Briones Regional Park Exploration

1a. Velcro Plant

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- You'll find this weed, also known as "bedstraw", growing along the trails of Briones. The leaves of the Velcro Plant (Galium aparine) have tiny hooks, much like Velcro, that help it cling to other surfaces.

1b. Cow Tracks

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- Briones is still used as pasture land for cattle herds, much as it was used in its early history as a working ranch. The grazing is carefully managed by the park to help keep fire danger low.

2a. Oaks

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- California is home to 18 native oaks and you can see six of those in Briones. In this spot, you can see Valley Oaks, a species most often found along the coast and Black Oaks, a species found in the foothills and mountainous areas of California.

2b. Galls

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- These "oak apples" are actually created by gall wasps. Female wasps lay their eggs into the branches of oak trees. The oak forms the gall around the larvae as a defensive response.

2c. Gall Close Up

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- The gall protects the wasp eggs and larvae until they tunnel out of it, as these tiny holes show.

2d. Mistletoe

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- High in the branches of oaks and other trees, you'll see mistletoe growing in Briones. It actually acts as a parasite, pulling water and nutrients from its host.

3a. Wolf Spider

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- Spring is mating season for wolf spiders and these solitary hunters can be spotted around Briones. Male spiders can be identified during that time by their enlarged pedipalps - the pseudo fangs near their mouth - where they keep their reproductive material.

3b. Wildflowers

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- The hills of Briones are normally a dry, golden color. But winter rains turns the hills bright green and small wildflowers can be seen among the grass. This flower is known as red maid (Calandrinia ciliata).

4a. Bee

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- A bee investigates a catkin - the reproductive structure of a willow tree.

4b. Corral

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- This corral on the side of th trail is still used by the cattle herds. Old Briones Road Trail was once a road used by the ranchers in the area.

5a. Sinkhole

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- The rock and soils of Briones are actually very sandy. Millions of years ago, this was a shallow inland sea, where many nearby rivers were depositing material. This loamy soil combined with the three active faults in Briones means much of the landscape is constantly shifting.

5b. Fossils

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- Twelve million years ago, the East Bay was home to a shallow inland sea. You'll see shells and other fossils that were laid down then in the rocks of Briones.

5c. Shell Fossil

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- Another shell fossil found in the rocks along the Old Briones Road Trail.

6a. Oak Tree

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- You'll find a wide array of oak species in Briones because it is a transitional area. Both California coastal species and California interior species can live in Briones' climate.

6b. Two Oak Species

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- These leaves are from two oak species found in Briones. The leaf on the right is from an Interior Live Oak (Quercus wislizeni), and the left is from a Coast Live Oak (Quercus agrifolia). You can tell you're looking at a Coast Live Oak leaf, because they have small, fuzzy hairs on the underside of their leaves.

7a. Western Fence Lizard

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- Western fence lizards are common in California. Amazingly, scientists have found that they may play an important role in limiting the spread of Lyme disease. When ticks feast on the lizards, something in the lizards' blood helps destroy the Lyme disease microbes found in ticks. Photo by Squamatologist

8a. Stock Ponds

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- You'll see several small ponds like this one throughout Briones. Some are stock ponds, created for the cattle herds that use the park. Others are vernal pools, which fill in the rainy season and dry up during the summer. Both types of pools provide important habitat for amphibians and other species.

8b. Pacific Chorus Frog

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- If you're near a body of water, these small frogs will let you know. Despite their size, Pacific Chorus Frogs (Pseudacris regilla) have a loud, high pitched call. You probably won't see them, though. These frogs hide in burrows and holes around bodies of water.

8c. Frog Eggs

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- Many species of frogs lay eggs in loose clusters, such as this one. They're often attached to sticks or foliage in ponds or pools.

8d. California Newt

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- During mating season, you'll see California Newts (Taricha torosa) in many of Briones' ponds. They arrive beginning in December each year for mating season, having migrated to the ponds from their homes on land. If you do encounter newts in the ponds, make sure to give this sensitive species plenty of space.

8e. Newt Egg Cluster

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- Female California Newts lay their eggs in dense balls in the shallow areas of ponds or pools. After mating, both the female and male newts leave the ponds and head back to their life on land.

9a. View from the Ridge

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- From this spot, hikers can see Mt. Diablo and the San Francisco Bay. On clear days, you can often see the snow-capped Sierra Mountains directly east.

10a. California Newt

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- The bright orange color of California Newts (Taricha torosa) is a warning sign. These newts contain a neurotoxin called tetrodotoxin that helps protect them against predators like garter snakes. It's the same toxin that is found in pufferfish.

10b. Newt Migration

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- Each year beginning in December, California Newts (Taricha torosa) leave their land dwellings and make a slow migration to ponds for mating season. If you see them on the trails, make sure to give them plenty of space.

11a. Yellow Star Thistle

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- This invasive was introduced to California in 1849 with alfalfa brought from Chile. It has now spread to 15 million acres in California. The spiny plants causes problems for livestock and wildlife, and also has high water usage, competing with native plants for resources.

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