04-07-2023

Resistance in oceans?

Two years ago, we wrote about the pollution of the world's major rivers by residues of pharmaceuticals. It was about painkillers such as ibuprofen, which humanity has been swallowing by the ton every day for decades.
The ecosystem is not able to break them down.

  

 However, this is only the tip of the iceberg, as we have entirely overlooked the increase in antibiotic resistance among (pathogenic) bacteria in the oceans. What is more, the low doses at which these antibiotics are dissolved in the sea encourage resistance. In short, the oceans have quietly got sick, and if they are, so are we. In fact, human beings are very much dependent on marine life.

Meanwhile, like the peloton in a race, we are on the same track with the antibiotic problem as we are with the nitrogen problem:  "It is by definition too late". It will not be long before the systematic measurements that are now being taken will confront us with the unpalatable truth, and we will have to ration these life-saving drugs heavily because the eco-toxicity is too great.

Admit that Comed has warned about this (long ago)...

 

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I wrote two blogs ago about Willem Debruijn's fancier Wybren Breeling. He commented on the overwhelming determination with which the pigeons always came home.

Such a drive ensures that all available physical strength is used in the service of speed... 

The loft-return trajectories of two groups of homing pigeons were analysed (by researchers from the Universities of Frankfurt and Jerusalem) (*). The aim was to detect differences between individual pigeons and also to see if there were correlations between characteristic variable parameters. On the one hand, the initial phase, when the pigeons were still at the release site, and on the other hand, the final stage of the homeward journey were studied.

In the early stages, there was considerable variation in the flying speed of individual pigeons. Some pigeons also stayed longer at the release point than others. All pigeons returned home equally well, with no significant constancy or efficiency differences.

Differences in the use of navigational information, with some pigeons apparently using less complex information than others, are reflected in differences in the correlation dimension (a variable related to the complexity of the navigational process). (For comparison, one would do this with a simple compass and the other with GPS technology).

The speed of flight during the initial phase was in direct proportion to the speed of flight during the return phase.
During the return phase, the flight's stability (constant speed) was directly proportional to the return flight's efficiency (certainty of returning).
In other words, a more stable flight is, to some extent, also a guarantee of a particular return home. Both factors (stability and efficiency) were directly proportional to the correlation dimension (using more complex navigational information).

Conclusion

Indeed, the study concluded that each pigeon has its skill level and that those with more complex navigating techniques are better home fliers.

 

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It is worth linking the above data to another fascinating study …👇

A new study from the Department of Zoology at the University of Oxford shows that, like humans, homing pigeons can build on the knowledge of others and improve their navigational efficiency over time.

This capacity for collecting, transmitting and improving knowledge over generations is known as cumulative culture.

Until now, the only species thought to be able to do this were humans and probably some other primates (ape-like animals).

Remarkably, Noël De Scheemaeker wrote in “Pigeon Laughs" before the 2nd World War: "You must buy pigeons from your land".

In this study, paired individuals were removed and replaced as they learned to navigate a particular route. Ten groups of pigeons were released from the same site. Generational succession was simulated by constantly replacing pigeons familiar with the road with inexperienced pigeons that had never flown it. The idea was to test whether these individuals could pass on their route experience to the next generation and also to allow the collective intelligence of the group to improve route efficiency continuously.

The results, published in Nature Communications, suggest: Over time, the student does indeed become the teacher. There was a consistent improvement in the couples' return performance over generations - they also streamlined their route to be more direct.

Groups from later generations performed better than individuals flying alone or in groups without the opportunity to share their experiences. Return routes were also more similar in successive generations of the same chain of pigeon pairs than in crossing chains. This suggests a knowledge transfer between generations or a 'culture' of return routes.

Scientists used to think that only humans had the cognitive (intellectual) capacity to acquire knowledge as a society. Our study shows that pigeons share this capacity with humans, at least because they can gradually improve a behavioural solution over time. However, we claim they achieve this through different processes.

Pigeons share our human ability to build knowledge across generations.

Of course, everyone knows the benefits of training young pigeons with more experienced ones. In the experiment, the behaviour of 2 pigeons was paired together each time. Studying the effects of experience transfer on paired groups becomes even more fascinating.

Appointing a leader during the return is essential, as a previous blog describes. If the pigeons are good followers and choose a good leader (navigator), they can achieve great results even though each pigeon has its navigational talent and approach.

This experiment goes further. As people share and pass on knowledge from generation to generation, our culture becomes more complex over time. Industrial manufacturing and engineering, which build on the ability of ancestors (predecessors), are good examples. 

In contrast, when the process occurs between homing pigeons, the result is an increase in efficiency (in this case, navigation) but not necessarily an increase in the complexity of behaviour..

Nuance

The researchers added: 'Although they have different processes, our findings show that pigeons can acquire knowledge and gradually improve their performance, which aligns with the cumulative culture criteria. These results also suggest that this cumulative culture does not require advanced cognitive (far-reaching) skills, as was previously thought to be the case.

Conclusion

This study of animal behaviour shows that collective intelligence, which is usually focused on single performances, can result from accumulated knowledge over time. An important novelty is that the gradual improvement is not due to new 'ideas' about improving the path introduced by individual pigeons. Instead, the necessary innovations in each generation come from collective intelligence from two pigeons solving the problem together; in other words, "two heads are better (know more) than one".

As we advance, the researchers plan to build on this study by investigating whether a similar style of sharing and accumulating knowledge over multiple generations occurs in other species' social groups. Many animal groups have to solve the same problems repeatedly in the natural world. Using feedback from previous outcomes of these tasks or events could influence and improve the decisions the groups make in the future.

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Decision

It is crucial for the colony's survival that the swarm gets home efficiently.

Complex navigation is more efficient and could stem from a certain 'sanity' built up due to passing information between generations.

A pigeon is, therefore, not so much an individual as part of a social whole. To this end, it is endowed with the ability to adapt through mutual "intelligent" exchanges and the accumulation of information. Therefore, a colony of pigeons is more and more experienced, especially concerning the return flight.

These findings should give us pause for thought about the magical qualities of our precious homing pigeon. We are privileged to partner with science in unveiling its mysterious talents.

Sources:

https://pubmed.ncbi.nlm.nih.gov/30260962/

https://phys.org/news/2017-04-homing-pigeons-human-ability-knowledge.html