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!

So, for all the single ladies who:
• don’t like being inconvenienced by trite ‘pillow talk’ – take a page out of our  Ghost Mantid’s (Phyllocrania paradoxa) book and consume your partner post-amour.

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.

Of all the animals displayed in our Rainforest Exhibit, none convey a sense of other-wordliness quite like our Madagascar ghost mantids (Phyllocrania paradoxa).

                                                                                                     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.

Here at the California Academy of Sciences, we are lucky to be able to work with some pretty fascinating species. Recently there were two interesting news articles about some of these species.

The first article looks at how leaf-cutter ants coevolved with the fungus that they farm, and it turns out they utilize a bacteria as a pesticide to keep their crop intact. The researcher says leaf-cutter ants have been farming for 50 million years! Looks like they got just a little head-start on humans. Read the article HERE.

The other article looks at the snakes of Southeast Asia that have evolved the ability to glide in the canopy. One of the species they looked at is the paradise flying snake Chrysopelea paradisi , which you can find right here in the Borneo level in the rainforest at the Academy (see photo above). They have some pretty neat video. Read the article HERE.

Here’s a video of some of their research. I thought it was interesting how much of the snake hangs off the branch before it launches itself into the air.

Tis the season to celebrate a bountiful harvest. The rainforest biologists would like to give thanks that we are able to offer a wide variety of high quality food for the animals in our charge. This exhibit contains many different taxa that require many different food items. Here is a sample menu of what some of our rainforest inhabitants will be having for their Thanksgiving weekend….

Macaws
Their diet consists of fruit, nuts, seeds, pellet, and vegetables.

Neotropical Passerines
Their diet consists of fruit, seeds, vegetables, pellet, and protein items.

We use several feeder insect species, including the larvae stage of mealworms Tenebrio molitor, waxworms Galleria mellonella, and soldier fly Hermetia illucens

Reptiles
Carnivorous, herbivorous, or omnivorous; reptile diets are as diverse as the reptiles themselves. Some reptiles even eat other reptiles!

Below are some of the feeder rodents we utilize. We order these frozen from a company that raises them specifically for food and humanely euthanizes them. They are then thawed out over a 24 hour period and then warmed so that the heat-sensing reptiles find them deliciously attractive.

Amphibians
Not as diverse in their nutritional requirements as reptiles, most of our amphibians enjoy insects.

Below is the ubiquitous cricket Acheta domesticus, probably the most popular feeder insect. We feed out various stages, from newly hatched (called pinhead) to adults, like below.

Butterflies
Most butterflies are nectar eaters, though the owls and blue morphos like over ripe fruit as well. Here is a Heliconicus ismenius drinking nectar from one of the many nectar-producing plants in the rainforest. We also provide artificial nectar daily along with ripe fruit.

Fish
Fish eat almost everything that is dropped into their tank!

Some of the frozen fish we feed to our collection fish and other creatures at the Academy: capelin Mallotus villosus, herring Clupea spp, and trout Oncorhynchus mykiss.

It takes quite a bit of research and time to create diets that fulfill so many varied nutritional requirements for our hugely diverse live animal collection. Below you can see one of our paradise tanagers Tangara chilensis next to its diet. Enjoy your Thanksgiving everyone!

But true… like any planted exhibit or landscape our Rainforest exhibit has its share of unwanted pests. Horticulture biologists have become very creative in figuring out ways to prevent these pests (mostly insects) from damaging our plants without causing harm to the other animals living in our forest like the butterflies, Amazon fish and birds.

Lucky for us the Rainforest isn’t just a collection of pretty plants, it’s also a complex living system that we can use to our advantage. Of course the best pest prevention is to grow healthy plants. Every day we give lots of attention to all our plants, big and small, to keep them as healthy as possible and catch health problems early on.

Healthy plants are able to resist pests which reduces pest damage to the plants and slows down the growth of the pest population. When we see pests on the plants in our exhibit we first check to see what might be stressing the plant, making it susceptible to pests.

We also rely on the animals in the exhibit to help us out. We have naturally occurring spiders living in our forest that trap our pests and birds that will pick an insect snack off the plants now and then.

Of course we don’t want to use a lot of pesticide chemicals in the Rainforest that may harm our animals or our visitors so we rely on other strategies to control pests. What’s our favorite tool for pest control? WATER! Hosing pests off of plants is often as effective, if not more effective, than pesticides. Luckily we have volunteers to help us with the task.

In a real tropical rainforest, plants benefit from a diversity of naturally occurring predators and parasitoids that feed on insects in the forest and help keep them in check. We don’t have quite enough diversity of natural predators in our forest to manage our different pests so we have released our own beneficial insects to help keep pests under control.

Two of our most common pests, scale and mealybug are successfully controlled by our beneficial insects. Scale is a tiny (~1/4″) insect that pierces the plant with a straw like mouth parts. We have controlled scale using a tiny, non-stinging, parasitic wasp. We can tell that the highly magnified scale in the photo below was parasitized because of the perfectly round exit hole where the adult wasp emerged.

The mealybug in the photo below was parasitized too. The adult wasp popped the top off the mealybug when it emerged, like popping a lid off a can.

Mealybug, also feeds on plant sap through its straw-like mouth parts and is under attack from a few predators in our rainforest. The pink/orange pupa to the right in the photo below is the midge Aphidioletes aphidmyza, which was released to control aphids and decided to expand its diet.

And… we release the well named ‘Mealybug destroyer’ beetle Cryptolaemus montrouzieri which feeds voraciously on this pest.

All in all, our goal is to have an attractive exhibit with healthy plants and animals. We don’t mind having a few pests around as long as they don’t get in the way!

Last fall our orb weaver spider (Nephila clavipes) on the Costa Rica level of the rainforest laid several egg cases. And recently one of the egg cases hatched with approximately 800 offspring! They’re tough to photograph, but below is a picture of a group of the hatchlings at a couple days old:

Orb weavers in the Americas have an interesting natural history. They range from southeast United States (North Carolina to Texas) through Central America into the warmer parts of South America. In the U.S. they are a seasonal species, hatching from previously laid egg cases in April/May and then dying after they reproduce in Oct/Nov. In more tropical climes, they typically live 2-3 years. Here is a photo of an adult taken near Puerto Viejo de Sarapiqui, Costa Rica:

With a body length of two inches and ~4 inches with their legs, these are good sized spiders. They have extremely strong silk with a tensile strength six times that of steel! There are species of Nephila throughout the world’s tropical areas. Come visit our 800 baby orb weaver spiders next time you are at the Academy. They can be seen on the third (Costa Rica) level hiding out in the terrarium accross from the elevator doors. Here’s what one of the little cuties looked like on Thursday the 22nd of April:

Look closely into the leafcutter ant mound and you will see many ants of varying sizes working within their fungus garden. Leafcutter ants have evolved a system of farming in which they grow fungus, their sole food source. Each ant has a job which is dictated by its size. There are foragers who venture out of the nest to cut leaves and bring them back. From there, another set of ants of a different size takes over, chewing up the leaves and using it as a substrate for the fungus to grow on. There are smaller ants that act as nursemaids and take care of the brood and keep house. They also help protect their co-workers from phorid flies, who will parasitize the ant when she has her mandibles full. The smaller ant rides on the cut leaf a forager is bringing back to the nest and fights off this fly. You can see it below.

Larger ants, the soldiers, defend the colony and keep everyone safe, although smaller ants will attack invaders as well. There is one queen ant, and she is the largest of them all, about 1 inch in length. Her sole purpose is to lay eggs and produce more workers. She is very well taken care of by her daughters who feed her and groom her regularly.

All the ants in the colony are female; they are all sisters working together, and they can not reproduce. In their natural habitat, once a year, the queen will produce males and virgin queens. These are about the same size as the queen, but they have wings. They then leave the nest to go mate with others from different colonies. The virgin queens take a small piece of fungus with them and after mating, the fertilized females fly off to start their own colonies.

Here in our exhibit in the rainforest, the queen has produced males and virgin queens! We are very excited to see winged ants in our colony as it suggests the colony is productive and healthy. We don’t expect to see more than a few produced but they are quite visible in the fungus chambers as these ants are substantially larger than worker ants. Unfortunately, they will not get to fly away, as they are contained within the mound.

Those of us that work with animals and plants on a daily basis often take our vacations where we can see even more animals and plants! Recently I had the opportunity to travel to one of the regions exhibited in our rainforest here at the Academy- the island of Borneo. There I witnessed first hand the world’s oldest tropical forests and the island’s amazing biodiversity. Below is a photo of Mulu National Park.

Borneo is the world’s third largest island and is divided politically between Indonesia (73%), Malaysia (26%), and Brunei (1%). We explored the Malaysian sections of the island. First, I met my friends in Singapore where we spent some time adjusting to the 13 hour time difference. From there we traveled to Kuching, Sarawak state, then made our way east across the island, ending in Danum Valley, Sabah state. Below is one of the emergent trees in Danum Valley.

We were led by talented author Eric Hansen, along with biologist Ch’ien Lee, and botanist Anthony Lamb. Borneo has a rich history and great cultural diversity in addition to its unique ecology. And we saw some pretty cool stuff…including this pitcher plant Nepenthes bicalcarata . We have the same species growing in our rainforest here at the Academy- look for them growing on the wall on the Borneo level.

Borneo has some pretty fascinating insects, including this rhinocerous beetle and millipede:

At one point we found a Little Spiderhunter Arachnothera longirostra that had flown into glass and stunned itself. We gave it some fluids and a quiet spot in the shade to recover. Spiderhunters are the Bornean equilvalent of the honeycreepers Cyanerpes spp that can be seen in the neotropics and in our rainforest exhibit.

We even found a land planaria, sometimes called hammerhead leech. Remember those planaria from 7th grade biology class? This is what they look like in Borneo!!

And of course, no trip to the tropics would be complete without some sort of habituated monkey that’s causing trouble. In this case, long-tailed macaques Macaca fascicularis, sometimes called crab-eating macaques, were the smart ones that kept an eye on unattended bags, waiting for the chance to thieve some treats.

The reality is that most of what we saw was in protected areas such as national parks or conservation areas. Land that is not protected is being “developed,” mostly into oil palm plantations. It is a very complex issue compounded by the fact that Borneo has some very unique and charismatic species along with the need to provide jobs and infastructure for its people.

Monocultures of oil palm have extremely reduced species diversity (12 bird species compared to 220+ in lowland primary forest). Palm oil is used in a variety of products, from processed foods to soaps and shampoos. The effect of oil palm plantations on habitat in Borneo is one we as consumers can shape, by using our purchasing power to support sustainably grown palm oil.

For more info, check out fellow AZA member Cheyenne Mountain Zoo’s palm oil resource site or GreenPalm, a certification program designed to address the social and environmental issues surrounding palm oil production.