encourage small birds, discourage crows
I love crows, but I am miss the small flocks of tiny birds and robins that used to come live in our backyard. I know crows are aggressive and often push the smaller birds out. Is there something I can do to discourage the crows, while encouraging the small birds? I especially miss a tiny plump finch-like bird with a yellow breast and a cheerful song. Any ideas? Thanks much!
Multnomah County Oregon
Hello and thank you for contacting OSU Extension Service.
I can understand your concerns regarding our native American Crows. They can be a raucous bunch when they get into their social groups. And, yes, crows can take nestlings and eggs from other birds' nests, as they are opportunistic predators, but so do other species, including California Scrub Jays and even, surprisingly, tree squirrels and ground squirrels. Crows also eat a wide variety of other foods, including tree nuts, and, if not secured, garbage from our curbside bins. Deterring crows can be a challenge, as scare tactics and other visual methods tend to stop working once they realize there's no real danger (they're very intelligent birds!). As such, preventing their presence is a matter of controlling their food supply, which means altering our own behaviors so we aren't leaving easily accessible and tempting foods around for the taking. Given that they are also adapted to a wide variety of habitats, there's only so much one can do to keep them from being a member of the bird community in our neighborhoods. And, as the seasons change, they do tend to move around to new locations.
While noisy, visually obvious to the casual observer, and potential predators, they are not likely the main reason our song birds may not be as common now or at other times of the year.
Generally, songbird numbers rise and fall throughout the season. That you aren't seeing as many as you expect from past experience isn't necessarily cause for alarm. Many of our song birds are migrants from the tropics and sub-tropics, and their numbers as they migrate north during the spring are high, with many moving through to their nesting territories farther north. This is the best time of year to watch birds, as their plumage is at its showiest, and numbers are generally most abundant. After this first wave, you would expect the numbers to decrease to just those who are setting up nesting territories on your property and surrounding landscape. The nesting season tends to be very active, with birds singing and flitting around looking for nest material and insects for nestlings. In my experience, this is when I get the most activity at my feeders and around my yard. Later in the summer, like at this time of year, the usual pattern is a slowing down of activity, with most of the nestlings having fledged and on their own or soon to be. Migratory birds right now are stocking up on food for their late summer/early fall migration south. They are less vocal and may be seeking foods that you aren't able to provide to them if you have bird feeders. Incidentally, bird feeders provide a minority of the total food wild birds need for survival.
However, there are factors affecting our wild bird populations. For many decades now, summer breeding bird surveys have documented a steady decline of many migratory birds (see https://www.mbr-pwrc.usgs.gov/ - click on a bird species from the list on the left, then click on the map of North America to see a line graph of population trends for that species). The factors that have been linked to these declines include habitat loss in over-wintering tropical areas and habitat loss and fragmentation in summer nesting territories. Additionally, other studies are showing a significant loss of insect diversity and abundance. Insects are a vital part of bird diets, especially for female egg development and feeding nestlings. These declines and changes are cause for concern and point to the importance of managing habitat for greatest diversity of plant and wildlife species.
Less concerning and possible reasons you aren't seeing as many birds now is that it might not be as good a year for their preferred food. Like all wildlife, birds require food and water, and the amount of fruiting trees and shrubs, insects and other food types year-to-year can affect the number of birds you see. Personally, it seems to be a terrific berry year here in western Oregon, but just because there are berries available, not all species require or prefer berries. Late summer is also the time when most wild food sources are available and so birds are elsewhere looking for preferred foods. Water is in shorter supply this time of year as well, and birds have to go farther afield to find reliable supplies.
Wild birds, as do all wildlife, require areas of cover (shelter), which they use to rest, hide from predators, nest and search for food. Adjacent land management also affects the wildlife you see on your property. For example, construction work that significantly changes the vegetative cover, a neighbor who has made changes to existing vegetation in their yard, and other activities that cause changes to the landscape all can have spillover effects on your property when it comes to the kinds of birds you see.
These and other factors (such as seasonal and year-to-year weather patterns) affect bird populations over time, and this article from Cornell Lab of Ornithology offers more insight: https://www.allaboutbirds.org/news/im-seeing-fewer-birds-in-my-yard-is-something-affecting-their-populations/
Finally, while I'm sure you are no stranger to bird feeding strategies, a few things to consider when creating a bird feeding station that may enhance your success at attracting the kinds of birds you want to watch: set up a variety of feeder types, including hopper, tube, suit and tray - different species feed from different types of feeders; have feeders at different heights, as some species feed up high and others near or on the ground; monitor the kinds of food you are feeding and use the variety(ies) that work best for you; avoid bird seed mixes that contain fillers and less nutritious (low fat and protein percentages like millet) - these tend to attract undesirable species like the English House Sparrow and European Starlings; pair food with water and keep water clean and filled; feed fresh seed and keep your feeders clean, doing a thorough cleaning at least twice, once at the end of winter and once at the end of summer. And, consider enhancing the vegetation in your yard, choosing native trees, shrubs and flowering plants that offer fruits, seeds and nectar throughout the seasons. Your local Soil and Water Conservation District (East or West Multnomah) should have helpful plant lists on their websites and also have native plant sales each spring that are affordable sources of plants.
I hope this response helps. If you have any other questions, don't hesitate to respond here. I wish you the best as you enjoy the wild birds. In time, as the seasons change and strategies to encourage wild birds are used, you are bound to see a return of the variety and numbers of birds you are accustomed to (including perhaps, the black-headed grosbeak or American or Lesser Goldfinches, which you might be referring to in your inquiry - https://www.allaboutbirds.org/guide/Black-headed_Grosbeak/overview, https://www.allaboutbirds.org/guide/American_Goldfinch, and https://www.allaboutbirds.org/guide/lesser_goldfinch).
Thank you again for contacting OSU Extension.