African Elephant

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Lisbeth
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Re: African Elephant

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Bull elephants mate more as they get older – research

Posted on 9 July, 2019 by Africa Geographic Editorial in Research, Wildlife and the Decoding Science post series.

Image
The new study suggest that bull elephants, like Archimedes here in Samburu National Reserve, are capitalising on their increase in size by spending more effort searching for females as they get older. © Jane Wynyard / Save the Elephants

Males of many species slow down in their pursuit of females as they age – but not when it comes to elephants. A new study has found that elderly bull elephants invest more energy into tracking down and mating with females than their younger counterparts.

The study, published recently in the Journal of Animal Ecology, compared the movements of male African savannah elephants while they were in musth – a periodic state of intensive testosterone-fueled sexual activity – and when they were not. The results reveal that, as they age, bull elephants move more in musth and move less out of musth. The combination of these two diverging factors meant that, despite having similar speeds and range sizes between states at age 20, by age 50 males were travelling twice as fast in 3.5 times larger area in musth compared to non-musth.

Researchers from the University of Oxford, Save the Elephants and Colorado State University, made use of visual observations and GPS tracking data from 25 bull elephants aged between 20-52 years old for their study. The data was collected in the Samburu and Buffalo Springs National Reserve, northern Kenya, as part of Save the Elephants’ long-term monitoring project between 2000 and 2018.

African bull elephants continue to increase in body mass throughout their lives, which means that older bull elephants often reach twice the size of both females and young males.

“Older bulls are not only larger and more energetic in mating than younger bulls but female elephants tend to prefer them, perhaps because their size demonstrates their survival skills over many years and seasons” said Iain Douglas-Hamilton, founder of Save the Elephants.

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Matt, an old bull elephant in Samburu National Reserve, Kenya © George Wittemyer / Save the Elephants

Given that older bull elephants tend to be both the target of trophy hunting and poaching, man-made interference could disrupt the age structure, which could bring on musth prematurely and lead to changes in the reproductive dynamics of elephants.

Dr Lucy Taylor, a postdoctoral researcher at the University of Oxford who led the study, says “Investigating how elephant reproductive tactics vary with age is crucial to our understanding of the behavioural ecology of the African savannah elephant and, ultimately, the driving forces shaping the evolution of their life history. The fact that mature male elephants make such dramatic changes in their movement patterns when they are in musth also means that we can now use GPS tracking data alone to detect musth”.

The ability to detect musth remotely can be used to study male reproductive behaviour in difficult conditions across Africa, and to identify and protect important corridors for genetic transmission between different elephant populations in human-dominated landscapes.

Key findings from the study include:

• Unlike other species, African bull elephants increase the energy they put into reproduction as they get older.
• Male elephants move faster and further in musth as they age.
• 50-year-old males moved 50% faster and twice as far when in musth compared to those of 35-years-old. Compared to 20-year-olds, who have yet to come into full musth, the 50-year-olds move twice as fast and over three times as far.
• Simultaneously, the elephants move less when in non-musth as they get older.
• The change of behaviour as older elephants go into musth is so clear that it can be detected remotely just by using their movement patterns, rather than having to observe the elephants directly.

Full report: Lucy A. Taylor, Fritz Vollrath, Ben Lambert, Daniel Lunn, Iain Douglas‐Hamilton, George Wittemyer (2019). Movement reveals reproductive tactics in male elephants. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.13035


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Re: African Elephant

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Kruger Park elephant that died of human TB still a puzzle for vets
BY PENWELL DLAMINI - 29 July 2019 - 15:32

Scientists working with SanParks have begun an intensive research project after an elephant died of human tuberculosis at the Kruger National Park.

In 2016, an elephant died at the Kruger National Park next to the road and vets moved quickly to investigate as the scene was unusual. When they got to the carcass, the vets found that the elephant had died thin. The first call was to check its teeth as this is the first point to verify an illness but its teeth were okay.

It was then clear to the vets that the elephant had died of some chronic illness and a postmortem was immediately done.

“We found that the lungs were very badly affected. About 80% of its lungs were not functional. We took the necessary samples and took them to various laboratories. When the results came back, they confirmed that it was TB - but not bovine but human TB,” said Dr Peter Buss, head of veterinary services at SanParks.

Since then, Buss and a team of experts have taken samples from over 30 elephants trying to establish if there are other elephants that could have the human TB.

On Monday, an elephant was darted with drugs at the Skukuza part of the park in Mpumalanga in order to take samples for lab testing as part of this research.

“At this stage it is only one case. It is very difficult for us to predict what may or may not happen…Although we are looking for other cases, so far the evidence is suggesting that it is only one case. But we have to keep looking because we really don’t have the numbers to compare with statistical evidence," said Buss.

Buss said there were many diseases among animals in the park, including foot and mouth, African swine fever and others, which did not impact the wildlife.

“TB is a new disease in Africa. We don’t know how the animals will react to it. Elephant populations are now fragmented, therefore, much more vulnerable to these kinds of disease. That is why it is important for us to get a feel as to what impact will the disease have on our population,” Buss said.

The current population of elephants at the Kruger National Park is about 20,000.

Buss and Stellenbosch University professor Michele Miller conducted a procedure called bronchoalveolar lavage which is used to wash the lungs. A fluid is put into the lungs through a tube which has a camera and it gets mixed up with fluids in the elephant’s lungs. The researchers then take the drained substance to the labs for testing.

“We have not yet found another elephant that died of human TB in Kruger National Park. It is total speculation as to how this elephant may have got exposed. Obviously the disease is spread through people coughing up the organism at very close contact. That would not have happened between a human and an elephant.

"The one way it could have happened is through a person who was eating food that got dropped or thrown away and the elephant got it,” Buss said.


https://www.sowetanlive.co.za/news/2019 ... v1Z2IBXj_Q


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Re: African Elephant

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Very interesting


Next trip to the bush??

Let me think......................
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Re: African Elephant

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Please check Needs Attention pre-booking: https://africawild-forum.com/viewtopic.php?f=322&t=596
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Re: African Elephant

Post by Lisbeth »

What a strange case :-?


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Re: African Elephant

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:shock: :-?


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Re: African Elephant

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Part of the media promotion tours around ranger day :O^


Is it really necessary to immobilise 50 elephants and spend a lot of money, only to get a sample that is of irrelevant size :O^


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Re: African Elephant

Post by Peter Betts »

Richprins wrote: Mon Jul 29, 2019 5:57 pm :ty:

A thread here: viewtopic.php?f=79&t=7299
Humans throwing food out of windows again


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Re: African Elephant

Post by Klipspringer »

TB can easily spread without direct contact

http://www.tbonline.info/posts/2016/3/3 ... -spread-1/


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Re: African Elephant

Post by Klipspringer »

Research does not know why some elephants have large tusks

From an article by Ian Whyte:
It is difficult to imagine that very
large tusks would be more useful as weapons
or tools than smaller ones, but it may be that
larger tusks are of symbolic value in dominance
skirmishes or displays. Males with larger tusks
might be expected to occupy higher positions
in the hierarchical structure or to be favoured as
mates by females. However work in Amboseli
National Park, Kenya (Moss, 1983; Poole,
1989a) suggests that the phenomenon of ‘musth’
is far more important than body size in determining a
male’s hierarchical position and its success in mating.
The condition of musth is easily recognisable to other
elephants and the position in the social hierarchy of
a male in musth is immediately elevated above all
non-musth males. Even when two large males are
simultaneously in musth, Poole (1989b) found that
the factor determining dominance rank in both musth
and non-musth males was body size. Tusk size is not
mentioned by Moss (1983) or Poole (1989b) as a factor
affecting hierarchical position. The evolutionary reason
why some elephant males have large tusks is therefore
still unclear, and would be an interesting subject for
further research.
http://www.pachydermjournal.org/index.p ... ew/503/410


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