Home |
Search |
Today's Posts |
#61
|
|||
|
|||
|
#62
|
|||
|
|||
"Nick Maclaren" wrote in message ... In article , "BAC" writes: | | Trouble is, when predators are introduced in the hope they will deal with a | problem population, you're never certain what they'll actually choose to | eat. In the case of the most relevant ones, lynx and wolves, we have a pretty good idea. The former are unlikely to harm anything that is endangered - and probably wouldn't even kill many cats, which many people would regret. I understand one thing European Lynx do is attempt to suppress the fox population within their hunting range - perhaps because foxes are reputedly the number one predator of immature roe deer. If released lynx were to start killing people's pets, their future would be bleak, IMO. | Interestingly, the population of Roe Deer is said to have plummeted when it | lost Royal protection status back in the middle ages, from which I'd guess | it used to be effectively kept in check by hungry commoners. So I'd have to | add changes in dietary preferences (or a reduction in persecution, depending | on your POV)to my list of possible human contributory 'causes'. And it exploded when people no longer walked through fields with guns and dogs, and dogs were not allowed to roam at night. I suspect it's true that fairly widespread human predation on Roe deer in the UK used to help keep the wild population numbers low. |
#63
|
|||
|
|||
"Malcolm Kane" wrote in message ... In message , writes On Tue, 12 Apr 2005 08:47:22 +0100, "Tumbleweed" wrote: "Paul" wrote in message ... Why do the RSPB and other conservation hooligan charities such as the Woodland Trust kill wildlife rather than manage it properly. We all know killing large numbers of animals merely causes them to breed more and quicker. Thats must be why there are lots of whales then? No, It is always possible to slaughter a species almost to extinction. But surely Angus when the main pressure was taken off a number of years ago this principle you have quoted before that it causes faster breeding would by now have been making a really noticeable difference. The concept of population rebound in some species may not be as far fetched as you seem to believe. From Deer-UK's ecology of the Roe Deer, http://www.deer-uk.com/roe_deer.htm "In good conditions Roe have a high fecundity rate. In the South of England twins are the norm and in very good conditions triplets are not uncommon. Many triplet fetuses are found during a post-mortem examination, though not all would necessarily have been born alive. But if all three fetuses are the same size, the indications are that all three will be live at birth. Should one or more be smaller than the others, then it is unlikely it would have been born alive. In a particularly cold and/or wet early summer and autumn, the survival of all three triplets is greatly reduced and it is normally buck kids that fare worst. This could be due to nature perpetuating the species by saving the does for the following breeding season." So, following extensive culling, it seems probable there would be reduced competition for available fodder etc amongst the survivors, hence the incidence of multiple births would be likely to increase, until the population reached 'normal' densities for the prevailing conditions. I do not know whether the near extinction of some of the planet's cetaceans will have had any effect on their species' birth rates, (it seems less likely) but some experts are estimating the annual population growth of some species at between 7 and 8% since the general ban was introduced. |
#64
|
|||
|
|||
"Malcolm" wrote in message news In article , writes On Wed, 13 Apr 2005 07:44:32 +0100, Malcolm wrote: In article , Tumbleweed writes wrote in message ... Absolute rubbish. Old and weak will undoubtably succumb to cold but that's natural and can improve the gene pool. Over time without un-natural pressures deer populations like any other species will stabilise in accordance with their habitat. Its a myth that populations stabilise. Try reading some modern textbooks. He won't. He has been recommended to do this before, including being given some actual titles of such books, but he prefers to remain ignorant on such basic matters as ecology, conservation, population control, woodland management, deer management, etc., etc., because he is presumably afraid that if he actually studied the subjects he might learn something that ran counter to his prejudices. What you mention above are reasons why man is not allowing populations to stabilise. You never disappoint when you show your ignorance :-) There's no such thing as a stabilised population, just as there is no such thing as a "state of equilibrium" which you were waffling about some while back. Every population is in a state of flux and always has been since the first bacteria appeared on earth. It has nothing to do with man "allowing populations to stabilise". Populations just don't do that. If you think they do, then doubtless from your extensive reading on the subject you will be able to produce some examples. Still, if, as you appear to do, you believe in "the balance of nature", then you will doubtless be interested to know that you share this belief with landowners and gamekeepers who regularly claim that birds of prey "upset the balance of nature" and want to use this meaningless phrase as an excuse to kill them. Come, come, it's a well known fact that gamekeepers only kill birds of prey and so on to save them from a horrible death by starvation once their masters have shot the raptor's food. |
#65
|
|||
|
|||
"Malcolm" wrote in message ... In article , snip I am surprised you are not aware of this. You shouldn't be. I have made my views on the matter clear on a number of past occasions. I await your examples of "the balance of nature" in action, of populations that have managed to "stabilise in accordance with their habitat". He has you there, Malcolm - there are far more species with a stable population than unstable. All the extinct ones. |
#66
|
|||
|
|||
On Wed, 13 Apr 2005 09:17:22 GMT, Karen wrote:
On Wed, 13 Apr 2005 10:33:06 +0200, Tim Challenger wrote: On Tue, 12 Apr 2005 07:09:47 GMT, Paul wrote: We all know killing large numbers of animals merely causes them to breed more and quicker. That's the solution to our overfishing problem. Damn, I wish I'd thought of that. Just as well you're not allowed out much. I was being sarcastic. -- Tim C. |
#67
|
|||
|
|||
On Wed, 13 Apr 2005 17:09:21 +0200, Tim Challenger
wrote: On Wed, 13 Apr 2005 09:17:22 GMT, Karen wrote: On Wed, 13 Apr 2005 10:33:06 +0200, Tim Challenger wrote: On Tue, 12 Apr 2005 07:09:47 GMT, Paul wrote: We all know killing large numbers of animals merely causes them to breed more and quicker. That's the solution to our overfishing problem. Damn, I wish I'd thought of that. Just as well you're not allowed out much. I was being sarcastic. So was I. |
#68
|
|||
|
|||
"Malcolm" wrote in message ... In article , BAC writes "Malcolm" wrote in message ... In article , snip I am surprised you are not aware of this. You shouldn't be. I have made my views on the matter clear on a number of past occasions. I await your examples of "the balance of nature" in action, of populations that have managed to "stabilise in accordance with their habitat". He has you there, Malcolm - there are far more species with a stable population than unstable. All the extinct ones. Ho, ho! I think, though, that you will need to consider whether, if an animal is extinct, it can be said to have a population of any kind..... For it to be extinct, it has to have a stable population of zero. No extant species, of course, is likely to have a stable population (in the sense of a static, fixed, unvarying number of individuals), even if it were possible to count its numbers accurately at any given time. I think what Angus means when he says populations 'stabilise in accordance with their habitat' is that they tend towards equilibrium abundance. Of course, there will be many factors likely to disturb any such equilibrium, I'm sure he knows that, since it has been discussed at length here several times in the past. The 'balance of nature' he is on about is, I believe, a term to describe the various mechanisms which prevent a population from increasing indefinitely beyond the carrying capacity of its range. |
#69
|
|||
|
|||
"Malcolm Kane" wrote in message ... In message , BAC writes "Malcolm Kane" wrote in message ... In message , writes On Tue, 12 Apr 2005 08:47:22 +0100, "Tumbleweed" wrote: "Paul" wrote in message ... Why do the RSPB and other conservation hooligan charities such as the Woodland Trust kill wildlife rather than manage it properly. We all know killing large numbers of animals merely causes them to breed more and quicker. Thats must be why there are lots of whales then? No, It is always possible to slaughter a species almost to extinction. But surely Angus when the main pressure was taken off a number of years ago this principle you have quoted before that it causes faster breeding would by now have been making a really noticeable difference. The concept of population rebound in some species may not be as far fetched as you seem to believe. From Deer-UK's ecology of the Roe Deer, http://www.deer-uk.com/roe_deer.htm "In good conditions Roe have a high fecundity rate. In the South of England twins are the norm and in very good conditions triplets are not uncommon. Many triplet fetuses are found during a post-mortem examination, though not all would necessarily have been born alive. But if all three fetuses are the same size, the indications are that all three will be live at birth. Should one or more be smaller than the others, then it is unlikely it would have been born alive. In a particularly cold and/or wet early summer and autumn, the survival of all three triplets is greatly reduced and it is normally buck kids that fare worst. This could be due to nature perpetuating the species by saving the does for the following breeding season." So, following extensive culling, it seems probable there would be reduced competition for available fodder etc amongst the survivors, hence the incidence of multiple births would be likely to increase, until the population reached 'normal' densities for the prevailing conditions. I do not know whether the near extinction of some of the planet's cetaceans will have had any effect on their species' birth rates, (it seems less likely) but some experts are estimating the annual population growth of some species at between 7 and 8% since the general ban was introduced. I would suggest that the climate etc. is far more of a difference between North and South than the difference in fodder due to removal of population. For example if we take deer which we have been discussing. Roe are the commonest round here and getting commoner if the sightings I have over the years are any guide. There is obviously more than ample fodder after all they eat what the sheep and cattle eat. Using the fodder theory killing off a significant proportion should increase the numbers being born. I would see this as doubtful as they aren't at the moment restricted by food supplies. Population dynamics will be determined by the interplay between mortality and recruitment within the population. If a local population is already in optimal conditions for reproductive success, such that a reduction in the population would be unlikely to lead to better conditioned females with an increase in multiple births, and/or an increase in infant survival rates, then I would agree no change would be likely to be evident, since 'recruitment' would already be at maximum rates. However, if culling or a natural catastrophe were to create more favourable conditions for multiple births and/or infant survival rates, then the existence of the mechanism previously described suggests a faster than anticipated 'rebound' would be possible. |
#70
|
|||
|
|||
On Wed, 13 Apr 2005 18:20:34 +0100, Malcolm Kane
wrote: In message , writes On Wed, 13 Apr 2005 08:40:35 +0100, Malcolm wrote: In article , writes On Wed, 13 Apr 2005 07:44:32 +0100, Malcolm wrote: In article , Tumbleweed writes wrote in message news:s2bo51d3u4dno3lvj4n22g808bkicg9s2k@4ax. com... Absolute rubbish. Old and weak will undoubtably succumb to cold but that's natural and can improve the gene pool. Over time without un-natural pressures deer populations like any other species will stabilise in accordance with their habitat. Its a myth that populations stabilise. Try reading some modern textbooks. He won't. He has been recommended to do this before, including being given some actual titles of such books, but he prefers to remain ignorant on such basic matters as ecology, conservation, population control, woodland management, deer management, etc., etc., because he is presumably afraid that if he actually studied the subjects he might learn something that ran counter to his prejudices. What you mention above are reasons why man is not allowing populations to stabilise. You never disappoint when you show your ignorance :-) There's no such thing as a stabilised population, just as there is no such thing as a "state of equilibrium" which you were waffling about some while back. Every population is in a state of flux and always has been since the first bacteria appeared on earth. It has nothing to do with man "allowing populations to stabilise". No you're confused. Man does not allow populations to stabilise. As I have just written in another post Angus will be right nobody who does not fit in with his prejudices and AR agenda can possibly right - even if it is the rest of the world. Denial or what? You're paranoid :-) Angus Macmillan www.roots-of-blood.org.uk www.killhunting.org www.con-servation.org.uk |
#71
|
|||
|
|||
On Wed, 13 Apr 2005 11:15:31 +0100, Malcolm
wrote: In article , writes On Wed, 13 Apr 2005 08:40:35 +0100, Malcolm wrote: In article , writes On Wed, 13 Apr 2005 07:44:32 +0100, Malcolm wrote: In article , Tumbleweed writes wrote in message news:s2bo51d3u4dno3lvj4n22g808bkicg9s2k@4ax. com... Absolute rubbish. Old and weak will undoubtably succumb to cold but that's natural and can improve the gene pool. Over time without un-natural pressures deer populations like any other species will stabilise in accordance with their habitat. Its a myth that populations stabilise. Try reading some modern textbooks. He won't. He has been recommended to do this before, including being given some actual titles of such books, but he prefers to remain ignorant on such basic matters as ecology, conservation, population control, woodland management, deer management, etc., etc., because he is presumably afraid that if he actually studied the subjects he might learn something that ran counter to his prejudices. What you mention above are reasons why man is not allowing populations to stabilise. You never disappoint when you show your ignorance :-) There's no such thing as a stabilised population, just as there is no such thing as a "state of equilibrium" which you were waffling about some while back. Every population is in a state of flux and always has been since the first bacteria appeared on earth. It has nothing to do with man "allowing populations to stabilise". No you're confused. Man does not allow populations to stabilise. No, I'm not confused. So you're confused about being confused. You often accuse me of being that, but it is merely an indication that you're not able to answer my points. Whether or not man is affecting populations, they still won't ever "stabilise". Of course they will in accordance with their habitat. If the habitat changes, so will the organism. Pretty basic stuff. Populations just don't do that. If you think they do, then doubtless from your extensive reading on the subject you will be able to produce some examples. All populations stabilise in accordance with their habitat. If you believe that, then doubtless from your extensive reading on the subject you will be able to produce some examples of this happening, won't you? Don't be daft, Malcolm. This is your favourite ploy. When you can't justify something you ask for intangible examples. Still, if, as you appear to do, you believe in "the balance of nature", then you will doubtless be interested to know that you share this belief with landowners and gamekeepers who regularly claim that birds of prey "upset the balance of nature" and want to use this meaningless phrase as an excuse to kill them. Of course I believe in the balance of nature. And thereby give encouragement to landowners and keepers who want to cull birds of prey :-(( Not at all, because their breeding systems are not natural nor is the introduction of birds of prey. You really suffer from silly wooly thinking :-) And like all balances it is subject to movement as the weight on either side changes. The movement will be greatest when a population is out of balance with its habitat but if left alone will gradually approach a position where there is hardly any movement at all unless influenced by outside forces. If you believe this, then you will be able to give some examples of it happening, won't you? I would be very interested to learn of the existence of a completely closed system with "hardly any movement at all" which has no "outside forces" influencing it. There's no such thing as a closed system in nature, Malcolm. I thought you might know that. You're showing your confusion again :-( I am surprised you are not aware of this. You shouldn't be. I have made my views on the matter clear on a number of past occasions. Your views don't mean you understand the matter. I await your examples of "the balance of nature" in action, of populations that have managed to "stabilise in accordance with their habitat". Don't be daft, Malcolm. This is your favourite ploy. When you can't justify something you ask for intangible examples. Tell you what. If there's no such thing as the "balance of nature", why would it be in your favourite reference book you use all the time? The SOED. I think you're confused about the word "stabilise". It doesn't mean cast in stone. A ship can be stable but also move about. A population can be stable but also move in relation to its habitat. If you're still confused, consult a real doctor :-) Angus Macmillan www.roots-of-blood.org.uk www.killhunting.org www.con-servation.org.uk |
#72
|
|||
|
|||
|
#73
|
|||
|
|||
In message , BAC
writes "Malcolm Kane" wrote in message ... In message , BAC writes "Malcolm Kane" wrote in message ... In message , writes On Tue, 12 Apr 2005 08:47:22 +0100, "Tumbleweed" wrote: "Paul" wrote in message ... Why do the RSPB and other conservation hooligan charities such as the Woodland Trust kill wildlife rather than manage it properly. We all know killing large numbers of animals merely causes them to breed more and quicker. Thats must be why there are lots of whales then? No, It is always possible to slaughter a species almost to extinction. But surely Angus when the main pressure was taken off a number of years ago this principle you have quoted before that it causes faster breeding would by now have been making a really noticeable difference. The concept of population rebound in some species may not be as far fetched as you seem to believe. From Deer-UK's ecology of the Roe Deer, http://www.deer-uk.com/roe_deer.htm "In good conditions Roe have a high fecundity rate. In the South of England twins are the norm and in very good conditions triplets are not uncommon. Many triplet fetuses are found during a post-mortem examination, though not all would necessarily have been born alive. But if all three fetuses are the same size, the indications are that all three will be live at birth. Should one or more be smaller than the others, then it is unlikely it would have been born alive. In a particularly cold and/or wet early summer and autumn, the survival of all three triplets is greatly reduced and it is normally buck kids that fare worst. This could be due to nature perpetuating the species by saving the does for the following breeding season." So, following extensive culling, it seems probable there would be reduced competition for available fodder etc amongst the survivors, hence the incidence of multiple births would be likely to increase, until the population reached 'normal' densities for the prevailing conditions. I do not know whether the near extinction of some of the planet's cetaceans will have had any effect on their species' birth rates, (it seems less likely) but some experts are estimating the annual population growth of some species at between 7 and 8% since the general ban was introduced. I would suggest that the climate etc. is far more of a difference between North and South than the difference in fodder due to removal of population. For example if we take deer which we have been discussing. Roe are the commonest round here and getting commoner if the sightings I have over the years are any guide. There is obviously more than ample fodder after all they eat what the sheep and cattle eat. Using the fodder theory killing off a significant proportion should increase the numbers being born. I would see this as doubtful as they aren't at the moment restricted by food supplies. Population dynamics will be determined by the interplay between mortality and recruitment within the population. If a local population is already in optimal conditions for reproductive success, such that a reduction in the population would be unlikely to lead to better conditioned females with an increase in multiple births, and/or an increase in infant survival rates, then I would agree no change would be likely to be evident, since 'recruitment' would already be at maximum rates. However, if culling or a natural catastrophe were to create more favourable conditions for multiple births and/or infant survival rates, then the existence of the mechanism previously described suggests a faster than anticipated 'rebound' would be possible. Would it be faster than * anticipated*? It appears that you at least would anticipate it. -- Malcolm Kane |
#74
|
|||
|
|||
On Wed, 13 Apr 2005 20:51:46 +0100, Malcolm Kane
wrote: In message , writes If you believe that, then doubtless from your extensive reading on the subject you will be able to produce some examples of this happening, won't you? Don't be daft, Malcolm. This is your favourite ploy. When you can't justify something you ask for intangible examples. NO NO Angus the very thing he does not want is intangible examples. He (we) always want very tangible ones please. Stop twisting. Angus Macmillan www.roots-of-blood.org.uk www.killhunting.org www.con-servation.org.uk |
#75
|
|||
|
|||
On Wed, 13 Apr 2005 16:47:42 GMT, Karen wrote:
On Wed, 13 Apr 2005 17:09:21 +0200, Tim Challenger wrote: On Wed, 13 Apr 2005 09:17:22 GMT, Karen wrote: On Wed, 13 Apr 2005 10:33:06 +0200, Tim Challenger wrote: On Tue, 12 Apr 2005 07:09:47 GMT, Paul wrote: We all know killing large numbers of animals merely causes them to breed more and quicker. That's the solution to our overfishing problem. Damn, I wish I'd thought of that. Just as well you're not allowed out much. I was being sarcastic. So was I. Difficult to tell. -- Tim C. |
Reply |
Thread Tools | Search this Thread |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Forum | |||
Farm size and population story | Edible Gardening | |||
Who is Responsible for the Size of Our Troll Population? | United Kingdom | |||
Responsible pet ownership (was nancy' pet) | Australia |