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Mayanca

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About Mayanca

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  1. Sharks' hunting ability destroyed under climate change University of Adelaide The hunting ability and growth of sharks will be dramatically impacted by increased CO2 levels and warmer oceans expected by the end of the century, a University of Adelaide study has found. Journal Scientific Reports
  2. Unfortunately, humans are responsible for over fishing many species to the point where their populations cannot be sustained. At the present rate of catch and bycatch the oceans are losing. We watched BBC film an episode about overfishing while in Puerto Jimenez in June. There are so many fisheries that have collapsed or are collapsing because of overfishing..the anchoveta in Peru, the sardines in Central California coast, Pacific salmon, blue fin tuna, Orange Ruffy, etc. Shrimp trawlers scrape the sea bed and leave it barren. What we call resources are finite, and even with the variety of laws to protect them, the difficulty of managing is massive. Note the recent 1000 meters of netting that was recovered in the Gulf of Nicoya, and the pirating of boats and motors. Not to mention the constant vigilance needed to protect Cocos Island..Multiply those around the world, include the enslaved people in Thailand fisheries..Dorado caught in Asia and sold in California Safeway is too small to be reproductively viable. We try as best we can to only eat products that are as sustainable, but it is very difficult. We stopped buying Dorado off the fishing boats because of the often illegal fishing practices. One boat we had purchased Dorado from was caught illegally fishing in Panama territorial waters. Our employee recognized a crew member when they were arrested. Others use prohibited fishing methods. I would say "eat more beans" but don't want to think about the replies I would get about that....smiles..
  3. Absolutely right Lucybelle, about eating or encouraging shark sales. Unfortunately, people do mistakenly sometimes buy shark miss labeled. Shark finning is outrageous, and has to be stopped. Killing off top predators has many unintended consequences for Earth.
  4. This is a major problem everywhere...fish is mislabled. A lot of shark is sold as swordfish. Rockfish in California is sold as Red Snapper. Many fish in restaurants in Costa Rica are called Corvina and Dorado...they could be anything. In the US there have been lots of investigations about mislabled fish. In Costa Rica, as elsewhere, unless you buy a whole fish, you are taking your chances. If the spine in the example you described seems more like cartillage (softer, more friable, and simpler looking) than bone, it is probably shark...I try to by fish in Costa Rica directly from the fishing boat as it comes into the distribution wharehouse. Obviously not possible unless you live on the coast where the boats come in. But even there the method of fishing may be illegal, or the place where the fishing was done illegal. In essence, it is enredado, totally messed up!
  5. Truly; Now I will have to watch the fruit fly larvae in my compost bucket to see if they escape as a swarming mass or as uncoordinated individuals.
  6. Thank you for that! Those larvae must be very tiny if they are the offspring of gnats. If that is the case I would think they might attract rather than repel predators...but in any case it is certainly fascinating, and an experiment could easily be designed to test opposing hypotheses. Lincoln Brower long ago tested the palatability of monarch caterpillars with jays and had very interesting results. This topic has been a lot of fun.
  7. I just post this to demonstrate that this topic is very complex and diverse..each species of toxic amphibian and even populations and individuals are different in their biochemistry. I was just thinking that being careful and thoughtful is more functional than being fearful. Some of the same people we know also teach their children to be afraid of dogs. Answer to question..... always best to be cautious if you are able.... The chemistry of poisons in amphibian skin by J.W Daly Proceedings of National Academy of Science AbstractPoisons are common in nature, where they often serve the organism in chemical defense. Such poisons either are produced de novo or are sequestered from dietary sources or symbiotic organisms. Among vertebrates, amphibians are notable for the wide range of noxious agents that are contained in granular skin glands. These compounds include amines, peptides, proteins, steroids, and both water-soluble and lipid-soluble alkaloids. With the exception of the alkaloids, most seem to be produced de novo by the amphibian. The skin of amphibians contains many structural classes of alkaloids previously unknown in nature. These include the batrachotoxins, which have recently been discovered to also occur in skin and feathers of a bird, the histrionicotoxins, the gephyrotoxins, the decahydroquinolines, the pumiliotoxins and homopumiliotoxins, epibatidine, and the samandarines. Some amphibian skin alkaloids are clearly sequestered from the diet, which consists mainly of small arthropods. These include pyrrolizidine and indolizidine alkaloids from ants, tricyclic coccinellines from beetles, and pyrrolizidine oximes, presumably from millipedes. The sources of other alkaloids in amphibian skin, including the batrachotoxins, the decahydroquinolines, the histrionicotoxins, the pumiliotoxins, and epibatidine, are unknown. While it is possible that these are produced de novo or by symbiotic microorganisms, it appears more likely that they are sequestered by the amphibians from as yet unknown dietary sources.
  8. For awhile, it was quite faddish to lick Bufo marinus toads, as supposedly it caused the lickers to get high. We do have lots of toads, but never have had any incidents with dogs, toddlers, or drug seeking adolescents. Where we live, the poison dart frogs are quite secretive, and it would be very very rare for a toddler to encounter one...I studied in Costa Rica with Jay Savage, who wrote the book on Costa Rican Reptiles and Amphibians, and he never ever said a word about being careful when handling a poison dart frog.I think it requires more than a casual contact to do any sort of damage. Sort of similar to the difference between coca leaves and cocaine... concentration of the toxin is necessary. I will re read the section in his book and see if he says anything at all, but i do recall that wild Phyllobates vittatus has the highest toxin levels of the different species..when poison dart frogs are raised in captivity, they are not toxic, because they derive their toxins from their food, and crickets are quite edible for humans.
  9. Unfortunately, I do know too many people who are afraid of frogs, toads, bats, and even geckos, because of what they have been taught. I have handled virtually every sort of frog and toad in Costa Rica with no adverse effects. This as an OTS student and later teaching Natural History courses in Costa Rica and elsewhere in the tropics. Of course, you are not supposed to lick the Bufo marinus toads or rub your eyes after handling the poison dart frogs, but there is no reason to be afraid of them. (One rare toad in Colombia shouldn't be touched, but it is an exception) Its best to leave them alone, but not be afraid. So many amphibians are on their way to extinction because of habitat destruction, climate change, the infamous fungus, that we need to do everything we can to protect what is left. I well remember being able to find salamanders under almost every rock up on Cerro de la Muerte...no more. The Golden Toad in Monteverde...gone....The beautiful Antelopus frogs...nearly gone. I am much more afraid of what humans are doing to the wildlife then what the wildlife are doing to humans.
  10. I too looked up millipede swarm and what I saw was not anything organized...just random hordes....going in all directions. Anyone seen a water opossum? Friends just back from Corcovado saw them...Amazing creatures with duck-like back feet..found a great video showing them swimming under water...
  11. They could be millipedes...the photo just isn't clear enough to tell for sure...I have only seen this behavior in butterfly /moth larvae, so it certainly would be interesting to get a closer photo...since these guys appear totally harmless, no harm in picking one up and looking at the number of true legs....
  12. This is what swallowtail caterpillars look like at rest on a mandarin tree...They use more than one type of predator defense.. camouflage, mass protection, and nasty taste. Other groups of butterfly and moth larvae are coral snake mimics, bird poop mimics, mimics of toxic insects, covered with urticating hairs, full of cardiac glycosides, all sorts of fabulous defenses. And then....most amazing, they morph into beautiful butterflies and moths.
  13. An interesting topic for the nerds amongst us. http://www.wired.com/2013/07/why-are-these-caterpillars-climbing-over-each-other-the-surprising-science-behind-the-swarm/ This experiment shows that the swarm of caterpillars moves faster than does an individual caterpillar...brings me way back to my childhood when I raised caterpillars in my bedroom...nerd heaven.
  14. Some species of butterfly larvae...caterpillars...spend time resting on tree trunks in a mass. When they migrate from tree to tree will do a group swarm move. Citrus trees are hosts for swallowtail caterpillars, and they exhibit this behavior. It most likely is a defense against potential predators...the caterpillars are distasteful in general or have some distastefu organs that they extrude when disturbed. Swallowtail caterpillars have stinky antennae-like glands that are extruded when they feel threatened. The caterpillars may be quite well camouflaged while at rest. Your photo looks much like the Swallowtails I frequently see on our mandarines...there are lots of forest trees in the citrus family also that have larvae similar to these. I have seen them in the Amazon basin and also in a migrating swarm in Corcovado.
  15. Is it a palm or a cycad? From the photos, it looks like a cycad...they are surprisingly hardy, although sometimes the outer leaves do die off. Keeping it clean and replanted should help...we had something similar on another type of indoor plant, and repeated washing of the leaves and cutting back all the old leaves and stems did finally work.
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