Giraffe
- Lisbeth
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Re: Giraffe
"Education is the most powerful weapon which you can use to change the world." Nelson Mandela
The desire for equality must never exceed the demands of knowledge
The desire for equality must never exceed the demands of knowledge
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Re: Giraffe
Some new research about colouration:
https://phys.org/news/2019-09-dark-giraffe-horse.html
The dark giraffe, the new dark horse
by University of Queensland
Darker male giraffes have been found to be more solitary and less social than their lighter-colored counterparts, according to new research from The University of Queensland.
A long-term study revealed that the color of male giraffes' spots more strongly relates to their patterns of social association, rather than their age, as previously thought.
The paper's lead author, Dr. Madelaine Castles, said male giraffes tend to increase in darkness as they age, but some males never darken and others even lose pigmentation.
"We now know that—rather than simply indicating age—color may display males' physical condition and be used as a way to signal competitive ability to others," she said.
"Male giraffes' color may function in a similar way to the lion's mane, as lions with dark manes are usually dominant and are preferred by females.
"We think that darker, more dominant male giraffes use an often-successful but risky mating tactic, roaming between groups of giraffes looking for sexually receptive females.
"In contrast, the lighter, less dominant males may be making the best of a bad situation so to speak, by remaining with females in the hope of getting lucky when a dominant male is not around."
The researchers used photographs and data on 66 males collected over 12 years in the Etosha National Park in Namibia.
Fellow author, Associate Professor Anne Goldizen, said these findings are just the beginning of understanding giraffe color.
"The next step is to find out how color could be a signal of a male's condition," she said.
"color could be linked to testosterone, to heat stress, diet, genetics or a combination of multiple factors.
"The more we learn about giraffes, the more questions we have.
"And giraffes have recently been moved from 'of least concern' to 'vulnerable' on the IUCN Red List, so further research on these gentle giants is critical."
This study was published in Animal Behaviour.
https://phys.org/news/2019-09-dark-giraffe-horse.html
The dark giraffe, the new dark horse
by University of Queensland
Darker male giraffes have been found to be more solitary and less social than their lighter-colored counterparts, according to new research from The University of Queensland.
A long-term study revealed that the color of male giraffes' spots more strongly relates to their patterns of social association, rather than their age, as previously thought.
The paper's lead author, Dr. Madelaine Castles, said male giraffes tend to increase in darkness as they age, but some males never darken and others even lose pigmentation.
"We now know that—rather than simply indicating age—color may display males' physical condition and be used as a way to signal competitive ability to others," she said.
"Male giraffes' color may function in a similar way to the lion's mane, as lions with dark manes are usually dominant and are preferred by females.
"We think that darker, more dominant male giraffes use an often-successful but risky mating tactic, roaming between groups of giraffes looking for sexually receptive females.
"In contrast, the lighter, less dominant males may be making the best of a bad situation so to speak, by remaining with females in the hope of getting lucky when a dominant male is not around."
The researchers used photographs and data on 66 males collected over 12 years in the Etosha National Park in Namibia.
Fellow author, Associate Professor Anne Goldizen, said these findings are just the beginning of understanding giraffe color.
"The next step is to find out how color could be a signal of a male's condition," she said.
"color could be linked to testosterone, to heat stress, diet, genetics or a combination of multiple factors.
"The more we learn about giraffes, the more questions we have.
"And giraffes have recently been moved from 'of least concern' to 'vulnerable' on the IUCN Red List, so further research on these gentle giants is critical."
This study was published in Animal Behaviour.
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Re: Giraffe
https://www.smithsonianmag.com/smart-ne ... 180973243/
Color of Giraffes’ Spots Reflects Social Status, Not Age
New research suggests male giraffes with darker coloring are more solitary, dominant than lighter-hued counterparts
SMITHSONIANMAG.COM
SEPTEMBER 30, 2019
The color of a male giraffe’s spots may reveal insights on its behavior, new research suggests. As scientists led by Madelaine Castles of Australia’s University of Queensland report in the journal Animal Behaviour, dark-furred giraffes tend to be both more dominant and solitary than their lighter-hued counterparts.
These findings, based on a survey of 66 males living in Namibia’s Etosha National Park over a 12-year period, contradict previous research associating darker coloring with advanced age rather than social status.
Per Cosmos’ Tanya Loos, the latest study—drawing on 1,793 photographs and calculations of gregariousness versus sociability, as represented by time spent alone or within a group—supports the idea that most giraffes’ spots darken over time but identifies significant exceptions to this trend.
In a press release, Castles notes, “We now know that—rather than simply indicating age—colour may display males’ physical condition and be used as a way to signal competitive ability to others.”
Of the 66 subjects surveyed, nine actually grew paler as they aged. Others retained the light coloring seen in their youth, never making the switch from sienna brown to darker black. As the study’s authors explain, “This suggests that color is not solely an age-based trait but could be a secondary sexual trait.”
According to the statement, dark-hued males assert their dominance through what Castles calls an “often-successful but risky” mating strategy. Whereas paler male giraffes travel in packs with females, darker ones roam alone, moving between groups in search of potential mates.
“In contrast,” Castles says, “the lighter, less dominant males may be making the best of a bad situation so to speak, by remaining with females in the hope of getting lucky when a dominant male is not around.”
Staying in close proximity to females offers several benefits for younger subordinate males. Per the study, delaying breeding gives these giraffes time to grow and increase their physical fitness—a decision likely to “prove more beneficial over a lifetime.” At the same time, the researchers write, females in heat may be more willing to mate with familiar males than unknown ones.
According to Cosmos’ Loos, the researchers’ findings suggest giraffes’ coloring acts similarly to African lions’ manes, which signal bearers’ fitness to potential female mates. The study further notes that lions’ mane growth and coloring tend to change with age but are also influenced by a wide array of factors, including injuries, testosterone, nutrition and ambient temperature.
In the press release, study co-author Anne Goldizen, also of the University of Queensland, notes that scientists’ next step will be determining how color can signal a male giraffe’s physical condition.
Much like lions, she adds, giraffes’ “color could be linked to testosterone, to heat stress, diet, genetics or a combination of multiple factors.”
Color of Giraffes’ Spots Reflects Social Status, Not Age
New research suggests male giraffes with darker coloring are more solitary, dominant than lighter-hued counterparts
SMITHSONIANMAG.COM
SEPTEMBER 30, 2019
The color of a male giraffe’s spots may reveal insights on its behavior, new research suggests. As scientists led by Madelaine Castles of Australia’s University of Queensland report in the journal Animal Behaviour, dark-furred giraffes tend to be both more dominant and solitary than their lighter-hued counterparts.
These findings, based on a survey of 66 males living in Namibia’s Etosha National Park over a 12-year period, contradict previous research associating darker coloring with advanced age rather than social status.
Per Cosmos’ Tanya Loos, the latest study—drawing on 1,793 photographs and calculations of gregariousness versus sociability, as represented by time spent alone or within a group—supports the idea that most giraffes’ spots darken over time but identifies significant exceptions to this trend.
In a press release, Castles notes, “We now know that—rather than simply indicating age—colour may display males’ physical condition and be used as a way to signal competitive ability to others.”
Of the 66 subjects surveyed, nine actually grew paler as they aged. Others retained the light coloring seen in their youth, never making the switch from sienna brown to darker black. As the study’s authors explain, “This suggests that color is not solely an age-based trait but could be a secondary sexual trait.”
According to the statement, dark-hued males assert their dominance through what Castles calls an “often-successful but risky” mating strategy. Whereas paler male giraffes travel in packs with females, darker ones roam alone, moving between groups in search of potential mates.
“In contrast,” Castles says, “the lighter, less dominant males may be making the best of a bad situation so to speak, by remaining with females in the hope of getting lucky when a dominant male is not around.”
Staying in close proximity to females offers several benefits for younger subordinate males. Per the study, delaying breeding gives these giraffes time to grow and increase their physical fitness—a decision likely to “prove more beneficial over a lifetime.” At the same time, the researchers write, females in heat may be more willing to mate with familiar males than unknown ones.
According to Cosmos’ Loos, the researchers’ findings suggest giraffes’ coloring acts similarly to African lions’ manes, which signal bearers’ fitness to potential female mates. The study further notes that lions’ mane growth and coloring tend to change with age but are also influenced by a wide array of factors, including injuries, testosterone, nutrition and ambient temperature.
In the press release, study co-author Anne Goldizen, also of the University of Queensland, notes that scientists’ next step will be determining how color can signal a male giraffe’s physical condition.
Much like lions, she adds, giraffes’ “color could be linked to testosterone, to heat stress, diet, genetics or a combination of multiple factors.”
- Richprins
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Re: Giraffe
Please check Needs Attention pre-booking: https://africawild-forum.com/viewtopic.php?f=322&t=596
- Lisbeth
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Re: Giraffe
There are continuous explanations on this topic and one does not know which one to believe
"Education is the most powerful weapon which you can use to change the world." Nelson Mandela
The desire for equality must never exceed the demands of knowledge
The desire for equality must never exceed the demands of knowledge
- Richprins
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Re: Giraffe
Please check Needs Attention pre-booking: https://africawild-forum.com/viewtopic.php?f=322&t=596
- Richprins
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Re: Giraffe
A strangely-coloured giraffe by Heksie on the S128 in 2013
Please check Needs Attention pre-booking: https://africawild-forum.com/viewtopic.php?f=322&t=596
- Lisbeth
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Re: Giraffe
Funny couple
"Education is the most powerful weapon which you can use to change the world." Nelson Mandela
The desire for equality must never exceed the demands of knowledge
The desire for equality must never exceed the demands of knowledge
- Lisbeth
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Re: Giraffe
Yes exactly! One of the thin ones
"Education is the most powerful weapon which you can use to change the world." Nelson Mandela
The desire for equality must never exceed the demands of knowledge
The desire for equality must never exceed the demands of knowledge