Nest met sigaretten peuken,tegen bloedluizen ???


Heeft u ook wel eens een vogeltje met een sigarettenpeuk zien vliegen en vreesde u toen voor het leven van het diertje? Wees gerust, ze eten het niet op maar gebruiken de peuken voor de bouw van hun nest.

In tegenstelling tot mensen lijken vogels alleen maar te profiteren van sigaretten. Mexicaanse wetenschappers ontdekten dat sigarettenpeuken in nesten van veel voorkomende stadsvogels het aantal parasieten drastisch doet afnemen. De vogels lijken zich dus aan te passen aan hun stedelijke leefomgevingsigaret nest.
Om dit te onderzoeken bevestigde het team Constantino Macías Garcia van de National Autonomous University van Mexico een soort warmteval aan de nesten van 55 mussen en vinken. Als parasieten hier op af kwamen, bleven ze vastplakken aan een plakband.
Nadat de vogels het nest hadden verlaten, werden de nesten verzameld en geanalyseerd. Uit de analyse bleek dat hoe meer peuken een nest bevatte, des de minder parasieten er op het plakband zaten. Bovendien ontdekten de Mexicaanse wetenschappers dat nesten met gebruikte peuken tot wel 60 procent minder parasieten aantrokken.
Isolatie Het is nog onduidelijk of de vogels de peuken ook voor dit doeleinde gebruiken. 'Het is ook goed mogelijkheid dat de vogels de peuken voor isolatie gebruiken uit gebrek aan veren of dons', zegt Macías Garcia tegen New Scientist.
Opvallend was wel dat de nesten vooral Marlboro sigaretten bevatten. 'Ik weet niet of dit aan de smaak van de vogels of die van de studenten ligt. 

Cigarette butts help urban birds ward off mites.

  • 13:03 05 December 2012 by Joanna Carver.                                                                       

It's not just people that have a penchant for cigarettes. Birds living in urban environments often use cigarette butts to line their nests. Unlike in humans, the cigarettes seem to have a beneficial effect – they cut the number of parasites in the nests.

Nicotine-based sprays are already used on some crops to repel insects. To see whether cigarette butts might have a similar effect in urban birds' nests, Constantino Macías Garcia from the National Autonomous University of Mexico in Mexico City and colleagues lured parasites to these nests.

The team set up thermal traps in the nests of 27 house finches and 28 house sparrows, species commonly found in cities. The traps had electrical resistors placed on either side of the nest to generate heat, attracting parasites – such as mites – which then got stuck to a strip of adhesive tape attached to the resistor. The team also placed cellulose fibres from smoked or unsmoked cigarettes on top of each resistor to see whether the mites had a preference for either.

Once any chicks had left, the nests were collected for analysis. The team found that the more cigarette fibres the nest contained, the fewer parasites moved in.

Nicotine nest

What's more, traps containing cellulose from used cigarettes butts attracted 60 per cent fewer mites, on average, than ones with unsmoked cigarettes. This suggests it is indeed the nicotine and other chemicals in a cigarette that repel mites, since these substances are only released once it has been smoked.

Does that mean birds line their nests with cigarette butts to repel parasites? Not necessarily, says Macías Garcia. "One possibility is that the birds are using the cellulose from smoked cigarettes for its thermal properties, as a substitute for other materials such as feathers, down or fur," he says.

"Much of the work on urban environments has focused on the negative impacts of human activities on birds and other animals," says Paige Warren of the University of Massachusetts, Amherst, who was not involved in the study. "But there are also many resources that humans provide for animals in the city."

The team's next step is to determine whether birds that had a choice between spent butts and unsmoked cigarettes would prefer the former. Birds can distinguish between the two by their smell, and if they prefer to line their nests with spent butts, that would suggest they are aware of the butts' ability to deter parasites. The team also plan to investigate whether the chemicals in spent cigarettes harm the birds.

Dave Shutler, a biologist at Acadia University in Wolfville, Nova Scotia, Canada, described the study as "very interesting", but says its results are only vaguely suggestive.

As for the birds' preferred brand, the nests contained more Marlboro Red butts than any other brand. Montserrat Suárez Rodriguez, who co-authored the study, says she doesn't know if that's because the birds prefer Reds or because the students do.

Biology Letters, DOI: 10.1098/rsbl.2012.0931