This spring I began to look at what pollinates a species of wild cotton (Gossypium aridum) found here in Jalisco. A chapter by Parra Tabla and Bullock in the Historia Natural de Chamela suggested that, given the floral characteristics of G. aridum, I was most likely to find that hummingbirds were the main pollinators.
It didn’t take much time to discover that hummingbirds did indeed visit G. aridum. Initially these were mostly migrating female Black-chinned Hummingbirds (Archilochus alexandri) although males also occasionally visited. In all cases, though, these birds did not collect nectar through the floral opening but rather between the petals at the base of the flower.
In the past, I would have called this nectar theft and as I thought of putting this post together, a number of witty titles came to mind. However, in looking over some background for this post I ran across a note in the journal Ecology by David Inouye titled “The Terminology of Floral Larceny” where I discovered that using the term nectar theft for what I had seen would not be consistent with what the experts in the field would call it.
Once you know something about a group of animals, you come to expect that they will eat particular things. When one thinks of the family Parulidae (New World Warblers) and their diet, the first thing that comes to mind are insects or other small invertebrates and most warblers have fine thin bills ideally suited for catching these things. Also, anyone who has watched these hyper-energetic little birds forage can’t but be impressed by how actively they search out their prey.
In terms of being energetic, the Parulidae are perhaps outdone only by the hummingbirds. Maybe it shouldn’t be surprising then that like the hummingbirds warblers might occasionally put their fine thin bills to use collecting floral nectar to satisfy their energetic needs. While the evidence that warblers do this is circumstantial — I know of no experiments or close observations ruling out the possibility that they are instead visiting flowers to catch small invertebrates — this evidence suggests that it is more likely that many are collecting nectar than not.
Not well-known to many of those visiting the Costa Alegre part of Mexico (that area along the Pacific Coast of Mexico between Puerto Vallarta and Manzanillo) is that an ancient Nahua community of about 3,000 people — the Ayotitlán community — resides in the mountains above Manzanillo. Most of the pueblos making up this community are within the Sierra Manantlán Biosphere Reserve, a place of remarkable natural beauty and a possible cradle for one of man’s most important crops, corn.
The Nahua of Ayotitlán, like indigenous peoples the world over, have experienced a long history of marginalization and dispossession of their lands. For these people, recent struggles stem from the fact that while the Ayotitlán’s Nahuas live in one of the most beautiful places on earth, that same place is also covered with valuable timber and underlain by nearly pure iron ore, two things that outsiders covet zealously and will go to almost any extent to obtain.
In the midst of this, one group of Nahua women on the northern edge of the Ayotitlan community have found a way to quietly better their lives and in the process are casting a ray of hope for their community and other communities like theirs. These women and their families have organized a collectiva, “Color de Tierra” that runs a remarkable little store in the pueblo of Cuzalapa, Jalisco.
In the Sierra de Manantlán Biosphere Reserve in the southern part of Jalisco, near Cuzalapa and in the Nahuatl pueblo Lagunillas de Ayotitlan, I found some interesting cotton plants.
The bolls were very compact and the seeds were not dispersed about in the cotton boll but were instead attached to one vaguely reminiscent of grains of wheat in a head of wheat (minus the central stalk).
I sent this photograph of the bolls and seeds to Dr. Mauricio Ulloa at the USDA-ARS, W.C.I.S. Research Unit, Cotton Enhancement Program. His reply was interesting. He indicated that this sort of seed arrangement goes under the common name of kidney cotton and is found most commonly in landraces of the cotton species Gossypium barbadense. The unusual seed arrangement results from fusion of the seeds of a locule (Ulloa et al. 2004).
G. barbadense is not native to Mexico but was instead apparently domesticated over 6000 years ago somewhere along the coast of Peru or Ecuador (Damp and Pearsall 1994). At some point in the past it made its way into Mexico. Ulloa et al. (2004) in a survey of currently existing cotton resources in western Mexico found G. barbadense plants in garden plots in Chiapas but no farther north.
Interestingly, all G. barbadense plants found in Mexico were of the subspecies brasiliense commonly known as “kidney cotton”.
Ullola et al. (2004) suggest the presence of G. barbadense in Chiapas is most likely the result of “early trade”. While this is a bit vague, the presence of this species only in southern-most Mexico and among indigenous groups suggests that by “early” the authors are suggesting that the trade was pre-Hispanic. If so, the finding of G. barbadense subspecies brasiliense in southern Jalisco has cultural significance in that it extends the range of this trading and broadens the number of indigenous groups involved. It is also further reason for the careful stewardship of the Sierra de Manantlán Biosphere Reserve and the respectful treatment of its people.
References
Damp, J. E.; Pearsall, D. M. (1994). Early cotton from coastal Ecuador. Economic Botany. 48 (2): 163–165.
Ulloa M, Stewart JM, Garcia EA, Godoy S, Gaytan A, et al. (2006). Cotton genetic resources in the Western states of Mexico: in situ conservation status and germplasm collection for ex situ preservation. Genet Resources and Crop Evolution53: 653–668.
