Alors que les français commencent à râler des coûts de l’essence, plutôt que de se réjouir d’un effet prohibitif naturel à la combustion des énergies fossiles, et plutôt que de réfléchir aux comportements qu’il conviendrait d’adopter en ce qui concerne une crise qui risque fort de s’enliser et de durer, des scientifiques tirent encore plus fort la sonnette d’alarme à propos du réchaufement climatique: à force de céder devant les lobbys négationnistes et les illusions gouvernementales (si délires ne conviendrait pas mieux), nous avons considérablement sous-estimé la vitesse à laquelle le dérèglement climatique pourrait se manifester. Qu’à cela ne tienne, la réponse est prévue pour dans 7 à 10 ans… Investissez donc dans la crème solaire!
Archive for May, 2008
Pomegranate (Punica granatum), is a fruit originating from Iran and now cultivated in many countries around the Mediterranean Sea. It used to be cooked as juice though this role is now way past. We can find it sold for consumption as a fruit by now, and indeed, it’s really fresh and amazingly accomodate life at the warmest part of the day. But wait, I didn’t track back to the few papers about domestication yet, that I was already swamped into an incredibly huge amount of litterature dealing with its potential other economical uses as pharmaceutical. You won’t believe it!
Seedsaside was ‘translated’ from google.jo, see the result here. I find the result very appealing, despite untranslated words to be read –> while anything else <– (but numbers)… I wonder if the automatized translation worked good enough, but I really like the resulting page. And I was trapped by the scrolling tool being on the left, not on the right.
That may not be news (the study in question* was published in 1992), but this is a rather interesting result… Bees are able to detect if flowers have been visited by another bee, and more readily leave those that have recently been. This behaviour is not difficult to explain: you better have to move if there is less to forage (don’t waste your time where reward is probably lower). Direct cues to assess nectar availability can be used by bees (when nectar content of a flower can be seen, or smelled), but this way isn’t always possible with any flower morphology and requires some level of inspection, i.e. there is a time cost. But bees are making the process easier by marking the flowers they visit with a special scent.
The effect of the scent was here experimentally reduced in the study (with artificial flowers) via an air extractor. When on, flower rejection dramatically decreased, flower inspection and visit time were also increased, while the number of visits was unchanged between the two experimental conditions. I find it amazing how far and finely tuned behaviours have evolved in these insects…
But we may also notice that the experimental flowers were still providing a great reward even after they were visited. This means bees in the experiment were stuck into their innate foraging method and losing resources aside. This probably means there is no such thing as a continuously rewarding flower in nature… :-)
M. Giurfa and J.A. Nunez (1992).Honeybees mark with scent and reject recently visited flowers. Oecologia 89: 113-117.
Berry Go Round #5 will be hosted at A Neotropical Savanna. Please send your submissions before the 25th… Any post plant related does it, and don’t forget you can suggest your favourite posts even if not your own (BGR is still a young carnival and unsollicited submissions are readily accepted: it allows diversifying the still sparse plant blogosphere!).
More or less late about these, but here are some recent and quite cool carnivals:
- Tangled Bank #105 (at the Beagle Project)
- Festival of the Trees #23 (at 10000 Birds)
- Linneaus Legacy #7 (at the Ethical Palaeontologist)
- Oekology #16 (at Scientific Blogging)
I guess this is enough to read until this evening… :-)