The birdy breeding cycle 2020 – 1: courtship and mating

Although we in the Northern hemisphere are already a little more than a month into summer, many species among our avian friends have not yet completed their breeding cycle. In my yard, many parents are still feeding begging (sometimes almost adult) children. Others are feeding young ones in the nest and some appear to be busy constructing new nests for a second or third brood. So, after a long hiatus in blogging, I decided to feature some of my bird friends, including the American goldfinch pair below (Spinus tristis) as they have worked on their new family lives in 2020.

American goldfinch P7130178 © Maria de Bruyn resSome of these photos go back to early spring. A series of misfortunes (including a crash of my laptop hard drive, a broken camera, loss of Internet) meant that I had a backlog of photos to process and then suddenly a large gap in photos taken. But I managed to recuperate some of the work and hope you enjoy the coming series of posts about the birds’ breeding and family life!

belted kingfisher

Breeding season is heralded by increasing bird song in the meadows, forests, fields and our yards. Males especially sing to attract mates and establish territories, but females treat us to songs and calls, too. This makes it easier to spot birds as the tree foliage gets thicker, especially if you have good hearing!

pine warbler P4175086© Maria de Bruyn                     white-eyed vireo P4123164 © Maria de Bruyn res

Pine warbler (Setophaga pinus)            White-eyed vireo (Vireo griseus)

Eastern meadowlark P4279816© Maria de Bruyn res            Orchard oriole P4279889© Maria de Bruyn res

Eastern meadowlark (Sturnella magna)     Orchard oriole (Icterus spurius)

Carolina wren P3316544 © Maria de Bruyn res                 blue grosbeak P4291500© Maria de Bruyn res

Carolina wren (Thryothorus ludovicianus)      Blue grosbeak (Passerina caerulea)

summer tanager P4291520© Maria de Bruyn res

Summer tanager (Piranga rubra)

Indigo bunting P6308502© Maria de Bruyn

Indigo bunting (Passerina cyanea)

Courtship is usually a sweet behavior to watch in my view. The male Northern cardinals (Cardinalis cardinalis) are especially devoted suitors, seeking out nice morsels to present to their intended mates, while among the American crows (Corvus brachyrhynchos), it’s the females who loudly call to their mates for some tasty bites.

Northern cardinal P4164873© Maria de Bruyn res

American crow P4080661 © Maria de Bruyn res

A fact that perhaps many bird lovers do not know is that few male birds have a penis. Like the female birds, most species’ males have a cloaca, a cavity externally located just under the bird’s tail and internally at the end of the digestive tract. Feces, urine, sperm and ova are all deposited in the cloaca. Birds who reproduce with this organ briefly rub their cloacae together (an activity called the “cloacal kiss”) whereby sperm from the male bird’s testes are transferred into the female’s cavity to unite with her eggs. During breeding season, the cloaca is slightly swollen and protrudes a bit from the bird’s body, facilitating the transfer. In the photo of this Carolina wren, you can see a slightly darker area under the tail indicating where the cloaca is found.

Carolina wren P7059955 © Maria de Bruyn res

red-headed woodpecker P4217162© Maria de Bruyn res

When ready for mating, the red-headed woodpeckers (Melanerpes erythrocephalus) seem to focus mainly on chasing away rivals and then snatching a quick mating session. The female woodpecker then takes a break from the chase to rest and have a bite to eat.

Some cliff swallow males (Petrochelidon pyrrhonota) seem to take advantage of females who are preoccupied with gathering mud for their nests for a quick tryst.

cliff swallows 2G0A3283© Maria de Bruyn res

The brown-headed cowbirds (Molothrus ater) seem to take their time for mating. This pair was occupied for at least 5-10 minutes in preparing for the upcoming production of eggs. At times, it seemed like the male was giving the female instructions on what to do once “the deed” was done!

brown-headed cowbird P5097676 © Maria de Bruyn res   brown-headed cowbird P5097677 © Maria de Bruyn res

Many birders do not like the cowbirds because they are parasitic nesters, i.e., they lay an egg in another bird’s nest so that the other bird will raise the young. Since the cowbird baby usually hatches before the other eggs, they either monopolize the food that the foster parents bring or they may even destroy the eggs laid by their foster mother.

brown-headed cowbird P5097682 © Maria de Bruyn res      brown-headed cowbird P5097686© Maria de Bruyn res

It’s been posited that the cowbirds evolved to use this strategy because they followed the bison in migration and therefore couldn’t stay in one place to raise their young. Others believe, however, that the birds developed the practice because dispersing their eggs over several nests gave their young a better chance of reaching adulthood.

brown-headed cowbird P5097689© Maria de Bruyn res

chipping sparrow P6256620© Maria de Bruyn sgd resThe quickest mating scenario I’ve witnessed came from a pair of sweet little chipping sparrows (Spizella passerina). I’d seen the two fluttering together at the feeders and had noted one sparrow chasing another away – which I now think was the victorious suitor driving away a rival. Then one July afternoon, the two flew to a dying cedar and sat close to one another on a branch. Suddenly, Mr. Victory mounted his mate but for what only seemed a few seconds – really very quick work indeed! She sat there with her rear end elevated for a bit and then the two went back to feeding – and soon after I saw them collecting nesting materials.

chipping sparrow P6256622© Maria de Bruyn res    chipping sparrow P6256623© Maria de Bruyn res

The birds in which the males do have a penis include some duck and swan species, ostriches, cassowaries, kiwi and geese. They differ from other birds in that development of the penis is NOT stopped in the male bird embryos during development (the case in cloacal birds).

The mallard males (Anas platyrhynchos), like some other ducks, unfortunately do not treat their partners well. They may mount the female very roughly. During a mating, she may be dunked underwater repeatedly and at length; occasionally, this results in her drowning. This behavior has been the subject of various studies and some newspaper articles with sensationalistic headlines (e.g., “The horrible thing you never knew about ducks)”.

Mallard duck P1232837 © Maria de Bruyn

Mallard duck P1232839 © Maria de Bruyn     Mallard duck P1232840© Maria de Bruyn

Once the actual mating is over, the birds devote most of their energy toward building a nest. While female ruby-throated hummingbirds (Archilochus colubris) must construct her nest and tend her babies alone, many other birds cooperate in the venture, like the Eastern bluebirds. Their efforts are featured in the next blog. (And if you’d like to see a previous post on courtship, it is here.)

ruby-throated hummingbird 2G0A4084© Maria de Bruyn res

Hopping into springtime

I’ve been planning new blogs for quite some time; then I keep taking new photos that will fit into them and the blog writing gets delayed. But two days ago, I saw such a cool natural event that I resolved to produce a blog quickly and here it is!

One welcome feature of springtime is that many insects emerge from their over-wintering spots. Some are bugs we dislike (mosquitoes, ticks and chiggers), but others are fascinating and wonderful members of our natural systems. Pollinators like this spicebush swallowtail (Papilio troilus) keep our gorgeous plants and important food crops going and many bugs provide other wildlife with meals.

On my trip to Costa Rica last year, our guide not only pointed out birds but also some mammals and insects. He had developed an interest in treehoppers, a group of insects with about 3200 species worldwide that specialize in eating plant sap. He was unable to find any to show me, but I resolved to keep an eye open for them when I returned home. I had forgotten that I had seen my first one the year before, a pretty green Ceresini species.

As I stared at plants during nature walks, I was lucky and managed to find my first treehoppers when I was actually looking for them. These were of a dark-colored species (Acutalis tartarea) that favors the sap of black locust trees, sunflowers, goldenrod and ragweeds.

The treehoppers, which are related to leafhoppers and cicadas, are popular with some entomologists because many species have elaborate “helmets” at the top of their heads. I got to see my first example of this type on my recent walk when I happened to find a young oak tree with numerous nymphs and recently eclosed (emerged) adult oak treehoppers (Platycostis vittata).

The mother treehopper is known for staying close to the nymphs to protect them against wasps and other predators.

The hoppers get plant sap by piercing plant stems with their beaks. The nymphs have extensible anal ducts that deposit the sap away from their bodies. This is important because the concentrated excess sap, called honeydew, can get moldy.

 

                              

The honeydew attracts ants, which like the sugar-rich liquid, so the hoppers and ants have a mutually beneficial relationship.

Just how the helmet develops into an unusual shape has been a source of investigation. One team of entomologists theorized that the helmet was formed by body parts that were actually modified wings. Another researcher countered that this was impossible and that the helmet was an unusual pronotum — the foremost dorsal section of the thorax. More recently, a third group of evolutionary biologists postulated that the helmet is indeed a section of pronotum but one that developed with the aid of genes that code for wings.

In various species, the pronotum has developed into a quite unusual and oddly shaped appendage; examples can be seen in this article. When the helmet resembles a plant thorn, it is thought to aid in camouflage.

When I discovered the group of oak treehoppers, one was just in the process of emerging from its nymph form. A friend who saw the photo remarked that it reminded her of the film Alien but this process was slow and deliberate and not a heart-thumping explosive emergence as shown in the movie.

As you can see, the oak treehopper is quite a beautiful insect with its pristine white body decorated with pink/red stripes and hints of yellow. They made me think of mints and Candy Stripers (a sign of our times when almost anything makes me think of health and health-related concerns. For younger readers: young female volunteers who work under nurses’ supervision in hospitals used to wear pink and white striped smocks and thus got the name Candy Striper).

Not all the adults had the horned pronotum; some had rounded heads.

This close-up of a hopper’s face could evoke all kinds of thoughts. I thought it looked as if it had a pig’s snout. Another friend thought it looked like a grumpy old man. What do you think when you see this visage?

Or about this one, with its head upside down? (It looks a bit more “innocent”, don’t you think?)

In any event, I found these insects just adorable and I felt very privileged to have had the chance to see them emerge into adulthood. It turns out that in this species, older individuals may change color, turning a dull brown or green color. Some mottled forms may be blue with yellowish spots. It would be interesting to see those forms as well one day – or perhaps one of the other treehoppers with a different fabulous helmet!I hope you, too, are able to get out in nature during these social distancing times so that you can connect with the wonderful wildlife around us!

Finding joy in troubled times

While working on photos for other blogs, it occurred to me that it might be more productive right now to focus on what we, everywhere, are facing with the current pandemic. It’s my hope that as many of us as possible will survive, thrive and overcome the distress we are facing. As we hunker down, like this beautiful mourning dove (Zenaida macroura), we can intensify our nature observations – or begin paying more attention to the wildlife around us when we do go for walks.

 

Practicing social quarantine and distancing is essential –- even if we live somewhere where authorities are not yet requiring this. Keeping away physically from those outside our households can protect them as well as ourselves. In most places, social distancing rules still allow us to get outside for walks in the fresh air and nature. I have never seen so many people, including families with children, in the local nature reserves and that is a welcome sight. Hopefully, a side effect of this will be much more social support and advocacy for environmental conservation and expansion of natural areas, parks and reserves now and in the future -– that would be an unexpected positive outcome to the measures we are taking to get through these troubled times! (Yellow trout lily above, Erythronium americanum).

For people who haven’t had the pleasure of getting out much on walks, I wanted to share something about how to possibly enjoy nature even more. From my perspective, a key element is learning to practice patience and to stop, wait, watch and explore frequently. Here are some examples of what you might find. (Common Blue Violet, Viola sororia)

Looking down at the ground can be a fruitful exercise, especially in spring. Fresh new blooms are emerging and can delight us with their beauty (like the Eastern spring beauties, Claytonia virginica).

Bloodroot (Sanguinaria canadensis) – the leaves look like jigsaw puzzle pieces

Rue anemone (Thalictrum thalictroides)                  Tiny bluet (Houstonia pusilla)

Common chickweed (Stellaria media)

   

Little sweet Betsy (Trillium cuneatum)

   

Ground ivy – also known as creeping Charlie (Glechoma hederacea)

Henbit (Lamium amplexicaule) and purple deadnettle (Lamium purpureum)

If you are out with kids, you can pay more attention to the plants –- take photos of them (most reserves and parks don’t want people to dig up and pick flowers) and then look them up at home and learn about them. Or make a game out of fallen leaves –- find three with very different shapes and identify the trees.

If you look closely at the flowers, you might glimpse small bugs flitting around the blooms. If you have a camera or phone camera, try to get a photo. When you enlarge it, you might find that you have actually seen a beautiful fly, bee or other insect whose shape and colors you couldn’t see with the naked eye. If you want to identify it, post the photo to the site BugGuide.net, where entomologists can perhaps tell you what species you saw.

Parasitic fly (Goninii, above)

 

 

Greater bee fly (Bombylius major)

Various species of syrphid flies are shown below; they are often mistaken for small bees. The first photos are all of the species Toxomerus geminatus.

 

Male                                                               Female

And below the male and female together.

 

A species of syrphid fly with a striped abdomen (Syrphus torvus) is characterized by “hairy” eyes (more so in males, like this one). Click to enlarge and see the hairs.

A larger species, Brachypalpus oarus, is not so colorful.

Even if you can’t get outside much, you might see an interesting insect around your house. For example, this male brown-tipped conehead katydid (Neoconocephalus triops) appeared on my porch when I was sweeping.

Butterflies are really starting to fly around now. The bluish spring azures (Celastrina ladon) are abundant right now.

I’ve been seeing falcate orangetips (Anthocharis midea), too.

Damselflies are also starting to appear; we tend to see them earlier than the dragonflies, who spread their wings horizontally when they alight on vegetation. This fragile forktail damselfly (Ischnura posita) was getting covered in yellow pine pollen –- much of North Carolina’s Piedmont region is bedecked in yellow dust during the spring weeks when the pine trees emit clouds of pollen.

 

Looking in the water can be productive, too. One day, I spent some time scanning the edge of a pond where the water was shallow enough to see the bottom. As I watched little fish darting to and fro, I suddenly noticed something larger moving about quickly. I looked more intently and discovered Eastern newts (also called red-spotted newts, Notophthalmus viridescens) down there – the first time I had seen these amphibians!!

When you see an Eastern gray squirrel (Sciurus carolinensis) scurrying across the leaves in the forest or even alongside a road, stop and watch a bit. I did the other day and saw the mammal locate a winter stash and dig up some food it had stored. This article describes their storage process and reveals that they can probably remember where up to 95% of their stashes are hidden!

Paying attention to fallen logs can reveal beauty, too. This tree that fell across a creek ended up providing a growing place for common blue violets (Viola sororia).

As I walked by some other fallen trees, a common five-lined skink (Plestiodon fasciatus) popped briefly into view, gave me a pensive look and then disappeared into the leaf and twig litter.

Looking up at the trees, you might be lucky to see a wasp nest. The paper wasps (Polistes) make compartmentalized nests, with a place for each individual egg.

Or you may see a large bald-faced hornet’s nest (Dolichovespula maculata).

               

If you take the time to watch birds, you may see them engaged in looking for food (like insects, nuts, berries and seeds).

Tufted titmouse (Baeolophus bicolor)         Brown-headed nuthatch (Sitta pusilla)

Carolina chickadee (Poecile carolinensis) White-throated sparrow (Zonotrichia albicollis)

Blue jay (Cyanocitta cristata)                          Cedar waxwing (Bombycilla cedrorum)

 

Black & white warbler (Mniotilta varia)    Field sparrow (Spizella pusilla)

On one of my latest walks, I heard rapid knocking and was able to watch a yellow-bellied sapsucker (Sphyrapicus varius) engaged in beginning a new series of sap holes, which provide sweet drinking spots for themselves and other birds.

If you’re able to look at trees, bushes or nest boxes during walks or from your windows, you might catch birds collecting materials for their nests. Just the other day, I saw a Carolina chickadee gathering up some spider web to use in a nest.

If you find a nest, be sure to maintain a good distance, but then watch the parents bringing food to their nestlings after they hatch. If you’re lucky, you may even see the babies fledge! And if you are not near any trees, watch some birds at their nests through webcams online: https://www.allaboutbirds.org/cams/ – https://www.audubon.org/birdcamshttps://birdwatchinghq.com/live-bird-cams/
https://birdcams.live/

If, at some point, we are “stuck” inside, we can follow this link to international wildlife days. If we find one to celebrate during our quarantine, we can spend some time learning about that animal and drawing or painting it. And we can do the same for other environmental days as well at this link.

To end, I’d like to share some resources with free online nature activities – for children and adults! Not all the sites require having a yard; even readers living in apartments could get out for a short walk and find something to see, investigate, etc.  Enjoy!!

 

 

 

 

Leapin’ lizards! Remarkable reptiles in Costa Rica

Today is the United Nations’ World Wildlife Day, a time to especially raise awareness about and celebrate the earth’s plants and animals. The holiday was instituted in 2013 to be commemorated on 3 March, the day of the year on which the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) was signed. The theme for World Wildlife Day 2020 is “Sustaining all life on Earth”, which includes all wild animal and plant species as key components of the world’s biodiversity.

To honor this international day of commemoration (and hopefully awareness-raising and action), I’d like to share some of the reptiles that I’ve seen in Costa Rica. But first, let me show you one North Carolina turtle that I saw yesterday and that I don’t think I had seen before. It’s a large turtle called a Florida cooter (Pseudemys floridana), which has a nice pattern with yellow accents on the carapace.

In Costa Rica, we came across one turtle at which we got a good look — a black wood turtle, also called a river turtle (Rhinoclemmys funerea). This is the largest turtle among the reptiles in its genus; individuals can grow to 14 in (35 cm).

black wood turtle

We came across several snakes during our trip in 2019, but a few of them were dead on the road and I decided not to show those. One feisty individual was the cloudy snail-eating snake (Sibon nebulatus); when our guide neared it, the snake reared up in self-defense. Of course, it’s good to remember that most snakes will not strike if they do not feel threatened, as we are reminded by the North Carolina Carolinas Reptile Rescue & Education Center.

 

A snake that I found particularly beautiful was spotted during the 2018 trip in which I participated; our guide spotted it after we had stopped at the side of a road. The neotropical bird snake (Phrynonax poecilonotus), also known as the puffing snake, eats small vertebrates such as small mammals, frogs, lizards and insects, but it is known to have a preference for birds and bird eggs.

These are non-venomous snakes, but they will bite hard when feeling threatened. They also will inflate their neck area in a way reminiscent of a cobra in order to appear dangerous.

The presence of caimans was advertised in various places we visited in Costa Rica but I didn’t see one until a spectacled caiman (Caiman crocodilus) was spotted as we were driving down a highway one day.

This brings me to the various types of lizards I saw. Anoles (Anolis) were in all the areas we visited, Although I couldn’t identify the specific species for several, I enjoyed seeing the differences between them.

 

While searching for birds in a heavily shadowed marshy area, we caught sight of what I thought was a slender anole — obviously a male given its prominent inflated neck flap. However, it turns out that slender anoles have white dewlaps with a small orange blotch so this was a different species.

 

I do believe that this anole was a ground anole (Norops humilis) but would welcome correction if I’m wrong. Their diet includes various insects such as termites, beetles, crickets, termites and flies.

 

 

A somewhat larger reptile than the anoles was the – in my opinion – quite attractive Central American whiptail (Holcosus festivus occidentalis). Like the other lizards that you will see below, they have exceptionally long tails.

Juvenile whiptails have blue tails; their skin patterns are quite lovely, which may account for part of their species name – festivus which means merry or joyous in Latin.

Not much information is available online about these lizards, despite their apparent wide distribution. Some studies have been done about another whiptail genus seen elsewhere that aroused scientific interest because reproduction is by parthogenesis. This has not been reported for this species.

 

The iguanas are the very large reptiles seen in Costa Rica. Despite their size, they appear to be quite agile; it was not unusual to see the large black spiny-tail iguanas (Ctenosaura similis) high up in trees.

The male black spiny-tails can grow as large as 4 ft 3 in (1.3 m), while females are a foot or more shorter. During breeding season, the males develop blue- and peach-colored hues on their jowls, as can be seen in the portrait below, captured by fellow traveler Janet Kurz in 2018.

 

They have been said to be the fastest lizard species, reaching a speed of 21.5 mph (34.6 km/h) in a sprint. Running away is a strategy to avoid predators but they can also bite and lash with their tails if cornered. They are mostly herbivorous, although they will also consume small animals and insects. Unfortunately, they are eaten by humans, some of whom think they can cure impotence.

 

The green iguanas (Iguana iguana) are somewhat smaller than the spiny-tails but they are also large, growing to 4.9 ft (1.5 m) or more. We were lucky to see a juvenile green iguana meander along a smaller tree, posing for quite some time. There might have been others nearby but we didn’t see them. It turns out that these iguanas are quite social – juveniles form pods of about four animals and then spend time grooming one another and sleeping together.

 

 

Their coloring is quite bright but can be other hues such as reddish brown, black, lavender and blue. These iguanas are good climbers, often staying high in trees; reportedly, they can fall as far down as 50 ft (15 m) and still land unhurt.

 

The green iguanas are often found near water and they swim well, being able to stay submerged as long as 30 minutes at a time. Like the spiny-tails, they can use their tails in defense. They can also drop their tails when caught and grow new ones.
 

The basilisks are among the “showiest” reptiles even though they are smaller than the iguanas (e.g., growing up to about 2.5 feet/76 cm in length). They gained the name Jesus Christ lizard because they can “walk” across water when rapidly moving (up to 15 mph/ 24.1 km/h) to escape predators. They have special webbing between the toes on their hind legs and cross the water “standing up” on those legs.

The male common basilisks (Basiliscus basiliscus) have a distinctive fin-like crest on their backs. Both sexes range in color from olive to brown; they are distinguished by a light-colored stripe along their upper lip.

 

The common basilisks also have a stripe along their body, although this fades as they grow older. The females and juveniles look somewhat similar. The females do not care for the young, leaving the eggs once laid. The hatchlings instinctively know how to care for themselves.

 

 

The green basilisk (Basiliscus plumifrons) is also known as the plumed basilisk. Males have three crests (on the head, back and tail), while females (shown in the photos here) only have a head crest. The juveniles have no crests.

 

Like the other basilisks, these lizards can dive under water after running along the surface for a time. They can stay submerged up to an hour but often do not do this as they could fall prey to aquatic predators.

 

 

Like the common basilisks, the green basilisk females leave their eggs and the newly hatched babies are able to run, climb and swim right after birth.

Among the brown basilisks (Basilicus vittatus), also called striped basilisks, the juveniles (shown below) can often run further across water than the adults.

   

The crests are similar to those in other species. These basilisks have dark bars across their backs and quite yellow stripes.

Like the other basilisks, these lizards often eat insects but also eat berries and other fruit, making them omnivores.

 

The last type of lizard in this reptile review is another iguana known by a couple popular names: the casque-headed lizard or the smooth helmeted iguana (Corytophanes cristatus).They have several distinct features that make them quite unique.

They are characterized by very long toes, a long tail like the other lizards and highly variable coloration, ranging from olive, grey, black, brown to reddish-brown, often with irregular blotches of other color.

 

 

 

They are also able to change their color rapidly as a form of camouflage. Unlike the other lizards, they tend to freeze in place when predators approach (a strategy called catalyptic freezing). If this and trying to appear larger by erecting their crest and expanding their gular pouch do not scare off predators, they will bite and attack.

 

 

 

They differ from the other iguanas and basilisks in that they often do not actively seek out prey. Rather, they sit and wait for worms, other lizards, insects and spiders to wander by and then pounce on them.

One final noteworthy and unexpected fact: because these lizards sit still for very long periods of time, both a fungus and a plant have been found growing on their skin!

Happy World Wildlife Day!

 

Awesome amphibians in Costa Rica

During my two trips to Costa Rica (so far?), it was my good fortune to see different kinds of animals besides the birds which were the focus of the trips. There are a lot of interesting amphibians and reptiles to see; in this blog, we’ll see some of the amphibians that I managed to photograph. I was ultimately able to identify almost all of them except the one to the right; if anyone can tell me which frog this is, it would be appreciated!

 

One of the most famous frogs in the country is the little (0.75-1 inch) strawberry poison dart frog (Oophaga pumilio), also known as the blue jeans frog because many individuals have a bright red upper body accented by a bright blue lower half. It turns out that the species has an estimated 15-30 color variations – in 2000, totally blue individuals were seen at the La Selva Field Station.

The female lays 3-5 eggs on a leaf and the male then keeps the eggs hydrated with water he transports in his cloaca. After the eggs hatch and tadpoles emerge, the female frog transports them on her back and deposits each one separately in a small pool formed in the crevice or hole of a tree or a large bromeliad. There, the tadpoles consume only unfertilized eggs that their mother feeds, a practice called obligatory oophagy,

 

The feeding habits of the adults (certain ant and mite species) are what makes them poisonous when touched or eaten. Their skin is toxic and humans should wash their hands vigorously after touching them.

A very tiny frog that we saw last year was the common tink frog (also called dink frog; Diasporus diastema). I’m not absolutely certain that the two shown below are tink frogs but think they are. These tiny frogs change color, having grayish brown skin with spots or bars during the day and a pale tan or pink color at night, when it is most active.

 

 

A somewhat larger amphibian that we saw at the same pond as the tink was the hourglass tree frog (Dendropsophus ebraccatus). Part of the species name comes from the Latin term ebraccata, which means “without trousers”. Some people call this frog the “pantless frog” because they think the smooth yellow thighs that contrast with its highly patterned back make it look as if it is not wearing pants. These individuals had patterns on their thighs, however!

The attractive hourglass frogs were in an amorous mood when we spotted them. The female chooses her mate and he mounts her to deposit his sperm. She then will seek out a suitable place for her eggs, either in the water or a leaf overhanging water. When the arboreal eggs hatch, the tadpoles roll off the leaf into the water below.

These frogs are of interest to scientists because their skin contains bioactive peptides which have anti-fungal and anti-bacterial properties and might even have therapeutic properties useful in treating diabetes.

 

The pond had quite a few frogs in residence and several brilliant forest frogs (Lithobates warszewitschii)were among them. They are slender-looking frogs with pointy heads. Their sides are apparently always darker in color than their backs.

 

 

Their coloring seems to vary somewhat, being browner in some individuals and featuring more green highlights in others. They tend to have yellow spots on their legs.

They do not have vocal sacs or slits but do make trilling sounds.

 

 

We were lucky to catch a glimpse of a red-eyed tree frog (Agalychnis callidryas) at the pond. Although some lodges will ask you to avoid using a flashlight during night-time walks to see amphibians, it’s very difficult to spot them without some use of a light. That’s how we managed to spot the tree frog.

We came across the Canal Zone tree frog (Boana rufitela) taking a daytime nap, right out in the open on a large leaf next to a walking path. This frog is also known as the red-webbed or scarlet-webbed treefrog. It used to have the scientific name Hypsiboas rufitelus, which was changed for a reason I couldn’t determine.

The smoky jungle frog (Leptodactylus pentadactylus) is Costa Rica’s largest frog species; males grow to as much as 7.3 inches (18.5 cm). The adults are so big that they can eat small mammals (e.g., bats), small birds and lizards. They have some interesting characteristics. In contrast to the little blue jeans frogs, who only lay 5 or fewer eggs, female smoky jungle frogs lay about 1000 eggs at a time! They can secrete copious amounts of mucus, which makes them difficult to hold for predators; in addition, these secretions are toxic. They can even vaporize the toxin, causing people to sneeze and get swollen eyes.

What has further contributed to making them famous is the alarm call that they emit when captured; some liken it to a human person screaming. It doesn’t sound like that to me; rather, what I heard in a video sounds to me like a sound that a distressed cat might make.

That brings us to Costa Rica’s largest amphibian, the cane toad, also known as the marine toad. They are not only this Central American’s biggest amphibian, though; they are the largest toad in the world, growing as long as 9 inches long (22.86 cm) and weighing up to 3.5 lbs (1.59 kg).

This animal has also gotten a new scientific name; while it used to be called the Bufo marinus, it is now known as the Rhinella marina. Like some of the frogs, this toad has toxic skin and they are especially dangerous for dogs.

They were introduced to different countries to control pests as they have voracious appetites. Now they are considered an invasive species and pests themselves.

In 2018, I came across these toads in different places. There are a few living around a fountain in the hotel in San José where our tour groups stayed; they enjoy taking a shower under the running water.

To end today’s offering, I’ll show you the frog that really fascinated me most — the reticulated glass frog (Hyalinobatrachium valerioi). Our guide, Cope (who showed us the awesome spectacled owls and bats shown in previous blogs), led us to this awesome amphibian. It has a green and yellow back but its ventral (abdominal) skin is completely transparent! The frog’s heart is covered by white tissue and its liver and digestive tract are also white. Here you see the male frog on a leaf guarding eggs – he actually looks pretty much like the egg masses!

Isn’t nature endlessly interesting? Next blog: Costa Rican reptiles!