tag:blogger.com,1999:blog-7443075087825368900.post4356181826722782147..comments2024-01-04T05:26:02.451-07:00Comments on Life is short, but snakes are long: Galápagos Racers: answers to your questions about the BBC Planet Earth II iguana chase sceneAndrew Dursohttp://www.blogger.com/profile/04720822623046554913noreply@blogger.comBlogger14125tag:blogger.com,1999:blog-7443075087825368900.post-45819164328685086322018-08-31T00:23:16.226-06:002018-08-31T00:23:16.226-06:00@LerahPike Thank you for the compliment! Galapagos...@LerahPike Thank you for the compliment! Galapagos racers are pretty small snakes. The species in Planet Earth II (P. occidentalis, at least for now) is the largest, reaching about 45 inches in total (35 for the body, 10 for the tail). The other species are smaller, from about 17 to 36 inches total length. It's a testament to the camera operator's & film editor's skill that they were able to make them look so large & scary (although people's general fear of snakes probably helped).<br /><br />@BkJeong Thanks! I saw that mentioned in the GQ interview linked above.Andrew Dursohttps://www.blogger.com/profile/04720822623046554913noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-32969407832602736242018-08-19T16:29:15.137-06:002018-08-19T16:29:15.137-06:00If it's of any interest, the crew apparently d...If it's of any interest, the crew apparently did see cases of cannibalism when multiple snakes grabbed the same iguana/BKhttps://www.blogger.com/profile/03759189747932749283noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-83433745850122317152018-07-25T19:56:32.607-06:002018-07-25T19:56:32.607-06:00The racer snakes in the planet earth episode look ...The racer snakes in the planet earth episode look like their lengths go on forever. How long are they? I really enjoyed reading this wonderful Q&A. Thanks. <br /><br />Lerah PikeLerah Pikehttps://www.blogger.com/profile/11487680609798210940noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-72345197444783792092018-05-02T01:43:50.670-06:002018-05-02T01:43:50.670-06:00These are excellent questions. The iguanas in Plan...These are excellent questions. The iguanas in Planet Earth II are marine iguanas. Having not been to the location where the scene was filmed, I can't say what the access to the beach would be like, but I'm certain that the nesting area is close enough to the beach that the juveniles can disperse there (even if they have to run from snakes while doing so).<br /><br />I suspect that often the snake with the best grip gets to eat the whole iguana. It's possible that a snake could eat both the iguana and another snake, but I suspect this is rare. I don't think the snakes are capable of such strategic thinking, but I like the idea that they could get a double meal by trying to consume a fellow snake tail-first while it's eating. Most snakes eat their prey head-first though, jaw-walking backwards (from tail to head) is more difficult because the feathers, fur, or scales of the prey are normally aligned pointing head-to-tail. It's probably more profitable to go chase a different iguana.<br /><br />Certainly snakes in the process of predation are vulnerable to predation (e.g., from hawks) themselves, but I have no idea how often this happens. Hawks likely also eat the baby iguanas.Andrew Dursohttps://www.blogger.com/profile/04720822623046554913noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-81539751253421281702018-05-02T01:29:15.056-06:002018-05-02T01:29:15.056-06:00Hi, I thought the snake-escapist iguana in the Pla...Hi, I thought the snake-escapist iguana in the Planet Earth II video was a marine iguana. In that case, I was concerned that it escaped in the wrong direction and would be unable to cross the beach to get to its food sources in the water. I understand marine iguanas need to warm up on the rocks to restore their body temperature. But this was a land iguana?<br /><br />My more gripping question is what happens when multiple Galapagos racers converge on a single iguana, given that they can't split the iguana into parts. If multiple snakes try to eat the same iguana or other food item, what happens when they meet in the middle? Does a snake sometimes continue to jaw-walk past the head of the other snake so that it eats the other snake as well as the iguana, winner-take-all? Does all but one snake release the prey, and if so, how do they settle which snake gets to keep the prey? While a snake is eating an iguana, what's to stop another snake from swallowing the iguana-eating snake tail-first so as to eat the whole snake-iguana tandem? Would a snake eating a snake eating an iguana in turn be eaten the same way, and so on, until the onion-like snake-iguana formation gets too large to be swallowed? Would snakes busy eating iguanas, plus whatever other snakes are cannibalizing them, and so on, often fall prey to a hawk or other predator?<br /><br />Anonymoushttps://www.blogger.com/profile/01721011707275362207noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-25519186169066256662018-04-06T02:25:49.564-06:002018-04-06T02:25:49.564-06:00That's awesome! I hope your students enjoyed i...That's awesome! I hope your students enjoyed it and learned something.Andrew Dursohttps://www.blogger.com/profile/04720822623046554913noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-66620479499043963292018-04-04T13:24:33.628-06:002018-04-04T13:24:33.628-06:00I'm using this blog post in my herp class tomo...I'm using this blog post in my herp class tomorrow! It's fun to read again!<br />Thanks, Dr. Durso!Lorihttps://www.blogger.com/profile/05316395383731666203noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-5665900826881574362017-05-08T12:37:39.869-06:002017-05-08T12:37:39.869-06:00Hi Rory, thanks for reading and for the compliment...Hi Rory, thanks for reading and for the compliment! I agree that they look too large, but they are not. Snakes have amazingly flexible skulls that allow them to eat things much larger than their heads. It's one of the evolutionary adaptations that has allowed them to take on such large prey relative to their body size.Andrew Dursohttps://www.blogger.com/profile/04720822623046554913noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-73579424324939541492017-05-08T12:35:23.766-06:002017-05-08T12:35:23.766-06:00Awesome info here, Andrew! In the videos it looks ...Awesome info here, Andrew! In the videos it looks like the baby iguanas are too large to actually be swallowed by the racers. Do you think that is a camera angle thing or do these snakes take on big prey similar to the Brown Tree Snakes in Guam? Anonymoushttps://www.blogger.com/profile/03495693751771804922noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-71946098213828217922016-12-31T04:29:53.757-07:002016-12-31T04:29:53.757-07:00Thanks John, that is amazing!Thanks John, that is amazing!Andrew Dursohttps://www.blogger.com/profile/04720822623046554913noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-84759971852899350622016-12-31T01:58:13.116-07:002016-12-31T01:58:13.116-07:00Excellent and informative as always, Andrew.
Ther...Excellent and informative as always, Andrew. <br />There's an interesting exception to your remark about aquatic reptiles having to lay eggs on land; one species of turtle is too lazy to do that, nesting on flooded sandbanks where the eggs don't start developing until the water goes down again (http://www.nrcresearchpress.com/doi/abs/10.1139/z98-041#.WGdwGfPseG8).John Scanlon, FCDhttps://www.blogger.com/profile/02917650979531249640noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-82680191971951952912016-12-06T04:52:58.744-07:002016-12-06T04:52:58.744-07:00Thank you very much, Sir!Thank you very much, Sir!Anonymoushttps://www.blogger.com/profile/08018509419180605508noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-23646175364367918542016-12-05T05:51:51.059-07:002016-12-05T05:51:51.059-07:00Yes, the males stay near the shore their whole liv...Yes, the males stay near the shore their whole lives, whereas the adult females come back to the nesting area once every 2-3 years to lay eggs. Andrew Dursohttps://www.blogger.com/profile/04720822623046554913noreply@blogger.comtag:blogger.com,1999:blog-7443075087825368900.post-2027464762604002012016-11-30T06:33:56.069-07:002016-11-30T06:33:56.069-07:00Hello Sir,
I have a question that is not listed a...Hello Sir,<br /><br />I have a question that is not listed above,<br />that is: when the hatched baby iguana successfully climbs onto the rock(reef?)<br />(not hunted by the snake), whether it will stay there all its whole life unless it is a female iguana and has to lay eggs on the shore?<br /><br />sincerely, Tegan,<br />from TaiwanAnonymoushttps://www.blogger.com/profile/08018509419180605508noreply@blogger.com