Size and weight siberian tiger

[peter]

(07-01-2023, 07:20 AM)AlejoBravo96 Wrote: Hola a todos. Quisiera preguntarles si es posible que los datos sobre el tamaño y peso del tigre de amur publicados por la wcs, wwf o el centro de tigres de amur puedan tener inconsistencias o estén alterados a propósito. Digo esto porque parece que la mayoría de los datos tomados se hacen en primavera o verano cuando los tigres disminuyen su masa corporal, en segundo lugar porque la mayoría de los ejemplares analizados rondan los 3-4 años de edad, es decir, están lejos de su plenitud. desarrollo. , en tercer lugar porque la población oficial del censo se establece entre unos 60-70 ejemplares y en cuarto lugar que han sido manipulados como estrategia para restar interés a los furtivos por la zona. Muchas gracias.

English:
Hello everyone. I would like to ask you if it is possible that the data on the size and weight of the amur tiger published by the wcs, wwf or the amur tiger center may have inconsistencies or are altered on purpose. I say this because it seems that most of the data taken is done in spring or summer when tigers decrease their body mass, secondly because most of the specimens analyzed are around 3-4 years of age, that is, they are far from its fullness. development. , thirdly because the official population of the census is established between 60-70 specimens and fourthly that they have been manipulated as a strategy to reduce interest to poachers in the area. Thank you so much.

Hi Alejo,

Welcome to the forum! Hope you'll like your stay.

As to the issues you raised. There's a lot of information about the size of wild, and captive, Amur tigers in the thread 'On the edge of extinction - A - The tiger'. The info on the length and weight of captive Amur tigers is very recent. 

In the period 1992-2010, biologists captured quite a few wild Amur tigers. The method used (referring to the Aldrich footsnare), however, had disadvantages. Some of them were described in 'The Snare for tiger'. For this reason, healthy wild Amur tigers are no longer captured in the Russian Federation. The Russians only capture wild Amur tigers considered as a nuisance. 

In northeastern China, however, wild tigers are captured every now and then. According to Feng Limin, the heaviest actually weighed was 270 kg. Large males in the northern part of the Khabarowski Krai (Russian federation) could compare.

The WCS-table you referred to was published in 2005. The average weight of 10 males captured in the period 1992-2004 was 176,4 kg, whereas females averaged about 120 kg. These averages were used by many forum members. The question is if this average was representative. The answer is we don't know. We do, however, know the samples were smallish. We also know most animals were captured in or near one reserve only. Finally, we know quite a few males were young adults. One of them was in such bad shape, he had to be euthanized later. 

Until a few years ago most of us assumed adult males (6 years and older) ranged between 160-212 kg, but recent information suggests the real range could be 140-270 kg. 

It's not easy to compare today's tigers with those shot a century ago. The reason, again, is a lack of reliable information. The heaviest male accepted by biologists is a male shot by N. Baikov near the Korean border in 1911. That male was 254 kg. The heaviest female was 168 kg. The 'historic' averages (217 kg for males and 137 kg for females) were higher, but the samples on which these averages were based are very small.  

Rumour has it there was an Imperial Hunting Reserve on the border of China, Russia and Korea many moons ago. As only few were allowed to hunt there, the conditions were all but perfect. When the social system in China collapsed, the animals in the reserve spread out. It's quite likely most tigers moved to Manchuria, back then considered as a 'sea of forest'. Most reports about exceptional tigers are from Manchuria. In 1943, a large male was shot near the Sungari river by a member of Jankowski's team. Measured 'over curves', he was 11.6. In a letter to V. Mazak, Jankowski said the tiger, not weighed, was at least 300 kg. In a book published later, he said the tiger was 350 kg. 

There are more reports about tigers of similar size shot in Manchuria and Russia, but the only tiger of that size photographed was the tiger shot in 1943:

*This image is copyright of its original author

In the period 1900-1950, Amur tigers walked the edge. They survived, but the population bottleneck had an effect for quite some time. In the last decades, however, individuals well exceeding the average have been seen occasionally. This is a very recent photograph of a large male known as 'The Beast'. Although not as bulky as the big old brown bear (right), he compared in most respects: 

*This image is copyright of its original author

          

As to averages. 

A healthy population consists of young adults, mature and old animals. Young adults (and so-called 'problem animals') range between 125-185 kg. Old males only seldom exceed 160 kg. Most mature males (6 years and older) range between 160-200 kg. Big males range between 200-225 kg. Males exceeding 225 kg are few, but there are reliable reports about tigers ranging between 250-270 from northeastern China. According to feng Limin, these tigers were actually weighed. 

So what is an 'average' adult male? It depends on the criteria used. Miquelle thought 430 pounds (195 kg) could be close to the mark. If young adults and old males would be included, chances are it's closer to 390-410 pounds (177-186 kg). 

Not as heavy as an average captive male (495 pounds or about 224 kg), but that could change when the conditions improve and the number of tigers increases. Is an average male smaller than a century ago? According to Baikov, most young adults back then ranged between 160-200 kg. In that period of time (see 'The Tiger's Claw'), a male of 575-600 pounds (261-272 kg), like today, was considered as exceptional as well. It is, however, known exceptions in large subspecies are more outspoken than in small subspecies. A report about a tiger exceeding 700 pounds from India, Nepal, Russia or northeastern China, therefore, can't be excluded out of hand. In captivity, healthy males have exceeded that mark more than once. Reply