Обсуждение:Наблюдение гомосексуального поведения у овец

message: Damián et al (2017) пишут: «... sexual behavior in pen tests is not a direct predictor of rams’ sexual behavior in field conditions [26, 27]». Посмотрите на источник [27], он говорит, что: «The level of sexual behavior of rams can be both stimulated and inhibited by their social environment. <..> Furthermore, when rams are joined in groups to ewes social interaction between rams is inevitable and has been observed to have both inhibitory and stimulatory effects on the sexual behavior of individual rams.<..>The sexual behavior of rams may be influenced by their early sexual experiences and there is evidence that the practice of rearing rams in all-male groups may contribute to low levels of sexual activity and to homosexuality.<..> Furthermore, it seems that the sexual preferences of rams can be modified by rearing in all-male groups. A number of authors have noted a direct relationship between a lack of interest of adult rams in ewes and a high level of courtship and mounting being directed towards male pen mates during rearing (Zenchak et al., 1973; Zenchak & Anderson, 1980; Katz et al., 1988). Zenchak et al. (1981) found that rams that had been reared in all-male groups, and had previously shown little response to oestrous ewes, directed their sexual behavior towards a tethered ram rather than a tethered ewe. <..> In contrast, during the "adolescent" phase male sexual behavior became selectively oriented towards females (Thwaites, 1982; Orgeur & Signoret, 1984) and sexual segregation during this period led to a delay in the onset of copulatory activity, although the frequency of sexual behavior patterns were not adversely affected (Orgeur & Signoret, 1984)».
В дополнение к этому, работа Stellflug, Berardinelli (2002): «... test conditions, such as restrained and unrestrained ewes and number of serving capacity tests, may affect conclusions in studies that evaluate sexual performance of rams. <..> Other researchers have reported that sexually inhibited rams began breeding ewes after a period of time if left in breeding pens with marking harnesses and where human activ-ity was either absent or minimized (Hulet et al., 1964, Mattner et al., 1973). Hulet et al. (1964) reported that 35% of 23 inhibited rams began breeding within 24 h, and 70% started mating within 48 h, after they were placed into breeding pens with marking harnesses. Therefore, human presence and associated activities may be important in determining the level of sexual performance in some rams».
Ungerfeld (2014) пишет: «Male homosexual behavior is observed in many ruminant species, including goats, sheep and cattle (see review: Dagg, 1984). Nevertheless, the factors that influence the expression of this behavior have been scarcely studied. Some researchers claim that male homosexual behavior is related to social hierarchies (see review: Dagg, 1984; Klemm et al., 1983). In this sense, Grubb (1974) proposed that Soay sheep impose social dominance through homosexual matings. However, it has been reported that other environmental and social factors, such as seasonality (Holečková et al., 2000) and isolation from females (Ungerfeld et al., 2013), also affect the display of homosexual matings in male ruminants. Many species of male ruminants show seasonal reproductive patterns (Prendergast et al., 2002). In male goats, the concentration of testosterone, the main hormone related to male sexual behavior (Hull et al., 2002), varies with seasons (Howland et al., 1985). In male Iberian Ibex goats, the highest frequency of male–male mounts was observed at the beginning of the breeding season (Freitas-de-Melo et al., 2014) and in Dama deer bucks during the early period of antler growth, when the testosterone concentration is increasing before the onset of the breeding season (Holečková et al., 2000). Thus, homosexual behaviors in male goats may also have a seasonal pattern and may be related to testosterone concentration. The social environment in which male lambs are reared influences the sexual behavior of rams (Casteilla et al., 1987; Katz et al., 1988): rams reared in all-male groups show little interest in females when they are used for breeding (Zenchak and Anderson, 1980). Srivastava et al. (1989) reported that homosexual behavior in rams is a consequence of prolonged isolation from females and exclusive contact with males. In the same vein, Ungerfeld et al. (2013) recently reported that bucks reared in isolation from females displayed mating behaviors to-ward a greater number of novel bucks than bucks that were reared in permanent contact with females. This led these authors to propose that males that were reared in isolation from females considered other males as possible sexual partners. Therefore, isolation from females may be a determinant of a greater frequency of male–male sexual interactions.»
Тезис 1: тесты с привязанными баранами ("стойка для изнасилования" [англ.: rape rack], где близко крепились 4 особи) в экспериментальных условиях не демонстрируют поведения баранов при свободном разведении. Это может повлиять на результаты. Кроме того, надо учитывать что даже свободное рзведение с контактами баранов с самками — это тоже неестественыне условия разведения домашних животных, которые обременены результатами селекции, выбирающей необходимые человеку свойства.
Тезис 2: Количество работ, которые демонстрируют 8% гомосексуальных баранов, невелико. Есть работы, где был показан другой процент. Пример: Price (1999) На втором году четыре барана были сексуально неактивны, однако, как отмечают авторы, эти бараны никогда не тестировались на сексуальную ориентацию. Авторы только предполагают, что «они могли быть ориентированы на самцов» или «вероятно, ориентированы на самцов», но это только предположения. Опираясь на данные, представленные в исследовании, мы имеем 0% ориентированных на самцов баранов. Предположим, что эти четыре барана ориентированы на самцов - 4 барана из 104 - это 3,8%, а не 8%, В вышеуказанной работе Stellflug, Berardinelli (2002) — в каждой линии разведения был идентифицирован только один баран, ориентированный на самцов это ≈1-2% баранов с однополым поведением.
Тезис 3: учитывая тезис 1 и тезис 2, точное значение 8% следует заменить на «некоторые» (как в этой статье, так и в основной). Необходимо указать, что выбор баранов в соответствии с характеристиками, установленными заводчиками, может повлиять на поведение баранов. Это исследование проводилось в неестественных условиях, в которых не учитывалось социальное влияние и влияние человека на эксперимент, что необходимо указать в статье.
Более подробно указанные недостатки работ по баранам, а также условия их разведения описаны в рецензированной статье, которую можно взять как обзорный источник, и использовать указанные там работы для доработки статьи. — Путеец (обс.) 08:24, 20 октября 2019 (UTC)
thread_title:  Вернёмся к нашим баранам