The Great Beyond

This "Buzz" leads, (by clicking on "here"), to more details about Srinivasan's research and new discoveries, where I found , through a mere cursory reading, several serious errors, explained below.
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The information provided here was copied from that Buzz:

1.• "First convincing demonstration that honeybees gauge distance flown in terms of the extent to which the image of the environment moves on the eye en route to the goal. (Science 2000; Nature 2001). These studies rewrite the classic, textbook notion that distance flown is estimated in terms of energy consumption, as put forward originally by the Nobel laureate Karl von Frisch."

Srinivasan M.V., Zhang S.W., Altwein M. and Tautz J. (2000) Honeybee navigation: nature and calibration of the 'odometer'. Science 287, 851 – 853. (With cover illustration and accompanying Perspectives article)

2.. H. Esch, S.W. Zhang, M.V. Srinivasan and J. Tautz (2001) Honeybee dances communicate distances measured by optic flow. Nature 411, 581-583. (With cover illustration).

3. • "First demonstration that scent can trigger complex navigational memories in honeybees (Nature 2004). Scent injected into a hive can stimulate experienced bees to fly to previously visited sites, through previously formed associations between scent and location."

Reinhard, J., Srinivasan, M.V. and Zhang, S.W. (2004) Scent-triggered navigation in honeybees. Nature (Lond.) 427, 411.
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Here are my comments, according to the numbers I gave the different items:

1. This item concerns the "discovery' of the honeybee "odometer". The authors found that foragers who flew to food inside a very long narrow tunnel, indicated in their dances a far greater distance when the inside of the tunnel was covered by a very complex pattern, than when it was covered by a simple pattern. They concluded that honeybees have an "odometer" , which enables them to measure distance flown, based on"optic flow", i.e. on "the total of the angular deviations of background images".

The conclusion is unwarranted, because the results lend themselves to a far simpler explanation, that has nothing to do with any "odometer", but only with the expenditure of energy.

The authors, who could see the bees flying inside the tunnel, (through the insect-net that covered the top of the tunnel, to enable the bees to see the sky), report that the bees flew through the center of the tunnel; which immediately led me to consider that in order to be able to fly through the tunnel without crashing, the bees must fly through the center, and also reduce their flight-speed, the more confusing the background pattern, the greater the required eduction of flight-speed. Srinivasan verified for me, (through e-mail), several years ago, that my guess that the bees flew much more slowly when the tunnel had the complex pattern, than when it had the simple pattern, was indeed correct. The difference was so conspicuous that it was quite obvious even without taking any actual measurements, which the authors could have done very easily, but did not bother to do.)

The slower flight-speed has a double effect on the expenditure of energy. It obliges the bees to spend much more energy per unit time, to merely stay aloft, and it also lengthens the duration of the trip. In other words, the study provides no evidence for the existence of a honeybee "odometer" based on "optic flow".
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2. This study claims to have experimentally confirmed that recruits used the misleading distance-information provided by foragers that flew to a feeder inside a long narrow tunnel, with a complex background pattern. The conclusion is based on distributions of new-arrivals, (that actually landed, or merely "searched" in the very close vicinity of a station), among man-made field-stations provided at different distances from the hive. The distributions showed a positive correlation with the distribution of distance-information in the dances of the foragers.

In fact, all of v. Frisch's claims, and almost all the claims later provided by very many other scientists, (including Esch et al.), that honeybee-recruits use "dance language" (DL) information contained in their foragers'-dances, are based on data concerning distributions of new-arrivals.

Contrary to Esch et al. (2004), and to all other DL supporters, such distributions, however, provide no evidence for any use of DL information, because Wenner & his team, (Johnson 1967; Wenner 1967), had already shown in their first challenge of v. Frisch's DL hypothesis, that distributions of new-arrivals are totally independent of DL information.
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3. The authors of this study were by no means the first ones to discover that experienced foragers can be re-recruited to their familiar food-source by merely introducing their familiar food-odor into the hive. Their study only further extends the original discovery , made long ago by Wenner & his team, in a study which Reinhard et al. (2004) actually cite. The study by Wenner & his team was, in turn, an extension of far earlier study by v. Frisch, who discovered that experienced foragers can be re-recruited to their familiar food-source, by attending a dance, or even merely coming in contact, in the hive, with successful foragers that bring in the same kind of food, with the same artificial odor, (from the same source, or from any other source).Wenner & his team simply excluded the foragers that brought that familiar odor into the hive. In fact, in the only excursus penned by Wenner alone , in the book Anatomy of a Controversy, by Wenner & Wells (1990), Wenner explains that it was the findings about the re-recruitment of experienced foragers, that first led him to question v. Frisch's DL hypothesis, (concerning the recruitment of new bees), which had already become a revered ruling paradigm.
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I cannot comment on any of the other publications by Srinivasan, which I have not yet read.