We learned so much! For me, the nesting Great Egrets were the most impressive: I never knew that they rested in tree tops like so many chickens (see many white birds at top of tree at center of photo below). There was a Great Blue Heron nesting among them, too. It looked impressive from below and above even with the naked eye, but the Audubon Center had an established look out deck with powerful scopes trained on the nests and the close up views of these beautiful birds squawking and feeding their chicks in their nests was incredible. (Gabriana took off with the big kids, saying "Mommy, we'll see you at the top!")
From scopes to magnifying glasses, it was also interesting to look down. One of these cliff swallow chicks had fallen to its death and the docents used its decomposing body to discuss the process of decomposition in the cycle of forest life. We also learned that cliff swallows arrive together at the canyon all on the very same day and that they do an amazing amount of work to build their mud nests, flying to the mud flats with a speck of mud on their beaks, then repeating the process 1,000 times.
Looking at small things is always interesting and we had lots of opportunities to do so, from this cucumber beetle to banana slugs, lichen, and even frass (insect poop).
One of the last things that we did was to catch newts, examine them, then release them. Note the bright red underbelly of the one in Gabriana's hand! The experience became extra memorable when Gabriana fell off the boardwalk and into the pond; thanks to Jacki's super-mom reflexes, she only got wet on one leg to her hips. Thanks, Jacki!
At the pond, we also saw awesome looking dragonflies and damselflies; the red ones were depositing eggs, the male and female flying in tandem. A great book piqued our interest in dragonflies, Laurence Pringle's "Dragon in the Sky." http://www.amazon.com/Dragon-Sky-Junior-Library-Guild/dp/0531303152/ref=sr_1_55?ie=UTF8&s=books&qid=1276671134&sr=1-55 BTW, the scummy-looking stuff on the surface of the pond is actually a type of fern, which, we learned, is one of the only plants without a flower (it has spores instead).
More notes:
When you see lichen, you know you have good, clean air. All lichens are algae and fungus living togther and they fall into three categories: crustose (crusty), foliose (leafy),and; fruticose (shrubby). More at: http://www.backyardnature.net/lichens.htm
Orinthologists are starting to study bird sounds with sound tracking; this has helped them learn not only that birds communicate about the presence and even size of observed predators, but that there are overlapping communication patterns between bird species as they share this relevant information.
Morning glory flowers act as beds for insects, closing up to keep them cozy overnight.
Most breeds of birds (Great Egrets are an example) show no observable difference between males and females. We also relearned that banana slugs aren't male or female (hermaphrodillic) and that they have four eyes.
Wood rats are matriarchal; the nest, which is on the ground, is passed from mother to daughter and grows in size from generation to generation. Males live elsewhere - in a nearby nest, usually in a tree.
King Alfred's cakes: fungus on dead or dying trees, so named after a fable in which King Alfred was supposed to be watching his dinner cook and instead was planning his next war, resulting in burnt cakes.
Douglas fir trees can be identified by their cones, which look, in Native American lore, like a tiny mouse has jumped inside with just legs and arms hanging out. As one story goes, the mice were eating too many acorns and were punished by being confined to the pinecone. Other versions found include:
http://www.planetozkids.com/oban/dougfir.htm
http://www.growsonyou.com/gilli/blog/2529-the-legend-of-the-douglas-fir-cone
We saw a Dawn Redwood tree! "Dawn redwoods once blanketed the entire Northern Hemisphere and were thought to have been extinct for millions of years until their rediscovery in 1941 by a Chinese forester in a remote corner of the Sichuan (at the time, Szechuan) Province in south-central China. Somehow, a little over one thousand trees had survived for millennia in a region that ironically is not even Metasequoia’s ideal environment! How then, did it survive in the Shui-sha Valley when it perished elsewhere? That is one of the great modern silvicultural mysteries. " More at: http://www.dawnredwood.org/ Most interestingly (to me), they are deciduous - I never imagined a redwood that lost its needles annually!
Whew! And that was just a slim taste of all that we saw and learned on this great day. Thanks, EB for organizing; thanks Audubon Canyon and especially Marge for the perfect tour: entertaining, interesting, and never in-the-least-bit condescending. (A needed acecdote to a tour elsewhere a couple of weeks ago in which the docents undermined an otherwise good program by using fake names such as "Sponge Bob" to identify sea creatures. Ugh!)
The theme evolved over the day through various iterations, some that involved costumes, some just tap shoes, some water play on the back deck. Warm day, fun play... they didn't even want to go to a special storytelling event at the library. Instead, we stayed home and read several books and then did art, crafts, and lots of math - all outside - until the inventive play took over. In my role as interrupting photographer they tolerated me only briefly, but in the play I did get "guest spots" in which K fed me my lines, telling me what to say to "the princess" or helping said princess to find "the mouse" when she "escaped." 
