Teachers’ Lounge

Species: Golden-crowned Sparrow
Scientific name: Zonotrichia atricapilla
Sounds: song
Species: White-crowned Sparrow
Scientific name: Zonotrichia leucophrys
Sounds: song (two sound files:1, 2)

About this column>>

This story behind this post begins with Facebook. Sometimes, ironically, technology can help us stay in touch with the natural world. I’ve been so busy recently, that I’ve failed to notice some of my favorite sounds of fall. Fortunately, I connected with an old birdwatching friend on Facebook who posted the following comment: “White-crowned Sparrows are back….yeah! Now where are the Golden-crowned???” A few days later she announced that the Golden-crowned Sparrows had returned as well.

Adult Golden-crowned Sparrow. Photo credit: Linda Tanner, Los Osos, CA

That day, as I walked to work across Golden Gate Park, I noticed a whole cacophony of White-crowned and Golden-crowned Sparrow song, right across the street from the Academy: how had I missed them?!

I thought I’d share their sounds with you. Here is a portion of a recording I made of Golden-crowned Sparrows (Zonotrichia atricapilla) at the spot across from the Academy. Golden-crowned Sparrow song is characterized by a doleful, descending series of three whistles. This recording consists of at least two counter-singing males: notice that the second iteration of the song is weaker and more distant-sounding, and that it is higher-pitched than the first iteration. Note also that the last two song iterations on this recording consist of only one and two whistles each. Sometimes Golden-crowned Sparrow song is heard in such shortened versions.

[As a side note, the recording also includes the calls of other birds--most prominently a chickadee overlapping with the second Golden-crowned Sparrow song iteration.]

Golden-crowned Sparrows breed along western-most Canada and in much of Alaska. They spend the winter mostly along the Pacific coast from southwestern-most Canada to northern Baja California. While in California, their song can be heard most often when they first arrive in the fall, and when they gear up for their migration north (April and early May). However, they sing throughout the winter to some extent, so keep yourself primed to hear their moving song! In the winter, they can be found in a variety of brushy habitats, and are very common in local parks and even urban gardens.

Adult White-crowned Sparrow. Photo credit: Michael “Mike” L. Baird flicker.bairdphotos.com

White-crowned Sparrows (Zonotrichia leucophrys) can be found in the same sorts of places as Golden-crowned Sparrows during the winter, and the timing of their migration and the frequency with which they sing during the winter are roughly similar to those of Golden-crowns as well. There is an additional complexity to the story of wintering White-crowns, however. In comparison to Golden-crowned Sparrows, White-crowned Sparrows have a much broader geographic range–they breed throughout much of the western United States and Canada, and all the way east across northern Canada.

And in the Bay Area, three different subspecies can be found in the winter. (They can be told apart by subtle physical differences as well as differences in song.) White-crowned Sparrows of the subspecies gambeli, which arrive here from Alaska, are not very common. Birds of subspecies pugetensis, from the Pacific Northwest, are abundant. White-crowned Sparrows in the subspecies nuttalli, which breed locally in northern California, stay put, and in fact, can be heard year-round in appropriate habitat: foggy, brushy areas, such as seaside vegetation and coastal hills.

While volunteering a few years ago for Jay McEntee, a graduate student in U.C. Berkeley studying, among else, vocal evolution in birds, I learned that some of the historic populations of the locally breeding subspecies of White-crowned Sparrows have disappeared. The most widespread subspecies of White-crowned Sparrow around here during the winter is the Northwestern pugetensis, and it is the one most likely to be heard.

A typical song of a White-crowned Sparrow wintering in the Bay Area begins with a whistle on a single note followed by a second whistle or buzz on a higher note. What follows is variable: one or more additional whistles/buzzes? A trill (quick repetitions of the same note)? Repeated notes followed by a buzz or whistle? See if you can pick out the two White-crowned Sparrow songs in this recording made in the San Francisco Arboretum. Here is another recording of White-crowned Sparrows singing over the noise of a cheerful baseball game.

One of my greatest joys during the fall is in following the changes that occur in bird vocalizations. Different species move through the Bay Area or arrive here at different times, so there is almost continually something new to hear. As you proceed about your daily routine–going to school or returning home, walking about your neighborhood, taking your dog to the park, making a trip to the grocery store–if you remember, consider taking a few moments just to listen to the different sounds around you. Do you hear anything you haven’t heard in a while? Anything you haven’t heard before? Over the years that I’ve been birdwatching, I’ve come to associate particular bird sounds with different parts of the fall: beginning of the school-year, the onset of cold, the approach of Christmas. And this adds a great deal of color to my life.

So, it’s worth it to pay attention to what’s going on out in nature at this time of year. But if you don’t find enough time to do that, connect with someone on Facebook who does!

Immature Golden-crowned Sparrow. Photo credit: “black_throated_green_warbler” from Flickr

Immature White-crowned Sparrow. Photo credit: Jamie Chavez, Santa Barbara Co., CA

Previous posts:
June 27, 2009: Female vocalizations in birds
May 29, 2009: Which hummingbird did we spot?
May 1, 2009: Chicks of the season
April 22, 2009: California Towhee
April 24, 2009: Update on California Towhees
March 24, 2009: Mid-March Medley
February 26, 2009: Allen’s Hummingbird
January 28, 2009: Ruby-crowned Kinglet

About this column>>

I received another comment to which I’d like to reply publicly:

This comment brings up a few very important issues, and I must admit that I’ve been quite neglectful. I’ve just returned from a week-long workshop on recording of natural sounds—birds in particular—and one message we received is that, while most people who record bird sounds like to focus on the most palatable ones—namely male song—there is a real need to document other vocalizations, among them call notes uttered under various circumstances, the vocalizations of young, and, of course, the vocalizations of females.

I’ve neglected female vocalizations, and, indeed, even female images, partly because I’ve aimed to keep my blog as simple as possible, and as accessible as possible, and the fact of the matter is that, often, the most easily visible and audible birds are males.

But there is no longer an excuse! I will therefore do my best to address the issues that I perceive in Gay Bishop’s comment.

First, female-specific vocalizations. In some birds, there are vocalizations that are specific to males, and others that are specific to females. This is true for several local species in the blackbird family (Icteridae). For example, when a male Brown-headed Cowbird (Molothrus ater) sings to a female, she often answers with a trill, or “chatter” call. An example of a male song can be found here. Males have several types of song—this is only one. Some more examples of song, as well as an example of the female chatter call, are posted here.

Male and female Brown-headed cowbirds. The female is on the right. Photo credit: Tom Talbott, Seattle, WA

Male and female Red-winged Blackbirds. The female is below the male Photo credit: Jeff McCrory, Tacoma, WA

Male and female Red-winged Blackbirds (Agelaius pheoniceus, also in the blackbird family) form separate flocks in the winter, and I’ve noticed that their flight vocalizations are distinctly different. Unfortunately, I cannot find a recording of flying flocks of blackbirds. However, I did come across this page from a blog by Paul Driver, with examples of other Red-winged Blackbird calls unique to males and females. Paul Driver’s blog is incredible for documenting so many different kinds of vocalizations of so many species. The blog focuses on birds from the eastern United States, but many of the species occur here in the Bay Area as well.

Red-winged Blackbirds are common breeders in marshy areas. Flying flocks can be encountered in the winter in various places, such as Coyote Hills Regional Park in Fremont, where you might be able to see the birds close enough to tell whether they are male or female. A more impressive sight is the seemingly endless stream of giant flocks of blackbirds one sees in the winter in the Sacramento Valley.

Flock of blackbirds. Photo credit: Mike Baird, Morro Bay, CA

Another bird with male and female specific calls is the Dark-eyed Junco (Junco hyemalis). This bird is very common in the Bay Area, and is often easy to find even during nesting. When you (unknowingly) approach a nest, the male may begin sounding deep “tup” calls. (A couple of examples of this call can be found on this page. Scroll down to the track labeled “Alarm call and other call notes.”) If you approach even closer, the female will appear and begin sounding sharper “tick” calls. (Unfortunately, I have not been able to locate a recording of this call.) The Dark-eyed Juncos’ local breeding season is quite long, beginning early in the spring and lasting well into summer, so you may still have a chance to observe these vocalizations firsthand. If you notice a male Junco tupping, approach it and see what happens.

Female Dark-eyed Junco. Photo credit: Jamie Chavez, California Male Dark-eyed Junco. Photo credit: Nathan Hamm, Roseburg, OR

Bishop asked specifically about female song. In some species, females do indeed sing. In Black-headed Grosbeaks (Pheucticus melanocephalus), females sing a song similar to, but not quite exactly like, that of the males. They can however sing the male version of the song. I learned from Dr. Alan Kaplan, former naturalist at Tilden Regional Park in the East Bay, that females will sometimes take advantage of this ability when sharing incubation duty with males. If a male has been out foraging a bit too long for the female’s taste, she will sing a male song. He, interpreting her song as that of an intruding male, will rush to the nest, at which point she will relinquish her post to leave him to incubate the eggs for a while.

Female Black-headed Grosbeak. Photo credit: Maggie Smith, San Luis Obispo County, CA

While I have never knowingly heard female Black-headed Grosbeak song, as opposed to male, here is an example of the song of this species. Black-headed Grosbeaks are native to the Bay Area. However, I recorded this particular bird during my sound-recording class in the Sierra Nevada. I never saw this individual, and do not know whether it was male or female.

Male Black-headed Grosbeak. Photo credit: Steve Ryan, Groveland, CA

Wrentit with morsel in its bill. Female and male wrentits look alike. Photo credit: Larry Tunstall, Brookrails, CA

Another species where both males and females sing is the Wrentit (Chamaea fasciata), a unique denizen of thick chaparral restricted to coastal California, Oregon, and Baja California, and the western Sierra Nevada foothills. In Wrentits, both male and female song consists of an accelerating series of “yips,” reminiscent of the pattern of sound of a ball bouncing on a table. The male version of the song (a recording of which can be found here) accelerates to a trill, whereas the female version does not speed up as much. (An example of a song that does not speed up quite enough to end in a trill can be found on this page—I don’t know whether it accelerates little enough to qualify as female song.)

Finally, Bishop asked whether there is a resource that lists which native species’ females sing. I did not find such a resource! As may be evidenced by my blog entry, even recordings of female vocalizations are (surprisingly) difficult to find!

Some simple google searches, however, for ‘female vocalization in birds’ or ‘female bird song’ and similar terms, retrieved some very interesting information, and I managed to track down quite a few studies on the subject. I discuss just a handful of them briefly below.

First of all, it should be noted that female birds can often be induced to sing male song via implantation of testosterone, and this practice has been used by researchers to study the acquisition of song.

Naturally occurring female song is another story.

Perhaps the most provocative study I came across was a collaboration between researchers in Belgium and France (L. Z. Garamszegi et al., 2006, published in the journal Behavioral Ecology), who searched the literature for mention of female song in European songbirds, and used statistical and phylogenetic methods to ask whether the ability of females to sing is ancestral—in other words, whether it is the rule rather than the exception. Despite a dearth of available data, they still managed to show that female song is the norm in two families, and they suggested that, with more information, it may turn out to be the norm for all European songbirds.

Many families of songbirds are common to Europe and North America, and so, what is found to be true of European songbirds is likely to be true of our songbirds as well.

In fact, female song may be ancestral to all songbirds. Songbirds are thought to have originated in Australia, and female song, apparently, has been commonly noted in Australian songbirds!

Garamszegi and his colleagues mention several possible explanations for the existence of female song, and these are identical to explanations that have been pursued for male song: attraction of mates, fending off of competitors—two hypotheses that I have mentioned in a previous column—and several that I haven’t, including coordination of breeding activities, and maintenance of contact with mates.

A study by researchers from the University of Cambridge (N. E. Langmor and N. B. Davies, 1997, published in the journal Animal Behavior) has provided direct evidence that female song may evolve for the purpose of competing for mates. The study focused on Dunnocks (Prunella modularis, a European bird). The researchers experimentally removed males from the study area to increase competition for mates between females. Females use a “trill” call to induce their mate to approach them. When two females were in direct competition for a single male, they increased their trill rates. Also, some of the females who shared males produced complex “songs,” which summoned their mates, but females who had a male all to themselves did not produce these songs!

For me, this study raises an interesting question: What is female song? If we remain male-biased, we may fail to recognize a female vocalization as “song” if it does not match a male “song.”

And this, of course, harks back to the question of what “song” is, and how it is distinguished from a “call,” which, as I have also discussed before, is quite a murky question. “Song” seems to imply a complex, or a palatable vocalization. However, for the purpose of a rigorous definition of “song,” the function of the vocalization has often been invoked. If a female utters a relatively simple and (to us) unpalatable vocalization in order to attract a mate, is it song?

As you probably see, bird song in general is a complex issue, and female song not well enough studied. I have provided a few examples of female-specific vocalizations, a few of female-song, and a few of research on female song. However, I have failed to find any central resource on female song. If you come across such a resource, please leave a comment, and let us all know!

Vocalizing female Red-winged Blackbird. Photo credit: Julie Falk, Southern Michigan

About this column>>

I received the following comment in response to my February entry on hummingbirds: Daniel Kreeger and Mom on May. 24th, 2009 at 7:31 AM: ‘We saw the most extraordinary hummingbird this morning. I had never seen it, but my kindergartner said he was very close to one in Sacramento…(he says “I was so close and it was so cool”) it was completely black, but for a bright red head. Anyone know what we saw? Thanks!’ I thought it would be worth sharing my response with all readers of this column.

Partially silhouetted male Anna’s Hummingbird Photo credit: “stonebird,” Inglewood, CA

A good example of this is the picture on the right of the head of a a male Anna’s Hummingbird. The entire cap and throat (or “gorget”) should appear to us pink, but notice how much of the head appears blackish-brown—the result of seeing it ‘at the wrong angle.’ I flipped through some field guides to hummingbirds to see if there are any black hummingbirds. There are over 300 species of hummingbirds! Most of them are restricted in range to South America, Central America and Mexico. Only a small number occur in the United States, and just a handful in the Bay Area.

male Anna’s Hummingbird (Calypte anna) Photo credit: Len Blumin, Mill Valley, CA

male Anna’s Hummingbird Photo credit: “randomtruth” male Calliope Hummingbird Photo credit: “prayingmother” male Black-chinned Hummingbird Photo credit: Marj Kibby, Newcastle, Australia

The most typical hummingbird in the Bay Area—and the only one we can see year-round—is Anna’s Hummingbird (Calypte anna). Also nesting here is Allen’s Hummingbird (Selasphorus sasin), and a common migrant is the closely related (and very similar-looking) Rufus Hummingbird (Selasphorus rufus). Occasionally, we see other species of hummingbirds here. Though I have never seen it myself, the Calliope Hummingbird (Stellula calliope) occurs as a migrant in the spring, typically in inland chaparral. Going further inland—to the Sacramento delta—another species that can be found in the spring and summer is the Black-chinned Hummingbird (Archilochus alexandri). One winter, a vagrant Costa’s Hummingbird (Calypte costae) graced my neighborhood in Berkeley; and I’m sure there are many more instances of locally rare or vagrant hummingbirds that I’ve either forgotten, or haven’t heard of.

male Allen’s Hummingbird Photo credit: “sgrace” male Rufous Hummingbird Photo credit: “ianredan” male Costa’s Hummingbird Photo credit: Christopher Fritz, San Diego, CA

Incidentally, blue feather coloration is also generally a structural color. In this case, the structure of the feather tissue absorbs most wavelengths of light, but scatters the shortest (blue) wavelengths. That means that we will only see the color when the light rays that reach our eyes are ones that have been reflected off the bird. Compare the two pictures of a Western Scrub-Jay below. In the one on the left, the sun is behind the bird, and we cannot see its blue color. In the other, the sun’s rays are reflecting off the bird, and the and we can see the blue in all its glory!

Western Scrub-Jay (Aphelocoma californica) Photo credit: Sandy Harris, Central Coast, CA

Western Scrub-Jay (Aphelocoma californica) Photo credit: Debra Roby, Hercules, CA

Last month, five scientists spoke to an audience of teachers about conservation biology during an all-day event called BioForum. The day ended with a panel question and answer session. During this lively conversation between the teachers in the audience and the scientists on the panel, a theme began to emerge: our new policy in science education should be “No Child Left Inside.”

Why is this so important? Several of the speakers agreed that their passion for science was first sparked by spending time outside as kids—“mucking about” in the natural world, exploring and experiencing, developing a life-ling curiosity and fascination with nature that led them into their current careers.

But with so many demands on our class time, how can we justify taking time out to turn our students loose in the great outdoors? From this question, the conversation turned to citizen science projects as a way to give students the chance to spend time in a natural setting, but with content, structure, and value built into the experience.

So what is citizen science, anyway?

Imagine a scientist who is studying, for example, birds. Suppose the scientist focuses on a migratory bird species, and needs to figure out when and where it goes on its migration. If the bird species has a small population in a restricted area, it might be feasible to go out and watch the migration first-hand. But what if the species is spread all across the continent? How can the scientist follow all these populations at once?

One day the scientist realizes that she is not the only person paying attention to birds. There are thousands of amateur birdwatchers across the continent who like to keep track of the birds they see in their area. Whether individual watchers record what they see in pictures, words, or not at all, the combined observations of thousands of people contain a wealth of data with great potential.

Recognizing this potential, the scientist reaches out to the birdwatchers. “Hey guys, if you happen to notice this type of bird passing through your area, can you tell me about it?” Before she knows it, she receives hundreds of sightings from around the country and has all the data she needs to complete her research.

Meanwhile, birdwatchers from different areas are suddenly united and start to compare notes. Instead of making their observations in isolation, the birdwatchers are now part of a community with a common interest and a shared task.

The scientist gets to use the data to map out migratory route of the birds and publishes a paper. The birdwatchers get to see the observations made in their own backyards shared with the entire scientific community. Everybody benefits from the experience—including the birds.

Sounds interesting, but how does that help my students?

Okay, suppose you are starting a unit on birds. You can talk about them, show your students pictures and videos, but you know the best thing would be to take your students outside and show them real birds in action.

Then you hear about the scientist collecting observations from birdwatchers. You realize that this is the perfect opportunity for your students: not only will they get to learn about birds, they will be participating in real scientific research. You can teach them observation and data-collecting skills in a real-world context. Then your class can follow the project and see what happens to the data they send in, giving them front-row seats to science in action.

This is an excellent way to bring your students outside. So much of our teaching takes place indoors, and of course our lectures and lab activities are essential for students to learn science content. But true science is not confined to indoor settings. Science is all about understanding the world around us, and the best way to do that it is to go out into the world and experience it. While most students imagine that scientists spend their whole careers in the lab, the fact is that many scientists spend significant time outdoors doing field work. Involvement in citizen science allows your students to experience this firsthand.

That’s great, but what if we’re not studying birds?

This hypothetical example is only the tip of the citizen science iceberg. A vast array of projects are underway involving volunteers, teachers, and students in collecting valuable data on just about everything, from birds to bees and beyond. Citizen science is not limited to biology either; projects exist focused on weather, light pollution, astronomy, and more. Many of these projects are producing real-world results with remarkable impact.

For example, the Christmas Bird Count, which is the oldest citizen science project in existence, has had some remarkable impacts. Data collected by volunteers during 109 annual Counts since the tradition began in 1900 provides scientists with a long-term picture of bird populations and how they change over time. This project documented a significant decline in populations of the American Black Duck in the 1980s, leading to new conservation measures to protect the species.

Citizen science is more than just a way to teach your students science content and science skills; it’s also a way to involve them in valuable work that can make a genuine real-world impact. I’ve compiled a list of 11 Citizen Science Projects in the Bay Area with which you can involve your students.

“Tell me and I forget. Teach me and I remember. Involve me and I learn.”
Benjamin Franklin

Species: Bushtit (Psaltriparus minimus); Chestnut-backed Chickadee (Poecile rufescens); Dark-eyed Junco (Junco hyemalis)
Sounds: Bushtit adult and fledgling calls, Chestnut-backed chickadee nestling begging calls and (adult?) defensive noises, Dark-eyed Junco song and fledgling calls (1, 2).

About this column>>

Bushtit Psaltriparus minimus Photo credit: sgrace

One challenging part of identifying birds by sound is identifying the calls of young birds—nestlings and fledglings. Nestlings are birds that have hatched and grown a little, but are not yet capable of leaving the nest, and fledglings are birds that have developed enough to be able to leave the nest, but are still guarded and fed by their parents. Parents tend to keep their young well-hidden, to protect them from predators. In addition, the calls of young birds can be very subtle—also as a protection against predators.

However, the young of some species of birds are relatively conspicuous, and some have distinctive vocalizations. I’ve decided to feature three such species of birds that happen to be breeding in the Bay Area right now, so that you’d be able to go out and look for them with some possibility of success!

Bushtits (Psaltriparus minimus) are tiny, grey birds that seem to constantly jump about and make soft, pattering calls. In the winter, they may gather in large flocks of up to 75 individuals! However, during the breeding season, much smaller groups can be seen—a male and a female, sometimes assisted by young males born the previous year. Breeding birds construct incredible, sock-shaped, hanging nests of soft plant materials and cobwebs. These nests can take several weeks to construct! I photographed the nest pictured to the right on a recent local birdwatching trip. They are some of the easiest nests to locate around here—they are often placed in Live Oaks.

Bushtit nest in dead branches of oak tree

While all Bushtit calls are rather soft and subtle, there is a distinct difference between the calls of the adults and the calls of the young. Listen to the calls of these adult Bushtits, which I recorded in Golden Gate Park (amidst the noise of cars and other birds!), and compare them with the calls of these fledgling Bushtits, which I managed to record near the campus of San Francisco State University. Notice that the calls of the young are much faster, and seem to consist of a repeated cascading pattern.

I spent a great deal of time trying to find young Bushtits this early in the season, so as to be able to post their calls on this blog entry. In my (brief) experience as a birdwatcher, the sounds of nestling and fledgling Bushtits in the Bay Area become suddenly apparent en masse right around May 1—so prick up your ears! This is the moment to listen for them!

Another local bird whose young produce distinctive vocalizations, and which fledges around this time of year (in fact, often slightly earlier than Bushtits), is the Chestnut-backed Chickadee (Poecile rufescens).

Chickadees nest in tree cavities, and I suspected I had come across a Chestnut-backed Chickadee nest-cavity one day on campus last week, when I heard these Chickadee begging calls. However, as there were no adults around, I couldn’t confirm my suspicion. I returned later, but by this time it was already dark. Resting my microphone against the cavity elicited this response, which I conjecture was a defensive sound produced by one or both parents brooding the young (keeping them warm). I have never heard this sound before, but have since been told that chickadees will hiss at nest intruders.

The following day I managed to confirm that the nest cavity was that of a pair of chickadees. I took the following pictures of one of the parents with food in its mouth about to enter the cavity (which lies out of view to its right), and of several begging nestlings within the cavity, necks stretched upwards, and gapes wide open. Note the yellow color at the base of the nestlings’ bills. Colorful gapes are thought to facilitate feeding of the young by adults.

[By the way, I featured some calls of adult chickadees in my March entry, “Mid-March Medley.”]

Chestnut-backed Chickadee parent with food

Chestnut-backed Chickadee nestlings in tree cavity

The final species I will mention today is the Dark-eyed Junco (Junco hyemalis), which nests on the ground in thick ground cover or leaf litter. Juncos are often found in human-altered habitats. As an example of where you might find Junco fledglings, I took this (poor!) photo below of a fledgling on the San Francisco State University campus: the habitat in this case consists of a ground cover of non-native English Ivy with scattered non-native shrubs.

Dark-eyed Juncos produce a variety of vocalizations. The frequently heard song of the male Dark-eyed Junco consists of a long trill. The begging calls of the fledglings are somewhat variable, but these dry rattles are typical. These ticking calls, which resemble the calls of adults, are also typical begging sounds.

Junco fledgling in English Ivy ground cover

Adult Dark-eyed Junco (Junco hyemalis) Photo credit: Marcus Smith, Los Angeles

If you happen to watch birds this time of year, please note that the fledglings of Chestnut-backed Chickadees and Bushtits greatly resemble adults in appearance. Young juncos, however, look quite different from adults. Adults, in our area, have dark hoods, brown backs, and light bellies, whereas fledglings are covered in streaks.

Go out there and find some young birds!

Your homework assignment: I posted some rather subtle recordings in this entry! If you feel motivated, listen to them, and familiarize yourself with the sounds of nestlings and fledglings likely to be encountered at this time of year; then pay attention while you’re out and about in case you hear one of these sounds.

However, I have an additional suggestion this time around: Pay attention to the world around you with all your senses! While preparing this blog entry, I heard a sound I had never heard before (the hissing of chickadees at their nest)! It pays to listen! But also keep your eyes open—there is little that is more heartwarming than a parent bird feeding young. Especially at this time of year, when you hear birds, look, and when you see birds, follow them with your eyes. Incessantly calling birds may turn out to be begging fledglings (fluttering their wings and pursuing adults), and if you watch them long enough, you’ll see them get fed.