The Year of the Beard

The year of the beard

Ok, ok, so I have had a beard continuously for years. However, I have not trimmed my beard in a year to the day (September 29, 2010-September 29, 2011), and thus it was certainly a year of an ever-thickening beard. Here are some of places and things this beard has been and done...

Battery Park, September 29, 2011, last night living in New York City and the
last day I trimmed the beard, as I had an interview for my current position
the next day

November 14, 2010 Lincoln Park Zoo, Chicago
studying African birds

I tried trimming it in college with scissors and after one time, I bought an electric trimmer. I intended to trim my beard with little scissors that I brought to Rwanda. I did not bring my trimmer as I thought electricity may only be available irregularly, and I did not have that much space to bring extraneous things. In fact, the only electric items Michele and I brought were our netbook computer and camera battery charger.

December 9, 2010, as the sun sets, flying south over the Sudan
to arrive later in Rwanda

January 9, 2011 at Lake Muhazi, Rwanda, on Michele's first camping trip.
She woke me up in the middle of the night, just convinced there were
crocodiles surrounding our tent. Wouldn't that have been
an awesome picture? (this one taken by Amy Price)

February 11, 2011 at Agahozo-Shalom Youth Village, combing the top
of our hill for birds. I have seen about 130 bird species on this one hill.

The response locally to my beard is suggesting that I look like Jesus. I got it at first at Agahozo, but I still get it any time I am outside the village, even in the local marketplace. People call out at me "Jesus, Jesus!" One man even told Michele that he loved me and prayed to me. In Uganda, I got called Jesus mostly but was also called a notorious villain (OBL). It was interesting to be called one of the most revered bearded men and then one of the most hated. Beard is in the eye of the beholder?

March 21, 2011, keeping bees at Agahozo-Shalom Youth Village

When people ask why I don't shave, I tell them the beard protects my face from sun and from bugs. I am not kidding. In fact, in June, I was followed by a few bees back from the hives. As I was taking off my suit, a bee started dive bombing at my face, but it got caught in my beard and I did not get stung. Beard 1, bees 0.

April 29, 2011, standing on top of a kopje (hill), overlooking the Serengeti
in Tanzania

May 26, 2011, at Agahozo-Shalom Youth Village, with carpentry students.
We built 11 shelves, 5 benches, and a projector stand that first term.
(photo by a student)

June 25, 2011, planting a native acacia tree with Agahozo-Shalom's
head landscaper, for Environment Day in Rwanda (photo by a student)

The beard does not get itchy. The itchy stage of a beard, at least for me, is in the first few weeks after shaving. I haven't known that feeling in a long time. I do trim my mustache because it can get oppressively thick (and hinder the eating of food).

July 2, 2011, tracking chimpanzees in Nyungwe
Forest in Rwanda

August 13, 2011 in Uganda at Murchison Falls on the Nile river

September 18, 2011, Lake Gisenyi, Rwanda. It is a rare occasion to meet
someone in Rwanda with a beard.

I expected the beard to get longer and longer. This is only partially true. As with all hair, some of it falls out and other strands break. While some of the beard is very long, the overall beard got quite dense. I would actually compare it to a rain forest. There are the longest, oldest hairs that stick out (emergent layer). There are the vast majority of hairs that are long but blend into a large canopy of beard. There is the under story where hairs are growing back to replace ones lost and that are not really observable. And then there is the forest floor, my skin and the baby hairs, which have not seen the light of day in some time. Fortunately, this forest on my face has no animals, but I wouldn't be opposed to housing some little birds, a la Peter Griffin. 

September 27, 2011, Agahozo-Shalom Youth Village, Rwanda. Once a week
for the past year I coached an introductory basketball program for
first year boys (9th grade). I focus on teaching them to master fundamentals
like shooting, passing, and dribbling. There is no "fearing the beard" on
this court; within a couple months, my students school me handily. 

Thanks for reading! BEard well!

Alien invasion!

Flowers of Lantana camara. Look closely- each one of those blooms is
a small flower on a bigger 'head.' Each head can have up to 20 flowers.

I have met the enemy, and its name is Lantana.

Lantana camara is a plant species originally from Central and northern South America. Sixty years ago this beautiful plant was still in its native range, but it was taken to Europe as an ornamental. People then took it around the world, and now sixty countries or major islands are grappling with its effects on their ecosystems.

Lantana thick and tall in Agahozo-Shalom Nature Park, 7:30 am one morning.
You can barely make out the tree inside.

Lantana is all over East Africa (Kenya, Tanzania, Uganda, Rwanda, Burundi). On our hillside in Rwanda, outside of landscaped and cultivated areas, Lantana is the dominant plant. You pass it on the way to the dining hall and school, you sit near it in the amphitheater, and you see it in Parike W’Agahozo (Agahozo-Shalom Nature Park). In the park especially, where we are promoting the growth of native species, Lantana is a major problem; it is a non-native (alien), invasive species.

The same view of the tree as above five hours later with Lantana removed.
There is still more to remove from the back and sides, and several stumps
still need  to be removed. Clearing Lantana from this tree was particularly
tricky because there are swarms of honeybees that live in it!

Most non-native plants do not cause problems. Generally plants are adapted to a certain climate, soil type, variety of pollinators, and other environmental factors and thus do not succeed outside of their established range. Some plants are extremely tolerant of different conditions. It is these plants that can become problematic when they are introduced to new areas. They can have devastating consequences when other plants, animals, bacteria, and all the forms of biodiversity are not adapted to such a new factor. Lantana outcompetes the local plants and quickly forms a dense monoculture of Lantana. Any associated animals must either move on from their former habitat or adapt to living with Lantana.

The small shark-tooth shaped thorns that can make removing Lantana
tough on the hands, arms, and any other part of the body they scratch.

To understand Lantana’s imposing grasp on the landscape, we need to examine its biology. Lantana is a flowering plant that produces fruits. These small berries are eaten by birds (other animals) and are spread through their feces. This takes Lantana far and wide across the landscape.

Lantana fruits

Once the seeds germinate, they grow quickly. In just its second growing season, Lantana can produce flowers. The flowers are very small, but grow on heads that can contain twenty flowers per head. A mature plant “flowers prolifically” and can produce 12,000 seeds annually.

I counted 87 flower heads (assuming just 10 flowers per head, that is 870
flowers). Each one of these flowers may produce a fruit. Now, try to count
the heads that have already fruited. You get the picture.

In addition to its reproductive attributes, Lantana grows quickly and shades out all other species in an area. In shaded areas, their shoots grow tall and sprout leaves above the cover. They can grow thick stems that lean on trees and within just a couple years, they can completely shade out a 3 meter tree. Taller trees in a dense forest may prevent Lantana growth, but in an area that is being reforested like Parike W’Agahozo, Lantana will plague native regrowth until the trees are tall enough to shade it out.

Lantana regrowth, just two months after we cut away the rest of the plant.
Because of its ability to regrow quickly, we have to remove the roots.

It is difficult to estimate how much Lantana is in the 1.7 hectares of Parike W’Agahozo. Mature plants might be easy to count, but many younger plants have small stems and number in the 1000s. Young plants that have sprouted in the past year number in the tens or hundreds of thousands.

A student uses a saw to cut Lantana.

Upon realizing the depth of the problem, it became apparent to me that without mitigation, the park would become a protected place of Lantana, a stronghold for it to continue its spread. In order to plant native trees and to conserve the native species we already have, we had to get rid of the Lantana.

Students removing the roots of Lantana.

But is not as easy as cutting it down. Lantana can grow back from any part of itself. We have to remove the roots to fully disrupt Lantana regrowth. Agahozo-Shalom students participate in removing Lantana from the park each Saturday. Our tools include hand saws, pruners, hoes, pitchforks, and gloves. We have removed maybe half the Lantana in the park, but we have a long way to go.

Students participate in Lantana removal each week.

Looking back on my photographs of birds at ASYV, it is telling that a large number of them are on Lantana branches. I do not believe we can fully remove Lantana from East Africa. What we can do is find the places that need protection the most, like parks and Important Bird Areas, and make sure that Lantana does not invade them. We also need to educate people outside these areas to certainly not plant Lantana, but also to remove it and favor other plants so we can reduce its spread.

In the much bigger picture, we cannot blame the plant. We brought this plant here. We transport invasive species all over the planet. Everyone in every environment can promote native species and help stop the spread of non-native, invasive species.

Works Consulted

• "Invasive Species in Eastern Africa: Proceedings of a workshop held at ICIPE, July 5-6, 1999." UNEP Convention on Biological Diversity. Accessed September 29, 2011 at http://www.cbd.int/doc/meetings/cop/cop-05/information/cop-05-inf-33-en.pdf
• Walton. C. "Lantana camara." Global Invasive Species Database. Accessed September 29, 2011. http://www.issg.org/database/species/ecology.asp?si=56&fr=1&sts=
• “Invasive Pest Fact Sheet: Lantana camara.” Asia-Pacific Forest Invasive Species Network. Accessed September 29, 2011. http://www.fao.org/forestry/13375-06ba52ce294a4e15f8264c42027052db0.pdf
• “Pest Plants- Lantana camara.” Rwanda’s the Eye Magazine. Accessed September 29, 2011. http://www.theeye.co.rw/pestplants.php.php

She spoke for trees and people: In Memory of Wangari Maathai

The world just lost one of its greatest environmentalists. Wangari Maathai, a Kenyan woman who started the Greenbelt Movement, died yesterday.

A snapshot of Greenbelt Movement's home page today

I never met Wangari Maathai, but she had a profound influence on my understanding of what I think this world needs and how we should go about doing it. She will be remembered and indeed, her work will live on if we continue to live better through environmental stewardship.

There is a lot out there on Maathai so I would prefer to focus on her impact on my life instead of reporting from other new sources about her achievements and life.

In 2004, I read in the MU Environmental Studies newsletter about how Maathai had just been awarded the Nobel Peace Prize for her work in helping reduce poverty and conflict by empowering women to plant trees. I was president of an organization called Sustain Mizzou at the time, and within the year we wrote into our mission statement about the interconnection of human welfare and the environment. I am not sure it was her direct influence, but she had gotten me thinking about how humans really benefit from ecosystems.

In my “last lesson” at PS/MS 15 in June 2010, after teaching science and math for three years in the Bronx, NY, I presented a series of four quotes to my 7^th graders. One quote was from Aldo Leopold, one from Chico Mendes, and two from Wangari Maathai. I asked the students to read them and then facilitated a discussion about what they thought the speakers meant and what it meant for us. The quotes were largely about the role of humans and especially about how youth have the power to stand up for what they believe and try to make the world a better place. It was a discussion that had no right or wrong answers but in their thoughtful interpretations and analysis, my students showed me they had been learning all along.

In May 2011, as the Agahozo-Shalom Youth Village Environment Club was about to start one of its main projects for the year, I printed a letter that Maathai wrote about the importance of planting African trees (and not just fast-growing Australian eucalyptus trees) in Africa. We read the article and discussed what it meant to us. Since then the club and all the students of Agahozo have removed invasive species from a small plot of land to protect over 50+ native trees. We have collected seeds and started many seedlings for planting. We had an Environment Day event that highlighted the importance of trees. Most recently, this past Saturday, we planted nearly 300 native trees along the fence at Agahozo.

An Agahozo Environment Club member and Michele plant a native
tree (African Tulip (Spathodea campanulata) along the edge
of Agahozo-Shalom Youth Village on September 25, 2011.

It was today, September 26, at the end of our 7pm weekly club meeting that the club president, a first year student at ASYV, came up to me and said he had something to tell me. He said he was listening to the radio yesterday and that the lady that protected the environment in Kenya had died. I was shocked. He told me that she died of cancer. I looked it up afterward, and sure enough, she died at age 71 of ovarian cancer (the same disease that took my maternal grandmother).

In this conversation, the club president told me he was very sad. I told him something that I believe, and that I hope he will remember always. I said that we have made our last year about planting and protecting African trees. She may be gone, and it is very sad, but she can live on if we keep protecting the environment. I looked at him and said, “She will live on through you.”

Seedlings of native Kigelia africana started by students at Agahozo-
Shalom Youth Village. Some day these little seedlings will be large
shade trees for everyone to enjoy.

You can read more about Wangari Maathai and her work at:

Greenbelt Movement Programs

Wangari Maathai biography and quotes

New York Times Obituary 

Advice from little hornbills

Crowned Hornbill, Tockus alboterminatus, in trees near the shore 

of Lake Victoria, at Mabamba Swamp, Uganda

My first exposure to hornbills was likely Disney’s Lion King, where Zazu tries to keep Simba out of trouble. Much to my dismay, Zazu appears to be a fictionalized hornbill species. I can’t find a match*. The only “little hornbills” are the dwarf-hornbills of the Congo rainforest and Western Africa, and even they are not that small. Certainly, none of the hornbills have given me any advice, although I am no king lion.

Red-billed Hornbill, Tockus erythrorhynchus, West of Arusha, 

near Tarangire National Park, Tanzania. This is the species the Lion King

character Zazu is based, but see my discussion at the bottom of the page.

Hornbills are pretty special birds. They have long tails and are relatively large compared to most birds, ranging from 38 to 100 centimeters in length (about 15 to 40 inches). Hornbills have thick, down curved bills; some hornbills have large keratin casques that extend from the head over the bill. Hornbills are loud in their calls, hooting, rasping, and piping various sounds. Especially with the bigger species, they are noisy in flight too. In the West Usambara forests of Tanzania, I took pause to describe in my notes the sound of the Silvery-cheeked Hornbill in flight, a “huuh-huuh-huuh,” each “huuh” being a downward thrust of its wings. 

Von der Decken’s Hornbill, Tockus deckeni, West of Arusha, 

near Tarangire National Park, Tanzania

Hornbills are omnivores. They eat fruits, invertebrates, and small vertebrates like lizards. You will sometimes see a hornbill flick up its bill, tossing the food into the air, and catch its food further back in its mouth. 

African Pied Hornbill, Tockus fasciatus, Mabira Forest, Uganda

There are about 56 hornbill species in the world and that number may increase if certain subspecies are considered distinct. Different hornbill species live in different habitats, from savannas to rain forests. Twenty-four species (of the 56) can be found in Africa. The rest are in tropical Asia. We have a couple of birding friends who have lived in Asia and tell us that African hornbills have nothing on Asian hornbills. If that is the case, I have no idea, because all my hornbill sightings have been in Africa. 

African Grey Hornbill, Tockus nasutus, Akagera National Park, Rwanda

Michele and I have seen twelve species of hornbills, including the ground-hornbills. In some places, hornbills are quite common. In central-eastern Uganda, where native trees and even small patches of forest remain, hornbills could often be heard and fairly easily seen, especially the large Black-and-white-casqued Hornbill. In Rwanda, in my experience, I have only seen one hornbill out of a national park once, and that was by one of the only tiny native-wooded areas left. The Black-and-white-casqued Hornbill was present in Nyungwe Forest in Rwanda, but it was never easily seen (in fact a group of birders that we met there missed them altogether). I suspect that Rwanda’s lack of abundant hornbills outside protected areas has to do with the fact that nearly all its large native trees outside the parks are gone (hornbills breed in large trees). 

Black-and-white-casqued Hornbill, Bycanistes subcylindricus,
Entebbe Botanical Gardens, Uganda.  Note that the male on the left has
a larger casque and the female on the right has red bare skin around her eye.
This is a good example of sexual dimorphism, which means that males
and females of the same species differ in shape, plumage, or size.

With the sunbirds or weavers, the males are bright, and admittedly I photograph the males more than the females. But upon reviewing my shots of the hornbills, they were also all male. Female hornbills are very similar if not identical in plumage and their bills only differ in size of the casque and sometimes color. Why were there all males in the pictures? Michele suggested that maybe the males are showier; in fact, she was very close!

White-thighed Hornbill, Bycanistes cylindricus, Budongo Forest, Uganda.
The male and  female display very similar sex differences as the above
black-and-white-casqued hornbills. These two species are very similar
but can be told apart by amount of white on their primary feathers and the
differences in their tail feathers.

Hornbills have a unique reproductive strategy that makes the females less visible during parts of the year. The female hornbill seals herself in a tree cavity with the eggs, where she incubates them and rears the young. The male brings food to feed her and the young until the young birds are nearly ready to fly out. She even molts, losing her flying feathers, during her time inside the tree. All species of hornbills breed like this except the ground-hornbills.

Silvery-cheeked Hornbill (female), Bycanistes brevis, Amani Rainforest,
East Usambara Mountains, Tanzania

Silvery-cheeked Hornbill (male), Bycanistes brevis,
Lake Manyara National Park, Tanzania

The ground-hornbills are unique (endemic) to Africa. Ground-hornbills are also different from all other hornbills in several ways. The two species of ground-hornbills have different ranges, with one basically in Africa north of equator and the other in Africa south of the equator. Visually, they differ in two main ways. First, the casque on the bill of the Abyssianian species is larger and more pronounced than the Southern species. Second, the coloration of the exposed skin on the neck and face of each species is different. The Abyssinian has blue skin around the eye and on the neck with the male having a red neck with a blue patch. The Southern has red skin around the eye and on the neck with the female having a red neck with a dark blue patch. It sounds confusing, but these are huge birds without much overlap in range, so they are easy IDs.

Southern Ground-hornbill, Bucorvus leadbeateri, Lake Manyara
National Park, Tanzania. While this photo is poor, is hows the bird
in the process of flipping up food to catch further back in its mouth.

Abyssinian Ground-hornbill (male), Bucorvus abyssinicus,
Murchison Falls National Park, Uganda

Abyssinian Ground-hornbill (male), Bucorvus abyssinicus,
Murchison Falls National Park, Uganda. They fly too!

Abyssinian Ground-hornbill (female left, male right), Bucorvus abyssinicus,
Murchison Falls National Park, Uganda

The two hornbills that we saw but did not photograph are the Piping Hornbills and the Trumpeter Hornbills. If there is any advice to be taken from hornbills, it is that you need to take a lot of photos to get a good shot. And to keep big native trees so that birds can nest in them!!

* According to the Lion King Wiki, Zazu is a red-billed hornbill. This species would make sense in terms of distribution and habitat. The bill is red and it does have some yellow at the base. However, there are some serious differences between Zazu and red-billed hornbills. Differences are extremely important in birding, and the following differences are more than enough to say Zazu is not a red-billed hornbill.

Zazu’s tail has a white line going across the center of his tail feathers; red-billed hornbills have white trailing down the edges of their outer tail feathers with no white line going across. Legs and feet of Zazu are red, whereas red-billed hornbill legs and feet are black. Zazu has one white bar on his wings whereas red-billed hornbills have white splotches all over their wings. Zazu has no yellow bare skin around the eyes whereas red-billed hornbills do. Zazu is blue, light blue, and white. Red-billed hornbills are black and white.

These differences are major enough to rule him out as a red-billed hornbill (the argument of simplification in kids’ movies is possibly valid until you see that other illustrated birds in animated movies have the details near-exact). I am not trying to split hairs here with Zazu’s illustrators or imply that an animated bird should be true to form. I think it is cool to see species that are famous from movies or are exhibited in zoos; in this case, there is no Zazu species to see.

Works Consulted

• Fanshawe, J. and Stevenson, T. Birds of East Africa. Princeton and Oxford: Princeton University Press, 2002.
• Pearson, D.J., Turner, A.T. and Zimmerman, D.A. Birds of Kenya & Northern Tanzania. Christopher Helm: London, 1999.
• Roberson, Don. "HORNBILLS: Bucerotidae." Bird Families of the World. Accessed 21 September 2011. http://creagrus.home.montereybay.com/hornbills.html
• Roberson, Don. "GROUND-HORNBILLS: Bucorvidae." Bird Families of the World. Accessed 21 September 2011. http://creagrus.home.montereybay.com/ground_hornbills.html
• Ryan, P. and Sinclair, I. Birds of Africa south of the Sahara. Struik Nature: Cape Town, 2003

Sipping the sun

Scarlet-chested Sunbird, Chalcomitra senegalensis (male), at Agahozo-
Shalom Youth Village, Rwanda

Sunbirds are little gems that will catch your eye. Bright reds, greens, blues, and then woah, is that the same bird? Where did its color go? What just happened? Male sunbirds seem to change color as they move around. The males of many sunbird species have iridescent feathers, which reflect light differently depending on how light hits them. 

Bronzy Sunbird, Nectarinia kilimensis (male),  at Agahozo-Shalom Youth
Village, Rwanda

Sunbirds and hummingbirds are similar but they are not related. They fill the same niche in that they find flowers and sip nectar. In my experience, hummingbirds are considerably faster and buzz around, blurring their wings; sunbirds are much slower, perch when they sip, and appear much like any other bird in flight.

Bronzy Sunbird, Nectarinia kilimensis (female) at Gisenyi, Rwanda

Like hummingbirds, most sunbird males are different than sunbird females (sexual dimorphism). Most would describe the males as beautiful and the females as dull. The males are certainly more colorful, but I like to remind people the females do the choosing, so the pretty boys are at the mercy of the females.

This is a fun picture, but a tricky ID. This is either a female Bronzy Sunbird
or a female Marico Sunbird, feeding a moth to a youngster. The females of
each species are incredibly similar in size, plumage, and field marks. Taken
at Agahozo-Shalom Youth Village, Rwanda, where both birds are common.

Marico Sunbird, Cinnyris mariquensis (male) at Agahozo-Shalom
Youth Village, Rwanda

An endemic bird is generally a treat for any birder because endemism means that a species is only found in a certain area or habitat in one part of the world. Several of these birds, like the Regal Sunbird, the Blue-headed Sunbird, and the Purple-breasted Sunbird, are only found (endemic) in the forests of the mountains along the Albertine Rift in central Africa (sorry, no pictures yet). Others, like the Green-Headed Sunbird and the Red-chested Sunbird are endemic to the East Africa region (pictured below). Still others, like the Amani Sunbird and the Banded Green Sunbird, are endemic to tiny little patches of forest that top mountains in eastern Tanzania (no pictures). Endemism occurs because species evolve over time to fit new environmental opportunities. Some endemic species are very similar to other species in other habitats or regions while others have adapted to be quite unique. 

Red-chested Sunbird, Cinnyris erythrocerus (adult male) in Gisenyi,
Rwanda

Michele and I have seen 30 species of sunbirds between Rwanda, Tanzania, and Uganda. I did not really succeed in photographing them outside of Agahozo and one other location in Rwanda. Sunbirds are generally active and snapping a picture takes a fast camera or a lot of patience. Only with the Usambara Double-collared Sunbird and the Blue-throated Brown Sunbird did we get lucky. All of the other pictures shown here took considerable time and are what I consider the best of hundreds of shots. 

A female Red-chested Sunbird? Nope! This one is a juvenile male in
Gisenyi, Rwanda.

We have seen the following sunbird species in Africa: Golden-winged Sunbird, Bronzy Sunbird, Purple-breasted Sunbird, Blue-headed Sunbird, Blue-throated Brown Sunbird, Green-headed Sunbird, Malachite Sunbird, Olive-bellied Sunbird, Eastern Double-collared Sunbird, Usambara Double-collared Sunbird, Northern Double-collared Sunbird, Rwenzori Double-collared Sunbird, Regal Sunbird, Banded Green Sunbird, Amethyst Sunbird, Little Green Sunbird, Copper Sunbird, Superb Sunbird, Olive Sunbird, Purple-banded Sunbird, Marico Sunbird, Hunter's Sunbird, Scarlet-chested Sunbird, Red-chested Sunbird, Beautiful Sunbird, Variable Sunbird, Collared Sunbird, Amani Sunbird, Uluguru Violet-backed Sunbird, Eastern Violet-backed Sunbird.

Usambara Double-collared Sunbird, Cinnyris usambaricus (male), in the
West Usambara Mountains, Tanzania. This bird is endemic to
the West Usambara Mountains, but it has only recently been considered a
separate species from the Eastern Double-collared Sunbird. 

All of the sunbirds, bright and dull, have their charm as they cruise from flower to flower, inserting their bills to extract nectar or snatch an insect. So sit back, take a sip of the sun, and enjoy the colors!

Green-headed Sunbird,  Cyanomitra verticalis (male) in Gisenyi, Rwanda

Blue-throated Brown Sunbird, Cyanomitra cyanolaema (male) at Mabira

Forest, Uganda

Variable Sunbird, Cinnyris venustus (female) at Agahozo-Shalom Youth
Village, Rwanda

Variable Sunbird, Cinnyris venustus (male) at Agahozo-Shalom Youth
Village, Rwanda

Works Consulted

• Fanshawe, J. and Stevenson, T. Birds of East Africa. Princeton and Oxford: Princeton University Press, 2002.
• Pearson, D.J., Turner, A.T. and Zimmerman, D.A. Birds of Kenya & Northern Tanzania. Christopher Helm: London, 1999.
• Roberson, D. "Sunbirds: Nectariniidae" 1999. Bird Families of the World. Accessed 19 September 2011. http://creagrus.home.montereybay.com/sunbirds.html
• Ryan, P. and Sinclair, I. Birds of Africa south of the Sahara. Struik Nature: Cape Town, 2003