| 10. |
- Bergvall, Ulrika A., et al.
(författare)
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Directional associational plant defense from Red deer (Cervus elaphus) foraging decisions
- 2017
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Ingår i: Ecosphere. - : Wiley. - 2150-8925 .- 2150-8925. ; 8:3
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Tidskriftsartikel (refereegranskat)abstract
- The concept of associational plant defenses is widely accepted and implies that an unpalatable plant can protect its neighbors from grazing. We have investigated the new but similar question of whether a part of a plant, for example, the top or bottom, can protect other parts. At the same time, we investigated whether the previously observed selection of the apical shoot and upper leaves of plants is a direct consequence of food quality (the plant vigor hypothesis) or whether there is an innate or learnt foraging pattern behind the observation. In experiments, we used 1 m high artificial trees, made from aspen branches, and measured red deer browsing from the top (above 0.5 m) and bottom (below 0.5 m), with application of condensed tannin to the top or bottom as a proxy for plant part unpalatability. There were four treatments where either none, both, or one part (top or bottom) of the artificial trees had tannin applied. As expected, we found that red deer consumed less from parts with tannin. We also found that a defended top protected an undefended bottom, but we found no evidence for the opposite relationship, which could be explained by foraging behavior. When examining the behavior, we found that adult red deer prefer to start feeding from the top of a plant. We also found that they spent a shorter time feeding on a defended top. This behavior might cause a defended top to protect an undefended bottom. Such directional associational plant defense could be the result of selectivity with limited flexibility and might be more pronounced for mammalian herbivores than for insects, since mammals are bigger in size and more restricted in their head position. An important applied aspect of these results is that when saplings are protected by adding a repellent, for instance in forestry, it might be enough to apply repellent to the tops. On the other hand, according to this directional associational plant defense, protected bottoms will not protect tops, so newly grown apical shoots may need new protection.
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