Taipan

Jul 9 2014, 06:30 PM

JackLumber

Jul 9 2014, 05:37 PM

Taipan

Jul 9 2014, 04:41 PM

Black Ice

Jul 9 2014, 07:45 AM

Monitor lizards apparently control feral cat populations in Australia somewhat.

Unfortunately no. Feral cats threaten many of Australi's reptile species - including species of Monitor Lizards.

Taipan

Jul 2 2012, 01:32 PM

"Research with Rosenberg’s Goanna (Green, Rismiller, McKelvey) has shown that feral cats are persistent predators. They frequently catch subadult goannas, opportunistically kill adults and in two cases have been documented to deliberately stalk and kill adult goannas. “…At 1600 hrs on 27 March 1996 we were radio tracking a female goanna which had been known in the study population for seventeen years. The signal came from an area that she seldom used. She was tracked to the entrance of a cat den in a mallee root burrow. The freshly killed carcass was found with six other dead goannas. All animals had been dead less than six hours. All had been killed with a single bite in the back of the head. Five were known individuals with implanted identification microchips. Using daily tracking records and home range maps for each individual goanna it was calculated that the greatest distance of probable catch from the cat den as approximately two kilometres. Circumstances suggest that the female cat had prior knowledge of each goannas activity pattern (at this time of year, many goannas have a daily foraging circuit) and had deliberately stalked, killed and brought the prey back to her kittens. The female cat was trapped and over the next five days six kittens were trapped or shot at the den (unpublished data, PLRC 1996).”
http://www.echidna.edu.au/projects/feral/feral_peggy.pdf

An adult Rosenberg's Goanna reaches up to 1.5 metres in length.
http://www.pittwater.nsw.gov.au/environment/plants__and__animals/threatened_species/animals/rosenbergs_goanna

1 he is actually entirely correct, adult large Goanna seem to take kittens with a fair amount of regularity which does indeed mean they are atleast minorly aiding in the supression of their population and thus aiding in their control.

Read this from the link you posted:

"Mr Birkett said when feral cats grew to adult size the tables were turned.

‘‘They are a significant predator of lizards, including young goannas,’’ he said.

In this case, the goanna won, which Mr Gorman said was not only incredible to witness, but also pleasing.

‘‘I have a big problem with seeing feral cats around because they do damage to the native wildlife, it was good to see the natives having a win,’’ he said.

Mr Birkett said despite their armoury of weapons, including a tail-flick, sharp claws and even sharper teeth, goannas would never win the numbers game.

‘‘The goanna won’t need a feed for quite some time after that,’’ he said, meaning the rest of the litter would be free to grow, breed and add to the number of feral pests in the bush."
http://www.mmg.com.au/local-news/shepparton/life-and-death-struggle-1.39884

Monitors can't keep up.

Bandog

Jul 9 2014, 06:35 PM

Oddly enough, I see loads more monitors than feral cats. The cats are more elusive I guess

JackLumber

Jul 9 2014, 06:41 PM

Taipan

Jul 9 2014, 06:30 PM

JackLumber

Jul 9 2014, 05:37 PM

Taipan

Jul 9 2014, 04:41 PM

Black Ice

Jul 9 2014, 07:45 AM

Monitor lizards apparently control feral cat populations in Australia somewhat.

Unfortunately no. Feral cats threaten many of Australi's reptile species - including species of Monitor Lizards.

Taipan

Jul 2 2012, 01:32 PM

"Research with Rosenberg’s Goanna (Green, Rismiller, McKelvey) has shown that feral cats are persistent predators. They frequently catch subadult goannas, opportunistically kill adults and in two cases have been documented to deliberately stalk and kill adult goannas. “…At 1600 hrs on 27 March 1996 we were radio tracking a female goanna which had been known in the study population for seventeen years. The signal came from an area that she seldom used. She was tracked to the entrance of a cat den in a mallee root burrow. The freshly killed carcass was found with six other dead goannas. All animals had been dead less than six hours. All had been killed with a single bite in the back of the head. Five were known individuals with implanted identification microchips. Using daily tracking records and home range maps for each individual goanna it was calculated that the greatest distance of probable catch from the cat den as approximately two kilometres. Circumstances suggest that the female cat had prior knowledge of each goannas activity pattern (at this time of year, many goannas have a daily foraging circuit) and had deliberately stalked, killed and brought the prey back to her kittens. The female cat was trapped and over the next five days six kittens were trapped or shot at the den (unpublished data, PLRC 1996).”
http://www.echidna.edu.au/projects/feral/feral_peggy.pdf

An adult Rosenberg's Goanna reaches up to 1.5 metres in length.
http://www.pittwater.nsw.gov.au/environment/plants__and__animals/threatened_species/animals/rosenbergs_goanna

1 he is actually entirely correct, adult large Goanna seem to take kittens with a fair amount of regularity which does indeed mean they are atleast minorly aiding in the supression of their population and thus aiding in their control.

Read this from the link you posted:

"Mr Birkett said when feral cats grew to adult size the tables were turned.

‘‘They are a significant predator of lizards, including young goannas,’’ he said.

In this case, the goanna won, which Mr Gorman said was not only incredible to witness, but also pleasing.

‘‘I have a big problem with seeing feral cats around because they do damage to the native wildlife, it was good to see the natives having a win,’’ he said.

Mr Birkett said despite their armoury of weapons, including a tail-flick, sharp claws and even sharper teeth, goannas would never win the numbers game.

‘‘The goanna won’t need a feed for quite some time after that,’’ he said, meaning the rest of the litter would be free to grow, breed and add to the number of feral pests in the bush."
http://www.mmg.com.au/local-news/shepparton/life-and-death-struggle-1.39884

Monitors can't keep up.

Considering that wildcats coexist with monitor lizards naturally in other enviroments, I find the idea of their watered down cousins taking out the aussie monitors less than likely but that's not the point.
Black ice said monitors lizards somewhat control feral cats, you said they don't but considering that large lizards are potential predators I don't see how that statement could be anything but false, whether they are making a large impact or not the numbers are still lower than if they didn't eat the young cats and thus they are aiding in the control of their numbers.
I really don't get how you can see it anyother way.

JackLumber

Jul 9 2014, 06:47 PM

Bandog

Jul 9 2014, 06:35 PM

Oddly enough, I see loads more monitors than feral cats. The cats are more elusive I guess

Feral cats are pretty skittish and fearful animals so there probably is a lot more than you see but its still entirely possible that the lizards out number them in your area.

FelinePowah

Jul 9 2014, 06:46 PM

Maybe the amount of kittens that the monitors kill just isnt enough to have any real effect on feral cat population size...so yes in effect they are not really helping keeping the population down.

The odd kitten here and there is nothing on the grand scheme of things..

Taipan

Jul 9 2014, 06:51 PM

JackLumber

Jul 9 2014, 06:41 PM

Taipan

Jul 9 2014, 06:30 PM

JackLumber

Jul 9 2014, 05:37 PM

Taipan

Jul 9 2014, 04:41 PM

Black Ice

Jul 9 2014, 07:45 AM

Monitor lizards apparently control feral cat populations in Australia somewhat.

Unfortunately no. Feral cats threaten many of Australi's reptile species - including species of Monitor Lizards.

Taipan

Jul 2 2012, 01:32 PM

"Research with Rosenberg’s Goanna (Green, Rismiller, McKelvey) has shown that feral cats are persistent predators. They frequently catch subadult goannas, opportunistically kill adults and in two cases have been documented to deliberately stalk and kill adult goannas. “…At 1600 hrs on 27 March 1996 we were radio tracking a female goanna which had been known in the study population for seventeen years. The signal came from an area that she seldom used. She was tracked to the entrance of a cat den in a mallee root burrow. The freshly killed carcass was found with six other dead goannas. All animals had been dead less than six hours. All had been killed with a single bite in the back of the head. Five were known individuals with implanted identification microchips. Using daily tracking records and home range maps for each individual goanna it was calculated that the greatest distance of probable catch from the cat den as approximately two kilometres. Circumstances suggest that the female cat had prior knowledge of each goannas activity pattern (at this time of year, many goannas have a daily foraging circuit) and had deliberately stalked, killed and brought the prey back to her kittens. The female cat was trapped and over the next five days six kittens were trapped or shot at the den (unpublished data, PLRC 1996).”
http://www.echidna.edu.au/projects/feral/feral_peggy.pdf

An adult Rosenberg's Goanna reaches up to 1.5 metres in length.
http://www.pittwater.nsw.gov.au/environment/plants__and__animals/threatened_species/animals/rosenbergs_goanna

1 he is actually entirely correct, adult large Goanna seem to take kittens with a fair amount of regularity which does indeed mean they are atleast minorly aiding in the supression of their population and thus aiding in their control.

Read this from the link you posted:

"Mr Birkett said when feral cats grew to adult size the tables were turned.

‘‘They are a significant predator of lizards, including young goannas,’’ he said.

In this case, the goanna won, which Mr Gorman said was not only incredible to witness, but also pleasing.

‘‘I have a big problem with seeing feral cats around because they do damage to the native wildlife, it was good to see the natives having a win,’’ he said.

Mr Birkett said despite their armoury of weapons, including a tail-flick, sharp claws and even sharper teeth, goannas would never win the numbers game.

‘‘The goanna won’t need a feed for quite some time after that,’’ he said, meaning the rest of the litter would be free to grow, breed and add to the number of feral pests in the bush."
http://www.mmg.com.au/local-news/shepparton/life-and-death-struggle-1.39884

Monitors can't keep up.

Considering that wildcats coexist with monitor lizards naturally in other enviroments, I find the idea of their watered down cousins taking out the aussie monitors less than likely but that's not the point.
Black ice said monitors lizards somewhat control feral cats, you said they don't but considering that large lizards are potential predators I don't see how that statement could be anything but false, whether they are making a large impact or not the numbers are still lower than if they didn't eat the young cats and thus they are aiding in the control of their numbers.
I really don't get how you can see it anyother way.

No. Try foxes and dingoes - they suppress cat numbers. Monitor Lizards support and increase cat numbers - they are a key part of the cats diet. Its pretty basic.

JackLumber

Jul 9 2014, 07:06 PM

]Rubbish, key parts of a predators diet are species that the predator relies on for survival
Ie cougars and deer, lynx and hare, wildcats and small rodents etc etc
The idea that if monitors did disappear it would cause a sharp decline like if the prey animals in the above relationships were removed is not something I'm about to swallow without a proper study into the diet of australian feral cats.

Its pretty basic, the number of cats would go up if large lizards stopped eating any of them and so large lizard help control feral cats.
Simple really.

Quote:

 

He learned they're not picky eaters. Bugs, frogs, smaller lizards, turtles, birds, rodents, baby alligators, endangered gopher tortoises, endangered burrowing owls, the eggs and offspring of any of these animals, feral cats, domestic cats, possibly even the family dog, road kill, whatever.

Black Ice

Jul 9 2014, 07:28 PM

I doubt it's one sided

Quote:

 

He learned they're not picky eaters. Bugs, frogs, smaller lizards, turtles, birds, rodents, baby alligators, endangered gopher tortoises, endangered burrowing owls, the eggs and offspring of any of these animals, feral cats, domestic cats, possibly even the family dog, road kill, whatever.

http://www.tampabay.com/news/environment/wildlife/nile-monitor-lizards-invaded-florida-and-theyre-winning-the-battle/1011745

FelinePowah

Jul 9 2014, 07:37 PM

Black Ice

Jul 9 2014, 07:28 PM

I doubt it's one sided

Quote:

 

He learned they're not picky eaters. Bugs, frogs, smaller lizards, turtles, birds, rodents, baby alligators, endangered gopher tortoises, endangered burrowing owls, the eggs and offspring of any of these animals, feral cats, domestic cats, possibly even the family dog, road kill, whatever.

http://www.tampabay.com/news/environment/wildlife/nile-monitor-lizards-invaded-florida-and-theyre-winning-the-battle/1011745

Thats not Australia...