Behavioral Factors Affecting Reproduction in Domestic Horses: Sociobiological Approach

Fetal loss is a common phenomenon in domestic horses, being usually highest (up to 40%) of all domestic ungulates. However, in all studies investigating this problem, sociobiological approach, such as conflict between the evolutionary interests of individuals of the two sexes, has been neglected. Here we summarize results of three consecutive studies considering infanticide as a male’s reproductive strategy and a mare’s counter strategies against it. When a mare was either artificially inseminated or removed from her home environment and transported elsewhere for mating and then returned back into her home environment, containing a stallion (and/or gelding) who did not sire her fetus, she got into a potentially infanticidal danger. She more likely disrupted her pregnancy than a mare living in an environment with the sire of her fetus. This was highly affected by the social environment. Lowest percentage of pregnancy disruption can be achieved when the pregnant mare was released into an enclosure shared with the non-sire male whom she can “convince” he is the father of her expected foal by promiscuous mating. The effects of social environment leading to pregnancy block and/or disruption may thus explain substantial part of the high incidence of domestic horse fetal loss

Survival rates and causes of death in Tengmalm’s owl offspring during the post-fledging dependence period in Central and North Europe

Offspring survival rates in altricial birds during the post-fledging period are an essential factor in determining the fitness of parents and have a significant impact on general population dynamics. However, our current knowledge of post-fledging mortality and its causes remains fragmentary in most bird species, and even less information is available on the mortality of individuals of the same species in different environments. In order to address this gap in our knowledge, we studied fledgling mortality and its causes in Tengmalm’s owls (Aegolius funereus) during six breeding seasons in Central and North Europe using radio-telemetry. A total of 80 nestlings from 18 nests in Czechia (2010–2012, 2015) and 60 nestlings from 24 nests in Finland (2019, 2021) were radio-tracked during the post-fledging dependence period. The overall survival rate was much higher in Czechia (83%) than in Finland (53%), with predation identified as the primary cause of mortality in both areas. Avian predation was far higher in Finland, but mammalian predation was equivalent at both study sites. Pine martens (Martes martes) and goshawks (Accipiter gentilis) were the most common predators in Czechia and Finland, respectively. Starvation and disease, or mostly a combination of both, formed the second most common cause of death in both areas but were much more frequent in Finland than in Czechia. Offspring survival in both study sites was considerably higher in years of food abundance than in those of food scarcity. We suggest that the interactive effects of infections and poor body condition due to scarcity of main prey species induced higher mortality rates in offspring, particularly in the more challenging environment of North Europe. In contrast, fledgling owls were found to be able to fight off infections more successfully during rich food seasons. Finally, we encourage researchers to pay greater attention to the mutual influences of parasites and their definitive hosts and stress the importance of using radio or satellite tracking for mortality studies to identify causes of death more accurately

Long-term trends in the body condition of parents and offspring of Tengmalm's owls under fluctuating food conditions and climate change

Physical condition is important for the ability to resist various parasites and diseases as well as in escaping predators thus contributing to reproductive success, over-winter survival and possible declines in wildlife populations. However, in-depth research on trends in body condition is rare because decades-long datasets are not available for a majority of species. We analysed the long-term dataset of offspring covering 34 years, male parents (40 years) and female parents (42 years) to find out whether the decline of Tengmalm's owl population in western Finland is attributable to either decreased adult and/or juvenile body condition in interaction with changing weather conditions and density estimates of main foods. We found that body condition of parent owl males and females declined throughout the 40-year study period whereas the body condition of owlets at the fledging stage very slightly increased. The body condition of parent owls increased with augmenting depth of snow cover in late winter (January to March), and that of offspring improved with increasing precipitation in late spring (May to June). We conclude that the decreasing trend of body condition of parent owl males and females is important factor probably inducing reduced adult survival and reduced reproduction success thus contributing to the long-term decline of the Tengmalm's owl study population. The very slightly increasing trend of body condition of offspring is obviously not able to compensate the overall decline of Tengmalm's owl population, because the number of offspring in turn simultaneously decreased considerably in the long-term. The ongoing climate change appeared to work in opposite ways in this case because declining depth of snow cover will make the situation worse but increased precipitation will improve. We suggest that the main reasons for long-term decline of body condition of parent owls are interactive or additive effects of reduced food resources and increased overall predation risk due to habitat degradation (loss and fragmentation of mature and old-growth forests due to clear-felling) subsequently leading to decline of Tengmalm's owl study population

Effect of Different Factors on Proliferation of Antler Cells, Cultured In Vitro

Antlers as a potential model for bone growth and development have become an object of rising interest. To elucidate processes explaining how antler growth is regulated, in vitro cultures have been established. However, until now, there has been no standard method to cultivate antler cells and in vitro results are often opposite to those reported in vivo. In addition, many factors which are often not taken into account under in vitro conditions may play an important role in the development of antler cells. In this study we investigated the effects of the antler growth stage, the male individuality, passaged versus primary cultures and the effect of foetal calf serum concentrations on proliferative potential of mixed antler cell cultures in vitro, derived from regenerating antlers of red deer males (Cervus elaphus). The proliferation potential of antler cells was measured by incorporation of 3H thymidine. Our results demonstrate that there is no significant effect of the antler growth stage, whereas male individuality and all other examined factors significantly affected antler cell proliferation. Furthermore, our results suggest that primary cultures may better represent in vivo conditions and processes occurring in regenerating antlers. In conclusion, before all main factors affecting antler cell proliferation in vitro will be satisfactorily investigated, results of in vitro studies focused on hormonal regulation of antler growth should be taken with extreme caution

Dogs Discriminate Identical Twins

Earlier studies have shown variation among experimental attempts to establish whether human monozygotic twins that are genetically identical also have identical individual scents. In none of the cases were the dogs able to distinguish all the individual scents of monozygotic twins living in the same environment if the scents were presented to them separately. Ten specially trained police German Shepherd dogs of three Czech Republic Police Regional Headquarters were used for scent identification in our study. The dogs were supposed to match scents of two monozygotic pairs (5 and 7 years old) and two dizygotic twin pairs (8 and 13 years old). Scents were collected on cotton squares stored in glass jars. Dog handlers were blind to the experiment details. In each trial (line-up), one scent was used as a starting scent and the dog was then sent to determine if any of the 7 presented glass jars contained a matching scent. Scents of children of similar ages were used as distractors. In the matching procedure, the dogs matched correctly the scent of one twin with the other, as well as two scents collected from every single identical and non-identical twin to prove their efficacy and likewise, the presence of the matching twin scent in any given glass jar. All dogs in all trials distinguished correctly the scents of identical as well as non-identical twins. All dogs similarly matched positively two scents collected from the same individuals. Our findings indicated that specially trained German Shepherd dogs are able to distinguish individual scents of identical twins despite the fact that they live in the same environment, eat the same food and even if the scents are not presented to them simultaneously

Verification of the reliability of some selected company predictive patterns when being applied in various sectors

Tato bakalářská práce vytvořená s pomocí odborné literatury se snaží vystihnout nejdůležitější metody hodnocení podniků finanční analýzou. V souladu se zadáním a zaměřením práce byl poskytnut pohled do prognostiky a metod, které se v této prognostice používají. Byly zmíněny a aplikovány nejznámější a nejpoužívanější predikční modely. Následně v další části byla zvolena a stručně charakterizována různá odvětví reprezentovaná úspěšnými a neúspěšnými vybranými podniky, které se v těchto odvětví nacházejí. Poté byly v těchto odvětvích aplikovány Beaverovi ukazatele, Altmanovo Z´ Score model, model IN05 a Kralickův rychlý test. U těchto modelů bylo provedeno ověření jejich spolehlivosti a vyhodnoceno, s jakou přesností jsou schopny zařadit podniky v jednotlivých zvolených odvětvích. Všechny modely byly seřazeny do přehledných tabulek tak, aby bylo již na první pohled zřejmé, nakolik byly tyto modely úspěšné v různých odvětvích. V samotném závěru práce byly zhodnoceny použité predikční modely, a jejich výhody i nevýhody při aplikaci v různých podnicích i odvětvích.Katedra podnikové ekonomiky a managementuObhájenoThis bachelor thesis is trying capture the most important methods of evalution companies through financial analysis. In accordance with the task and focus of this thesis were shown view of forecasting and methods which are used in forecasting. The most famous and important predictive models were mentioned and applied. Then in next parts were choosen and characterized few sectors that were represented by choosen failing and non-failing firms. After that were applied Beaver´s ratios, Altmans´s Z´ Score model, model IN05 and Kralicek´s Quick test in this sectors. In mentioned models were verified their reliability and evaluated with what accuracy they are able to classify firms in choosen sectors. All models were sorted in well-arranged tables so that we could see how successful the models were when applied in various sectors. In the end of thesis were evaluated used predictive models and their advantages and disadvantages when being applied in different companies and sectors

Chapter Behavioral Factors Affecting Reproduction in Domestic Horses: Sociobiological Approach

Fetal loss is a common phenomenon in domestic horses, being usually highest (up to 40%) of all domestic ungulates. However, in all studies investigating this problem, sociobiological approach, such as conflict between the evolutionary interests of individuals of the two sexes, has been neglected. Here we summarize results of three consecutive studies considering infanticide as a male’s reproductive strategy and a mare’s counter strategies against it. When a mare was either artificially inseminated or removed from her home environment and transported elsewhere for mating and then returned back into her home environment, containing a stallion (and/or gelding) who did not sire her fetus, she got into a potentially infanticidal danger. She more likely disrupted her pregnancy than a mare living in an environment with the sire of her fetus. This was highly affected by the social environment. Lowest percentage of pregnancy disruption can be achieved when the pregnant mare was released into an enclosure shared with the non-sire male whom she can “convince” he is the father of her expected foal by promiscuous mating. The effects of social environment leading to pregnancy block and/or disruption may thus explain substantial part of the high incidence of domestic horse fetal loss

Early ontogeny social deprivation modifies future agonistic behaviour in crayfish

Abstract Social deprivation early in life affects further individual development and leads to irreversible behavioural alterations later in life. Although the syndrome is well-studied in vertebrates including humans, its presence in invertebrates has been described only in eusocial insects and cockroaches. Here we show the first evidence of social deprivation in subsocial decapod crustaceans, based on analysis of video-recorded agonistic encounters of juvenile red swamp crayfish (Procambarus clarkii, Girard). In comparison with maternally incubated juveniles, isolated crayfish had altered repertoires, numbers and frequency of agonistic interactions similar to those described in vertebrates. Our results support the view on the syndrome of social deprivation as a ubiquitous trait in species with developed maternal care across diverse taxa

Differential movement patterns of juvenile Tengmalms owls (Aegolius funereus) during the post-fledging dependence period in two years with contrasting prey abundance.

Fledgling behaviour and movement patterns throughout the post-fledging dependence period (PFDP), especially in relation to changing environmental conditions, have been rarely studied, despite the fact that this period is recognized as of crucial significance in terms of high mortality of juveniles. The PFDP can extend over quite a protracted period, particularly in birds of prey, and a knowledge of the movement patterns of individuals is fundamental for understanding mechanisms underlying survival, habitat use and dispersion. We radiotracked 39 fledglings of the Tengmalm's owl (Aegolius funereus) in two years with different availability of prey: 2010 (n = 29) and 2011 (n = 10) and obtained 1455 daily locations. Fledglings reached independence on average in 45 days after fledging in 2010 (n = 22) and 57 days in 2011 (n = 6). Within years, the most important measures influencing the distance moved from the nest box were age of fledglings and number of surviving siblings present. Individual home range size and duration of PFDP in particular were dependent on maximal number of siblings seen outside the nest box. In the season with low prey availability fledglings were observed at greater distances from the nest box than in the year with higher prey availability (mean distance: 350 m in 2010 and 650 m in 2011) and occupied larger home ranges (mean: 30.3 ha in 2010 and 57.7 ha in 2011). The main factor causing these differences between years was probably the different availability of prey in these two years, affecting breeding success and post-fledging survivorship of the Tengmalm's owls