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Warm Winter Wishes
Marin Park Stewardship December 2017 Newsletter
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Dear Friend,
Let the winter begin! While the rainy season means we are officially in full planting mode here in Marin, we hope you are all finding plenty of warmth, friendship, and family at the beginning of this winter season.
Out in the park, we’re having fun trying to spot some of the many fascinating creatures we learned about at this year’s One Tam Wildlife Symposium in November (one of which you’ll meet in this issue).
Have a wonderful start to your holiday season, and hopefully we’ll see you in the park soon!
In This Newsletter
Our Dusky-Footed Friend: Woodrats as Interior Decorators
By Ailsa Harju
Photo by Mbmceach - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=21670492
At the One Tam Wildlife Symposium on Oct. 26, the Park Stewardship team learned about a small but important mammal: the dusky-footed woodrat.
This New World rat, also known as Neotoma fuscipes, is from the family Cricetidae of packrats. True to its classification, the dusky-footed woodrat is a hoarder! Individually, both sexes can create several massive piles of sticks and brush, which act as apartment complexes of sorts within their woodland habitat.
This is why the species is often referred to as keystone—they provide habitat for many other creatures: including mice, lizards, snakes, salamanders, frogs, and several insect species. But such high-density housing can bring unwanted pests like fleas. The rats combat them by placing chewed bay leaves throughout the structure, which release volatile organic compounds that are toxic to flea larvae!
Many of the apartment rooms, however, are reserved for the rat. Because they can eat several types of plants, seeds, berries, nuts, and fungi, the dusky-footed woodrat creates a separate room for stockpiling each type of food. They even create separate rooms for different uses, like a bathroom!
Additionally, the rats love to decorate their homes and show strong individuality in style and material preferences. Keep an eye out along the trails you hike in the Golden Gate National Parks—who knows, there could be holiday lights on some piles of sticks come December!
Those Plants Have Some Gall!
By Maria Pezza
Have you ever come across something that looks like this?
Photo by Mlogic - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=7148208
If you don’t know what you’re looking at, the sight can be unsettling. The first time I saw a leaf that looked like this, I was sure the poor plant was diseased! Thankfully, what you see here is just a leaf gall: an abnormal plant growth resulting from damage to the leaf surface. According to Colorado State University’s extension office, galls are largely harmless, even if they do look alarming.
Galls can form on leaves, twigs, and branches of trees, although they are most obvious on the surface of a leaf. While it’s true that most of the time the deformations are harmless, there are a few exceptions.
Galls on leaves might be so disruptive to the structure of the leaf that photosynthesis is interrupted, which may cause the leaf to fall early. Galls on twigs or branches can occasionally cause the death of an entire tree if it is too heavily covered, though these instances are rare. Many homeowners find the appearance of galls unattractive, and sometimes seek methods of control despite their generally innocuous nature.
But why do plants have galls at all? Gall formation is the result of abnormal cell growth around “compromised leaf tissue,” according to the Penn State College of Agricultural Sciences. Galls are most commonly formed on plants that are already experiencing a period of increased growth, so young, growing plants are more commonly affected by galls than mature plants.
“Compromised leaf tissue,” in the case of gall formation, is the result of the presence of insects. When a female insect lays eggs on the surface of a leaf, she—or her offspring—produces chemical secretions that stimulate localized, excess plant growth. Once a female lays her eggs on a plant, the offspring will often live inside their new protective casing on the surface of the leaf, feeding on gall tissue, until it becomes an adult and moves out.
A gall may continue to increase in size for a time, as the insect feeds and grows, but will stop consuming resources from the plant after this initial phase. The resulting gall can remain on the plant surface long after the insect has matured and vacated the premises.
Galls come in many shapes and sizes, as their appearance differs depending on the insect living inside it—so much so, according to Entomology Today, that we can identify insects based on the appearance of the galls they make.
There are many insects that cause plant galls. In fact, 700 different insect species produce galls on oaks alone! Insects have specific plant preferences when it comes to egg-laying and feeding, so we can often guess what type of insect is living inside a gall just by identifying the plant. Gall wasps, such as the horned oak gall wasp (C. cornigera) or the gouty oak gall wasp (C. quercuspunctata) are the most common gall-making insects, and the insect that most commonly affects oaks.
Next time you see an especially bumpy leaf or a strange-looking growth on the oaks in your neighborhood, take a second look. You may be looking at an insect nursery!
Sources:
Photo credit: https://en.wikipedia.org/wiki/Gall#/media/File:Gall_of_peach_tree_leaves.jpg
Insect and Mite Galls, W.S. Cranshaw, 2013, Colorado State University Extension. http://extension.colostate.edu/topic-areas/insects/insect-and-mite-galls-5-577/
Galls! Galls! Galls! The Insects Behind the Weird Growths on Plants, Leslie Mertz, 2015, Entomology Today. https://entomologytoday.org/2015/06/11/galls-insects-behind-the-weird-growths-on-plants/
Galls on Oak, Gregory A. Hoover, 2013, Penn State College of Agricultural Sciences. http://ento.psu.edu/extension/factsheets/galls-oak
Marin Volunteer Program Information and Work Day Schedules
Marin Park Stewardship
Saturdays, 10 am–1 pm, and Wednesdays, 1–4 pm
We alternate between sites, so check the details for each work day. Work day events include a combination of hands-on service and short natural or cultural history lessons.
Click here to learn more or sign up.
Wednesday Programs
December 6: Alta Avenue
December 13: Muir Beach
December 20: Wolfback Ridge
December 27: No Program
January 3: Alta Avenue
January 10: Muir Beach
January 17: No Program
January 24: Muir Beach
January 31: No Program
Saturday Programs
December 2: Alta Avenue
December 9: Alta Avenue
December 16: Muir Beach
December 23: No Program
December 30: No Program
January 6: Alta Avenue
January 13: Muir Beach
January 20: Muir Beach
January 27: Muir Beach
Meeting Locations and Directions
Muir Beach: Meet at the parking lot picnic tables. Map
Alta Avenue at Oakwood Valley: Meet at the park gate located at the end of Donahue Street. Map
Oakwood Valley Tennessee Valley Road Entrance Meeting Location: Oakwood Valley | Park on the right shoulder of the road opposite to the Tennessee Valley sign; do not drive all the way to the parking lot by the locked gate. Parking is limited, so please carpool. Map
Wolfback Ridge – Take a right on Bunker Road (immediately before the tunnel). Park in the lot by the bus shelter behind the Marin Headlands sign, only in a designated parking spot (not along the road). We will meet in the parking lot. Map
More Volunteer Opportunities
Marin Headlands Nursery
Wednesdays, 1–4 pm
1st and 3rd Tuesday of every month, 10 am–2 pm
Come grow with us at the Marin Headlands Nursery! Each year, we grow over 30,000 plants to restore natural habitats within the Marin Headlands. The dedication and support of our volunteers are vital in the effort to grow plants, collect seeds, maintain the nursery facility, and much more. Our projects are outdoors, fun, and always hands-on.
For program updates and registration, click here.
Habitat Restoration Team
2nd and 4th Tuesdays, 10 am–2 pm
Sundays at 9:30 am–2:30 pm
Help restore and monitor critical natural areas from the Marin Headlands to Bolinas Ridge. Volunteers and staff meet at different scenic locations each week to restore native habitat throughout the Golden Gate National Parks. Come out and explore beautiful areas while assisting in invasive plant removal, winter planting, and seed collection. For more information, click here.
Invasive Plant Patrol
Wednesdays, 10 am–2:30 pm
An ounce of prevention is worth a pound of cure. Invasive Plant Patrol volunteers hike throughout the Marin Headlands to find new invasions of exotics and remove localized infestations before they get out of control. Get to know the park trail systems and learn to identify plants, both native and invasive. Hikes will last approximately four hours. Locations vary from the Marin Headlands to Bolinas Ridge. For locations and to register, click here.
Thank you for supporting the Golden Gate National Parks Conservancy!
-Marin Park Stewardship
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