Well let me initiate this discussion. I think that for birds there is a wealth of data that is available. I have had a couple of students work on this and two of the trait categories that I have data for are the feeding groups, and the habitat preferences. This are readily available from most bird guides.

What I found in an article that I recently reviewed was the use of body size as an additional variable that was the authors claimed was directly tied to the scale of the effect of the species. Though I did not completely buy the arguement, it was attractive enough to warrent consideration.

For the feeding groups, my student Leonardo used the following:

1) Carnivorous, 2) Frugivorous, 3) Insectivorous, 4) Nectivorous, 5) Omnivorous. And added some habitat preferences that he adapted from a local bird guide.

I like this concept but think that the feeding guilds need to be more specific. For example, insectivores can be divided by those that catch on the wing (flycatchers), those that glean from leaves and branches (warblers) and those that search the ground (antbirds).

Thoughts?

What i wanted to add to my comments on the feeding guilds is that we have noticed that in agricultural systems the two feeding guilds that are the most dominant are the insectivores, and the seed eaters. Though I think that what we have not been able to point out is the flycathers really are the insectivores that dominate, and not the gleaners (though I have less data on this).

FYI - the mechanisms group has been working on extensive classification of foraging strategies/guilds for birds.
see our databases in the mechanisms, modified data folder and also on bird size.

sources:
Birds of Costa Rica (Stiles & Skutch), Birder's Handbook (Erlich et al.), Birds of Mexico and Northern Central America (Howell & Webb), Neotropical Birds: Ecology and Conservation (Stotz et al.).

Hi All,

I've been working on the two Estrada papers (05 and 98) as well as the Daily paper. From these three papers I have a list of 218 species. About 100 of these conincide with the birds in Stacy's list. I also looked at the classification that Stacy is proposing and made some changes. The traits that I have been considering are as follows:

1)Genus (Nominal)
2)Species (Nominal)
3)Mean Weight (Continuous, (g))
4)Mean Length (Continuous, (cm))
5) Habitat (Categorical): Primary Forest, Secondary Forest, Forest Edge, Scrubby Vegetation, Gardens, Riparian Forest, Grasslands, Pastures, Agricultural, and Paramo.
6) Primary Food Type (Categorical): Mammals, Birds, Amphibians, Reptiles, Insects, Large Fruit, Small Fruit, Nectar, Seeds and Foliage
7) Secondary Food Type (Categorical): Same categories as above.
8) Foraging Location (Categorical): Aerial, Upper Canopy, Mid Canopy, Lower Canopy, Stem (Trucks eg woodcreepers, nuthatch, woodpecker etc...), Shrub layer, Ground and Aquatic.
9) Foraging Habit (Categorical): Aerial capture, Hovering, Foraging leaves, Foraging Stems, and Foraging Ground.
10) Migrant (Binary): 1 = yes, 0 = no
11) Solitary (Binary): 1 = yes, 0 = no
12)IUCN (Binary): 1=yes, 0=no.
13) Reference (page): the reference book used and the page.

For all categorical variables, more than one selection is possible and acceptable.

Before I embark on the task of assigning these traits to the 218 species, it would be important to have you agreement on them. I think that it is also important for us not to use too many traits and to focus on those that might be important in agricultural systems (ie pest control or damage to crops). I'm using the same references as Stacy.