Serendipity in a stressful year

2020 has turned out to be quite a stress-filled series of months on multiple fronts, so unexpected pleasures and delights are very welcome. For birders in North Carolina (NC), that scenario has luckily been playing itself out this fall and winter. Several unexpected and unusual birds have been spotted in our state, including a Kirtland’s warbler, vermilion flycatcher, MacGillivray’s warbler, and sandhill cranes.

Many bird lovers have traveled to catch sight of these surprising visitors. While I’ve mostly avoided groups the past nine months as part of my COVID-avoiding measures, last week I did join the human migration to an NC home about 20 miles away to see a bird that is normally only found in the northwestern United States – a varied thrush (Ixoreus naevius).

The opportunity to see this lovely bird was offered to the local community by homeowners Tony Hewitt and Marla Wolf. They generously allowed people to come to their suburban yard (by appointment) to watch over the backyard fence to catch sight of the thrush.

When I visited on a “slow” day, it was easy to socially distance oneself from other birders and photographers. Only a couple other people were there for a while (and I was alone some of the time) waiting for the thrush to make an appearance. Everyone wore masks, some having double masked as well.

The varied thrushes normally migrate back and forth in the area stretching from Alaska, through Canada, down to northern California, as shown by this map from the Cornell Lab of Ornithology. The website remarks that a few of these birds occasionally wander outside their normal range to the Midwest and Northeast. Seeing one in the southeastern USA is highly unusual.

Map credit: https://www.allaboutbirds.org/guide/Varied_Thrush/maps-range#

This robin-sized bird is a real stunner – his orange, grey, yellow and white feathers grow in a wonderful pattern. The colors seem to vary a bit, depending on the quality of the light falling on them and the background against which you see him. But he is handsome from any angle – front, side or back!

Something I found particularly interesting was a pattern of wavy lines in his tail feathers when the light hit them in a certain way. This was not something that I saw mentioned in descriptions of its physical characteristics. The observation made me want to photograph the thrush again to see if this would show up again.

 

It is interesting to note that one varied thrush crossed the Atlantic and turned up in Great Britain in 1982. It was a unique bird since it represented a rare variant of the species in which the orange feather coloration has become all white. Only five such representatives of this mutation have been recorded since 1921.

In its home range, the varied thrush prefers to stay in dense, coniferous forests near water. The NC visitor is taking advantage of a backyard nook that Marla designed with multiple shrubs and some open space.

The home is not far from a lake, but the thrush is taking advantage of a bird bath for drinks, which Marla kindly had moved so that it was better visible for visiting birders looking over the fence.

Varied thrushes usually feed on insects, foraging on the ground and often under dense cover.

The thrush’s insectivorous diet can be wide-ranging and include ants, beetles, caterpillars, crickets, earthworms, millipedes, snails and spiders.

  

They also eat berries, either in trees or on the ground, during the autumn and winter months. 

Our NC celebrity bird is obviously enjoying seeds furnished daily by Tony and Marla.

A notice placed by Tony near fence announced that the thrush seemed to come out in the open every 30 minutes or so. It turned out that this was indeed the case the first hour that I was there; then the bird came after a couple 15-minute intervals.

He certainly seemed to be a creature of habit because I noticed that after eating, he would go back into the dense undergrowth for several minutes and then re-emerge to take a couple drinks at the bird bath. Eating obviously was making him thirsty and noticing this habit meant it was possible to get “camera-ready” for another appearance.

When it is breeding time, male varied thrushes begin to establish territories and confront other males with threat displays. These begin with the bird cocking his tail and turning it towards his rival, while he lowers his wings. If the rival bird does not go away, the thrush will lower his head, raise and fan his tail and then spread his wings out to the side.

Obviously, our NC bird had no rivals around but there were many other birds foraging in the ground underneath the feeders. They included Northern cardinals, white-throated sparrows, pine siskins and downy woodpeckers among others. And it seemed that “our” thrush was sometimes warning them off.

Or perhaps he was just flashing his wings to scare up insects hiding in the fallen leaves.

There are still large numbers of varied thrushes, with an estimate of some 20 million in the current global breeding population. However, the North American Breeding Bird Survey recorded a cumulative decline of the species of 73% between 1966 and 2015. Logging, wildfires and forest fragmentation are ongoing threats to their breeding habitat.

This is only the fifth time that a varied thrush has been seen in North Carolina. The first sighting was in 2005; three other birds were seen in 2010. No one has any idea what got this year’s bird so far off-course during its migration and no one knows how long it will stay around.

Tony and Marla have kept a visitors’ book (with hand sanitizer available for signers) and many people have been recording their visit. When I visited, more than 110 people had already come by, including some birders from Virginia and Tennessee. More people have since stopped by the Hewitt-Wolf residence to admire this vagrant bird. We are grateful to them for giving us this opportunity!

It’s apparent that the serendipitous sojourn of this gorgeous bird has been a welcome gift to many people – both those who saw it in person and those who’ve admired photos distributed through facebook groups. We hope the bird will survive the winter here and be able to return to its home grounds out West so that its journey has a happy ending!

 

Craving crawdads in Carolina – a buffet for night herons

Many people in the USA, especially but not only in the South, grow up knowing what crawdads (Cambarus bartoni) are. This was not the case for me. My immigrant family pretty much stuck to the dietary customs of their own and their friends’ home countries (The Netherlands, Belgium, Germany). Like pumpkin pie, sweet potatoes and okra, crawdads were not on those menus and so it was only recently that I actually learned that these crustaceans are the same thing as crayfish, of which I had heard as a child.

This year was my time to learn more about these members of the arthropod family who are related to lobsters – it turned out they were thriving in a pond created through a man-made wetlands installed between a shopping mall and several apartment complexes. I learned about their presence when local birders alerted one another that the crawdads were attracting a family of yellow-crowned night herons (Nyctanassa violacea).

Hoping to spot the herons, I also visited the wetlands and first noted the crayfish remains scattered around near the pond. Shortly thereafter, I came across one crossing a path in another local nature park (photos above and below). It was interesting to see how the crawdad first stayed stock still as I neared and then stood tall on its legs as its tail propelled it backwards while it made a dash for the nearby pond.

The crawdad females lay hundreds of eggs; scientists do not yet know how long they incubate before birth but estimate it takes somewhat longer than a month before they hatch. In North Carolina, there are almost 50 species of these animals and several species are found only in this state.

The crayfish at the wetlands must have had a successful year because the place became a real buffet for various birds. Both adult and young night herons stayed near this pond for quite a long time before leaving to migrate to more southerly climes for the winter.

The adult herons were attractive with their boldly patterned heads.

 

 

   

They kept up their looks through regular preening.

 

 

Sometimes, they emerged from the pond weeds to perch on a snag while peering into the water on the lookout for a meal.

 

It was interesting to learn that while the adults have yellow legs most of the year, their legs can turn red or pink during breeding season.

 

 

In my experience, the younger herons were a bit less shy and didn’t fly off so quickly when I neared.

 

One in particular decided to take the sun in mid-August, adopting a pose that I more often see taken by great blue herons and which I’ve nicknamed the “flasher stance.”

     

The young birds, like their parents, stalked the pond vegetation on the lookout for crawdad snacks.

They also showed the herons’ taste for other food such as snails, earthworms and insects.

 

The night herons, for which most birders visited the wetlands, weren’t the only birds at the buffet, however. Red-shouldered hawks (Buteo lineatus) also showed a fondness for the crustaceans.

 

 

 

The herons weren’t always alert to their presence. One adult, for example, decide to fly to a low perch when chased away from a tall snag by a hawk. S/he settled in for a bit of preening but was then rudely chased off by the same hawk. (That hawk was later harassed by a group of crows, who chased it away in turn.)

Other herons who were interested in outdoor crayfish dining during the humans’ Covid epidemic, included the great blue herons (Ardea herodias).

 

 

Green herons (Butorides virescens) visited the pond regularly as well, eating small fish in addition to the other wetland delicacies.

 

 

 

 

 

 

Belted kingfishers (Megaceryle alcyon) were busy flying to and fro over the length of the pond, but I didn’t see them carry off any crayfish so they must have been focused on fish.

 

A great egret (Ardea alba) was a regular visitor, too, stalking different areas of the pond.

The adult night herons obviously thought it was interesting to watch the egret’s foraging technique.

Other regular visitors to the wetlands included a flock of Canada geese, American and fish crows, Northern mockingbirds and wandering glider dragonflies (Pantala flavescens).

 

There were so many animals feeding on the crawdads this summer that the female crayfish must have had a lot of success with their offspring reaching maturity. The last reported sighting of the yellow-crowned night herons at the wetland was 24 October, but I’m guessing that they will be leaving soon and the pond will not be so busy this autumn. The crayfish population had to have been reduced mightily over the summer season, so it will be interesting to see whether it rebounds and attracts crowds of birds — and birders — next year!

What gets a birder really going? A rare bird!

People who are “into birding” are excited when they see a new bird for the first time. Many keep “life lists” – an account of each different species they have actually seen worldwide, in their country, in their state or province, or perhaps in their yard. When they see a new species, birders say they got a “lifer” – a first-time sighting in their life. Quite a few of these birders then decide to enjoy a reward – a lifer pie!

This past week, I was lucky enough to get a lifer, thanks to alerts circulated in the birding community. Doc Ellen Tinsley, the North Carolina Piedmont area’s main bald eagle researcher, also looks for other species when she goes out to see the eagles she knows. On 27 September, she was at the Jordan Lake Dam, where she often sees eagles whom she has come to recognize and know. Since it is the migration period for many birds that breed up North, she was also watching for warblers, a popular type of songbird because they are often beautifully colored.

She counted herself very lucky when she spotted a yellow striped bird that she had not seen before. After getting a confirmation of its scientific identification, she notified area birders that she had spotted a Kirtland’s warbler (Setophaga kirtlandii) and it was still foraging so people might be able to see it if they came to the Dam.

Until recently, the Kirtland’s warbler was considered an endangered species as it requires a very specific habitat in jack pine forest to breed. It depends on areas affected by fire; about 6 years after a conflagration, the space will be regenerated with small trees, shrubs and open areas that are favorable for its nests. When trees grow to about 10-16.5 feet high (3-5 m), the warblers leave to find a more suitable living area.

Compared to other birds, the Kirtland’s has the most restricted geographical breeding area of any bird in the continental United States. In the 1970s and 1980s, only about 167-200 males were counted in annual surveys. Conservationists in Michigan, Wisconsin and Ontario, Canada, collaborated on protecting the Kirtland’s environment and achieved success. This warbler has now been re-designated a threatened rather than endangered species. There are currently about 2,300 breeding pairs who migrate south to spend the winter in the Bahamas.

 

These birds’ diet comprises mainly insects and small fruit such as blueberries. Occasionally, they will catch an insect on the wing but more usually they glean pine needles and other vegetation for their meals. Spiders, moths and flies constitute part of their diet. Adults will also ingest pine sap.

 

 

These birds place their nests on the ground, underneath the small jack pines. The males will feed the females while they brood and both parents bring nutrition to the hatched offspring. In the past, brown-headed cowbirds often laid their eggs in Kirtland’s warbler nests and this contributed to their endangered status. Elimination of cowbirds from the environment for many years has now reduced the threat.

“As a condition for the warbler’s delisting, the USFWS, U.S. Forest Service, and the Michigan Department of Natural Resources signed a memorandum of understanding that the agencies will continue habitat management at sufficient levels to ensure a continued stable Kirtland’s Warbler population. Keith Kintigh, a forest conservation specialist with the Michigan DNR, says his agency will plant 1.8 million jack pine seedlings per year going forward to help maintain the 38,000 acres of suitable jack-pine habitat needed to keep the warbler population above the 1,000-breeding-pair threshold for recovered status.”
9 January 2020; https://www.allaboutbirds.org/news/kirtlands-warbler-delisted-after-47-years-of-conservation-work/

It’s likely that at least 100 people have traveled to Jordan Lake Dam to see this female bird. She was very popular because she didn’t particularly hide as some birds do. (She was sometimes a bit hidden by the pine needles, but that was because she was constantly moving about in the trees.)

She was foraging for insects along rocks bordering the dam area and in nearby trees, which gave the birders an opportunity to memorialize her visit with photos. Much of the time, she was seen in the company of a male bird of the Cape May species, who look similar (left).

The Kirtland warblers’ areas in Michigan and Wisconsin are closed to the public when they are breeding. They are rarely seen so there are guided tours in those two states to enable people to spot them.

 

Doc Ellen provided area birders with a wonderful opportunity to admire this rare bird! A much needed bright spot in a year that has been fraught with calamities.

 

Costa Rican mammals, part 2 – those quite different from our Carolina wildlife neighbors!

Seeing mammals that we don’t get to enjoy during nature outings in the Carolinas was one of the treats of my Costa Rican trip. Although we spotted spider monkeys during our outings, it was the mantled howler monkey (Alouatta palliata) that we saw – and heard – most often. My first sighting of one was last year, when its white scrotum identified it as a mature male.

These primates eat mostly leaves (50-75% of its food), designating its diet as folivorous (new word for me!).

This low-energy diet means that they sleep and rest a lot – all night and about 75% of the day! They will supplement their leafy meals with fruit and flowers, and they get their water from bromeliads and holes in tree trunks.

Their large hyoid bones amplify the sound coming from their vocal cords so that their calls echo up to 3 miles (5 km) throughout the forest.

Interesting fact: if the howler is disturbed or irritated by humans, it will sometimes urinate or defecate on them, having surprisingly good aim from high in the tree canopy!

Another arboreal mammal that everyone in our group found endearing was the three-toed (brown-throated) sloth (Bradypus variegatus). These animals are apparently quite popular with tourists and often appear in logos and signs. An orphaned sloth was brought to one hotel where we stayed; the staff let the youngster go up in a tree in the courtyard where we could see it.

     

I had seen (and touched) a sloth in a friend’s back yard in Bolivia once (right); seeing another one close-up outside a zoo was a new treat. I love how they move in slow motion. Their sluggish movement is a result of their diet – just like the howler monkeys, they are folivorous and conserve energy as a result of their mostly leafy diet.

 

That slow movement and the fact that they cannot walk on all fours, unfortunately can also be the cause of their undoing. Their movement on the ground consists of dragging themselves forward by their forearms and claws. Our guide told us that when they cross roadways in that position, drivers may not notice them on the pavement until it’s too late to avoid them. ☹

An interesting fact is that their rough hair eventually comes to harbor various organisms, including cockroaches, beetles, moths and algae. So picking them up and holding them is perhaps not advisable – both for the human who can get insects all over them and for the sloth, who can get upset by being held. (The sloth I touched in Bolivia, below, was at the base of a tree and when I put my hand on its chest, it made no movement but I could feel its heart rate suddenly increase rapidly, so I backed off!)

 

Another interesting behavior – once a week, the sloths leave their trees to defecate on the ground. At this time, they become vulnerable to predators. (The sloth in my friends’ yard unfortunately did this and was killed by a neighborhood dog.)

 

On the ground, a slender dark mammal that frequents hotel gardens, people’s yards and nature reserves is the white-nosed coatimundi (Nasua narica). These mammals are related to raccoons and people in Costa Rica will tell you that they are Costa Rican raccoons.

 

Coatis, as they are popularly known, travel both on the ground and in trees, although I only saw one arboreal individual. They usually spend the nights in trees and then come down to look for food, which includes small vertebrates such as mice and lizards, eggs, snakes, insects, carrion and fruit – a varied diet, for sure!

The coati below was busy at the side of a mountain road we walked; it was unclear to me what it was doing. There was obviously another animal there and at first, I thought it was a young coati, but I don’t think that was the case. I now wonder if another mammal had died and the coati was investigating it as a food source.

 

They do not appear to be very wary of humans; this one passed by fairly close in a wooded area. Apparently, people will feed coatis strawberries along roadsides, which will undoubtedly make them less wary of humans. This coati might have been a male as they are solitary except for mating season when they will join a female group for a time.

Another ground-dwelling mammal we saw on multiple occasions in different areas was the Central American agouti (Dasyprocta punctata). This rodent plays an important role in the forest as it is a seed disperser. Like squirrels, the agoutis bury caches of seeds and nuts for lean times; when they do not re-visit a storage area, the seeds and nuts may germinate to create new trees.

 

The agoutis eat other foods as well, including leaves, roots and fruit. They will sit on their hind legs and hold the food in their front paws to dine.

These cute animals mate for life; the young are unusual in that they are active right after birth. The mother takes them to nest sites dug by other animals so they can claim their own home burrows! The young then line their home with leaves and twigs.

It is worth noting here that the Costa Ricans are protecting their ground mammals and all other wildlife. The country was the first in Latin America to ban sport hunting in 2012; it is also forbidden to keep, import or export wildlife for the pet trade.

And finally we get to the smallest mammals we viewed during our August trip. Last year, our group had been surprised to find that a group of bats was flying into a hotel’s outdoor restaurant to roost each night. The staff accommodated the creatures, which they listed as two-lined bats. After reading about Costa Rican bats, I think these might be lesser white-lined bats (Saccopteryx leptura). It was interesting to see how they would hang by one leg as they engaged in some grooming.

This year, we came across a small group of similar-looking bats roosting under a bridge. They had white lines down their backs but appeared to be long-nosed proboscis bats (Rhynchonyceteris naso). Their colonies often number 5-10 individuals.

One of our most interesting walks took place the day after our bridge sighting. We were visiting a self-taught local artist named Cope, in La Union, Guapiles. He created a wildlife viewing site around his home where he welcomes tourists to see hummingbirds and other avians. He offered to take us into the nearby forest to find a particular owl (coming blog!), as well as a couple species of bats and some interesting amphibians.

While we may be used to thinking of bats living in caverns, various species in the rain forest have found other roosting sites. The tent-making bats (Uroderma bilobatum) create a home by biting through the middle vein of a large leaf so that the sides droop down and form a hanging shelter. The structure is recognizable and after Cope found us a couple tents, members of our group knelt or hunkered down so we could peer upwards at the sheltering mammals.

 

At one site, after photographing the bats, I unfortunately stumbled backwards after taking a photo; I startled the bats, who took off in haste. Apparently, it is known that they spook easily since the slightest movement of their leaf could indicate that a predator is approaching. Cope fortunately located another tent so that the other group members could peer upwards at the creatures.

Our guide was kind enough to use people’s cell phones to take photos of the little bats.

At another tent, it turned out that adorable Honduran white bats (Ectophylla alba) were roosting. Of the approximately 1300 known bat species, only six have entirely white fur.

These bats are frugivorous, with one fig species being a preferred food.

The Honduran white bats are unique in being able to convert lutein into a form that better helps protect the retina and it is speculated that understanding how they do this could be helpful in the treatment of macular degeneration.

Our final bat species had a different type of residence – a termite mound, which may be abandoned or actively harboring termites. I believe that the species we saw was the pygmy round-eared bat (Lophostoma brasiliense), an insectivore although it will also eat fruit. Their daytime roosting site is maintained by a resident male bat, who prevents termites from repairing the cavity made by the bats. Seeing these nocturnal mammals in an unexpected home was truly an interesting way to conclude our bat-watching outing.

 

Many thanks to Nan DeWire and Ylva Byars for letting me include photos they took in this blog. After a foray into North Carolinian wildlife in the next posting, it will be back to Costa Rica to take a look at the woodpeckers there – and elsewhere!

Costa Rican mammals, part 1 – those similar to our Carolina wildlife neighbors!

While the trip I took this past August to Costa Rica was mainly focused on birding, our guides fortunately were also quite willing to stop and look for mammals, amphibians, reptiles and insects – people after my own heart! Here I’ll focus on some of the mammals we saw, starting in this 2-part blog with those that were familiar.

Fellow traveler Nan especially was drawn to the canines we came across – there wasn’t a dog (Canis) that she was unwilling to pet!

 

And they often were very cute.

 

As we drove from one destination to another, it was not uncommon to see light-colored cattle (Bos taurus) grazing in fields. It turns out that about 75% of the country’s cattle are found in Guanacaste province (where we started our trip) and that the Brahman breed is the one commonly raised for the meat industry.

I saw mostly cows, but during a visit to southern Costa Rica last year, we also saw a laid-back steer.

 

There were horses (Equus caballus) grazing in some fields and mountain valleys.

Everywhere we went, there were squirrels scurrying about on the ground, in trees and at feeding stations. The most commonly seen squirrel in the country is the variegated squirrel (Sciurus variegatoides), which varies in color from gray hues to dark brown colors.

  

This species spends most of its time in trees and does not hoard food.

 

Their main dietary selection consists of various seeds, although they also eat acorns, fruit and insects.

   

Another cute rodent is the red-tailed squirrel (Notosciurus granatensis), which is usually found in the cloud forests and wet/humid areas.

Although in some places, people warn against feeding mammals, we saw a red-tailed squirrel enjoying fruit at a restaurant that attracts tourists with its plants that attract hummingbirds.

 

While we do have wild boars in some mountainous North Carolina counties, as well as feral swine in Eastern coastal areas, we will not see collared peccaries (Pecari tajacu) roaming our forests and woods. They share some characteristics of the pig family but are not classified as pigs.

They are both carnivorous and vegetarian, even eating tulip bulbs, which are poisonous for humans. It’s said they usually ignore humans and that was the case for this peccary, which paid us no mind as it plodded about the gardens in one reserve.

 

Our final, at least partly familiar, mammal was observed near the restaurant of a hotel where we stayed. We were lucky to see it since these animals are both arboreal and nocturnal. Fellow birder Ylva got a nice photo of the visiting Central American woolly opossum (Caluromys derbianus). Not only is this marsupial a real cutie, it is also a nectar feeder, pollinator and seed disperser so that we got to see a species that fulfills multiple roles in its rain forest habitat.

Next up – the mammals we won’t see in North or South Carolina (yet).