Category Archives: invertebrates

Bwindi’s Flying Jewels

Bwindi Impenetrable National Park is believed to hold the richest fauna community in East Africa, due in part to its provision of an extensive lowland-montane forest continuum (Afromontane forest is recognized as the rarest vegetation type in Africa) and exceptional species diversity, including many Albertine Rift endemics and 9 globally threatened species.

The park is also an ideal habitat for a wide variety of rare and endemic butterfly and moth species. At least 310 species of butterflies (Davenport 1995) have found home here and one can identify 50 species on a walk through the forest in a day. Eight of these are Albertine Rift endemics and yet 3 of these have only been sighted in Bwindi (or utmost the nearby forest in Congo). The three are Papilio leucotaenia, Graphium gudenusi and Charaxes fournierae.

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Numerous studies from ITFC’s two decades of existence have clearly brought out the fact that these delicate creatures are in fact highly specialized and each species has a range and unique flight pattern. Caterpillars belonging to different species feed on a diversity of plant species and more often specialize on the plant parts they eat, e.g. young or old leaves.

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Butterflies and moths are some of the most fascinating and eye catching flying insects in the world. A vast majority is brightly colored and is found all over the world, except in the Antarctica region. They are indeed one of the planet’s most beautiful creatures. People from all walks of life, irrespective of race, color or religion enjoy these beautiful winged flying jewels for their delicate beauty. Uganda has about 1200 butterfly species mostly found associated with tropical rainforests.

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The word butterfly has curious origins. Butterflies get their name from the yellow brimstone butterfly of Europe that is first seen in the early spring or “butter” season? The Anglo- Saxons used the word BUTTERFLOEGE because their most common butterfly was the yellow brimstone butterfly.

The Russians call them BABOCHKA, meaning little soul. Ancient civilizations have depicted butterflies as little angels or souls, such that when people die, their souls go to heaven as butterflies. The importance of butterflies in many early civilizations is recorded in prehistoric caves and their depiction in pottery and fresco paintings. The best known example is the representation of the goddess Xochiquetzal in the form of a two tailed swallow tailed butterfly. In all, irrespective of age, people from all walks of life associate butterflies as friendly and soothing to the eyes, mind. body and soul.

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Biologists estimate that worldwide there are about 150,000 different species of butterflies and moths, in which approximately 30,000 belong to the butterfly species. The sizes of a few species of butterflies range from less than an inch in size to a wing span of about 10 inches. The smallest species are no bigger than a fingernail and the largest swallowtails are larger than the smallest birds.

The world’s tiniest known species, the blue pygmy (Brephidium exilis), is found in Southern California and has a wing span of just over half an inch. Both the world’s smallest butterflies occur in peninsular India. The largest species, the New Guineas Queen Alexandria’s birdwing (Ornithoptera alexandrae) can measure up to twelve inches from wingtip to wingtip.

Butterflies provide aesthetic appeal and are connected with all plants and crops at all stages of their life cycle. Few are aware of the crucial role the butterfly plays in pollination of a large portion of economically important crops and flowering plants, which is second only to the honeybee. They pollinate about 75 per cent of staple crops in the world and 80 per cent of all flowering plants. The economic value of pollination is about $ 200 billion. Scientific studies have proved beyond doubt that pollinators account for 12% of the value of world wide agricultural production.

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BENEFICIAL ASPECTS OF BUTTERFLIES

Butterflies are categorized as keystone species, which enable many smaller species of insects to thrive and reproduce in an ecosystem. In simple terms, it denotes that conservation of butterflies also conserves other species of insects. In fact, the basic health of our ecosystem is directly dependent on the number of butterfly species.

  • Butterflies act as indicators in monitoring environmental health.
  • Play an important role in food chains and food webs.
  • Excellent pollinators
  • Bio control of weeds
  • Butterflies are very sensitive to pollution and have been used as bioindicators to detect the pollution levels.

FACTS

  • The fact of the matter is that most butterfly species have an average lifespan ranging from 20 to 40 days. A few species may live up to nine months.
  • Butterflies are found world wide except on the continent of Antarctica.
  • Butterflies can only see the colors red, green and yellow.
  • Most butterfly species are dark colored because they need to absorb heat from the surrounding environment.DSC01770
  • Caterpillars spend most of their time eating leaves using strong mandibles (jaws). A caterpillar’s first meal however is its own eggshell. A few caterpillars are meat-eaters – e.g. the larva of the carnivorous Harvester butterfly eats woolly aphids.DSC09309
  • Butterflies do not have any chewing mouth parts. They are gifted with a tubular straw like appendage known as proboscis which enables them to sip nectar. Butterflies “smell” with their antennae and taste with their feet.
  • Butterflies are one of the few creatures on earth that can orient themselves both in latitude and longitude
  • Male butterflies attract females by releasing pheromone chemicals (scent) from their abdomen.
  • Butterflies and moths are picky in choosing leaves for egg laying.
  • Butterflies and moths are picky in choosing leaves for their diet.
  • When folded, a butterfly’s wings are usually much less colorful, providing instant camouflage from would-be predators.

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  • The earliest butterfly fossils are from the early Cretaceous period, about 130 million years ago. Their development is closely linked to the evolution of flowering plants (angiosperms)
  • Butterflies are the only insect that has scales. Butterfly scales contains pigment, which in combination with light refraction gives butterflies their colors.

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Moth master of camouflage – Bwindi, Uganda. 2,250m

Moth master of camouflage – Bwindi, Uganda. 2,250m

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CONCLUSION

Butterflies play a critical ecological role and should therefore better protected and managed. There is mounting concern regarding the devastating losses of butterfly colonies because of unprecedented habitat destruction. This is the single greatest threat to butterflies. The rate of deforestation is accelerating and is already higher in the tropics compared to other parts of the world. Let us begin with the smallest steps by planting flowering plants in our backyards and help native butterflies survive. In schools we need to encourage gardening and so also in public places with green all round. Schools and colleges should conduct training programmes and guided field trips, so that students learn firsthand the wild behavior of these beautiful winged jewels. School children from the primary level should be taught about butterflies and the vital role they play in different aspects of human life. Awareness at all levels will definitely help these winged jewels survive and coexist in a world dominated by humans.

Ivan

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REFERENCES:

T. Davenport, P. Howard and R. Mathews Bwindi Impenetrable National Park Biodiversity Report

http://www.foremostbutterflies.com/learn_about_butterflies/butterfly_habitat.htm

http://www.ineedcoffee.com/09/butterfly/?page=all

http://www.fs.fed.us/monarchbutterfly/resources.shtml

http://www.nerdybirders.com/html/butterflies/butterflies.htmlhttp://butterflywebsite.com/conservation.cfm

http://www.defenders.org/wildlife_and_habitat/wildlife/butterflies.php

http://www.defenders.org/wildlife_and_habitat/habitat/forest.php

http://en.butterflycorner.net/Home.home.0.html

http://butterflywebsite.com/conservation.cfm

http://www.butterflyworld.com/start.html

http://www.defenders.org/wildlife_and_habitat/wildlife/butterflies.php

http://www.defenders.org/wildlife_and_habitat/habitat/forest.php

http://en.butterflycorner.net/Home.home.0.html

http://www.butterflyworld.com/start.html

Stealthy Spiders have Stood the Test of Time

The sight of cobweb layers over one of our institute’s car windscreen drew me into memories of one old tale as told by my grandfather.

King Robert the Bruce I was born at Lochmaben Castle in 1274. He was Knight and Overlord of Annandale. In 1306 he was crowned King of Scotland and henceforth tried to free Scotland from the English enemy.  After being defeated at a battle, Bruce escaped and found a hideout in a cave. Hiding in a cave for three months, Bruce was at the lowest point in his life. He thought about leaving the country and never returning.

While waiting, he watched a spider building a web in the cave’s entrance. The spider repeatedly fell down yet finally it succeeded in building its web. So Bruce decided also to retry his fight and told his men: “If at first you don’t succeed, try, try and try again.”

Days later, while studying in our library, I came across a report by Charles E. Griswold on the distribution of afromontane spider families in Bwindi and then another small but fascinating book- Spiders and Their Kin by Herbert W. Levi. What I found out almost blew me away! Let me share with you some of the interesting facts from my findings.

Spiders are remarkable. They have been on our planet for 400 million years. The story of how 40,000 species of spiders inhabit our Earth is intriguing. Spiders are found almost everywhere – from the Arctic islands to dry deserts; from the tops of tropical mountains to the valley bottoms of temperate forests.

All spiders have the ability to produce silk (photo taken from Ruhija - Bwindi)

All spiders have the ability to produce silk (photo taken from Ruhija - Bwindi)

Uganda has four endemic spider species: ant-mimicking jumping spider Ugandinella formicula, another jumping spider Mikrus ugandensis, the pholcid spiders Quamtana kitahurira and Buitinga griswoldi. The blood-hungry spider, Evarcha culicivora, is found only around Lake Victoria in Kenya and Uganda. This species usually hunts insects on tree trunks and buildings by stalking its prey rather than trapping it in a web.

Some people are arachnophobic (loath spiders). Perhaps it’s because they are extremely hairy and reports of them being poisonous. Spiders use their hair as a defense mechanism by brushing off clouds of abdominal hair with their hind legs. Each hair is covered by hundreds of microscopic hooks that cause severe itching when they come into contact with skin.

The majority of spider bites are much less dangerous to humankind than poisonous stings of bees, wasps and hornets. Their poison is designed to paralyze prey – mainly insects. Defensive bites against large animals including humans, are only secondary. Out of the over 40,000 known species, only about 200 are known to have serious, potentially lethal bites to humans.

Some spiders can go up to 200 days without food. Most spiders are active during the night and depend upon touch and smell to assist them in finding a mate and recognizing prey and predators. Over 1,000 hairs on the front set of legs are very sensitive to chemical odors.

All spiders have the ability to produce silk. Spider silk is awesome. It is said to be stronger than bone, tendon or cellulose (wood). Only steel – smelted iron-ore is stronger. This is because the silk is made up of multiple proteins and water, which gives it incredible elasticity.

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Spider webs, stronger than bone?

Spiders are extraordinary engineers. In just a half-hour at night, with the sense of touch rather than sight, they are able to spin 20 meters of silk web.

Spiders are worthy of our admiration; they have stood the test of time on our blue planet.  Maybe conservation for spiders and other neglected animals (remember Douglas’s blog?)  is not such a crazy idea.

Will you think twice before swatting a spider in your home next time?!

Stay tuned, I have high hopes for spider silk prospects in the near future…

Ivan

Save the shaggy rat! The challenge of conserving neglected animals

Protected areas in SW Uganda include significant populations of several globally threatened animals. While mountain gorillas, elephants and chimpanzees have received a lot of attention, many smaller animals in the region remain poorly known and neglected.

The last few weeks we have been putting together a proposal to address conservation of neglected species with a particular focus on local wetlands. There are quite a number of these animals in the IUCN red list that identifies vulnerable and endangered species: 5 amphibians, 11 small mammals and 4 birds. The list would be longer if we included endangered reptiles, fish and invertebrates. We also excluded several other frogs, mammals and birds about which we know too little to say if they are endangered or not (e.g. Bwindi’s new Boubou bird discovered last year). So our 20 species, though neglected, are not the most neglected animals — we don’t even have names for most of the forest’s insects, spiders and other invertebrates.

Bwindi Impenetrable National Park, Uganda. Good mountain gorilla habitat, but also home to many less charismatic animals, also in need of conservation

The majority of these species specialise on wetland habitats for some or all of their lives. Their persistence depends on maintaining particular wetlands within the wider landscapes they inhabit. These restricted habitats are threatened by a range of factors – both within and outside of protected areas. To safeguard these key locations and their endangered species we need to identify them and ensure that they are managed against both immediate and long-term threats.  That is the focus of the proposal we were developing.  But neglected species are not easily promoted.

Bwindi mouse – hard to sell as a conservation concern?

An unnamed Bwindi frog — easier to like?

Bwindi spider — if this was an endangered species would anyone care enough to try and save it?

Why have these species been neglected? Well, they are hard to see and don’t have the obvious charisma of the gorillas, chimps and elephants. I suspect that their names are also a problem — how many people are willing to visit the forest to see an animal called a “rat” even if it is the “Montane shaggy rat”, the ” Medium tailed Brush-furred Rat” or “Kemp’s Thicket Rat”? It’d be even harder with snakes and spiders. Not sure how we can change that. At least the birds and frogs are pretty.

Here is our list of the smaller species of immediate conservation concern, scientific name, common name and they the  IUCN red list category — limited here to only Vulnerable (VU) and Endangered (EN). All these species have been reported in the region (Bwindi Impenetrable National Park, Mgahinga Gorilla National Park, Echuya Forest Reserve and perhaps in some of the surrounding wetlands).  It’d be nice to have pictures for you but (aside from the birds) we dont have any …

Amphibians

1.        Afrixalus orophilus , Western Rift leaf-folding frog , VU

2.        Hyperolius castaneus, Ahl’s reed frog , VU

3.        Hyperolius discodactylus [= H. alticola], none, VU

4.        Hyperolius frontalis , none, VU

5.        Phrynobatrachus versicolor, none, VU

Mammals

1.        Delanymys brooksi, Delany’s swamp mouse, VU

2.        Lophuromys rahmi, Rahm’s brush-furred rat, EN

3.        Lophuromys medicaudatus , Medium tailed brush-furred rat, VU

4.        Praomys degraaffi , De Graaff’s praomys, VU

5.        Thamnomys kempi [=T. major] , Kemp’s thicket rat, VU

6.        Crocidura stenocephala, Kahuzi swamp shrew, Narrow-headed shrew, EN

7.        Crocidura tarella, Tarella or Uganda shrew, EN

8.        Dasymys montanus, Montane shaggy rat, EN

9.        Myosorex blarina , Montane mouse shrew, EN

10.     Ruwenzorisorex suncoides, Ruwenzori shrew, VU

11.     Sylvisorex lunaris, Moon shrew, VU

Birds

1.        Bradypterus graueri, Grauer’s swamp/Rush warbler , EN

2.        Cryptospiza shelleyi, Shelley’s crimson-wing, VU

3.        Muscicapa lendu [=M. Itombwensis], Chapin’s flycatcher, VU

4.        Pseudocalyptomena graueri, African green broadbill/Grauer’s broadbill, VU

So what do you think? Should we care about the rats and shrews and the spiders too? Let us know if you have any ideas how the plight of these animals might be better marketed to the World!

Best wishes

Douglas

Trees, bees and elephants – the well connected forest

Ecologists sometimes like to ramble on about how everything is connected. Perhaps you know what I mean already. Ecology is all about connections.

Let me give you a taste now that I have finally taken some reasonable photographs for illustration (earlier ones were too blurry to share). I’m the rambling ecologist and the connections are a small sample of those here in the Bwindi Impenetrable Forest World Heritage Site. The story takes us from elephants to bees and beyond via a tree ….

Elephants eat a lot of plant material every day. For elephants living in a tropical forest there are lots of plants to choose from. Some they seek out and others they avoid. These choices have their own implications.

There are a couple of big Symphonia globulifera trees that we often pass on one of the main trails in the forest below ITFC. Sometimes the trees drop their bright red flowers on the path encouraging us to look up into the branches. They’re tall trees.

It is a wet valley bottom with a mix of open vegetation and scattered trees. Elephants come here. We see their footprints in the mud.

One of Bwindi’s Symphonia globulifera trees. The lower bark has been removed by elephants.

Elephant damage on one of Bwindi’s Symphonia globulifera trees — see the small blob of yellow gum on the left edge!

These tree have been repeatedly tusked by elephants. The bark has been deeply gouged and has come away in large irregular patches. Presumably the elephants are eating the bark or the wet tissue beneath. It is no chance thing anyway — they come back and do it again and again. But somehow the trees are still alive.

Some of the trees’ wounds remain fresh. They exude drops of a vivid yellow gummy liquid — it looks bright like yellow paint. It is sticky to the touch and has no obvious smell to me. This is the trees’ way to protect itself from infections and opportunists like wood boring beetles. The gum seals the raw wounds.

Looking closely we can see that this yellow gum is visited by small busy insects. These are wild stingless bees about 4-5 mm long. They make their honey in nests in the forest (inside hollow trees and in old animal burrows).

The bees are carefully collecting the yellow gum and gathering it into balls on their back legs. Apparently (I’m told by a bee expert) they collect this as material with which to plaster the inside of their nests. Presumably the gum has useful structural and/or antibiotic properties that the bees value. They certainly spend a lot of time collecting it — they don’t hurry but slowly prod, poke and gather. It is a hazardous task dealing with this glue-like substance: one false step and they’ll be stuck forever to the tree.

Stingless bees collecting Symphonia gum in Bwindi 1

Stingless bee collecting Symphonia gum in Bwindi 2 – macro is not great but you get the idea

Stingless bees gather Symphonia gum 3

So the elephant damages the trees, the trees bleed and thus provide the bees with what they need to make their nests, and the bees make their honey.

You might also ask what other plants the elephants eat, and what other species that impacts. We could consider the  various other species that depend on the Symphonia trees and the species that the trees depend on: the birds which pollinate their red flowers perhaps, as well as the fungi and soil microbes these trees require for their roots to gather nutrients from the soil. We could also consider the stingless bees and their role in keeping the forest working: the flowers they visit and the plants that depend on them for their pollination or the animals that eat their honey. I’ve heard that the chimpanzees in the forest are very partial to this honey … I’ve also heard that the Mountain gorillas may eat it (others dispute this … it has never been reported by our local gorilla researchers).

In the old days the honey of the stingless bees used to be collected by the local Batwa pygmies (forest living people), and people of course used to hunt the elephants for ivory … so humans were pulling at both ends of the thread in this ecological tapestry. Perhaps we can remain connected by our knowledge and understanding. We are all part of the network.  But now I’m rambling on …

Best wishes

Douglas

Celebrating the small things 2: and naming names

I have mentioned before how living here in the Bwindi Impenetrable National Park we get to appreciate the many thousands of species that occur here.  Its about much more than just our famous Mountain Gorillas.  Even the insects and other invertebrates deserve more attention. We know little about most. It is difficult to even name them.

I know that it’d be hard to develop a popular conservation project to protect slugs and stick insects. Perhaps butterflies are easier. Anyway, see what you think.

Here are a few recent pictures. Perhaps you can help us name some of them?

Moth master of camouflage – Bwindi, Uganda. 2,250m.

Unnamed butterfly — we’d never seen this blue type before until it flew into the house. Does anyone know what it is? Charaxes? From Bwindi 2,300 m.

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Another champion of camouflage. I almost stood on this stick insect. Here it plays dead-stick in my hand. The two front legs are pressed together toward my thumb — so despite appearences it has 6 not 4 legs.

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In Bwindi even the slugs can be remarkable. An odd pale species feeds on lichen at 2,300m.

Best wishes

Douglas