Natterer’s bat — more goodies from en.Wikipedia science
Did you know that natterering bad science on en.Wikipedia’s main page continues.
Natterer’s bat is nocturnal and insectivorous, the bats emerge at dusk to hunt for insects and uses (sic) echolocation to find prey and orientate itself at night. Bats emit sounds at too high a frequency for most humans to detect and they interpret the echoes created in order to build a “sound picture” of their surroundings. The frequencies used by this bat species for echolocation lie between 23–115 kHz and have most energy at 53 kHz. The individual signals have an average duration of 3.8 ms. The wide bandwidth of its frequency-modulated search signals enables it to detect prey only a few centimetres from vegetation and it does not use vision, olfaction or sounds emitted by its prey for this purpose. The bat feeds on the wing and it mostly catches insects in flight but it is also able to feed on prey items such as spiders and caterpillars dangling close to foliage on silken threads. … This bat may use its interfemoral membrane to catch prey and the fringing hairs may have a sensory function. It has been shown that it can land on the ground to pick up and pursue invertebrates that are active at night, and continues to emit search signals in order to locate them precisely.
Oftentimes in en.Wikipedia science articles about taxa, or evolutionary groups of organisms, we have articles written by editors with almost no background in biology. If you have a background in biology, just the little bit gained from taking a high school or college introductory biology course, you wind up with the training necessary to know how and when to generalize. If you are going to generalize about a taxon, then you should understand at what level to generalize.
Wikipedia’s article on bats informs us that they can be divided into two suborders, the megabats, Megachiroptera, and the microbats, Microchiroptera (italicized in the en.Wikipedia article). The microbats are specifically known for their use of echolocation to find prey; and this technique is rare among the megabats (according to the en.Wikipedia bat article one species of megabat uses it).
Does the en.Wikipedia article on Natterer’s bat give us any information about it being a microbat? No, I can’t find the term microbat, and I can’t find the suborder anywhere in the article.
The article does go into detail about the Natterer’s bat’s hunting, though, after first telling us that all bats “emit sounds at too high a frequency for most humans to detect … to build a ‘sound picture’ of their surroundings”:
Bats emit sounds at too high a frequency for most humans to detect and they interpret the echoes created in order to build a “sound picture” of their surroundings.
Unfortunately, as is often the case, the bat article is not in agreement with the sub-bat article. It’s not same bat time; it’s never same bat-channel, when it comes to editors with no knowledge of biology writing en.Wikipedia articles on taxa. Some bats emit sounds at too high a frequency for most humans to detect; but other bats emit sounds at frequencies that overlap human hearing. Not all bats emit such sounds that are used to create “sound pictures of their surroundings,” only echolocating bats use echolocation. That is why they are called echolocating bats.
Bats represent about 20% of all classified mammal species worldwide, with about 1,240 bat species divided into two suborders: the less specialized and largely fruit-eating megabats, or flying foxes, and the highly specialized and echolocating microbats.
Generally speaking it appears there are two types of bats, the suborder to which Natterer’s bat probably belongs, and the mostly frugivorous bats (oh, and that word is like being Batman: always be yourself, unless you can be Batman; always speak plainly, unless you can use the word “frugivorous”). We don’t know this is the suborder to which Natterer’s bat belongs to from the article on en.Wikipedia, because, instead of discussing this organism as part of the evolutionary group of related organisms that use echolocation, the author has up-generalized the organisms that use echolocation to all bats. This is not correct; not all bats use echolocation, and if you had taken an introductory biology course in high school or college, you might not have made this mistake.
From a resounding, “No, not all bats echolocate,” and a failure of generalization, “No, don’t generalize this bat to its order; if you had actually read the articles you cite, you would have generalized to its suborder,” we are going to move onto numbers. Do these two sources support the numbers provided in the en.Wikipedia article? No, they don’t. The editor took two studies that include a higher and lower frequency recorded for the species in their studies, n=82 in Parsons and Jones, and n=100 in Obrist et al. and averaged them, then rounded up. That’s right, they are the averages of two studies, reported as pure fact. This is another type of generalization that you do, if you have no background in biology; you assume that you can just take two studies and average the information in them and come up with facts. Maybe they are weighted averages. Oh, well, you can do anything you want on en.Wikipedia. Still, you should report how you came up with the information when you are citing two sources for the information and your information matches neither. Basic.
The wide bandwidth of its frequency-modulated search signals enables it to detect prey only a few centimetres from vegetation and it does not use vision, olfaction or sounds emitted by its prey for this purpose.
How wide is this bandwidth? 135 kHz according to one of the citations in the en.Wikipedia article. So, this is wider than the range of frequencies it actually uses for echolocation, according to its en.Wikipedia article, so maybe the bandwidth of its search signal isn’t all that wide? Just a little plagiaristic collaging. The bat is uniquely known, according to the articles, for using a wide bandwidth frequency modulation echolocation technique that allows it to discriminate readily between prey and nearby vegetation. It does not appear to supplement its echolocation with visual clues or smell or listening for noise made by its prey. It is very accurate in catching prey.
The bat feeds on the wing and it mostly catches insects in flight but it is also able to feed on prey items such as spiders and caterpillars dangling close to foliage on silken threads.
You know, there is a word for this, catching flying insects while you yourself are flying around, called “feeding on the wing” in the Natterer’s bat article, and it is called “hawking,” but en.Wikipedia does not appear to use this word in bat articles. According to the en.Wikipedia article on hawking, this is a strategy only used by birds. So, again, as cool as bats are, en.Wikipedia is clueless, because, instead of reading for understanding, it is reading for copying and pasting a collaged mish-mash of information and calling it an article and getting a barnstar for it.
And, there we have it; it can catch “caterpillars dangling close to foliage on silken threads.” Cough.
That was, partially, the point of the wide bandwidth echolocation, but the article cannot tie these together because it is just a collage, not written from understanding of the topic.
This bat may use its interfemoral membrane to catch prey and the fringing hairs may have a sensory function. It has been shown that it can land on the ground to pick up and pursue invertebrates that are active at night, and continues to emit search signals in order to locate them precisely.
What the source says:
Both in a flight room and in the wild, Natterer’s bats foraged using a sequence of low searching flight, hovering, capture using the interfemoral membrane and prey consumption at a perch or on the wing.
Again, the en.Wikipedia editor turned an observation into a maybe. We still have that awful may on the tunicate article talk page:
Did you know … that although a tunicate is an invertebrate, its larva (pictured) may have a notochord and resemble a small tadpole?”
Contradicting the tunicate article:
Despite their simple appearance and very different adult form, their close relationship to the vertebrates is shown by the fact that during their mobile larval stage, they possess a notochord or stiffening rod and resemble a tadpole.
It is not uncommon for a bat to use its interfemoral membrane, whatever that is, for prey capture.
I do appreciate this of en.Wikipedia articles. It is either called the “interfemoral membrane” or it is called the “uropatagium,” a synonym according to this article. Now the fun part, click on the wikilink and half the time it is wikilinked to the article it is in, the other half of the time, in spite of just telling you the two words or terms are synonyms, it is wikilinked to another article, as is the case here.
In this case, uropatagium is wikilinked to patagium, where we learn, from a completely unreferenced article:
- The patagium of a bat has four distinct parts:
- Propatagium: the patagium present from the neck to the first digit
- Dactylopatagium: the portion found within the digits
- Plagiopatagium: the portion found between the last digit and the hindlimbs
- Uropatagium: the posterior portion of the body between the two hindlimbs
In the article on patagium, we have a wikilinked uropatagium that takes you back to interfemoral membrane. And, try not to notice that while a patagium is an extension of the abdomen uniting the forelimb to the body, it contains parts that unite the two hindlimbs.
Is your head spinning yet? Why not try a little English, en.Wikipedia? The interfemoral membrane, also known as the uropatagium, is the membrane that stretches between the legs of a bat. and is joined to the abdomen. It is part of the patagium, a thin membrane that stretches from the digits of a bat to the abdomen and is described by dividing it into four parts, the portions found stretching from various parts of the body.
It has been shown that it can land on the ground to pick up and pursue invertebrates that are active at night, and continues to emit search signals in order to locate them precisely.
I hope that once it picks up the prey, it no longer has to pursue it; but, this is what happens when you collage without understanding. And, you know, after it has already picked up the prey, and is continuing to pursue what it picked up, I don’t think it continues to emit search signals to locate them “precisely,” or even “accurately,” since it is probably eating the prey, thereby no longer needing precision, at least for that prey. Or, maybe it’s a sloppy eater, a dribbler. Maybe it has a fifth part to its patagium, a bib?
And, no, I did not know that. But, then again, neither does en.Wikipedia.