SPRING OF THE POSSIBILITY mating sable

Many famous zoologists have expressed an interesting idea that individual sables in late winter and early spring flows are not false in the true rut with the possibility of prolific pairings. It is believed that there may be the following forms of sables: constant latency period, with variable latency period, without latency, mixed — with a latent period without it. AT

1968 DV Ternovskii again said that they have a «reasonable hypothesis of heterogeneity of populations sables for their breeding cycle (in the wild).»

In 1970, VV Timofeyev found it possible to express the idea of ​​a sable from the «second» mating period, saying that its existence can be confirmed not only by field studies, but some preconditions histological studies.

However, as the DV Ternovskii and V. Timofeev has not provided any new facts in support of his statements. The absence of such evidence, as well as the history of the study of breeding sables in nature and in captivity, finally sobolevodstva long-standing practice and the results of an intensive study of the ecology of sable in modern times, are, in our opinion, persuasive evidence baseless allegations aforementioned researchers.

It makes sense to follow the evolution of views on sable breeding in nature, paying particular attention to the facts that were the reason for the restoration of almost forgotten misconceptions about this important process.

The catastrophic decline in the range and sable in Siberia at the beginning of the XX century led to attempts in some way to prevent its further development or to balance visible in the long term destruction of sables in the nature of these valuable breeding animals in captivity.

The latter circumstance has put sable biology researchers before the fact of obvious errors in the existing at the time the concept of the reproduction process (and especially) in this species.

For a long time it was considered firmly proved that rut and mating sables occur in late winter. The reason for this were numerous reports of hunters that in February — March, they observed increased activity — «chase» in the footsteps of male female, traces of fights, and so on.. All these signs attributed to sexual arousal and during mating.

Attempts to establish captive breeding sables in the first third of the XX century were built, as a rule, on this concept, perceived in the faith all zoologists. Experimental sable farms and nurseries in the period were created by private individuals and the state. However, it is widely known that all of the attempts at breeding sables taken until 1928, were futile.

It should be emphasized that, despite the numerous and persistent efforts to obtain offspring from sables, it would seem, at the usual time, anywhere litter nobody was obtained from these attempts had to be abandoned. That is the reality.

However, it should be noted that in the history of cellular sobolevodstva have been cases, seemingly confirming the possibility of the spring mating that within the context of failure gives us some hope of success. Let’s try to analyze them.

RV Claire writes: «In the period from October to January is very small testes, seminiferous tubules contain spermatogonia one alone, and occasionally single spermatocytes. In particular the sharp appendage testis atrophy exposed front and tail sections. The head office is changed relatively less. The epithelium in the middle portion of the epididymis nizkokubichesky without ciliated cover. Very interesting single case of finding sperm in the epididymis of the testis in the beginning of January, with a complete absence of sperm in the testes. The testes of males who died in late March and later were significantly more size autumn and winter. They have observed all stages of spermatogenesis".

RV Claire refrained from making any comments of the really cool facts. This was probably done because it was impossible to establish a prescription staying sperm in the epididymis of the testis, and the degree of their viability. The very same BV alive on the results of their research, apparently, had a very definite judgment, saying that the possibility of mating in February sables completely eliminated.

PA Manteuffel found that the act of mating in reality no one at the biological station has not seen, and there was an assumption that it was. Besides never reported delivery of offspring.

PA Manteuffel, better than anyone else familiar with all the ups and downs of the first stages of sable breeding in captivity, said that all development work in this direction ended in failure, except for cases when caught pregnant sobolyushki brought, but rarely in captivity breeding and fattening sables. After all attempts sable breeding in captivity at an impasse, the output of which has been found thanks to the well-known experiments PA Manteuffel and CG Tuomaynena, first proved that the mating period sable is in July-August, and the birth of the young — at April-May next year.

Meanwhile, the observation and description of summer mating animals kind of martens were known already in the twenties. In Russian literature, farmed in 1924 it reported the success of the American Farmer, establish that the American marten in heat takes place in July and August (Malner).

Discussing the mistakes of the past, we must bear in mind that even inexperienced sobolevodami, is also in the plan of the false concept of any anomalies in the behavior of sables (spring activity, attempted false mating) could easily be mistaken for the real acts of mating. Nowadays, such mistakes have unacceptable because knowledge and experience in the field of sobolevodstva immeasurably increased. VL Zaleker by examining changes in the generative system in several hundred females of sable in all seasons of the year, found it possible to state the following: «The state of the ovaries of female sables in January, February, March, shows that in the wild and in captivity sables in estrus does not come «. Such is the case with arguments about the likelihood of the spring mating.

It is necessary to discuss another set of facts also attracted DV Ternovskiy to substantiate the hypothesis of heterogeneity sable breeding cycle. Total allocated to them, as mentioned above, four «form» sable by the length of the latent period. We have already discussed the dilemma of the probability of the existence of one of these «forms» — sables without latency (the existence of a «form» also insists V. Timofeev) — and concluded that current information on the biology of the sable does not allow to take for granted the ability to existence in natural populations of species specified «form».

Further, according to DV Ternovskii, are «forms» with variable latency period, and «mixed» — with or without diapaueoy. To prove the existence of the first of these «forms» DV Ternovskii uses known births in Sable unusual periods: from January to March inclusive.

Except as described in PA Manteuffel, whose causes are unknown, the rest of the peculiar one thing in common — a reduction of diapause in pregnant sobolyushek resulted from the impact of sharply beyond the norms of environmental factors. It seems that the use of such examples to support the discussion and promotion of the hypothesis can not be considered methodologically appropriate reception. There are many facts of natural and artificially provoked by reducing the period of pregnancy in mammals, including humans. However, no one so far they have not been held for the construction of hypothetical positions, such discussion.

DV Tarnovo assumption about the possible existence in nature

«Forms» sable with volatile (by reducing diapauey I winter years) latency period does not hold water in terms of logic. It is clear that the offspring of such sables diapaueoy if it appeared before April, it would have been in conditions that are not exactly conducive to growth, development and survival of newborns Sable. There is no doubt that such a «form» (even if it appears at times) and her offspring will inevitably dropped out would be in the selection process for the latter is aimed at the survival of individuals who have a relatively stable and long enough diapaueoy in the development of the embryos to ensure the birth of a sable in the most favorable environmental conditions.

As for sables so-called «mixed forms» under which, apparently, should be suspected individuals to periodically disappearing and re-emerging diapause, the DV Ternovskiy does not a single reference to the existence of such individuals in natural populations. No mention of the existence of such forms and in the literature on sable.

Almost all of the above facts have been established on the sables kept in captivity. Meanwhile DV Ternovskii and V. Timofeyev also mentioned observations in nature, which, ostensibly, can serve as a confirmation of the hypothesis under discussion. What etinablyudeniya, neither one nor the other is not reported, even though the need for such an obvious fact.

We had to conduct field research on the ecology of the sable, accompanied by anatomical analysis produced sable both sexes in almost all months of the year. The behavior and physiological state of animals observed and anatomiruemyh never go beyond the usual seasonal ecological and morpho-physiological norms. Speaking from the perspective of a field ecologist, it’s hard to imagine any of the actual observations in nature, confirming the hypothesis of heterogeneity of sable breeding cycle, may be involved.

Our point of view on the process of population, based on observations in nature, is that the false rut is an essential preparatory stage of the reproductive cycle of general sable, without going through the full implementation of which the reproduction process is impossible.

Research carcasses sables, produced in January-May, suggests that the most rapidly maturing genital mutilation occurs in males. The process of developing the generative system of male and female balanced by the end of June — beginning of July, the period of the rut.

Like this post? Please share to your friends: