Germination Problems

[Tristan_He]

According to Wikipedia, stomach acid has a pH of 1.5-3.5. 5% distilled vinegar has a pH of about 2.5. Perhaps vinegar would be an acceptable (and easier to obtain) substitute?

[Hans J]

Good idea Tristan ,

I have it just tested :
Our vinegar has 5,5 % ...the PH value is 3,0 ....sounds perfect

Now we have to know how many hours ...

Hans

[Matt T]

Mr Google returned some interesting results for the search term "bird gut transit time". The results suggest 30-60 minutes would be a reasonable time to soak seeks in vinegar to replicate the avian gut environment.

Adaptations for Avian Frugivory: Assimilation Efficiency and Gut Transit Time of Manacus vitellinus and Pipra mentalis

Gut evacuation was rapid; maximum transit time of a labeled fruit was 30 min. Seeds passed through the gut faster (Manacus: 15 min; Pipra: 12 min) than the accompanying fruit epidermis (both spp: 22 min). Manakins regurgitated large seeds (> 5 mm diameter) in 7 to 9 min.

Intestinal Transit: How Can It Be Delayed Long Enough forBirds to Act as Long-distance Dispersal Agents?

...food passage in birds is generally rapid compared with that of mammals (especially ruminants) or other vertebrates (c.f. data in Warner 1981, Karasov et al. 1986). For example, studies have shown that color-marked barium sulfate required only 22.9 to 69.4 min to move through the gut of passerines,

Digestive System: Food & Feeding Habits

In general, typical mean retention times are ... 15 - 60 minutes for frugivores (Karasov 1990, Klasing 1998).

[Hans J]

Many thanks Matt 

[ashley]

Many thanks Carolyn and Gabriela for these comments and some new ideas to test

Giles and Gerry drew attention to advice from Hugh McAllister here.

[johnw]

And my thanks as well to all.  Now to find a parrot for rent.


johnw

[Hoy]

Can't you eat the berries yourself? I have seen lots of germination of several species (especially tomato!) in human stool. (I know it because we had an old fashioned outhouse at our cabin.)

Just kiding - but I think it works 

[johnw]

Yes, I need a parrot.

[Tristan_He]

Mr Google returned some interesting results for the search term "bird gut transit time". The results suggest 30-60 minutes would be a reasonable time to soak seeks in vinegar to replicate the avian gut environment.

Perhaps considerably less Matt - after all most of the gut is not "stomach" and therefore not acid. Would be interesting to experiment but quite possibly 10 minutes or so would do it.

[Tristan_He]

Yes, I need a parrot.

I think a parrot might crunch up the seeds a bit John!

[Hans J]

just received from a friend :

http://www.backyardnature.net/birdguts.htm

[Carolyn]

OK, this needs an experiment! I have gathered some berries from a very nice rowan along the road from our house. The tree keeps its leaves until November and they turn a beautiful red. It also holds onto its berries until Christmas - the blackbirds ignore this tree, but strip all the other ones in September. One autumn, this rowan was covered in waxwings, they seemed to like the berries.
Now, the experiment: 4 pots of seeds - berries squished in a paper towel to extract the individual seeds, then
1.  seeds wiped clean of pulp with a paper towel, but not rinsed.
2.  seeds washed and soaked. The soaking water will be changed each day for 7 days (this is my usual method for sorbus).
3. seeds soaked for 1 hour in lemon juice.
4. seeds soaked in vinegar (for one hour), white wine vinegar actually as it's what I have in the cupboard, apart from the expensive balsamic which I am not prepared to squander on an experiment.
There will be 14 seeds in each pot. The pots will be placed outside in the open, where they will be exposed to frost.
It will be interesting to see if these mild acids will have the same effect as a bird's digestive system.

[Cfred72]

Carolyn, how long are you going to soak the Sorbus seeds in the vinegar?

[Carolyn]

Sorry, Fred, 1 hour, same as the lemon juice.

[Matt T]

Excellent! Will be fascinating to see the results of your trial, Carolyn.