Panamanian Night Monkeys

The Panamanian Night Monkeys (Aotus zonalis) are one of the species of the Aotus genus. These genus are found in Central and South America. The Panamanian Night Monkey it’s restricted to different areas of the country and the North Western part of Colombia.

They sleep in hollow trees, during the day, and are active at dusk. The family in this picture was two parents and a sub-adult baby, they where sleeping in a dead peach palm tree near the cabins.

These monkeys live in small groups and are socially monogamous.  The female gives birth, usually, one baby at the time, and very sporadically twins. Once the baby is born the male plays a major role in the care of the offspring.

Much information regarding these monkeys is missing.  Many aspects of the species, including the major threats and status of the population are unknown.  They are currently  under the Red List Category and their Criteria is Data Deficient.  It is very likely that habitat destruction is one of the main threats for these beautiful creatures because of the significant forest loss within Panama in recent decades.

A very particular group of plants: Zamia

Cycad plants are found in tropical and subtropical areas around the world. Panama has the most diverse group of cycad plant in the Neotropics. The species found in Panama have a cylindrical trunk, with leaves that grow directly from the trunk, forming a “crown” of evergreen leaves, and a plastic texture, that sometimes could be confused with ferns or palms.

Within the forest of Bocas del Toro, we frequently find this plant defoliated by the larvae of the White-tipped Cycadian (Eumaeus godartii). The larvae can eat the entire plant, but do not kill it.

Eumaeus godartii

Larvae of the White-tipped Cycadian (Eumaeus godartii)

Cycads are gymnosperms (naked seeds), the unfertilized seeds are open to the air to be pollinated. Cones are the reproductive organs of the cycads and are composed by highly modified leaves.

Panama Flora

Female cones of a Zamia plant, at Tranquilo Bay grounds, Bastimentos Island.

Cycad plants are females or males; female cone carried ovules, and every male cone (is smaller in diameter, compared with the female) carries several pollen capsules. There are cases of cycad plants changing sex, but never producing male and female cones at the same time.

Cycad Zamia Male Cone

Male cones of a Zamia plant – Tranquilo Bay, Bastimentos Island

In the past the pollination of cycads was thought to be completed by the wind, but its been proven that it is completed by insects.

Thousands of this plant grow on the white sand beaches of Bastimentos Island.  Here it was observed and has been reported by researchers an unusual occurrence of salt water tolerance.  Cycad seeds can float in the water, allowing the plant to disperse from island to island within the archipelago – this was observed in this group of plants around 2004 in Bocas del Toro.

 

 

 

Dwarf squirrels in Western Panama

Fossil evidence proves that there were no squirrels in South America before the formation of Panama, the natural bridge that allowed migration in both directions, of a wide variety of species, known as the Great American Interchange.

Dwarf squirrels (Microsciurus), are found in evergreen tropical rainforest regions of Central and South America. Their small size, dull coloring, shy behavior and speed make them difficult to find. These are some of the reasons why not much is known about these little mammals.

Palo Seco Protected Forest

The home of the Pygmy Squirrel, evergreen tropical rainforest, Palo Seco Protected Forest, Bocas del Toro.

In Western Panama, two species of this group can be found, the Alfaro´s Pygmy Squirrel (Microsciurus alfari) and the Western Dwarf Squirrel (Microsciurus mimulus).

Both of the species look very much a like. The best way to differentiate them, is by the white ear spots on the Alfaro´s Pygmy Squirrel. However, the ear spots are absent on the animals found in Costa Rica and Western Panama, which makes it difficult to tell them apart in this part of the world, as their distribution overlaps and both species have similar behaviors.

Panama Wildlife

Pygmy Squirrel (Microsciurus spp.) photograph in the Palo Seco Protected Forest, Bocas del Toro.

None of the members of this genus are endangered, but it is hard to know the real numbers of their populations because of the lack of information and studies related to those cute creatures.

 

Coró-coró

The ibises have a very particular appearance overall, long and curved beak, long neck and legs and a chunky body, which makes them easy to recognize from a distance. Five species of ibises are reported in Panama, two of them have very few observations in the country, and are considered as vagrant species. In Bocas del Toro we can find the other three species: Green, Glossy and White Ibis, in this same order of abundance, with the Green Ibis the most common of the three, and the White Ibis the rarest one.

Birding Panama

Mesembrinibis cayennensis

In poor light, the Green Ibis (Mesembrinibis cayennensis), may appear as a black bird, but when you get the right light and angle, the beautiful iridescent feathers on the back of its neck may be appreciated.

In Bocas del Toro the Green Ibis (Mesembrinibis cayennensis) is frequently seen near the mangroves and wetlands of the lowlands, where it feeds on aquatic invertebrates (worms, snails, insects, etc.) by walking slowly and digging with its long bill into the mud, dirt, and shallow water.

Easy to recognize and locate by its peculiar loud call, they actively vocalize at dusk and down. Flying calls are a series of corocoro… sound, which explain the reason of the local name in some regions: “the coró-coró”.

Green Ibis call. Downloaded from zeno-canto (http://www.xeno-canto.org/sounds/uploaded/WNGXTLHREQ/GreenIbisDamani111028_26.mp3)

Birds are often seen in pairs or singles, but occasionally in small groups up to eight individuals (personal observations). Their nest is built with twigs, high in a tree over water, and separated from other nests of the same species.

Panama Birdwatching

Pair of Green Ibises

Typically, these birds vocalize on a high perch, in a clear area, at dusk or dawn. Notice the particular shape of these birds, it makes them easy to recognize from the distance.

Updated Bird List – Fall 2017

I recently finished updating our Western Caribbean Slope bird list, based on the August 2017 Clements List. This last version shows some significant changes, such as, removing from the Thraupidae family the Rosy Thush-Tanager (Rhodinocichla rosea) and the Dusky-faced Tanager (Mitrospingus cassinii) and putting them in to their own family, Rhodinocichlidae and Mitrospingidae respectively.

As of this update, we have a total of 522 species on our list.  It is very likely that during the year this number will change, owing to Bocas del Toro’s outstanding diversity.

One of the additions to our bird list, is the Forster´s Tern (Sterna forsteri), a rare species for the country; only one bird was observed, resting with a group of Royal Terns (Thalasseus maximus), at the Changuinola River mouth, months ago. This species is easy to recognize in its winter plumage, by the black, coma type of shape, ear patch.

Birding Panama

©Brooke A. Miller

You can download the current Clements based bird list on our Birding page.

Tarpon Working Baitball

So, we received a drone for Christmas and have spent some time learning how to fly it and capture footage around the neighborhood over the past month after the end of high season.

Jay called back on the radio from the boat as he headed out to pick up guests recently telling Jim he needed to go check out the tarpon rolling around a large baitball near the lodge.  Fortunately for us the baitball was near the lodge for a few days.  Check out this footage of the tarpon, sting rays and snapper corralling the bait fish.  The change in shape of the baitball is all due to predators working the smaller bait fish.  Nature at its finest.

Bocas Shorts #4: Two-toed Sloth Commute

Sloth CommuteAfter its nap, the two-toed Sloth start crawling up higher, looking for branches that connected, and using the palm leaves to get to the power line.  At least that’s what we thought, that he was planning on going across the power line, because we have seen this species use the wire as a way to get access to to some of the trees where they feed near the main building or just to move from one patch of forest to another, but…

In the end the sloth had something different in mind.  He successfully accessed the power line and then went on to the next palm tree.  Why? We are not sure, but we chose to move away and let it make its way alone.  A few minutes later I went back to look for it and could not find it.

Frog v. Robot

Frog v. Robot

We invite scientists from the Bocas del Toro Research Station of the Smithsonian Tropical Research Institute to come out to Tranquilo Bay and do their research.  On March 9, we had a group of three scientists come out to take some photos and videos of the poison dart frogs interacting with robot frogs.  They put a number of colored robot morphs in play with our resident frogs to see the interaction between the real frog and the robot.  The real frog did not enjoy any other frogs moving in on his territory.  We hope you enjoy the video they shared with us as much as we have.

Variable Seedeater Song Mimicry

Today’s post is by Scott Viola.  Our children, as some of you may know, learned all 200 yard birds we have at Tranquilo Bay for their science class last year.  Scott truly took to the birds and was especially interested in their songs and sounds.  He has learned to identify many of the birds by sound as well as visually.  Here is a report he prepared for me about a strange phenomenon he encountered.

Panama Bird Song Mimicry

I have acknowledged a phenomenon on which I can find almost nothing: the Variable Seedeater mimics other birds’ songs.

For months after learning the Variable Seedeater’s song in Bocas del Toro, Panama, it made me think of rubbing a wet window with rubber. One day around New Years, I was walking in a semi-open area less than a hundred feet above sea level and heard a string of bird songs issued back-to-back from an elevated position. I was mystified, there being nothing that I could see. I considered that someone had put a playback speaker in a tree, but that was unlikely. After a few minutes, I saw a small, black bird exit the tree, and the calls ceased. I knew what it was, a seedeater or seedfinch, but I didn’t consider that it could have been the thing making the noise. A few days later, I heard it again in a nearby location. This time, I had a clear view and identified it as a Variable Seedeater.

I took two recordings of it singing, and later made videos with text on-screen notifying what bird song it was imitating. I have observed it mimicking Red-lored Parrots, Blue-headed Parrots, something that I believe is based on the Groove-billed Ani or the Common Black Hawk, Black-cheeked Woodpeckers, Blue-gray or Palm Tanagers, Tropical Gnatcatchers, Yellow-bellied Elaenias, Great Kiskadees, Boat-billed Flycatchers (probably), and Roadside Hawk, all of which are common in the area. The seedeater also has a “Brr brr Brrr” sound, and a distinctive, high-pitched “eaw.”

It doesn’t include all the birds every time it sings, but there is a loose order in which it tends to put them: parrots, the Ani or the hawk-like sound, and the rest, often with the Black-cheeked Woodpecker next to the flycatchers. The song lasts around seven to eight seconds, with 3-6 dedicated in the beginning to the parrots, the Ani-like song, and its own add-ons.

The song also changes depending on region, as can be seen on http://xeno-canto.org/explore?query=variable+seedeater. I believe this is caused by the birds it mimics, which are different everywhere. On Xeno Canto, I managed to identify a parrot in the midst of unfamiliar noises. The sounds don’t even make me think of birds; they are higher pitched and from a different place, making it sound like the song I had heard before my epiphany. The seeming randomness is stated in every Variable Seedeater resource I can find, except for one. At “The Sights and Sounds of Costa Rica” (http://www.naturesongs.com/CRsounds.html), the author wrote in the section for the Variable Seedeater that it mimics, and had two recordings that clearly contained mimicking. He was hearing the same thing I did. In them, I can tell that the seedeater mimics bird sounds. In one, I hear a Black-cheeked Woodpecker.