In this issue: know your mast, browse your options, and share your fall berries.

The Dirt: News from YardMap
Joining together to break new ground for birds

October 2012

Setting the Woody Food Source characteristic in YardMap.
Setting the Woody Food Source characteristic in YardMap signifies mast availability.

Reaching Critical Mast

What are you eating for lunch today? Maybe you chose some nuts and fruits for quick energy. If you were a bird, biologists would say you were "enjoying some hard and soft mast." "Mast" simply refers to the fruits of trees or shrubs; fruits can be hard (e.g., acorns, beech nuts, hickory nuts) or soft (e.g., berries). When you set the "Woody Food Source" characteristic for a tree or shrub in your yardmap, you're telling us what kind of mast the plant provides for birds. Even if you can't identify all of your plants, you might be able to classify them as having nuts or berries, which are important data.

Birds rely on various kinds of woody fruits depending on their body size, season, and location. For example, Wild Turkeys feed insects to their chicks, but they eat plenty of acorns and other nuts as adults. American Robins, on the other hand, have no use for acorns, but they do enjoy a nice cherry or crabapple in the winter. Providing plants that produce nuts and berries in one area is great for biodiversity. Keep in mind that trees can be inconsistent from year to year, so having a variety of fruit and nut trees is desirable in case one species experiences a poor mast year. In a small space, you can use groundcovers (like strawberries), low shrubs (like blueberries), small trees (try hazelnut), and vines (such as wild grape). If you already provide mast, tell us about it by clicking on the "Woody Food Source" menu in the Characteristics section of your tree's or shrub's infowindow. If you provide mast in the fall, show us by entering our Challenge.

Just Browsing

An important part of maintaining a healthy forest is ensuring that trees are able to regenerate indefinitely. When a diseased or dead tree comes down, a gap is opened in the canopy. Young trees will compete to fill this gap and grow to maturity. But what if there are no young trees waiting in the wings?  Unfortunately, this can happen sometimes when local browsers (e.g., deer, rabbits, moose, etc.) are affected by severe winters or overpopulation, or as a result of past land use (e.g., certain kinds of timber harvest). You should be concerned about regeneration if you have fewer than 20 eye-level saplings per acre, or if saplings consist of exotic plants too noxious or thorny to be eaten by browsers (Japanese barberry, anyone?).

Other factors can affect forest regrowth, but browsing is one of the few factors that is actually under our control. For example, a hungry deer can nibble roughly 4,200 seedlings per day! Forest owners who want to protect valuable saplings from being eaten have several options:
  • Using brush piles to protect saplings from browsers over 5′ tall
  • Using metal or plastic collars to protect  saplings from small and large browsers
  • Tree planting, which should be accompanied by some form of sapling protection
  • Using fencing to exclude large browsers
  • Opening one's land up to hunters in areas where predator densities are low
Whatever method you choose, it is important to control competing vegetation. Invasive or overabundant plants can choke out a struggling seedling, so be sure to complement your efforts by clearing away interfering brush. By taking action in your forest, you can help provide for tomorrow's birds today.

A Berry Good Challenge

Red Chokeberry in autumn.
Red Chokeberry by Diane Hammond.
This month's challenge involves a race against time–and birds! See if you can photograph some fall berries before the birds gobble them up. Share a picture of any berries available in your yard right now, and tell us what you know about them. Are they eaten right away by migrating songbirds? Are they spared until winter’s chill makes them tastier? We want to know!
How to Enter
To participate in this challenge, just make a post in our Challenges blog under the "submit & browse" tab, or in the Community Challenges Group. Include the following information:
  1. A title (e.g., "My dogwood berries")
  2. A link to an image of your fall berries
  3. This hashtag: #berrylicious
To learn about how fall fruits help fuel songbird migrations, read more.
Bringing Nature Home: How You Can Sustain Wildlife with Native Plants by Douglas W. Tallamy
Bringing Nature Home front cover courtesy of Timber Press.

Bookworms Will Dig Bringing Nature Home

Bringing Nature Home: How You Can Sustain Wildlife with Native Plants, by Douglas Tallamy, covers what you need to know about the “why” and “how” of growing native plants in your yard. Tallamy is recognized as an expert in the field of entomology (the study of insects) at the University of Delaware in Newark, and YardMap writers often draw on content from this work to support bird-friendly recommendations. You'll enjoy the regional lists of garden-worthy wildlife food plants, that together with a table of butterfly and moth host plants, take the guesswork out of native plant gardening.

Take a Sneak Peek!

Be among the first to peek at new behind-the-scenes YardMap designs before they go live. We need volunteer testers to try out potential layout changes and design updates and to provide feedback. If you'd like to help influence the design of YardMap, please email us.


  • Ask your question in our tech support community, powered by Get Satisfaction
  • Ask fellow participants your bird and plant questions in The Community, our social network for habitat stewards
  • Email us

Keep in touch

Friend on Facebook Become a fan on Facebook.
Follow on Twitter Follow us on Twitter.
The Cornell Lab of Ornithology is a membership institution dedicated to interpreting and conserving the earth’s biological diversity through research, education, and citizen science focused on birds. Visit the Cornell Lab’s website at

Copyright © 2012 Cornell Lab of Ornithology, All rights reserved.

Our mailing address is:
Cornell Lab of Ornithology
159 Sapsucker Woods Rd
Ithaca, NY 14850

Add us to your address book