Jump to content


Cold kill of Burmese pythons in Everglades


  • Please log in to reply
35 replies to this topic

#21 Guest_keepnatives_*

Guest_keepnatives_*
  • Guests

Posted 29 March 2010 - 06:29 PM

These are ten, twelve foot long snakes. They're not going to eat a heck of a lot of wood rats beyond a certain point.


Yes, but since they are breeding there will likely be plenty of smaller ones taking advantage of wood rats to get to that 10-12 foot size.

#22 Guest_IsaacSzabo_*

Guest_IsaacSzabo_*
  • Guests

Posted 31 March 2010 - 08:55 PM

I was thinking about this topic recently after watching a PBS Nature show about it. You can watch it for free online here: Nature: Invasion of the Giant Pythons. I didn’t think the show was extremely informative, but it was interesting enough.

I’m no expert, but one way I thought about the possible impact of the invasive pythons was to think about the issue in terms of energy flow in the ecosystem. When you consider tens of thousands of snakes that can weigh up to 200 pounds each in a few years, you’re talking about hundreds or perhaps thousands of tons of biomass that is being redirected in the ecosystem. That, coupled with the fact that the snakes are pretty much apex predators, leads me to think that the pythons will have a significant effect on trophic cascades in the ecosystem. However, I have no clue as to the exact nature of the effects. Like Mikez said, a gut-content study with a large sample size would shed some light on the issue.

#23 Guest_wargreen_*

Guest_wargreen_*
  • Guests

Posted 31 March 2010 - 09:51 PM

some lines of evidence that certain invasives improve habitat for certain native species, just as certain human land uses are beneficial to some species. Witness the expansion of prairie-loving coyotes into the once-wooded eastern states, for example; I also suspect Dorosoma shads, among others, are far more abundant in reservoirs than they would have been in free-flowing large rivers.

The problem is not so much "exotics bad" as that we don't know what exotics will do; throw them into a dynamic ecosystem that hasn't been in a steady state at any point in the last 10,000 years at least (resulting in a lot of open niches) and who can say what effect they might have? Most introductions may be benign. Some are clearly negative. Some may have positive effects. We really don't know what all the effects of any introduction are. We get most upset about spectacular species like pythons and kudzu or nuisances like zebra mussels and fire ants, but that doesn't mean they're the worst or the most important. How have dandelions and white clover affected native species, or house sparrows and earthworms? We just don't know.
:ohmy: Human land uses have been good for a few native species at the expense of many. Coyotes are expanding into the once wooded eastern states because the wolves in many areas have been wiped out and the trees cleared, the resevoirs that the Dorosoma shads live in changed habitat that has drivin many species of fish that needed rapids and riverine conditions into extinction or onto the endangered list, zebra mussels have been shown to outcompete native mussels and are harder for our native fish to eat (they have thicker shells) I was stationed in the military in areas that had big snakes and have seen in the jungles what they can do (Panama),please read up on how much farmers and others have had to pay to get rid of fire ant infestations......and there are mounds of scientific evidence, and hundreds of articles on just zebra mussels and Kudzu. Here in Missouri studies have shown that House Sparrows (very territorial and vicious birds are responsible for the decline of many of our native Bluebirds (used to be common and is our state bird) I personally havent seen a Bluebird in years. We have alot of information gleaned from universities and state wildlife departments in the last 50 yrs in the US to prove this 8) .

Edited by wargreen, 31 March 2010 - 09:52 PM.


#24 Guest_Newt_*

Guest_Newt_*
  • Guests

Posted 01 April 2010 - 12:40 PM

I hope you don't think I'm defending the introduction of exotics- certainly I'm not! What I am defending is rigorous investigation, for reasons of principle (I'm against sloppy thinking) and pragmatism. If we use "just-so" stories about invasives to argue for policy change, our argument is weak and subject to easy refutation. "Where's the proof?"

A lot of the info indicating that decline of one species is "caused" by the presence of another species is anecdotal or correlational in nature. One species' population goes up, another's goes down; this doesn't mean that one is driving the other out, but could instead be related to some third trend, such as a change in habitat availability. Any number of bird hunters are convinced that turkey move into an area and destroy the quail or grouse living there, but the truth is that the smaller birds prefer habitat in an earlier stage of succession than the turkeys do. As an old field gets brushier, the small birds head out for more preferred haunts and the turkey move in.

Similarly with bluebirds and house sparrows- the conflict between them only arises when nest sites are in limited supply. This was not the case when field rows, woodlines, and windbreaks with standing dead timber were plentiful, but changes in land use (such as modern, "efficient" cropping) have eliminated many of these. Where bluebird box programs have been instituted or where succesional farmsteads are again providing lots of bluebird-useable nest sites, as here in Tennessee, both species are common. So, it's not a case of an invasive species causing a native to decline- it's more complex than that.

There is also precious little evidence to support the wolf/coyote exclusion hypothesis. Wolves were vanishingly scarce in the east for a century before coyotes made their way here, and coyotes were sympatric with both red and gray wolves in the west long before that. Wolves and smaller canids are not direct competitors in most environments.

In all of these cases, the common thread is a change in land use that sparked both the increase of invasives and decrease of natives. However, land use changes are a very complex issue. For one thing, there's no clear line between "natural" and "artificial" land use. The modern North American landscape developed with people in it. Many eastern populations of grassland-loving birds, flowers, insects, etc. relied on the vast "barrens" created or maintained by Native American hunters' fires; when the hunters were driven out and the fires suppressed, they switched to pastures and fallow fields. If we were to take a "hands off" approach and let the landscape "heal" itself, these pseudoprairies would be reclaimed by the forest and the grassland-lovers would disappear.

Sorry for the diatribe. More later if I remember.

#25 Guest_Newt_*

Guest_Newt_*
  • Guests

Posted 01 April 2010 - 12:43 PM

These are ten, twelve foot long snakes. They're not going to eat a heck of a lot of wood rats beyond a certain point.


They will if that's the largest mammalian prey available, which is likely the case on many of these keys. Which may wwell prevent them from acheiving 10-12 foot lengths. Unfortunately their most likely direct competitor, the indigo ssnake, is itself quite imperiled.

#26 Guest_wargreen_*

Guest_wargreen_*
  • Guests

Posted 02 April 2010 - 08:00 PM

Newt, I agree 100% with you for "rigorous investigation"; a good investigation sometimes can take years and for many endangered species I believe that is just too long (I believe they should still be done....and as we speak ARE being done by universities and state agencies). In many of the studies wildlife agencies do (Ive read the ones on cichlids in the Everglades and Gobies in the Great Lakes), they go by the biomass of a lake or river or even an area. If water quality, food resources and topography is unchanged and the biomass changes from a majority native to a majority exotic studies are done as to why. In the case of sculpins in the great lakes it was found that round Gobies would take the nesting sites of sculpins and or kill them and can reproduce at a greater rate than the sculpins can. Similar studies have been done on the relation between Cichlids and Tilapia and Sunfish in the everglades....those studies plus electroshocking for biomass results mean I would have to disagree on you calling this information " anecdotal or correlational in nature." :wink: I also agree that changes in land and water quality does play a huge part and have a big impact on our natives and should be addressed......but often the exotic invasives are taking the same niche that our natives once filled (snakeheads replacing LMBs, Gobies replacing Sculpins, Mayan Cichlids replacing Sunfish, Carp replacing some species of Suckers, LMBs replacing Sacramento Perch, Mosquitofish replacing Pupfish etc.). I would also like to argue that 10 acres of woodland can support more animal diversity than 10 acres of subdivision and that replacing rivers with lakes has lessened the amount of diversity in our watersheds, on prarie lands I would need to see the rigorous investigations you are referring too to understand. What Im worried about is preserving out natural heritage.....not the fact that the Oscar can fight harder and is easier to catch than Bluegill in some lakes in Southern Florida or that Asian Carp can get to 80lbs and that hundreds of people will travel from Europe to catch them (not good reasons in my book to support them replacing natives); Florida Bluegill, Flagfish, Everglades Pygmy Sunfish are only found in Penninsular Florida and Southern Georgia, and Paddlefish and many species of fish in the Mississippi drainage are only in North America; whereas the Mayan Cichlis is common in Central America and the Oscar is common in South America. I am not trying to be difficult or insolent Ive read your posts and know you are knowledgeable and intelligent but what Ive seen and read these are the facts.....and I believe not easily refuted (I once again would need to see scientific evidence to the contrary). :grin: Thanks Joe.

#27 Guest_Brooklamprey_*

Guest_Brooklamprey_*
  • Guests

Posted 02 April 2010 - 09:51 PM

In the case of sculpins in the great lakes it was found that round Gobies would take the nesting sites of sculpins and or kill them and can reproduce at a greater rate than the sculpins can.


Welcome to 2010....

things have changed drastically. At the risk of outing something I really should keep quiet until further work is done.(More really needs to be done) I have rather good evidence of Sculpin and Goby now working together. Populations of sculpin here are rising dramatically and where a few years ago they where non-existent they are now common again. Something very interesting is that Breeding and nesting sculpin are now directly associated with breeding and nesting Round goby. I'm regularly now finding both Goby and Sculpin nests (Or at least reproductive males) under the same rocks.

Anecdotally, They have begun to cooperate with one another for the purpose of nest protection...This is the trend I'm noticing. They are adapting to each other and both are benefiting. For quite a few years Sculpin where just non existent around here. I feared them as exterminated entirely. They are now back in force and not uncommon at all..The direct association of goby and Sculpin nests under the same rocks and shelter is very intriguing and quite interesting.

#28 Guest_wargreen_*

Guest_wargreen_*
  • Guests

Posted 03 April 2010 - 06:53 AM

Welcome to 2010....

things have changed drastically. At the risk of outing something I really should keep quiet until further work is done.(More really needs to be done) I have rather good evidence of Sculpin and Goby now working together. Populations of sculpin here are rising dramatically and where a few years ago they where non-existent they are now common again. Something very interesting is that Breeding and nesting sculpin are now directly associated with breeding and nesting Round goby. I'm regularly now finding both Goby and Sculpin nests (Or at least reproductive males) under the same rocks.

Anecdotally, They have begun to cooperate with one another for the purpose of nest protection...This is the trend I'm noticing. They are adapting to each other and both are benefiting. For quite a few years Sculpin where just non existent around here. I feared them as exterminated entirely. They are now back in force and not uncommon at all..The direct association of goby and Sculpin nests under the same rocks and shelter is very intriguing and quite interesting.

:blush:
Hmmmn that is interesting.....is this observation shown true in more than one area of the Great Lakes or is this isolated to the area where the a stream or river meets the Great Lakes. I really hope this becomes the norm in Sculpin/Goby interactions, maybe we could teach governments to do the same :lol: . My next question would have to be, did the gobies suffer a die off due to the cold winter we suffered through last season? If they did, would the Population dynamic affect the relational dynamic between the two :?: PS maybe they saw the Asian Carp coming :mrgreen:

#29 Guest_schambers_*

Guest_schambers_*
  • Guests

Posted 03 April 2010 - 11:52 AM

My next question would have to be, did the gobies suffer a die off due to the cold winter we suffered through last season?


Winter in the Great Lakes area was not abnormally cold, so I doubt it.

#30 Guest_Brooklamprey_*

Guest_Brooklamprey_*
  • Guests

Posted 03 April 2010 - 09:40 PM

:blush:
Hmmmn that is interesting.....is this observation shown true in more than one area of the Great Lakes or is this isolated to the area where the a stream or river meets the Great Lakes. I really hope this becomes the norm in Sculpin/Goby interactions, maybe we could teach governments to do the same :lol: . My next question would have to be, did the gobies suffer a die off due to the cold winter we suffered through last season? If they did, would the Population dynamic affect the relational dynamic between the two :?: PS maybe they saw the Asian Carp coming :mrgreen:


This is occurring smack dab in the center of where the Goby infestation began right at the Mouth of the Detroit river and Lake St. Clair. This is ground zero really.. From 1997 to 2008 we had zero or very rare sculpin around here . They where all but exterminated, since 2008 the population is growing. There where a few dramatic Goby kills associated with VHS in 2005 and 2007 we had a marked decline in Gobies. They Remain omnipresent but in greatly reduced numbers. What is being observed right now is a definite resurgence of Sculpins. This year alone I've seen at least a hundred Mottled and at least five slimy all on one study site. I have no idea what is going on elsewhere but this is what is being observed here in this locality.

As stated earlier a lot of careful work needs to be worked out with this. No one as of yet is looking at it and these are just the observations being noticed out of a Mudpuppy study in the area and not a direct Sculpin or Goby study.

#31 Guest_mikez_*

Guest_mikez_*
  • Guests

Posted 04 April 2010 - 06:32 PM

There are so many really bad actors - somebody mentioned moths, you wanna talk dollars and cents? Different ways to measure the disaster.

Blue birds are worth study, the past 50 years, with the bird box program, has made eastern blue birds a staple up and down the coast. I can show you six active blue bird boxes on the next block. You will not find a house sparrow use a bluebird box. The sparrows get the town and city, blue birds the suburbs and farms. They are mutually exclusive. Question is, would bluebirds nest in garage gutters and church stepples if no sparrows were there? Doubt it.

The bird that does the most harm to nesting song birds around here is the cow bird. That's a native of the prairies that adpated to man and became an invasive species in its own country.

Oh well, pythons can't be good but they're not gonna slither into DC any time soon. Hopefully cold snaps, prey availablity and possible managment options will knock them back.
My understanding is there is good science going on despite the diatribe online. I'd give anything to be on the crews bushwhacking the glades for big snakes. Hopefully it gets published and desimminated in good time..

#32 Guest_jase_*

Guest_jase_*
  • Guests

Posted 05 April 2010 - 10:24 AM

Blue birds are worth study, the past 50 years, with the bird box program, has made eastern blue birds a staple up and down the coast. I can show you six active blue bird boxes on the next block. You will not find a house sparrow use a bluebird box. The sparrows get the town and city, blue birds the suburbs and farms. They are mutually exclusive. Question is, would bluebirds nest in garage gutters and church stepples if no sparrows were there? Doubt it.

I haven't taken the time to look up primary sources, but I think it's pretty well documented that house sparrows do directly compete with bluebirds and other cavity nesters outside of urban areas. I'm not certain how significant that competition is on a population scale, but it does occur. http://www.sialis.or....htm#theproblem

#33 Guest_nativeplanter_*

Guest_nativeplanter_*
  • Guests

Posted 05 April 2010 - 02:02 PM

...They have begun to cooperate with one another for the purpose of nest protection...This is the trend I'm noticing. They are adapting to each other and both are benefiting...


Do you think the sculpins are benefitting from the gobies more than they would if their neighbor was another sculpin instead? (I don't know much about sculpins and whether they set up territories).

#34 Guest_mikez_*

Guest_mikez_*
  • Guests

Posted 07 April 2010 - 05:58 AM

I haven't taken the time to look up primary sources, but I think it's pretty well documented that house sparrows do directly compete with bluebirds and other cavity nesters outside of urban areas. I'm not certain how significant that competition is on a population scale, but it does occur. http://www.sialis.or....htm#theproblem


May be documented but I keep very close track of nesting birds and have several blue bird boxes and have never, ever, ever seen house sparrows in bird boxes or hollow trees.
Also, having oppurtunity to watch nesting blue birds closely for many seasons, I do not believe house sparrows can bully blue birds out of a box. They easily beat off tree swallows and starlings [who can't fit box entrances but try anyway].
I'm not arguing that house sparrows are benign, just that with human help, blue birds have rallied and are doing very, very well. At least in the Ma suburbs.
[Yah, I'm a freak - there are house sparrows singing and nest building outside my window as I type - and I like it :-$ ]

#35 Guest_nativeplanter_*

Guest_nativeplanter_*
  • Guests

Posted 09 April 2010 - 12:40 PM

May be documented but I keep very close track of nesting birds and have several blue bird boxes and have never, ever, ever seen house sparrows in bird boxes or hollow trees.
Also, having oppurtunity to watch nesting blue birds closely for many seasons, I do not believe house sparrows can bully blue birds out of a box.


Interesting. I had always been told that the sparrows intentionally kill bluebird chicks, and that nesting boxes should be monitored. (For example see http://www.nabluebir.../monitoring.htm)

I have never worked with them, though. It does get me thinking now that our new old house has a very nice yard that might be perfect for bluebirds.

#36 Guest_mikez_*

Guest_mikez_*
  • Guests

Posted 12 April 2010 - 07:45 PM

Interesting. I had always been told that the sparrows intentionally kill bluebird chicks, and that nesting boxes should be monitored. (For example see http://www.nabluebir.../monitoring.htm)

I have never worked with them, though. It does get me thinking now that our new old house has a very nice yard that might be perfect for bluebirds.


If you have open space, by all means you should put up blue bird boxes. In your neighborhood, I'd suggest a snake guard. Black rat snakes specialize in nest robbing and they are very abundant in your general area.

I was lucky enough to have a box right outside my window at work for five years [15 broods, 14 successful]. The family groups formed flocks that stayed all winter for our winter berries and slept in the nest box at night.
I also monitored and photographed a couple of other nests over the years. You can see a sample of my nest project pics on FaceBook here:My link




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users