Hi Richard, We have pheasant visits at our camera traps, typically for small bird fruit. We have seen seeds of lantana in droppings of red jungle fowl and peafowl. This surely needs further research, especially in Himalayan forests. Cheers, Soumya

That is interesting. Do you think the Lantana seeds would have been viable? There is evidence that some pheasants outside Asia destroys many seeds in their guts and also reports of viable seeds in droppings, with no obvious pattern. Lantana seeds are pretty hard and may survive treatment other seeds would not. I must find a diverse captive pheasant collection in China that I can experiment on, since they have been almost eliminated in the wild.

Thank you, Yang. Did you test if the seeds were viable? Do they look intact? If they are eating so many seeds they must, presumably, be digesting some of them!

Hi Richard. We studied seed dispersal by silver pheasant in Patagonian forests of Argentina, were it is naturalized since ca. 1940. We found that pheasants eat fleshy fruits of several species, including natives and aliens, usually defecate whole seeds, and in some cases improve seed germination capacity. Cheers, Valeria

Lophura nycthemera? It is native in the forests of SW China where I live. Very interesting! Thank you Valeria.

Hi Richard, in our study, we found that the Lophura nycthemera eat the seeds of Taxus chinesis in Fujian, which may have important effects on seed deposition pattern of this species.This surely needs further studies.

Hi Richard,

in case you are interested, these papers touch on seed dispersal by pheasants.

Krefting L.W. & Roe E.I. (1949). The Role of Some Birds and Mammals in Seed Germination. Ecol Monogr, 19, 271-286.

Cummings J.L., et al. (2008) Dispersal of viable row-crop seeds of commercial agriculture by farmland birds: implication for genetically modified crops. Environ. Biosafety Res., 7, 241-252.

For endozoochory by other galliformes you may be interested in:

Orlowski G. & Czarnecka J. (2009). Granivory of Birds and Seed Dispersal: Viable Seeds of Amaranthus Retroflexus L. Recovered from the Droppings of the Grey Partridge Perdix Perdix L. Pol J Ecol, 57, 191-196.

Orlowski G. & Czarnecka J. (2013). Re-evaluation of the role of the grey partridge Perdix perdix as a disperser of arable weed seeds. J Ornithol, 154, 139-144.

Orlowski G., Czarnecka J., Golawski A., Karg J. & Panek M. (2016). The effectiveness of endozoochory in three avian seed predators. J Ornithol, 157, 61-73.

Currently studying diet/toxicology of 4 game birds including ring-necked pheasants on the Big Island of Hawai'i. So far, the pheasant's diet has consisted of seeds, vegetation, and flower heads. Seeds include those of glycine, clover, and many types of invasive grass seeds. I've been collecting droppings and planting in a greenhouse to see what germinates. Will let you know when we find out more!

Please do! It is odd that we don't know this already.

Richard, I believe there are studies (perhaps unpublished reports) of the Black Kalij pheasants diet and seed dispersal in Hawaii Volcanoes Natl. Park, also on the Big Island of Hawaii. The Park research staff should be able to point you to those studies.

Thank you, George. It is curious that pheasants seem to be considered dispersal agents only when introduced outside their natural range.

It is human perception at the core, isn't it? "Evil aliens" that disrupt native ecosystems warrant detailed study of their biology and natural history, so we can try to control or eradicate them. In their native range, nobody would study these things - autecology died a long time ago. But it occurs to me that Charles Eliott, ages ago, wrote something about game birds dispersing seeds eaten as food, in his seminal book on ecology of invasions. I don't have that book any more to confirm that, but maybe you could take a look there if you have it. Also H.N. Ridley wrote a massive book on plant dispersal - I don't recall pheasants being mentioned in there under bird dispersal but it would be a likely place to check for info. Good luck!

I think the failure to recognize pheasants as dispersal vectors is part of the general blindness to the role of non-frugivorous birds as seed dispersal vectors. Pheasants are like corvids or waterbirds in this respect, see e.g.

Article Beyond Scatter-Hoarding and Frugivory: European Corvids as O...

Article The effect of gut passage by waterbirds on the seed coat and...

Pheasants are usually seed predators and destroy the seeds in the gizzard, so it is interesting that some seeds may pass through the gut and still be viable. I keep chickens and occasionally one passes whole seeds in its droppings. How does this happen and is it common?

"Seed predator" is a term that I think is misleading, since it implies there is zero dispersal. There's a whole gradient, not a dichotomy between seed disperser and seed predator. Digestion is far from a perfect process, and even fish eggs come out of ducks. That's because it would be suboptimal to keep feed in the gut until everything is digested, instead of digesting the easy stuff and then emptying the gut so you can feed again. Here's another example https://vegsciblog.org/2020/10/29/endozoochory-plants-lacking-fleshy-fruits/

I agree with Andy on this. Complete digestion is only the optimum strategy if there is not more food. However, a seed that looks intact may be dead so you need to test it.

Thank you for your response. Do you have any key references on granivorous birds passing viable seeds through their guts?

Yes Corlett, do you have references to this supposition ?

Hey Carl G Jones , I suppose you're asking this thinking of possible proxies for dodos. I would like to point the potential of dwarf cassowaries for this role. They are similar sized birds with a tremendous potential as seed dispersers.

Great idea. I did not believe there was a suitable ecological replacement for dodos. Although I suspect dodos would have been greater seed predators than cassowaries and I doubt they would have spread many seeds? Or am I thinking too traditionally?

You're probably right because dodos have strong beaks, and pigeons in general have strong gizzards, while cassowaries swallow whole fruits and mostly digest pulp.

Note that a whole clade of Old World pigeons - the Ptilinopini or fruit pigeons - passes all seeds intact. And the green pigeons in the genus Treron destroy only small seeds.

Thank you for the reference and comments on pigeons. I work on the Pink Pigeon Nesoenas mayeri that I have always considered a seed predator., although in light of what I have been told I need to revise my thinking.

Hy R. T. Corlett thank you so much for this article. So, i supposed that the plasticity of frugivory or seed dispersal can be related to clades and seed size.

I think Ridley 1930 cited pigeons as the most important seed dispersers of all birds. There are lots of references on granivorous birds passing viable seeds through their guts. Emus disperse all kinds of things:

Nield, A. P., et aW. (2020). The spatial complexity of seed movement: Animal-generated seed dispersal patterns in fragmented landscapes revealed by animal movement models. Journal of Ecology, 108(2), 687–701. https://doi.org/10.1111/1365-2745.13287

I already shared above a corvid paper in a previous Answer. Some examples of recent studies for waterfowl:

Lovas-Kiss, A., et al. 2020. Seed mass, hardness and phylogeny determine the potential for endozoochory by granivorous waterbirds. Ecology and Evolution 10: 1413-1424. DOI: 10.1002/ece3.5997

Costea, M., et al. 2019. The Effect of Gut Passage by Waterbirds on the Seed Coat and Pericarp of Diaspores Lacking “External Flesh”: Evidence for Widespread Adaptation to Endozoochory in Angiosperms. PLoS ONE 14(12): e0226551

Thank you Andy for these references

Many thanks for this feedback and references. I will never be able to look at Pink Pigeons in the same way again.

At FSD2020 Haruko Ando reported about pigeons dispersing small seeds (

Oddly the papers do not mention intact seeds, only crushed ones. Did they report viable seeds at FSD2020?

They reported intact small seeds in faeces during their presentation, called "Do japanese wood pigeons disperse seeds?" But they had not confirmed viability

The janthina group of pigeons show remarkable convergence with the Pink Pigeon in morphology and ecology although are not closely related and the Pink Pigeon is in a separate genus Nesoenas. It is suspected that Pink Pigeons may occasionally spread seeds although I have always been skeptical of the claim. There is a plant Erythrospermum monticolum that shows adaptations to avoid being eaten by pigeons. the fruits are on long pedicles at the terminal ends of fine branches that the pigeons find difficult to reach.

Large seeds are more likely to survive.

In waterfowl the opposite has been repeatedly reported, since small seeds tend to come out faster. But seed hardness is critical too. I think where possible the best thing is collect some faeces and take a look. Maybe get a student to take a look at 50 pigeon droppings and see what seeds they can find? There's a strong bias in the literature towards epizoochory, and a general underestimation of endozoochory potential. Darwin got that one wrong I'm afraid

We have captive birds so could design some experiments, feeding seeds of different sizes and hardness. Do you have any papers that give experimental design?

Sure, a good starting point could be: Bear in mind

Lovas-Kiss, A., et al. 2020. Seed mass, hardness and phylogeny determine the potential for endozoochory by granivorous waterbirds. Ecology and Evolution 10: 1413-1424. DOI: 10.1002/ece3.5997

But the germination data for that experiment are summarized here: Costea, M., et al. 2019. The Effect of Gut Passage by Waterbirds on the Seed Coat and Pericarp of Diaspores Lacking “External Flesh”: Evidence for Widespread Adaptation to Endozoochory in Angiosperms. PLoS ONE 14(12): e0226551

Bear in mind it is important to keep track of which individual bird the seeds came out of, if at all possible, to aid analysis. Also that seed survival will vary according to what else the pigeons are eating at the time, i.e. diet matters, as some other duck experiments have shown.

Many thanks Andy, I will have to look at all of these references. A recent paper by Julian Heinen et al in Ecography has got me thinking about this subjects. Seems to me to be a perfect student project.

Yes Andy, i think experimental design can give more information about seeds. For me, i suspectés that the Key in this precess is the seed (size, genus, ..)

A while back we were discussing Haruko Ando's work on seed dispersal by pigeons. She just gave a talk at our centre which is online here: https://www.youtube.com/watch?v=SPsAIXskLfg&feature=youtu.be

Here's a relevant pigeon paper Kreitschitz, A., Haase, E. & Gorb, S.N. (2020). The role of mucilage envelope in the endozoochory of selected plant taxa. Sci. Nat., 108, 2.

Many thanks, Andy. Both papers new to me.

Just found these papers, seed viability confirmed for a range of species, although the authors consider them as "seed predators" (not a term that I find very helpful):

Case SB, Tarwater CE (2023) Exploitation competition between seed predators and dispersers introduced to Hawaiian forests. Ecology n/a:e4038. doi: https://doi.org/10.1002/ecy.4038

Case SB, Postelli K, Drake DR, et al (2022) Introduced galliforms as seed predators and dispersers in Hawaiian forests. Biological Invasions 24:3083–3097. doi: 10.1007/s10530-022-02830-6

Best wishes

Botond@

Maybe these three papers are in problematic languages, but I was only able to publish them a long time ago. Please let me know when you receive them.

Best wishes

Thank you all these, Andy and Dr Kiss.

Even it is somewhat older those article might be relevant to:

W. G. Swank (1944): Germination of Seeds after Ingestion by Ring-Necked Pheasants. Journal of Wildlife Management 8(3): 223-231.

https://www.jstor.org/stable/3795702

Best wishes