Welcome back to the Rainforest Blog.  We have taken a break from blogging while the Rainforest team has refreshed, reoriented and restructured itself.  As we return to the blog I thought I would share some of what we has kept us busy.  3 times a year the Rainforest exhibit closes for 2-3 days to allow us to ‘refresh’ the exhibit and take care of projects we can’t accomplish during the morning hours before the exhibit opens.  In mid-September the Rainforest closed for two days and  brought together the Rainforest Biologists along with Electricians, Engineeres, Operations staff, Exhibits staff and Custodial staff to work on a dizzying array of projects and maintenance.  Here are some of the projects we got done in just two short days:

New Perching for the Blue and Gold Macaws:

Our two Blue and Gold Macaws got some new perching to keep them safely on the tree and give them some built in chew toys.

Refreshing Mist for Poison Darts:

Biologist Eric is extra pleased that Engineers were able to install a new misting system on the Poison Dart Frog exhibit.  The mist will keep humidity up which is critical for the frogs’ health and keeps the frogs visible and active during the day.

Busy Electricians:

Electricians were busy adding understory lighting to the second level of the Rainforest and installing  a mock up of a new design for overhead lighting. 

The new lighting when activated could dramatically reduce energy costs and improve light levels over the large trees to improve health.

To access overhead lights, Electrician Ross used the Sky Rider – a two person cart that runs on a track at the top of the Bolla.

Refresh of a Costa Rica Planted Wall:

One of the Costa Rica planted walls was completely overhauled.  This in itself was a two day process requiring the support of several volunteers.

Above is a ‘before’ picture of the wall.

First all the old plants and moss were removed.  Volunteer Celia separated old moss from living moss so living moss could be returned to the wall.

Here is a completely clean slate for the new wall.

Next we installed recycled styrofoam peanuts wrapped in shade cloth into the wall to provide drainage.  Styrofoam peanuts will not break down as the moss does, will provide aeration and drainage and reduce the need for moss which is a nonrenewable resource.

Next new moss was packed into the wall as volunteer Lois demonstrates here.

Finally the new wall was planted with a variety of orchids, ferns and bromeliads representing a small piece of the vast diversity of epiphytes living in the canopy of the Costa Rican rainforest.

Painting and Deep Cleaning

Meanwhile… the Operations crew was busy touching up railing paint,

cleaning exhibits,

deep cleaning the gallery

and performing regular maintenance on the elevators.

All and all it was a busy couple of days.  I hope you all enjoy the results!

Thanks Eric Hupperts and Laurie Kormos for all photos in this blog posting.

Photo by Kristen Natoli

Rainforest Biologists were very excited a few months back to discover a new fruit on the Cacao Tree (Theobroma cacao), the first fruit we have had on this tropical tree.  Originating in the Amazon headlands, Theobroma cacao is, of course, the source of one of our favorite foods, chocolate, which is made from the fermented and roasted seeds.

One of the most beautiful specimen plants in our collection, this tree has grown vigorously and flowered prolifically since it arrived but we were not sure we would ever see it fruit. 

Photo by Rachael Tom

Cacao trees typically don’t set fruit until they mature at about 5-10 years old.  Most Cacao trees are ‘self incompatible’ meaning they will recognize and reject their own pollen, preventing self pollination in order to maintain genetic diversity.   We were not sure our tree would ever fruit as it is the only plant of its kind in the exhibit. 

Photo by Rachael Tom 

 In the wild these trees are most often pollinated by midges in the Forcipomyia family.  As we do not have these insects in our exhibit our volunteer James has been patiently and diligently hand pollinating flowers each week. 

Photo by Kristen Natoli

Photo by Kristen Natoli

At last we have success.  Amazing to think these large 6-8″ long fruits are produced from one flower only 1/2” in size.  The Cacao Tree produces flowers right off the main trunk of the tree, an adaptation called cauliflory.  This adaptation, mainly seen in tropical trees, likely serves to hold the fruit closer to the ground where the seed disperser animals are most active.

Photo by Rachael Tom

Besides being delicious the Theobroma cacao is a particularly pretty tree exhibiting many adaptations unique to the tropics.   The new growth on our specimen is a rich burgundy color from the concentration of anthocyanins in the leaf tissue.  This adaptation is likely a means of protecting tender new leaves from the intense tropical sunlight at canopy and deterring insect feeding. The lower leaves are broad and thin to maximize capture of the limited light penetrating the understory.  The smooth surface and vertical drape of the leaves ending in a pointed ‘drip tip’ help shed water during heavy rains. 

Photo by Sarab Stewart

The seeds from our first fruit will be germinated to produce additional back up Theobroma plants as we are so pleased with how much the parent plant adds to the exhibit.

Photo by Brian Freiermuth                                  

Sometimes the rainforest aviculturists have to help to our resident tanager families.  The rainforest can be a challenging place for young birds and their parents.  When we find that tanager parents are unsuccessful at raising offspring on their own, we step in. 

Photo by Brian Freiermuth                                  

Pulling a chick and hand-rearing it off exhibit is a delicate and time-consuming process.  We are equipped with both incubators and brooders. 

  An incubator is used if an egg is pulled before its hatch date.  The incubator can retain the temperature and humidity needed for an embryo to develop.  Like a mother bird in the nest, it also gently rotates the egg periodically.

A brooder maintains the temperature and humidity that a recently hatched baby bird needs to thrive. 

Babies require frequent feeding.  Newly hatched tanager babies are fed 10 times per day.  Aviculturists feed the chicks a formula specific to the needs of nestlings. 

Photo by Brian Freiermuth                                  

When the babies reach a certain age, the aviculturists begin feeding them the same foods that the rest of the rainforest flock is fed.  At about two weeks of age the young birds are ready to leave the nest or ‘fledge’.  The aviculturists use this time to reunite the chicks with their parents before the family is put back into the rainforest exhibit.  This decreases the chance of parents considering the newly introduced chicks as a threat.  If the aviculturists feel that the parents will not accept the chicks, or that the chicks would be superfluous in the present population, homes will be found for them at another AZA accredited institution.  Institutions that house similar species often trade offspring in order to prevent inbreeding.

Hundreds of small, colorful and peaceful fishes call this tank home, including a brand new and quite rare species of ricefish, Daisy’s ricefish Oryzias woworae. The ricefishes are a family (Adrianichthyidae) of small fish that are found in fresh and brackish waters from India to Japan and out into the Indo-Australian Archipelago, most notably Sulawesi. The fact that many species are found in Japanese rice paddies gives this group of fishes its common name.

Named after Indonesian crustacean expert Daisy Wowor (who collected the fish), Daisy’s ricefish was collected from a freshwater stream on Muna Island, off the southeastern coast of Sulawesi in Indonesia in 2007 and was just described last year!

The Academy currently has about 30 of these rare fish on display in the rainforest. These beauties are about an inch long and can usually be seen schooling together. They can be identified by their remarkable color pattern of a steel blue body (in males), highlighted with brilliant red stripes on its abdomen, pectoral fins and caudal fins. They also have striking, iridescent blue eyes which are very visible against the slightly murky, sediment-laden water of the exhibit. Our specimens are doing wonderfully and, if you’re lucky, you might see a female carrying eggs attached to her body between the pelvic fins. This unusual method of spawning is thought by some to be an evolutionary precursor to internal fertilization and, even, livebearing.

Sulawesi is a unique center of global biodiversity that has very high numbers of species found nowhere else in the world. This is in part because it is tropical and made up of many islands and, in part, because of a complex geological history. In addition to countless endemic species of birds, mammals, reptiles, amphibians, invertebrates and marine fishes there are over 50 species of endemic freshwater fishes, including this one. It is a very poorly documented and understood ecosystem that remains critically threatened. Ricefishes as a group, and in particular this stunning new species, are fantastic icons to generate interest in and encourage conservation of the endemic freshwater biota of Sulawesi.

Come by the Academy and check them out!

Since the Academy reopened in Golden Gate Park, our Rainforest Exhibit has always had orbweaver spiders (Nephila clavipes)- it’s just that they were inside tanks. Recently, biologists have been gradually releasing individual spiders in key locations on the Costa Rica level of the exhibit. This allows visitors to witness the sheer magnitude of their webs which can be over a meter in diameter, and watch them capture prey throughout the day. Here is an informative video about our orbweavers previously filmed at the Academy with one of our biologists:

On almost any given day, our Rainforest Exhibit has roughly 200 butterflies that fly freely inside the exhibit. Occasionally these butterflies will fly into our orbweavers’ webs and become food, just as they would in the wild.

After being released, the orbweaver below is looking for a prime location to build its web:

If a spider decides to build its web a little too close to visitors, we simply relocate the spider so it can establish a web elsewhere. Oftentimes the spiders make their way to higher planters on their own.

Be sure to check out these beautiful spiders the next time you’re on the Costa Rica level of our Rainforest Exhibit. They might just be wrapping up freshly caught butterflies in their silk for a snack, eating their prey, building a new giant web or repairing their current one!

Of all the cichlids living inside the Flooded Forest, the Apistogramma eunotus is the smallest. These dwarf cichlids are one of the newest additions to this display. In order to increase their chance of survival in a tank full of predators, the Amazon Flooded Forest team released a large number of Apisto juveniles into the tank hoping that they would immediately seak cover.

The fish remained in hiding for several months while they grew and adapted to their new surroundings. These juveniles were bred in-house and when they numbered in the hundreds, it was time to experiment. Now, fully grown at around 3 inches, the feisty Apistos have secured territories in the nooks & crannies of the tank and have started to breed.

If you look closely around the complexities surrounding the tunnel, you may see a bright yellow female in brooding coloration leading her fry to forage. Even though she may only be an inch, she shows all the characteristics of being cichlid – she will defend her fry against the much larger inhabitants of the tank.

Amazon Exhibit forest floor.

Biologists Sarab Stewart and Horticulture Intern Patrick Carter took some samples of the soil in the Rainforest and Mangroves this week to send to a local lab for analysis.  The lab will send information back about the levels of nutrients in the soil and the overall condition of the soil along with recommendations for improvements.

Sarab collecting and bagging soil samples for the lab.

They use a use a soil probe to make sure the samples are deep enough to reflect the entire soil profile.   This is a good opportunity to look at soil moisture and see if we are watering correctly and check on the health of the roots systems.

Collecting deep soil samples.

Sarab uses the soil probe to check the soil moisture in the Costa Rica planters.

Healthy soils support lots life in addition to plant roots.  This earthworm is our main composter in this Costa Rica level planter.

 
Earthworm peeking out of the soil sample from Costa Rica planters.

Kristen Natoli, Assistant Curator is also sending some leaf samples of some of the larger specimen trees to the lab.  This way we can compare nutrients in the leaves to that of the soil and make sure the plants are getting everything they need. 

Kristen collects leaf samples from the Peach Palm (Bactris gasipaes).

 
Kristen collects leaf samples from the Mahogany tree (Swietenia mahagoni) while Vikki McCloskey puts out food for the birds.

The lab results will help us make decisions about how we provide nutrients to the plants from the diversity of methods we currently use, everything from the natural waste from our free flying birds and butterflies, mulch from excess Leaf Cutter Ant fungus, worm compost, bat guano, water soluble fertilizers and just letting the fallen leaves naturally decompose in the planters.

 
Patrick Carter adds worm compost to the planters in the Madagascar exhibit.

All this to make the Rainforest flourish!

Healthy Forest.

Female mantids often eat males after copulation.

• are interested in guys from South America who can co-parent might want to meet our Turquoise Tanager (Tangara mexicana).

Photo by Rachael Tom

Male tanagers help feed chicks and protect the nesting site.

• feel it’s always good to have a ‘spare’ might be interested in our Machete Savane snake (Chironius carinatus).

Photo by Brian Freiermuth

Snakes and lizards have a bi-lobed reproductive organ called the hemipene.

• don’t trust a guy with a wandering eye should avoid entanglements with our Panther chameleon (Furcifer pardalis).

Photo by Rachael Tom

Chameleon eyes are mounted on turrets that can move independently of each other.

• are suckers for sweet talk and don’t mind carrying extra baggage should visit our  Slipper orchid (Paphiopedilum transvaal).

Photo by Rachael Tom

The slipper-shaped pouch traps insects so they are forced to climb out collecting and depositing pollen that fertilizes the flower.

Photo by Brian Freiermuth

Amplexus is a form of pseudocopulation in which the male amphibian grasps the female with his front legs while fertilizing her eggs.

• prefer regurgitated fruit over a dozen roses might want to give our Blue and Gold macaw (Ara araruna) another look.

Photo by Rachael Tom

Parrots exchange food via regurgitation as part of a courtship ritual before breeding.

Among lizards, they are second in size only to the Komodo Dragon (Varanus komodoensis.) Reportedly, they can get up to 10 feet long, however they more commonly grow to 5-6 feet in length.

They are powerful hunters and their diet consists of just about anything they can catch and eat- birds, small mammals, fish, eggs, crustaceans, lizards, snakes, frogs, small crocodiles, turtles, carrion, etc. They are good climbers and may take to the trees to escape danger but will more readily escape into the water.

Our water monitor is the newest resident on the Borneo level of the rainforest exhibit. She came to us from a zoo in New Jeresy and has been settling in well. As she is very new to the exhibit, she does spend a fair amount of time hiding but can typically be seen basking in the late morning and early afternoon. Her diet here at the academy consists of mice, chicks and fish.
While most water monitors are greenish black with yellow to cream colored markings, she is completely black and patternless. It is a naturally occuring color pattern for this species, but not one that is commonly seen.

                                                                                                     Photo by Rachael Tom

Above: an adult Madagascar ghost mantid.  

These alien-looking insects hail from the island of Madagascar and other areas on the continent of Africa.  They sport projections off of their exoskeleton that offer an excellent camoflauge in the leaf litter and twiggy vegetation where they live out their short lives.

Like all mantids, P.  paradoxa are carnivorous, feeding stealthily on a wide variety of insect prey.  Here at the Academy they feed on crickets, soldier flies, fruit flies and silkworms.

The ghost mantid lifecycle begins in an ootheca or egg-case.  After mating, the adult female will lay 4-35 eggs in this ootheca.  She attaches the well camouflauged ootheca to a tree branch, rendering it virtually invisible amongst the forest foliage.

                                                                                                    Photo by Rachael Tom

Above: a cluster of ghost mantid egg cases layed on a branch.

After about a month the egg case hatches, releasing tiny baby mantids, also called nymphs.  The nymphs differ from adults not only in their small size, but they also lack wings.  The nymphs are independant and begin feeding almost immediately after hatching.  Since they are so tiny, we start our nymphs out by offering them fruit flies which are about the size of a pinhead.

                                                                                                    Photo by Rachael Tom

Above: A Biologist carefully moves a ghost mantid nymph.

As the mantids eat and grow  they will shed their exoskeleton.  This process is called molting.  In about three to six months the mantids will go through their final molt into adulthood.  It is at this stage that the mantids develop their wings.  The adult males possess longer and more well developed wings than the females.  It is thought that this allows the males to disperse greater distances in order to find receptive females and begin the cycle all over again.