Why Evolution is True is a blog written by Jerry Coyne, centered on evolution and biology but also dealing with diverse topics like politics, culture, and cats.
Today we have some guest photos from Belize sent in by reader Mark, but taken by a friend. The IDs are from an anonymous friend, and you can enlarge the photos by clicking on them:
I’ve already had posted here sets of bird photos from two of my friends in the local Audubon group, Ed and Jeff; here are some photos from a third friend, Cliff. These are photos he took on a birding trip to Belize in April 2024. All identifications are his; he’s not only a better photographer than I am, he’s a better birder as well. As always, posted with permission.
Today UC Davis ecologist Susan Harrison returns with some bird photos and, at the end, a couple of reptiles and mammals. Susan’s captions and notes are indented, and you can enlarge the photos by clicking on them:
Ibises, Meadowlarks, and Others
It’s early April and the skies are still often cloudy, snow is lingering on the distant mountaintops, and the wildflowers are getting underway. Birds are singing, chasing, nest-seeking, and flashing their breeding colors. These photos are from two of northern California’s wildlife refuges at this invigorating, promising time of year.
White-faced Ibises have gone from uncommon to quite abundant around here in the past 25 years, possibly because flooded rice fields are being managed to support wetland wildlife. To appreciate these Ibises’ iridescent beauty, it helps to get close to them on a sunny day, as I attempted to do at the Yolo Bypass Wildlife Area.
White-faced Ibises:
Western Meadowlarks (Sturnella neglecta) are abundant in open fields, dominating the soundscape with their complex resonant songs. One artfully arranged himself in a bed of Goldfields (Lasthenia californica), while another showed off his tonsils.
Western Meadowlarks:
Marsh Wrens (Cistothoruspalustris) are also loudly melodious in their namesake habitat:
Belted Kingfishers (Megaceryle alcyon) are quite hard to approach with a camera, but this one was perched next to a bird-viewing platform that obscured his view of me:
Nuttall’s Woodpeckers (Dryobates nuttalli) and other woodpeckers are in the same order as Kingfishers, and there is a bit of a family resemblance:
Black-necked Stilts (Himantopus mexicanus) are common in the refuges’ shallowly flooded fields:
Clark’s Grebes (Aechmophorus clarkii) are on the verge of doing their spectacular springtime mating dances:
P.S. Last night when I’d just gotten this post ready to send, we found two Gray Foxes (Urocyon cinereoargenteus) curled up on the patio furniture, in a picture of canid domestic bliss!
Reader J Monaghan from Australia sends us some urban birds from his area. It must be nice to live in Oz and see these around your house! Monaghan’s captions and IDs are indented, and you can enlarge the photos by clicking on them.
Urban Birds
These photos were taken in my garden and neighbouring streets in the Lake Macquarie area of New South Wales, one of Australia’s largest coastal salt water lakes. As we live in a “bird corridor” with many native and introduced different birds, we have had to learn to co-exist.
Australian magpie (Gymnorhina tibicen). During their August to October breeding season they become protective of their nests and young, swooping on and sometimes injuring unwary passers by. Cyclists resort to sticking plastic ties and pipe cleaners in their helmets to protect from direct injury:
Female Mallard (Anas platyrhynchos) are an introduced bird. Several families live near a creek at the bottom of my street and we all slow down and drive slowly past them as they take their time waddling off:
Mallards are not particularly shy and are happy to visit. If we walk and talk slowly, they will hang around for quite a while:
Australian Wood Duck (Chenonetta jubata) are common in our area, particularly around creeks and parks, as have adapted well to the urban environment:
Eastern Rosella (Platycercus eximius). The only two photos I have of these birds, as not only do they rarely come out into the open but they are skittish and fly away at the sight of my creeping cats:
Eastern Rosella. My second photo, just before it took flight:
Kookaburra (Dacelo novaeguineae, also known as the laughing kookaburra). A frequent visitor to my friend’s pottery workshop, where it checks out her latest creations. Their raucous call can be sleep shattering at 6am:
Little Corellas (Cacatua sanguinea). Increasingly common in urban areas and often seen feeding on lawns, shrubs and playing fields. They are very social and can be boisterous and playful with each other. These two stayed still long enough for me to photograph them:
Masked Lapwing (Vanellus miles novaehollandiae). May swoop during breeding season but rare actual contact (unlike the magpie!). They nest in small depressions in the ground, and sometimes beside roads or in the roofs of buildings. We have to take care not to disturb their nests, which may require mowing around them or relocating them if they are in a particularly unsafe place:
Masked Lapwing couple on guard duty:
Sulphur-crested Cockatoo (Cacatua galerita). These birds are highly intelligent and comical, using loud, raucous calls and screeches to call out to each other. They drown out converstion when a flock flies over, so best to just wait until they fly off again:
The Sulphur-crested Cockatoo on the right spotted me trying to photograph it, raising its crest in reaction to my threat:
Australian white ibis (Threskiornis molucca). Though they have many names (Tip turkey, Dumpster chook, Rubbish raptor), they are most commonly known as Bin Chickens, due to their ability to survive in cities by scavenging our leftovers, as their wetlands have been increasingly lost.
Australian White Ibis. Wary enough of humans that I couldn’t get close enough to take a better photo of them but brave enough to take over the local dog park:
These are additional photos from reader Loretta Michaels trip to the tropics (part 1 is here). Her IDs and identifications (the binomials are from me) are indented, and you can enlarge the photos by clicking on them. Some of the IDs weren’t supplied, so readers are welcome to try their hand. From Loretta:
These were taken in Oct/Nov 2024 on the Upper Amazon in Peru, as part of a boat trip around the region. If you wanted to add this to my description, I use a Sony DSC-RX10 M4 (a fantastic camera that for some reason Sony has discontinued, much to the disappointment of fans.)
Three more: The first one is a rare hybrid of a white-fronted capuchin and a red uakari (Cacajao sp.); when we visited a village, an old lady was caring for this juvenile, and said it had just shown up one day. Our guide was amazed, he’d never seen one. The other two are poison dart frogs:
Tara Tanaka has returned (this video was not shown for two years) with a lovely video of Roseate Spoonbills (Platalea ajaja) feeding, preening and dunking on her property. They remind me of my ducks!
Tara’s notes are indented below; her Vimeo page is here and her flickr page here.
A Vision in Pink
In the spring of 2023 we had at least 16 Roseate Spoonbills visit our swamp, some of them here for almost two months. Two of the birds were adults in full breeding plumage, and the rest were juveniles likely fledged the summer before. All of the birds in this video are juveniles. In the traveling I’ve done I’ve never seen 16 Roseate Spoonbills at one time, and to have that many here in our cypress swamp for such a long time was quite a gift.
This video includes some of the highlights of their time here, with the opening and closing scenes shot from the living room (!) They bathed, preened, dried, fed and spent a lot of time roosting. I’m not sure I’ve ever seen a bird species that had so much time to just roost without having to hunt for food — they must be very efficient feeders. One day there were very high winds and three of the spoonbills tried to hunker down in a large cypress where a wise old Wood Stork was easily riding out the winds. The old stork chose a very large branch and faced into the wind, while the young spoonies struggled to keep their balance in the middle of much smaller branches.
Last spring I kept hoping that some or all of these birds would return and nest, but I never saw even one spoonbill last year. I keep looking out the window hoping that this will be their year to nest here.
As these are all juveniles, I put a photo of adults from Wikipedia below. It’s labeled: “Foraging roseate spoonbills at Merritt Island, Florida, United States.” An excerpt from the article:
Little is known about the roseate spoonbill’s behavior outside of their foraging habits. This species feeds in shallow fresh or coastal waters by swinging its bill from side to side as it steadily walks through the water, often in groups. Moreover, the spoon-shaped bill allows it to sift easily through mud.
The bird feeds on crustaceans, bits of plant material, aquatic insects, mollusks, frogs, newts and very small fish (such as minnows) ignored by larger waders.[24][25][26] In Brazil, researchers found roseate spoonbill diets to consist of fish, insects, crustaceans, mollusks, and seeds, all foraged from limnetic/freshwater habitats.
Here’s their range: year-round is purple, and breeding range is blue. You can see that in the U.S. they are year-round only at the tip of Florida and along the Gulf Coast:
Today we have a batch of photos from UC Davis ecologist Susan Harrison. Susan’s comment are indented, and you can enlarge the photos by clicking on them. Don’t miss the baby possum (last photo)!
Backyard Visitations
Recently I was fortunate to have a large mob of brightly colored birds visit my back yard. A flock of over 100 Cedar Waxwings (Bombycilla cedrorum) had been zipping around the neighborhood in their tight flying formation, constantly conversing in their high-pitched whistles. These wonderful birds are like parrots of the temperate zone in that they are colorful, social fruit-eaters, flocks of which will quickly denude a berry-covered bush before swooping off to another one. They descended upon my backyard pond the for a boisterous communal drink, as I sat at my computer/cat-cuddling/birdwatching station.
The photo sequence below illustrates the Cedar Waxwing’s always-changing body shapes, lively social behaviors, and unusual coloration: “a silky, shiny collection of brown, gray, and lemon-yellow, accented with a subdued crest, rakish black mask, and brilliant-red wax droplets on the wing feathers” (per AllAboutBirds.org). [JAC: I always thought that if an Adidas sneaker could fly, it would look like a cedar waxwing.]
Amidst the more routine winter visitors like Yellow-Rumped Warblers (Setophaga coronata) and White-Crowned Sparrows (Zonotrichia leucophrys), other recent notables have included Purple Finch (Haemorhous purpureus) and, in our Oregon yard, a presumably amorous pair of Red-shouldered Hawks (Buteo lineatus).
Purple Finch:
Red-shouldered Hawks:
A friend in Davis has been so fortunate as to have Barn Owls (Tyto alba) take up residence in her yard. Actually, it’s not a matter of fortune, but of putting up several well-placed owl nest boxes.
Barn Owl:
Owl nest boxes:
This same friend has just released, in her yard, nine baby Virginia Opossums (Didelphus virginiana) that became effectively orphaned when their mother was trapped and relocated. May her possums not become dinner for her owls; there are plenty of rats around for the owls to eat!
I’ve been busy at the pond watching the ducks and giving a bit of a nosh to Mordecai and Esther, who are doing well. They look fat and happy, though I saw another drake at the pond today and the trio flew off together. (Yes, the males create a “rape culture” (the technical term is “forced copulation”) for the hens, who must constantly avoid ministrations of males other than their mate.) But now they are only two, and I check on them three times a day. Lots of people come by the pond and ask about the ducks, and when I tell them what I know (they like the names) they say that they can’t wait for the ducklings to appear. But Esther hasn’t nested yet, though she’s preparing to, and once she does and sits on all the eggs she lays, it’ll be 28 days till the babies hatch.
First, the stars of the show. Look at this beautiful hen! Esther’s speculum (the blue feathers) are bright and beautiful.
And her mate (for the moment, at least), Mordecai, with his iridescent green head. A friend of mine— the advisor to Team Duck—guesses that both ducks are two years old au maximum.
A video of Esther giving voice. She is one of the noisiest hens I’ve ever heard in the pond (remember, only females make the characteristic “quack,” while males make soft, low quacks). Here she is, loud and proud:
More quacking. I often think of having a wine-and-cheese party next to the pond, calling it “Cheese and Quackers.”
Esther is also busy “window shopping,” checking out the windowsills in adjacent buildings where she’ll build her next. So far she seems to have settled on the second floor of Erman Hall, part of our department. She hasn’t yet chosen the right window yet, as she appears in various windows. She seems to be favoring the second floor. One of our new faculty members has most of the second floor, and when I told her about the window-shopping, she was excited that Esther might nest on her lab window. (She likes ducks and the pond.)
Here’s Esther scoping out a second-floor window in Erman (she’s at the end of the arrow). Although wild mallards are ground-nesters, for some reason even young hens at Botany Pond start scoping out windowsills to avoid predators and pesky drakes. How they figure this out is a mystery to me, as they certainly can’t have the genes for nesting so high, and I doubt they learn it from watching other hens. One of my colleagues thinks that a window ledge is a “superliminal stimulus.” That is, mallard hens are known to nest on wooden platforms low to the ground or on bent-over tussocks of grass that are a foot or so from the ground. This protects them somewhat from predators like raccoons or possume. It could be that, like our evolved love of sweets and fats that now drives many us to a diet full of sugary foods, hens have an evolved preference for nesting a bit high, and that goes into overdrive when they see a safe windowsill with vines to anchor a nest.
More of Esther at Erman:
Here her head is tilted, a hen’s cutest pose:
After a nosh, both ducks like to preen, clean themselves by grooming and dunking underwater, and making big aplashes for futher cleaning. Here’s Esther doing all that. Note that her bill opens as if she’s quacking, but no sound comes out. I’m told that this is common in hens. When she rubs her head over her feathers, she’s oiling them.
Another loud bout of postprandial quacking and activity:
Ducks, like many birds, oil their feathers using the uropygial gland at the feathers near their tail. Wikipedia says this about it:
It is a holocrine gland enclosed in a connective tissue capsule made up of glandular acini that deposit their oil secretion into a common collector tube ending in a variable number of pores (openings), most typically two. Each lobe has a central cavity that collects the secretion from tubules arranged radially around the cavity. The gland secretion is conveyed to the surface via ducts that, in most species, open at the top of a papilla (nipple-like structure).
The uropygial gland is located on top of the tail base, on the lower back, just in front of the base of the tail feather quills. This area is generally featherless except for a tuft of feathers at the tip called the uropygial wick. The gland is bi-lobed, with two similar-sized sections.
The uropygial gland secretes a thick, transparent, complex oil (preening oil) that consists of diester waxes (uropygiols), fats, and fatty acids. Each lobe of the gland secretes oil through small papilla (nipple-like projections).
The oil secreted by the uropygial gland performs many functions, including waterproofing and maintaining the suppleness of the skin, feathers, and beak. The oil may have an antibacterial function.
During preening, a bird transfers this oil to its feathers by rubbing its head and beak against the oil gland and then spreading the oil over the rest of its feathers.
The uropygial gland is not normally visible unless the feathers are parted in this area or there is a problem with the gland.
Here you can see Esther rubbing her head and bill on the gland and then spreading it over her feathers. They mostly use their beak, but also dive and splash because mixing the oils with water helps spread it through the feathers, giving the duck essential waterproofing. They also use their heads and flexible necks to spread the oils, so there’s no part of her body (save her “chin,” perhaps) that she can’t reach:
Here’s a thorough cleaning and oiling of her wings. They don’t miss a feather! Ducks are immaculate, constantly grooming.
The drakes have to preen too, of course, as all mallards need to be waterproof and clean. Note Esther go for her gland at about 18 seconds in. Both ducks also engage in diving:
One more video of Esther preening. Notice how she goes for the uropygeal glands and uses her flexible neck to spread oils from her head and beak.
After bath time it’s nap time. They like to lie on the grass and cement on the pond edge in the afternoon, warmed by the sun to their west.
Notice how cryptic Esther is compared to Mordecai. His visibility is the price he pays for attracting a mate, but the females’ color and pattern help then hide from predators (and horny drakes). You can see her hunkered down to the right, looking like a clump of brown grass.
Here’s a cartoon map of the campus from 1932, labeled as ” Elizabeth Moore (“Betty”) Fisher’s (PhB’22) 1932 cartoon campus map. (University of Chicago Special Collections).” You can see the whole thing enlarged here (map below, click to enlarge):
and, enlarging Botany Pond, you see a lone duck (I added the arrow in the second picture below). Botany Pond was built in 1899 as part of the biology group’s research facilities, and you can see some early photos here. The pond and surroundings were designed by the landscape architects John Charles and Frederick Law Olmsted Jr., two brothers whose firm designed many notable spaces.
More than 100 years of ducks!
The pond has been under renovation for two years, as cracks in the walls, and an accumulation of schmutz, called for a ton of renovation. During that time the pond was empty and we were bereft from the lack of ducks (many also greatly miss the turtles and fish, which will be put back into the pond). During this slow period, I tended the squirrels, giving them high-class nuts like pecans and hazelnuts:
Fingers crossed for a good summer and a healthy crop of ducklings!
