Ramblings with Rebecca May 16, 2005 FINAL ISSUE
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Ramblings with Rebecca May 16, 2005 FINAL ISSUE Wow! Can you believe it is already the end of the spring hiking season? And what a great season it has been! Please check your backpacks for nets and hand lenses, and so forth before leaving the preserve on your last hike day of the season. California Sister, Adelpha bredowii This is my very LAST official issue of the Ramblings! I’ve been honored to write these field notes for you for the last 8 + years! Thanks for everything you give to these programs. I know you’ll join me in encouraging the incoming Bouverie Biologist to find his or her own way to share trail highlights with you next Fall. By the way - I’m looking forward to the June 2nd evening celebration and to the Annual Meeting and Night Hike on June 7th! I hope to see you at both! I just ordered new black lights for the night hike! Look out scorpions and fungi, here we come!! And, there are new books being processed for the library (summer reading?) and old books available for sale to support it…. So be sure to cruise through the stacks when you next come to Gilman Hall. Have a great summer, and let us all know what you see out there (Remember, you can post interesting natural history sightings to the Bouverie Docent page of the ACR Website… all summer long)! And, as you enjoy the changing seasons, please continue to spread the word far and wide about the GREAT opportunity for friends, family and colleagues to become Bouverie Docents this fall! Karen Sommer and Barbara Ramsey would love to tell you more about how you can help support the upcoming training. Applications are being accepted NOW!! GILMAN HALL / NATIVE PLANT GARDEN / PARKING LOT AREA As you hike through the garden take note of how amazing it looks and join me in thanking Susan Trembley for all of her diligent gardening efforts over the past few months, and in particular for leading a crew of Monday morning volunteers (including Ken Ackerman - thanks Ken!) in a recent purge of invasive weeds that were making a concerted effort to crowd out the carefully cultivated natives here! As a result, the garden looks absolutely GREAT! Calycanthus occidentalis, Western Spicebush, is in full flower right now, so you will probably see many of the gorgeous –if tropical-looking flowers and buds on these native plants growing under the Gilman Hall office windows. Spicebush flowers are well adapted for pollination by beetles, which can enter the flower through its many petals, but have a hard time escaping through the floral parts that function like prison bars. Once the beetle drops off the pollen it picked up from another flower and picks up pollen from the flower it is trapped in, the inner parts of the flower fold back, allowing the critter to escape with the goods! What’s in it for the beetle? The stamens and other flower parts produce food bodies, which attract and feed the beetles. Often on warm late spring days ( but not yet this year…), we have watched in wonder as Yellow Jacket wasps flew in and out of the spicebush flowers… apparently after the same protein-rich repast. After the flowers fade, look for the brown, woody, urn-shaped container Spicebush capsule. that forms around the small fruits. This container develops from the receptacle which surrounded and supported the flower parts. The individual fruits that form within contain poisonous seeds, which are unlikely to appeal anyway, since each is surrounded by a fruit the size, shape and color of hairy mouse droppings! ON THE TRAIL: YELLOW BRICK ROAD Trifolium campestre is the tall yellow Hop Clover blooming along the edges of the Yellow Brick Road trail. ON THE WOODLAND TRAIL: Here, I noticed a California Sister butterfly (Adelpha bredowii) sunning on the trail. The greenish-yellow caterpillars Hop Trefoil; a.k.a. Hop Clover, Trifolium campestre of this species feed on oak trees, and emerge after about a week from eggs that have been laid singly on the tips of Quercus foliage. Caterpillar photo from Each phase in the lifecycle of any butterfly is so Caterpillars in the Field and Garden remarkable that it is easy to begin thinking of that single used for this educational purpose only. stage as an entity in itself. It’s helpful to remember what this crawling stage of life is all about, though. Caterpillars have in common with the young of many species, the attributes of voracious feeding and rapid growth. An individual flutter-by-baby might outgrow three or four increasingly larger skins in the course of a two to three week period… reminding me of the rapidity with which our kids outgrew shoes and jeans when they were wee fry. As this lepidopteran larval phase matures, there can be other notable changes, including changes in coloration – in some species – even before each vermiform juvenile takes the irreversible leap into the “here-comes-the-transformation” chrysalis (I must be waxing nostalgic… my own larvae have morphed into awesome adults of late, and the transformation is no less wondrous, if a bit less dramatically externalized, in human form)! Although the late season rain has made me wonder a few times, I’m now, finally, convinced that it must indeed be May: The Mariposa Lily, Calochortus luteus, is a bright yellow chalice against a backdrop of grain-brown annual grass thatch, on the west (right) side of the trail just before the junction with the wildflower preserve overlook spur. After the Woodland Trail curves, on the down-hill side just past the broken Blue Oak branch, there are many true Brodiaea lilies in flower!! I know some of you have been waiting for the chance to call a Brodiaea a Brodiaea… and these are not Calochortus luteus, only Brodiaea, they are Elegant Brodiaea (Brodiaea elegans)! note the pollinator, wings outstretched. Mariposa Lily Liliaceae The golden days of summer are nearly upon us… and this is a wonderful time to appreciate a few of the native grasses of the preserve. One of my favorite perennial grasses at Bouverie is the California Brodiaea elegans, Melic, Melica californica. On the uphill side of the Woodland Elegant Brodiaea trail – about half way along the “straight-away” parallel with the A true Brodiaea at Bouverie! southern property boundary, watch for a large stand of tall Soaproot (Chlorogalum pomeridianum) flowering stalks, thick with unopened flower buds… and then notice the delicate, papery- textured spikelets of California Melic nearby…. Looking something like this: California Melic close up California Melic As I walked in the open oak woodland, Violet-green Melica californica Swallows were making quite a racket overhead. A native perennial grass These colorful swallows feed on a range of flying with a papery texture. insects, including leafhoppers, beetles, wasps, ants, flies, and bees. Unlike most other swallows, Violet-green Swallows often forage above the tree canopy. This is the behavior I see most often at Bouverie. They’re also known to forage off the surface of ponds and occasionally on the ground as well. If there is a lot of food, Violet-green Swallows forage in small flocks together and with other species. May is peak breeding season for these iridescent songbirds. The female does most of the nest building, using stems, twigs, grasses, fur, and sometimes horse hair. The male brings feathers for lining the nest. Nest building can take from about one week to as long as three weeks. Females lay one egg per day. A typical clutch holds four to six white, unmarked, smooth eggs… (unmarked white eggs are common among hole-nesting birds – while ground nesting birds more typically produce eggs marked with spots and streaks … why do you , and the kids, think that might be???). The female VGSW incubates the eggs, and, the male guards the nest when she takes breaks. After about 15 days, the eggs hatch. About 25 days later, the young fledge. Female Violet-green Swallows are very loyal to their nesting area… about 80% return to the same nesting area each year, and about half use the same nesting spot as in prior years! Í A number of insects can cause damage of this kind to oak leaves. One such critter is the California Oak Moth, Phryganidia californica, in its early larval stage. As the larvae mature, the damage they do to leaves increases. These effects also compound as the seasons progress and leaf damage can be more pronounced in summer than in early spring. Another possible leaf-eater is the Live Oak Ribbed Casemaker, Bucculatrix albertiella, which has larvae that chew out leaf-miner style tunnels when young but skeletonize the leaves as they mature…. So, different species of Lepidoptera can cause a very similar effect on leaves while at opposite ends of the larval maturation spectrum! I saw a few leaves showing evidence of this Blue Oak with skeletonized leaf. kind of insect feeding as I moved from the open oak woodland under the canopy of Blue and Oregon Oaks just before the Woodland Trail Lunch Spot. I only saw a little “damage” on this tree, which was very healthy. As I approached the Loop Trail which connects the Bark House area and the Yellow Brick Road, I saw scads of Blow Wives (Achyrachaena mollis) in fruit. A classic example of a wind- dispersed seed, this is also a typical example of a member of the sunflower family, and as such, has chaffy (papery-parachute) fruits which each contain a single seed. These fluffy fruit-balls are Blow Wives deconstructing as I write, falling apart and being caught by passing gusts of wind, to start anew somewhere else.