Beautiful birds of prey – Costa Rica

During my two trips to Costa Rica in 2018 and 2019, it was a pleasure to see the varied birds of prey flying by and sitting near roads. Unfortunately, both years my photography was not at its best so a good number of the following shots aren’t that great, but they give you an idea of the beauties that can be seen there. My favorite was this gorgeous baby spectacled owl (Pulsatrix perspicillata) who was staring through the rain forest foliage at us from a distance last year. This photo was taken with my phone through a scope.

 

But first let me explain which types of birds constitute the birds of prey as there are some slightly differing definitions. One explanation focuses on birds that mostly hunt vertebrates that are large in relation to their own size. It doesn’t seem quite specific enough as sometimes a great blue heron will eat a relatively big mammal such as a gopher, while I’ve had red-shouldered hawks in my yard fishing the pond for frogs that are fairly small in relation to them. This photo of a double-toothed kite (Harpagus bidentatus) in Costa Rica carrying a small lizard shows that they will feed on smaller prey as well, however.

Another definition is more specific, focusing on physical traits of these birds: relatively large, hooked bills with which they can tear flesh, powerful feet with sharp talons for catching prey animals, keen binocular vision for detecting prey at a distance, and good hearing. This roadside hawk (Rupornis magnirostris), seen in 2018 in the first photo below and in 2019 in the other two photos, illustrates these features.

The raptors are further divided into two major groups: the diurnal species that hunt in the daytime (e.g., eagles, falcons, hawks, vultures) and the nocturnal species that are mainly active at night (the owls). We’ll start with the owls, of which I’ve seen four species now in Costa Rica. I already mentioned the lovely spectacled owl. The immature owl is fuzzy and white with huge eyes; the adults have dark heads and backs but retain their striking yellow eyes. I only saw the young owl, which we observed thanks to our local guide, Cope.

 

Cope is not only a guide but also an artist and I couldn’t resist buying a print of his lovely portrait of the young spectacled owl.

 

Our trip guide, Steve, had heard at one reserve that a pair of mottled owls (Ciccaba virgata) were perched in a tree near a trail. They were exactly where predicted and though the heavy, dark vegetation made for a difficult view, we could see the two resting comfortably. These medium-sized owls lack ear tufts.

Last August, Steve spotted a ferruginous pygmy owl (Glaucidium brasilianum) for us near a creek but it was fairly far off, partly obscured by leaves from where I stood. We had seen one closer up in 2018, perched in trees near the road. This owl is crepuscular (mostly active at dawn and dusk) but they also hunt during the day, which may help account for its willingness to be out in the afternoon so we could get a good look at it.

An owl that I did not see last August was the bare-shanked screech owl (Megascops clarkia). One had been spotted at the top of a hill, but it was raining that day, the path was very muddy and slippery and my arthritic knees and ankles were not cooperating in pathway navigation. The rest of my group ascended while I birded below. But my disappointment was not too great as I had had some good looks at one in 2018. Steve had played the owl’s call, not expecting the bird to appear but thinking it might flush another bird that would be investigating if the owl was near. In flew the lovely little screech owl, perching nicely in view amid the forest foliage!

                             

Some scientists now think that the owls may be more closely aligned with the birds of the nightjar group than with diurnal raptors. The nightjars have small feet and don’t walk much. These nocturnal birds, which have quite short bills, feed on insects found on the ground or caught while flying. We saw a member of this family, the common paraque (Nyctidromus albicollis), resting on a pathway one evening; this one was likely a female as the male has more white on its wings and tail. Their plumage is quite mottled so that they blend in well with their backgrounds; these two photos were taken with different amounts of light illuminating the bird.

Another type of nocturnal bird related to nightjars (but also not considered a raptor) is the potoo. In 2018, Steve found us a common potoo (Nyctibius griseus) perched atop a snag along a very dark, unlit country road. This past August, we saw one perched high above us in a tree during the daytime. When this insectivore perches on a snag during the day, it often blends in so well and remains so completely motionless, people often don’t see it because it looks like it is part of the stump or snag!

This past year we also got to see a great potoo (Nyctibius grandis) as well. They eat not only insects but also small vertebrates with their short-beaked but very broad mouths.

 

The diurnal birds of prey that I’ve seen in Costa Rica include a hawk that I’ve also seen in North Carolina – the broad-winged hawk (Buteo platypterus). Some of these have quite long migratory paths but there are also five sub-species that are endemic to the Caribbean region that don’t migrate.

 

There are both white hawks (Pseudastur albicollis, seen flying very high overhead) and common black hawks (Buteogallus anthracinus) in Costa Rica. The white hawks prey on insects, mammals and reptiles. The black hawks mainly eat crabs, supplemented with eggs and small vertebrates. The one we saw was quite vocal.

 

 

Two other species of beautiful hawks are the gray (Buteo plagiatus) and gray-lined hawks (Buteo nitidus). We saw the gray hawk in roadside trees last August; this is a common perch from which they swoop down on prey animals, including lizards, snakes, frogs, birds and small mammals.

   

In 2018, we were able to admire a beautiful gray-lined hawk (Buteo nitidus) sitting atop a snag. These raptors are seen mainly in southern Costa Rica; their hunting style and favored prey are similar to those of the gray hawks.

The swallow-tailed kite (Elanoides forficatus) seems to be a bird of prey that is seen throughout Costa Rica. Adults feed their young frogs, lizards, snakes and small birds, while they mostly eat insects while flying about themselves.

 

Our guide, Steve, spotted a bat falcon for us (Falco rufiularis) but it was so far away that we had to get a reasonable view mostly through a scope (left). Here is a much better view. We had much better luck watching a laughing falcon (Herpetotheres cachinnans), which was also one of my favorite raptors.

 

We had been driving down a mountain road when this gorgeous bird flew from a stand of trees to a snag in a field.

 

This handsome avian is a raptor with a specialized diet – they mainly eat snakes, giving rise to the erroneous common name of snake hawk. They supplement this dietary preference with lizards, rodents, bats and centipedes.

I didn’t hear this bird but they can vocalize for up to 5 minutes at a time.

 

The next two birds I saw only in flight and only in 2018. The caracaras are members of the falcon family but, interestingly, they are among the few raptors that hunt for food on foot. The crested caracara (Caracara cheriway) has a widely varied diet, including: rabbits, ground squirrels, skunks, birds, frogs, snakes, lizards, turtles, young alligators, fish and large insects. Also of interest is the fact that they not only hunt live prey but also eat carrion.

 

The yellow-headed caracara (Milvago chimachima) does not eat birds but also hunts reptiles, amphibians and small animals. In some places, it is called the tickbird as it will take ticks from cattle. It, too, will eat carrion.

 

 

And then the final bird in this line-up – a much better known carrion eater, the king vulture (Sarcoramphus papa). This mainly white-colored vulture tends to soar much higher than other vultures and often does so without flapping its wings. They are the second-largest vultures in the Western hemisphere (only the condors are larger).

 

A North Carolina-based blog is next and then back to Costa Rica for some more “exotic” animals.

Thanks to fellow travelers, Ylva Byars and Nan DeWire for photos that they provided!

Oh, those ravishing raptors!

Numerous people who attract birds with feeders feel regret and sadness when one of their avian visitors is captured to serve as a meal for a raptor in the neighborhood. I, too, feel that pity and discomfort when I see one of the hawks or owls capture a bird or animal because my thoughts go to the pain and fear that the prey must feel. But of course all wildlife has to eat and I want members of the predator species to survive as well. And the beautiful predators can be really interesting to observe.

 

A Cooper’s hawk (Accipiter cooperii, left) sometimes frequents my yard looking for a bird to take. This particular day in November last year, the hawk flew to the front-yard feeders but came up empty-taloned. Raptors, also known as birds of prey, are not the only birds that eat something other than seed. Some smaller birds, like the shrike, do so and many songbirds eat insects. The raptors, however, often go after prey that is fairly large in comparison to their own body size. In January this year, I came across another Cooper’s hawk at a nature reserve. The bird flew soundlessly past me to land in a tree downslope and paused for a bit before flying on, providing time for me to get a gorgeous portrait.

I’ve been lucky lately in seeing barred owls (Strix varia) at the Brumley Nature Preserve North. This owl was sitting silently next to a walking path, looking out over the adjacent field.

A couple weeks ago, I was startled by this barred owl who suddenly flew in front of me from behind my right shoulder. I hadn’t noticed him/her in a tree behind me. I tried to follow its flight but lost it. I thanked the owl for letting me glimpse it and said it would be nice if s/he came back so I could get another look. Sure enough, after I had turned back to the vicinity where I originally was surprised by the silent predator, it flew in and perched on a branch. The bird had a snooze, keeping one eye partially open to keep me in view.

  

Lately, I’ve been seeing many red-shouldered hawks (Buteo lineatus). They have been flying overhead at the nature reserves. The other day, two flew by calling raucously and then they alighted at the top of a far distant tree. I couldn’t get a photo but did see them mating in silhouette against the late afternoon sky.

  

 

A few weeks ago, a pair of red-shouldered hawks began constructing a nest just down the street from where I live. One afternoon, I happened to see them and one was collecting twigs to build or refurbish a nest.

 

 

   

This pair roams our neighborhood looking for prey; sometimes, one or both will perch in my back-yard tree for a little rest.

    

When one of the red-shouldered or Cooper’s hawks pauses for some time in the tree over the small pond, I figure it is watching for frogs or one of the chipmunks that live in the rocks surrounding the pond. The chipmunks appear to be very good at eluding capture.

 

 

A couple weeks ago, our neighborhood family of American crows (Corvus brachyrhynchos) was making a racket in my yard and when I looked out the window, I could see them harassing a hawk. I couldn’t make out why they were so angry but grabbed my camera for some shots through the window.

 

  

It turned out that the Cooper’s hawk had caught one of the numerous Eastern gray squirrels that live here. The squirrels sometimes annoy me but on the whole, I enjoy watching their antics, so I felt badly for this squirrel, who obviously was not going down without some struggle.

What made it easier for me to watch was that I didn’t really see the squirrel’s head and it was not making a sound. I think the hawk had silenced it early on when it had its claws around its neck and chest.

The hawk was determined and kept hold of the rodent, eventually subduing it.

The hawk as not unscathed, however, as you can see from the wound on its leg.

When the raptor flew off suddenly with the squirrel hanging from its talons, the three crows chased it in hot pursuit. I don’t know if they were just upset that the hawk was present or if they wanted to steal the squirrel away. On walks through the neighborhood, I am now regularly seeing the hawks in trees and on power lines. They are not too shy and seem to be adapted to the human presence in their territory.

  

While I may be feeling a bit wary for the other animals and birds when the stunning raptors appear, it still is a thrill to see one up close. Only about half of the red-shouldered chicks make it through their first year of life, so I hope the hawks keep coming by. And who knows, maybe we will have some of the long-lived birds who can reach an age of 15-19 years!

 

 

 

An avian buffet appears!

In the town where I live, there is a private lake in a neighborhood of single-family homes. The little body of water was created by developers who dammed a local creek; now a neighborhood association levies annual fees for use of the lake for swimming, fishing and boating. In the past month, the neighborhood residents were surprised by an influx of birds that they do not usually see and some photos of the new avian visitors began circulating.

Given my interest in wildlife and birds, some colleagues passed on a couple of photos to me and one couple kindly invited me to come visit so that I could see the new arrivals in person. They were especially curious about the identity of a few ducks. When I arrived, no ducks were in sight, but at least 80 double-crested cormorants (Phalacrocorax auratus) were hanging out in crowds on two floating docks.

Their tightly-packed presence had displaced the Canada geese (Branta canadensis), who are more common lake residents. A group of 11 geese were off in the distance on shore leaving the open water to the visiting avian groups.

Some of the cormorants couldn’t fit onto the platforms, so they swam around in the company of the many dozens of ring-billed gulls (Larus delawarensis) of all ages who were swarming the waters as well.

From time to time, the gulls would begin edging their way onto the platforms, eventually taking up space vacated by the cormorants. There are both adult and immature gulls in the crowd.

From time to time, the gulls launch themselves into the air for aerial forays which end in dives down to pick up a fish, of which there still seem to be plenty. This is because the shad population with which the lake was apparently stocked is dying off as a whole.

Why is this happening? I don’t know the species of shad with which the lake was stocked, but it appears that threadfin shad (Dorosoma petenense) are common in the Southeastern USA and often introduced as forage fish for the bass and catfish that fisher-people seek. The shad are very sensitive to changes in water temperature; when it goes below about 42° F (5.5° C), they expire. In the past 6 weeks, we had an unusual early winter storm with about 8-11 inches of snow, followed by days and days of cold rains. Sometimes, it is cold 24 hours long; other days have nights and dawns below freezing and then afternoon temperatures of 50-60° F (10-17° C). The shad die-off is a result.

  

The newly arrived birds are obviously enjoying the easy pickings. When the gulls drop down to snatch a fish, they are almost always pursued by other gulls who try to make them drop the prize.

 

Even when they alight with a fish firmly held in their beaks, other gulls harass them in an attempt to make them give up the meal.

 

  

The shad often appear to be too large for the gulls to swallow. I saw several gulls try to position them to get them down their gullets but the fish just wouldn’t go down. So they drop the fish in the water and then try to pick off pieces for easier eating, while fending off neighboring gulls.

  

It is unclear to me how the birds who don’t usually populate the lake in winter knew that a spontaneous buffet had appeared. In addition to the cormorants and gulls, a group of seven bald eagles (Haliaeetus leucocephalus) was also fishing when I visited. There were some almost full adult eagles (with mostly white heads and tails) and several immature birds of varying ages (eagles reach maturity at 5 years of age). I guess that they came over from Jordan Lake, which is quite a fair distance away. Searching the Internet has not yet given me an answer to this question.

I didn’t see the eagles harass gulls who had gotten a fish but they were very carefully watching one another. When the eagle below managed to get a snack, other immature eagles closely followed him/her. A sub-adult who got a fish was harassed by an immature bird as well.

 

The eagles soared overhead and were joined at one point by a beautiful red-tailed hawk (Buteo jamaicensis). The larger raptors let the hawk fly alongside them with no problem.

It was quite a chilly morning when I got to see the visiting aquatic birds, so I only stayed a short time. But my friends invited me to return for another visit, which I hope to do soon as there is no telling how long it will take the visiting birds to eat the easily available shad. And the ducks? I was able to get one rather indistinct photo of a threesome across the lake and helpful folks in a Facebook group confirmed my guess – they are ruddy ducks (Oxyura jamaicensis). Maybe I can get a decent photo of them next time. 🙂

Growing up barred – Part 2: personal care

The young barred owls that I observed this past summer at the Mason Farm Biological Reserve could be found rather predictably in two places at the reserve, both of which were near water. They were quite beautiful to see.

Barred owls (Strix varia) are the only owls in the Eastern USA who have brown rather than yellow eyes. When adult, barred owls have short feathers on their heads but no ear tufts. Their eyelids are also feathered. The juveniles still have fuzzy down feathers on their heads and pink, barely feathered, eyelids as you can see here.

     

Adult barred owl                                                                Young barred owlet

Their feathers extend down their legs and feet right up to their talons. The owls’ claws are less curved than other raptors’ talons which makes it possible for them to squeeze their prey to death.

  

  

As they grow, the young ones will groom often, pulling out downy feathers.

    

They frequently stretch out their wings and tails when grooming.

                    

  

Baths were also a welcome form of personal care.

  

This was especially so during our very hot summer days. The fact that I was standing about 5 feet away did not deter the owlets from enjoying vigorous dunkings in the water ditch.

 

I did not see them bathe at the same time; they appeared to take turns. Perhaps each one was keeping watch for the other one when they were vulnerable.

The siblings did indeed seem to be very aware of each other’s activities and when I observed them, they didn’t stray far from one another. The next blog will show a little of their interactions.

 

My pond and the cycle of life

Undergoing cardiology exams can bring up thoughts of mortality and a life lived; perhaps they also made me more attentive to the cycle of life in my yard, particularly in the vicinity of my backyard pond.

Several years ago, a local garden center went out of business and they had a 175-gallon black plastic pond for sale. It was a good deal, so I invested in it and then had to dig a large hole in the rocky Piedmont clay ground of my backyard (with a bit of help from a neighbor teen). At a certain point, the ground was so hard we couldn’t penetrate it with shovels so the pond now sits a bit above ground level; the rocks I piled up around it have offered a home to Eastern chipmunks (Tamias striatus).

 

I transferred some of my beautiful koi and goldfish from a smaller pond, only to have a great blue heron (Ardea herodias) come by to clean them all out.

On the recommendation of the garden center staff, I had positioned a heron statue by the pond – they said herons don’t like competition, so the intruder would keep flying when s/he saw the one by the pond. It didn’t take long for the bird to figure out the stationary bird was not real, however.

After the heron had eaten all the koi and goldfish, I still had some tiny baby fish. At first, I thought they were from my now deceased koi but apparently the intruder heron had had fish eggs on its feet from a nearby natural pond and left them behind. So for a time, I had unidentified native fish in the pond. They were extremely shy, however, and I only got a brief look at them when they surfaced early in the morning; as soon as I came near, they dove down under the water plants (no good photos).

Then some green frogs (Lithobates clamitus) moved in this past summer and ended up being extremely prolific reproducers. Before I realized it, there were at least 500 tadpoles in the pond!! They were eating the fish food and at the same time I noticed that I wasn’t seeing the fish at all anymore. Going online, I found out that tadpoles will eat fish – their sheer numbers had to have spelled doom for the fish.

 

 

I collected lots of the tadpoles, gave some to a friend for her water feature and released hundreds into the local creek (they are native animals after all). A few of the tadpoles grew into frogs and the pond became a residence for some very loud croakers.

 

  

The next chapter in the story came a couple days ago. I had seen a pair of red-shouldered hawks (Buteo lineatus) visiting my yard recently. I thought they were after the chipmunks, numerous squirrels and songbirds populating the area. The other day, however, one hawk took up a position in the crepe myrtle tree next to the pond and just sat there calmly not bothering with any of those creatures. Numerous Northern cardinals (Cardinalis cardinalis) perched in the tree above her and many other species of birds were at the nearby feeders;  none of them were concerned at all with the hawk’s presence. The squirrels didn’t seem perturbed either.

She sat fairly still and I took some photos through my kitchen window. Then I ventured out into the backyard, sure she would take off as I left the porch steps. But Ms. Hawk just sat there, sometimes stretching a leg or engaging in a little grooming.

     

   

Occasionally, she looked up but often her gaze was fixed on the area around the pond.

She would stare intently down at the ground – I thought she might have spotted one of the pond chipmunks.

Then after a while, I noticed her shifting her stance – suddenly she plopped down into the pond with spread wings. It happened too fast for me to get out from behind dried plants to get a good photo, so I watched as she climbed out of the pond. Then it became apparent what she had been hunting – she had caught one of the green frogs.

  

It looked like she bit its head to kill it as soon as she got on dry land; the frog wasn’t moving.

Then she spent time ruffling and shaking out her feathers which had gotten a good soaking.

She spent a little time looking around and then abruptly took off with her prize, closely followed by another red-shouldered hawk who suddenly swooped in.

He chased her but she got away with her meal and he ended up sitting in a neighbor’s tree, somewhat disgruntled with his failed thievery attempt.

  

Ms. Hawk returned yesterday and spent quite a bit of time in a high tree surveying the yard and gazing down at the ground. Red-shouldered hawks sometimes eat birds, such as sparrows, doves and starlings (which are all numerous around my feeders) but more often they go after snakes, mice, toads, frogs, lizards and small mammals such as voles and chipmunks. They will also eat insects and earthworms. Since I’m leaving the leaf litter, there are undoubtedly more insects hiding there than in neighboring yards. I’m not sure what Ms. Hawk is seeking in my yard, but I hope she doesn’t get all the pond frogs. In any event, I’m sure new ones will find the water in the spring and in the meantime, I have a beautiful bird of prey to watch this winter.