2/7/2023
Walking under the canopy of the oak woodlands is always a pleasant experience. The rains over the weekend have left the low-lying swales and pools full of water. The ground is certainly well saturated at this point. The sun is shining through the occasional cloud, but the air remains crisp in the shaded woodland. The stillness is only interrupted by the chatter of Robins moving through and a Black Phoebe chirping softly on the edge of the tree line, perched and intent on catching insects as the sun heats up the grassland. The noiseless soaring of Turkey Vultures patrolling the sky adds to the peaceful ambience.
Many fascinating organisms that are not so vocal exist in the undergrowth – beneath leaf litter, decomposing logs, and rocks. Taking your time and flipping over logs to view these secretive creatures can be very rewarding. If you choose to do so, take care when placing the log back down gently so as to not crush any residents. It is best to carefully remove any critters before rolling the log back in place. Put the animal back next to the log where it can find its way back. Be especially careful with amphibians because their skin is extremely sensitive and secretes a mucous that protects their permeable skin. If handling is necessary, wet your hands or gloves and minimize the disturbance as much as possible.
The California slender salamander (Batrachoseps attenuatus) is a common sight under the substrate of Little Lake Valley. These elongated and skinny creatures love to huddle under moist moss-strewn logs in the winter. They have reddish-brown markings on their back and have short limbs with four toes on each foot. They are lungless salamanders, so respirate exclusively through their skin. All surfaces of the salamander need to be moist at all times in order to absorb oxygen. California slender salamanders are dependent on wet environments that range across oak woodlands, coastal redwood forests, grasslands, and riparian zones from the valley up to the mid-elevation coastal ranges. At the onset of the dry summer months, slender salamanders retreat deeper into tunnels and rodent burrows, seeking more moisture and cooler temperatures.
California slender salamanders are opportunistic feeders that also hunt for small insects, spiders, mites, and snails in underground tunnels. They have an extendable sticky tongue and catch their food just like a frog or chameleon would. Salamanders need to keep a low profile because they themselves are often sought out by snakes and foraging avian predators. Females lay their eggs at the arrival of fall rains, usually by December. They deposit the eggs with an ovipositor in sites that remain moist, such as subterranean tunnels or beneath ground debris. Multiple females may use the same site to deposit their clutch. A clutch contains up to twenty eggs, and the young hatch in the spring around March and April.
Another charming yet often misunderstood creature found among the leaf litter is the centipede. These invertebrates are arthropods and closely related to millipedes. Both have long multi-segmented bodies with many legs. Unlike millipedes, centipedes are predatory and possess modified front limbs that are able to pinch and hold on to prey. Prey are subdued when venom is injected through these ‘forcipules.’ Forcipules are only found on centipedes and are the only known example of front legs that act as venom injectors. Venom glands run through a tube, from adjacent segments to pores at the ends of each forcipule. Centipedes mainly prey on soft-bodied invertebrates such as earthworms, crickets, and spiders. Another distinguishing characteristic of the centipede is that it has one pair of legs per body segment, whereas millipedes have two pairs of legs attached to each body segment.
The lifecycle of the centipede is interesting. Centipede reproduction does not involve mating between the two sexes. Male centipedes will deposit a spermatophore in a safe place such as a web for the female to take up. The male will then either perform a courtship dance to entice the female to accept his sperm or just leave it for the female to find. Egg laying occurs mostly in the spring and summer. A clump of up to 60 eggs are laid in a nest in the soil or a rotting log. Females of the genus Geophilus (soil centipedes) and the genus Scolopocryptops (bark centipedes) display a great amount of parental care. The mother will guard the eggs and keep them clean to protect them from fungal infections.
The wet winter and spring months are a great time to observe and appreciate the fauna and flora that do not receive much attention.
