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Swallows and Bridges – Community Science Project Coming

Terry Rich

IdEEA Board Member

Cliff Swallow by Ken Miracle

IDEEA will be partnering with a new community science program from the Idaho Bird Conservation Partnership called Swallows and Bridges. The goal is to help educate Treasure Valley citizens about the conservation of aerial insectivores. Aerial insectivores are species that eat primarily by flying around and catching insects in their mouths. Appetizing, no? Many species of bats are in this group, but we’re talking about birds here. Aerial insectivore birds in Idaho include swifts (4 species), nightjars (2 species), flycatchers (22 species), and swallows (7 species).

The problem is most of these species have declining populations because of the general decline of insects around the world. That decline is estimated at 32% since the 1970s across North America. If you want to take a deep dive into the insect crash, check out the new book, “The Insect Crisis: The Fall of the Tiny Empires That Run the World,” by Oliver Milman (2022).

Insects are declining for a variety of reasons, but the use of pesticides is high on the list of villains. I cringe every time I see a lawn care company in my neighborhood spraying chemicals from a large tank on lawns and around houses. Every time I enter a garden shop and smell the tell-tale chemical stench, I hasten to another part of the shop. This stuff is nasty – don’t buy it and don’t use it. Check out more environmentally friendly solutions. Those solutions include birds who eat insects and better insects (ladybugs and mantids) who eat worse insects.

And while we’re at it, let’s give spiders a break. Some of the pest control companies try to scare you about spiders so they can make a buck and poison your house. Don’t buy it. Spiders are insect predators and remove more serious pests from your environment. Yeah, nobody wants a spider in their bathtub. But don’t contaminate your house when a newspaper will get rid of the offender.

Bold Jumping Spider by Eduardo Axel

Learn about spiders. Jumping spiders are super cool little invertebrate tigers who take out bugs we don’t want while not building webs. You can’t ask more from a tiny house guest. And check out their fuzzy faces! We are happy to see a jumper or two cruising our house like little expert cleaners. Love you! Hand-heart sunset.

Leaving swifts, nightjars, and flycatchers for another time, I want to zoom in on swallows. In fact, I want to zoom in on two swallows – the barn swallow and the cliff swallow. Both of these swallows nest under bridges in Ada County. Hence the title, swallows and bridges.

Thanks to help from the Ada County Highway Department, we learned there are 831 bridges and “large culverts” in Ada County. And they gave me a file of the locations of each of these that can be viewed in Google Earth. The idea of the Idaho Bird Conservation Partnership (IBCP) is to visit each one of these locations this spring, after the swallows return, and document which species and how many individual birds use each site. The visits can be made by anyone with an interest.

This can lead to several outcomes. One is to count and track populations of these swallows over time. But the other is to help communicate the biology of these birds and what citizens can do to help them prosper into the future. For the latter, we envision mounting educational signs on some bridges to inform passersby about these swallows and their conservation.

Barn Swallow immatures by Ken Miracle

Here's where you come in. With 831 sites, we need help from people around the valley to check these bridges and culverts. This can include something as simple as a single visit, to report what you found. You probably already know about bridges in your neighborhood. These might be quite small. I have two bridges in my neighborhood that host barn swallows and they span a small canal. One bridge has a single barn swallow pair and the other three or four.

You are free to visit your bridges as often as you like. You can also visit other bridges you m

ay cross from time to time, for whatever reason. The more visits, the better. Data will be fed into eBird, sooner or later, to contribute to the large-scale understanding of these species.

The second outcome is to present facts about these swallows and aerial insectivores via educational plaques on the bridges. We will convey suggestions on what people can do in their daily lives to make the lives of these birds better. Those include, 1) reduce or eliminate the use of pesticides in your yard, 2) plant native flowering and fruiting species, 3) replace lawns – a biological desert for most species – with those native species.

The idea of increasing insects may put some people off. But most of the insects gobbled up by swallows, swifts, flycatchers, and nightjars are invisible to us in our daily lives. And these birds also get some mosquitos, flies, and gnats that might annoy us from time to time. But there’s no downside to producing more insects flying around in the sky for swallows to take home to their young.

Barn Swallow feeding young by Terry Rich

Let’s take a closer look at our two swallows, who are so agreeable. There are many species of swallows on the planet, but few are more beautiful than our barn swallow. This swallow is the most common and widely distributed swallow in the world. Our birds leave in winter to spend the non-breeding season from central Mexico to the tip of South America.

They begin to return in the middle of March but don’t hit peak numbers until about the middle of May. There is a yet further increase once young are out of the nests and joining the adults flying around and sitting on wires. That peak occurs in the third week of August. Birds really start to leave our area around the first of September and are completely gone by the middle of October.

Unlike barn swallows, cliff swallows occur only in the Western Hemisphere. They winter over a good portion of western and central South America. Cliff swallows arrive and peak on about the same schedule as barn swallows, but they don’t show the same late summer peak. They clear out by the first of October.

Cliff Swallows gathering mud by Ken Miracle

Because both species build mud nests attached on and under bridges and culverts, we do not expect people to count nests. In fact, we don’t want people even trying because we don’t want to harass nesting birds. We’ll just be looking for a count of birds sitting and flying around. This can be quite challenging where there are large numbers of birds swirling in the sky. In fact, it may be impossible to get a count you would be your life on. But that’s OK. Following eBird guidance, we will do the best we can.

If you are interested in counting swallows at one or more bridges in your neighborhood, please send a note with the location of bridges you have in mind to the author ( For now, we are just talking about Ada County. But if this goes well, there’s no reason we can’t expand to surrounding counties. And states. One of our goals is to keep the counting easy and fun. Join us!


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