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!

“Wattle” I do to get a better photo of you?

In mid-August 2019, it was my privilege and good fortune to participate in an interesting, engaging and VERY fun “Birding Plus” tour in Costa Rica thanks to a great roommate, Nan, knowledgeable guide and tour organizer, Steve and Sherry, and group of fellow travelers (Ann, Art, Bill, Gordon, Len, Tom and Ylva). My next blogs will mostly focus on the birds, amphibians, mammals and insects we were fortunate to see there. The photos are not all great as taking shots in the rain and dark cloud/rain forests was challenging for multiple reasons. But they will give you an idea of the fascinating and beautiful sightings we had. (Clicking on photos enlarges them; then back arrow.)

One of the most difficult birds to “capture” in a good photo was likely the one about which I was most excited, the three-wattled bellbird (Procnias tricarunculatus). This species, which also lives in Honduras, Nicaragua and Panama, only breeds in the mountains of Costa Rica. These bellbirds are known to be shy, secretive and elusive as they remain mostly in the dense, high canopies of the forests. They apparently prefer to perch on uncluttered branches that are 33-72 ft (10-22 m) high and 0.98-2 in (25-50 mm) in diameter.

The males usually sing from March through June, so we were lucky that some of them were calling out in mid-August. Here we see a couple digiscoped photos of a male bird. The females look very different with olive coloring and a streaky yellow breast (we did not see a female). They are quite different in size, with males in one study having a mean wing length of 6.5 in (165.5 mm) compared to 5.7 in (145.1 mm) for the females.

 

 

The common name for these birds comes from the sound they make. In some articles, it is described as a 3-part song. To me, it sounded like they first made a high-pitched brief screech, squeak or whistle sound and then a deeper call.

 

Others have described their calls/songs as a “boink,” “bonk” or “Hee-aahh” sound. In any event, they obviously work at producing the sound. As we watched, “our” bird would open his mouth very wide, so that you could see the white and black lines surrounding the bill.

He seemed to be breathing in plenty of air as he sat there silently for a while. You could see his neck getting ridges, which I assumed was due to the oxygen he was gathering and holding to be expelled in the call. (This turned out to be a correct assumption according to one study!)

Then, he moved his head up and down a bit and you knew the sound was coming. It is unmistakable once you have heard it as in this brief video that fellow traveler Ylva made.

It is said that the bellbird’s sound is one of the loudest avian calls, audible to humans who are more than 0.5 miles (0.80 km) away. The calls and songs are not instinctive – the birds learn the calls and there are different “dialects” among the birds from different areas! One bird studied in Costa Rica could perform the song/call repertoires of Talamanca and Monteverde – in other words, he was bilingual!

 

Research has also shown that immature male bellbirds not only take 6 years to achieve their full adult plumage but also to perfect their entire song repertoire! Kroodsma et al. also note that: “Males appear to be highly attentive to the nuances of songs produced by their competitors, as both immatures and adults visit each others’ display perches, listening there for up to several minutes at a time.”

The other really striking characteristic of this species is the three wattles on the male’s head which begin growing when he is 6-12 months of age. One dangles from each side of the bird’s mouth and one is affixed to the base of the upper bill.

The wattles have been described as “wormlike”. Nan and I thought they looked a bit like hair-braids and on the flight home I sat next to a woman who had three braids ending in a point with interwoven gold thread that immediately made me want to give her the nickname “Bellbird”. (I didn’t tell her that though.)

The wattles are about one-third of the bird’s size (9.5-12 in or 25-30 cm). They cannot be controlled by muscles or made rigid, but they can be extended in length up to 3.9 in (10 cm) when the bird is interacting with others or singing.

The birds are frugivorous (eat only fruit) and prefer wild avocados (Lauraceae). They play an important role in the tree’s seed dispersal.

 

Due to habitat loss and hunting, the numbers of the three-wattled bellbird have declined to about 20,000 individuals and the International Union for Conservation of Nature (IUCN) has declared its conservation status to be vulnerable. They obviously inspire artists in Costa Rica, however, as witnessed by a mural at a restaurant where we stopped for lunch.

 

 

After three blogs in quick succession, I’ll now take a break to process and sort some more photos from Costa Rica to share with you. In the meantime, bye bye from the bellbird!

Further information

Quebec chronicles – passerines with yellow and green colors, part 2

My last “bird blog” from Quebec! The passerine birds that we admired during our trip there included the vireos and grosbeaks. But I saved one warbler for this blog since I often had to look at the photos to be sure which species I had seen. The Tennessee warbler (Oreothlypis peregrina) could namely be mistaken for a Philadelphia vireo if it goes by quickly and you are not an experienced or expert birder. (It also can be easily mistaken for a female black-throated blue warbler.)

This very charming bird seemed to be everywhere we visited in great abundance. I had seen one last summer in North Carolina; now I got to see dozens of these little beauties.

 

 

Like the bay-breasted warbler, it specializes in eating the spruce budworms and hence its numbers wax and wane along with the availability of this food source.It was gleaning in all kinds of trees as well as along the shore, however, and obviously also looking for other types of food.

 

Besides insects, this bird also likes nectar and gets it by piercing flowers at the base of their stems on trees.

 

On the one day that it rained, I saw one waiting out the shower in a yard tree. On another morning, I surprised a Tennessee taking a bath in a little puddle formed by a streamlet flowing from a yard to the street where we were staying. The bird was still wet but fluttered its wings and dried off very quickly, looking fresh and pretty for a possible new partner.

 

 

The Philadelphia vireo (Vireo philadelphicus) is another attractive avian. It has the same coloring as the Tennessee warbler but has a bit of a hook at the end of its bill.

Like the Tennessee warblers, they migrate to Mexico and environs during the winter. Their meals of choice are insects and some berries (e.g., bayberry and dogwood). The birding websites and Wikipedia do not have anywhere near the same amount of information on this species as some others, so they likely have not been studied very much.

 

One day as I walked a path in one of the nature reserves, a Philadelphia vireo followed me a bit as I walked, finally perching on a nearby branch and fluffing its feathers. S/he looked like someone showing off a party dress.

 

 

The blue-headed vireo (Vireo solitarius) is a much darker bird, with olive-green feathers, a blue-gray crown and white “spectacles”. I haven’t seen many in North Carolina and I only saw two in Quebec – decidedly a somewhat shyer bird than many of the others that crossed my paths.

Finally, some birds that gave me very good looks were the stunning evening grosbeaks (Coccothraustes vespertinus).

These birds only very rarely show up in the Piedmont area of North Carolina in the winter but last year I had the privilege of having a male and two females visit my feeders for one day. During this trip, we visited a neighborhood where a whole flock was busy feeding in the trees.

The males have rich deep yellow coloring offset by white and black accents on their heads, wings and tails. At one feeder, I was surprised to see one male apparently feeding another. It turns out that they may be territorial in wintertime around food sources but in the spring and summer, they are quite social and tolerant because there is a greater abundance of insects, buds, berries and seeds.

 

 

The females are much more muted in color with light yellow highlights against a pale gray background but they also have beautiful patterned black and white wing feathers. Their light yellow-lime-green beaks serve well to break apart seeds.

 

 

 

The oldest evening grosbeak on record reached the age of 16 years, 3 months. It appears that their numbers may be decreasing, although the population as a whole is not yet at risk. I look forward to another “irruptive” year, when they expand their winter territory – perhaps I’ll have a couple unexpected visitors again!

Quebec chronicles – passerines with yellow colors, part 1

People who journey to the Tadoussac Dunes area in Quebec during spring bird migration often are focused mainly on one type of bird. They are members of the group of passerine birds, i.e., birds that perch using four toes – three that face forward and one that faces backwards. The “new world warblers” (also called wood warblers) are a subgroup of passerines that are only found in the Western hemisphere. They are featured in this blog and include some of my favorite photos from our trip. The next blog, passerines part 2, will feature other bird species that perch.

The warblers really are quite beautiful in their breeding plumage and many birders spend long periods of time searching them out and admiring them. This often involves looking up at treetops since many species forage for insects in mid- and high forest canopies. This may lead to a condition in humans called “warbler neck”, the result of staying for a prolonged time in the posture indicated to the left. (The statue was in the lobby of our Quebec hotel and was called “Force intérieure” (inner force) by Julie Lajoie.)

One warbler that we didn’t need to strain to see was the Cape May (Setophaga tigrina), which was named for Cape May, New Jersey, where it was first observed by ornithologist Alexander Wilson in 1811. After that, these birds weren’t seen again in that area for more than a century!

The males really do call attention to themselves with their bright breeding colors – a distinctive rusty cheek patch, yellow throat and collar, dark crown and lots of vertical black stripes going down its sides and chest.

In spring, this warbler migrates almost 3,000 miles from the West Indies to the coniferous forests of Canada and the northern US to breed. As the fist-sized songbird flies north, its diet adapts to the environment. During winter among the palm trees, the Cape May drinks berry juice and the nectar from flowers thanks to its unusual semi-tubular and curled tongue. (It will also drink from nectar feeders!) But in summer in the boreal forests, it eats insects—especially the spruce budworm—with a special gusto.

The male and female build a nest together near the top of a tree (35-60 feet high!) and the female tries to prevent others from seeing the nest. She namely will not enter the nest directly but goes up and down the trunk of the tree, entering from below.

A second seemingly ubiquitous bird at our migration destination was the magnolia warbler (Setophaga magnolia). Like the Cape May, the male in breeding attire has vertical black stripes on a yellow chest but his face is marked by a black mask topped by a white stripe.

 

Most of my sightings of this species involved individuals looking for insects on the ground. At one point, it was interesting to see a “Maggie” fluttering his wings over sandy spots in the dunes, obviously to scare up insects that he then quickly grabbed. My attempts to get a photo of the fluttering were unsuccessful but it was very cool to watch.

 

 

 

Another warbler that sports a black “necklace” against a yellow breast is the Canada warbler (Cardellina canadensis). Males and females look similar except that the male has a bit longer tail and somewhat darker breast stripes.

 

Some of these birds spend the summer in the Appalachian Mountains of western North Carolina (NC), but I had not seen one before. Towards the end of our trip, a Canada warbler decided to forage in the yard of the house where we were staying – finally, I was able to get some good looks at him!

The male Blackburnian warbler (Setophaga fusca) also has black breast stripes but against a white background. His face is quite striking with a flame-orange throat against a yellow and black head.  The female is somewhat more muted in coloration but also quite lovely.

 

These birds do not appear to be shy around people. One was grabbing insects in a grassy patch near a parking lot and not at all perturbed when five of us stopped nearby to take portrait shots.

Another was intent on getting insects among the rocks alongside a pier.

 

 

 

 

 

The Nashville warbler (Oreothlypis ruficapilla) was a lifer for me, fairly easy to distinguish by its rufous cap.

 

 

An interesting bit of information about them is that they sometimes use porcupine quills in constructing their nests, which they locate on the ground under shrubs!

The Wilson’s warbler (Cardellina pusilla) also has a distinctive cap, but when I got to see one around dusk one day, it didn’t feel like turning around to face me. It was nevertheless another lifer.

They spend a lot of time in the understory and nest on the ground, but that apparently doesn’t make them easier to spot!

One warbler that I have seen several times in NC is the tiny yellow warbler (Setophaga petechia). They tend to like being near wetlands and streams and this has proved to be the case for my spottings. I have seen them near a water ditch in one reserve as well as near the Haw River. In Quebec, I also saw one searching for insects in the rocks bordering a pier.

 

You can see that this warbler has reddish striping on its chest and that is what I’ve noted in the birds seen in my area. However, below you can see a male bird without striping; our local guide said that a number of birds that breed in Quebec do not develop any striping but remain entirely yellow.

 

A behavior that distinguishes them from many other birds is that they are capable of recognizing when a brown-headed cowbird has laid one of its eggs in their nest. The yellow warblers try to avoid raising the nest parasite by smothering the cowbird egg with a new layer of nest materials. If they had already laid eggs of their own, they then produce a new clutch; sometimes, they just build a new nest elsewhere.

Another warbler that is quite familiar to me is the yellow-rumped warbler (Setophaga coronata). A group spends the winter at my yard feeders and begin changing into their breeding plumage shortly before migrating north. In Quebec, I got to see them in their full coloration, and they were handsome indeed!

My final bird for this blog is also one I’ve seen before, but I found it simply stunning when watching it in the Canadian trees. The black-throated green warbler (Setophagahy virens) as the striped warblers but the brightness of the yellow and black coloring on the breeding male is wonderful to see.

They seemed to “color-match” some of the trees in which I watched them foraging.

 

In other cases, they complemented the deep green of the deciduous evergreen trees in which they were perching.

 

 

 

These birds particularly like caterpillars but eat a wide variety of insects. An interesting behavior observed by researchers concerns its singing – the males really like to belt it out, with one male having been recorded singing 466 songs in one hour!

 

Having observed these wood warblers in their breeding habitat, I now have an increased understanding of why birders are willing to endure warbler necks. 😊

Unexpected loving care – a winter gift

One of the delights of my back yard is being able to look outside just about any time to see some sort of wildlife. Often, it is birds that I see but there are insects, mammals, amphibians and reptiles, too. Wooded areas in and near our neighborhood are being clear-cut, pushing the animals out of their long-time homes and they don’t have many places to go. So our yards become a refuge, at least when the residents don’t chase them away. I am fine with non-human species in my yard, so they sometimes rest here, get a drink from the pond and hunt for food. Among the most graceful visitors are the white-tailed deer (Odocoileus virginianus), who have been among my favorite mammals ever since I got to know one in particular, Schatje.

The past couple years, the resident does who most often traversed our streets had fawns, but they were mostly producing male offspring – five bucks to two does by my guesstimate. Since the availability of food is diminishing, as is the available natural territory, it may be that this will keep the local population somewhat limited as there will be fewer does to give birth.

In spring and summer, bucks do not visit my yard as often as does and their fawns but during breeding season, they put in more frequent appearances. One of the two daily visiting does (“Mama”, recognizable by a mark near her eye) fled this year whenever they arrived. At one point, her twins (born this past spring) began coming around with an older brother who was born last year (“Sweetie”; at left). Mama eventually stopped coming at all and I suspect she was perhaps hit by a car.

Sweetie has sometimes been challenged by one of his younger brothers and then he does a little practice “jousting” with him. He never pushes hard, just enough to give the younger button buck something to resist.

At the start of November, I was quite surprised to see a very small fawn that still had some spotting turn up in the yard. The other deer tried to drive it away but it hung around waiting for them to leave and then would lick up whatever remaining bird seed was still on the ground. The little one was never accompanied by a doe and I had to assume that the mother had died and the young one is an orphan. I had read that late-born fawns often do not survive as they haven’t had time to build up body mass and reserves to get through a winter but this little deer seems to be very resilient and persistent.

The persistence seems to have paid off and resulted in a winter gift. Sweetie and one of his younger brothers seem to have “adopted” the fawn! They not only allow the young deer to be around them when they look for bird seed on the ground; they are also grooming the orphan! This seems to me to be unusual behavior for bucks, but I’m happy they are doing it.

This development has just warmed my heart.

In the meantime, the remaining older doe has only come by occasionally, together with what I assume is her daughter from last year. They do not stick around when the larger bucks put in an appearance. The other day, the largest buck entered the yard holding up his left front leg. The injury does not prevent him from walking. When a younger adult buck came by, it turned out that the injury also does not prevent him from engaging in some jousting as well.

The “duel” between the two adult males that I witnessed did not seem very serious, perhaps because no does were in sight or perhaps because the healthy buck was still being careful not to challenge the larger deer even though he had an injury.

They did not really push one another much but spent more time entwining their antlers – which seemed pretty dicey to me as the points came close to their eyes! That didn’t stop their activity, however.

Eventually, the two parted, quite amiably it seemed, and each went his own way. It was a fascinating “performance” and kept me quite entertained. And I remain grateful that these beautiful mammals come by regularly, sometimes resting against the back fence and sometimes displaying behaviors that keep me learning something about their lives.