Organ Pipe Cactus National Monument

We spent a week camping at Organ Pipe Cactus National Monument -- with the adjacent Cabeza Prieta National Wildlife Refuge, the largest piece of relatively pristine Sonoran desert habitat within the U.S. -- for intensive natural history exploration, and the planning and execution of the first set of field research projects (in pairs, students developed research questions, designed experimental approaches, carried out the research, and reported results to the group).

(return to main desert ecology class page)

We hiked into the Ajo Mts to meet the desert more intimately. We also gained great views across the bajadas and ranges into Mexico.
After an unusually wet winter, the desert was greening up rapidly and early towards one of the most spectacular blooms in years. Mexican poppies (Eschholtzia mexicana) were among the annuals beginning to bloom.
Shira, Rachel, and Megan, field notebooks at ready.,
We saw no packrats in person (they are nocturnal), but plenty of 'middens' -- the piles of debris they accumulate and live in.  This one, full of pieces of teddy-bear cholla, would deter most predators.
A typical hillside behind the campsite.  High diversity, and a good example of a saguaro cactus growing up through its 'nurse plant', a palo-verde.
A young organ-pipe cactus beneath a bursage (Abmrosia deltoides) nurse-plant
Shira and Rachel working on journals
Preparing presentations of research projects.
Fairy-duster (Calliandra eriophylla): A winter-blooming shrub in the legume family.
A well-armed baby barrell cactus or 'bisnaga' (Ferocactus acanthodes); not very susceptible to herbivores.
Barriers, placed by helicopters, in a back-country wash to stop illegal vehicular traffic (mostly drug-smugglers; undocumented human foot-traffic continues at high volume, nightly)
Senita, or old-man cactus (Lophocereus schottii) at the northnernmost limit of its range; many stems are damaged by frost.

(return to main desert ecology class page)