Category Archives: Ecology

Weeds and Wildflowers = More Avocados!

One of my favourite plants (after cacao that produces chocolate!) is the avocado. They are one of the most delicious and nutritious fruits around…

Mmmmm… tasty avocado!

Mmmmm… tasty avocado!

Avocado trees are one of the many different crops that depend on wild insects pollinators. I recently spent some time in the Kerio Valley looking at the insects visiting the avocado flowers.

Here are what the avocado flowers look like:

Avocado flowers awaiting their appointment with a pollinator...

Avocado flowers awaiting their appointment with a pollinator…

The pollinators of avocado on this small farm in northwestern Kenya were mainly different kinds of flies and honeybees.

An unidentified fly visits some avocado flowers

An unidentified fly visits some avocado flowers

House flies and some smaller flies on Avocado flowers

House flies and some smaller flies on Avocado flowers

Copper-tailed Blowfly on avocado flowers (a major pollinator at this site)

Copper-tailed Blowfly on avocado flowers (a major pollinator at this site)

After pollinating visits by several different flies, the avocado flower is pollinated and a young fruit begins to form.

Newly pollinated flower with ovary swelling to form young fruit

Newly pollinated flower with ovary swelling to form young fruit

They develop over several months into the wonderful fruits that we so enjoy:

Developing avocado fruit - they stay on the trees for quite a long time.

Developing avocado fruit – they stay on the trees for quite a long time.

Honeybees were also visiting the avocado flowers and pollinating them too:

Hard-working honeybee on avocado flower

Hard-working honeybee on avocado flower

One of the key things we’ve learned about pollinators is that they depend on a wide range of plants for their own survival.

While crops are only in flower for a short period of time, bees and flies need to eat from a wide range of different wildflowers. Without these plants, the bees, flies and other pollinators would not be able to survive. This would result in far fewer avocados and poor or low yields on the crops that depend on pollinators. Some of the plants that the bees and flies depend on at this site are considered weeds. These weeds, including the infamous ‘Black-Jack’ (Bidens pilosa) are actually an important resource for wild insects pollinators.

Honeybee sips nectar from a 'Black-Jack' flower

Honeybee sips nectar from a ‘Black-Jack’ flower

Weeds can be an important resource for bees...

Weeds can be an important resource for bees…

Weeds and wildflowers growing around the farm are essential in order to support healthy wild insect pollinators.

At this small farm near Iten, there were lots of different flowers growing along the edges of the farm, including this lovely, scrambling yellow-flowered creeper in the Daisy Family (Asteraceae). Several of the avocado pollinators could be found visiting the flowering creeper later in the day after they had been pollinating the avocado flowers.

Wildflowers are important for wild insect pollinators

Wildflowers are important for wild insect pollinators

Honeybee visiting the flowering creeper

Honeybee visiting the flowering creeper

This is why it is important to have diversity in the farming landscape, like here in Kenya’s beautiful Kerio Valley.

More wildflowers and weeds around the farm support more pollinators that produce higher yields!

Wildflowers are important for pollinators

Wildflowers are important for pollinators

More from the wonderful world of bugs soon!

Please think of the pollinators when you next enjoy an avocado!

Celebrating Pollinators: Pollinator Conservation Handbook Launched!

Dear All

Many greetings.

Am very pleased to share with you a book featuring and celebrating pollinator diversity in East Africa.

You can download the book through link by clicking on the cover image below:

Our Friends The Pollinators!

Click on image above to go to the page where you can download the book

 

To whet your appetite here’s a sneak preview of some of the pages from the book:

pollinator-handbook-preview1

 

Pages from 'Our Friends The Pollinators: A Handbook of Pollinator Diversity and Conservation in East Africa'

Pages from ‘Our Friends The Pollinators: A Handbook of Pollinator Diversity and Conservation in East Africa’

You can download the book freely from this link:

http://discoverpollinators.org/pollinators/pollinator-handbook/

Please share this link and enjoy the beauty and wonder of East Africa’s pollinators!

(PS – if you are unable to download it from the link, please send an email to [email protected], and we will send you a soft copy).

Golden Ground-nesting Bee!

In keeping with the theme of where bees nest…

A few weeks ago walking back in the evening from a day of looking at bees on farms, I noticed something sparkle on the path.

All alone with nowhere to go?

All alone with nowhere to go?

 

Peering closer I discovered that it was a beautiful Seladonia bee and I wondered what she was doing out so late. Watching her for a few minutes, she flew a short distance and landed near the entrance of a tiny hole in the ground. Peeking out from the hole was another individual Seladonia bee.

Peekaboo!

Peekaboo!

 

She quickly retreated into the nest and the first bee the slipped closer. The reason they were being so shy was so as not to ‘reveal’ to me the location of their nest entrance!

Approaching the nest

Approaching the nest

 

Then she quietly slipped into the safety of her nest.

Goodnight!

Goodnight!

This encounter illustrates one of the many diverse ways that wild bees make their homes. Some, like the honeybees are strictly social, living in families with different castes. The vast majority of bees are solitary, going it alone in the world. But a few, like these lovely Seladonia, appear to have come to compromise of sorts and share their nests, probably with sisters or other relatives. Inside this nest are cells packed with pollen gathered diligently from flowers where the bees will lay their eggs for the larvae to develop with plenty of food and safe from the harsh world…

 

Many different bees nest in the ground especially those in the Family Halictidae. These sites, often at the edges of farms near natural vegetation are important for bees and should be protected as the allow the bees to survive and work as pollinators for us.

 

Seladonia bee gathering pollen

Seladonia bee gathering pollen

So much more to learn about bees!

 

Giant Carpenter Bee!

Dear All

On a recent hike in southern Tanzania at the edge of the Uluguru Mountains I came across one of East Africa’s largest bee: the Giant Carpenter Bee (Xylocopa nigrita).

Female Giant Carpenter Bee approaching Crotolaria flowers

Female Giant Carpenter Bee approaching Crotolaria flowers

This is a striking bee where the males and females are sexually dimorphic: meaning that they look very different. The females are boldly marked in black and white, while the males are covered in bright golden hairs that glisten in the sunlight.

Females visit flowers of many different species, and on this day they were feeding on flowers of legumes (a Crotolaria sp.) and also the flowers of pigeonpea (Cajanus cajan), which they are responsible for pollinating. Working the legume flowers requires a lot of skill and dexterity from the bees. The flowers need to be ‘tripped’ so as to expose the pollen from the anthers that slide out of the keel of the lower petals. The carpenter bees are experts at doing this:

 

Female bee grappling with Crotolaria flowers

Female bee grappling with Crotolaria flowers

 

While the females are busy visit flowers the males set up territories that they patrol during the day. These are usually near patches of habitat that females frequent. Male carpenter bees spend many hours flying back and forth around their territorial patch marking landmarks with scent and watching for females.

Golden male Giant Carpenter Bee!

Golden male Giant Carpenter Bee!

 

After a hard days’ work, they too visit the flowers for some refreshment in the form of nectar.

Male Giant Carpenter Bee grappling with Crotolaria flowers

Male Giant Carpenter Bee grappling with Crotolaria flowers

 

Several people have asked me how exactly I take these photos of bees. The key thing is patience and waiting at the flowers, with some understanding of the movements and behaviour of the bees. It took me over an hour of watching and waiting to get these photos of the Giant Carpenter Bees.

Patience is key to capturing bees in action!

Patience is key to capturing bees in action!

 

More from the wonderful world of insects soon!

 

Bees pollinating cucumbers in Turkana

Hello – greetings from Turkana in Northern Kenya…

Up here checking in on my lab at the Turkana Basin Institute and spent half a day looking at bees pollinating the cucumbers being cultivated at the institute. Cucumbers are one of my favourite salad items and make a refreshing snack up here in the desert at lunchtime. Cucumbers are yet another example of a food item that we enjoy thanks to pollinators.

Cucumbers are in the family of plants called Cucurbits (Curcubitaceae), that includes watermelons, pumpkins, squashes and gourds.

Most members of this plant family are dependent on pollinators, and many of them have separate male and female flowers (though these can occur on the same individual plant).

It has rained up here in Turkana about a week a ago and the ground is delicately painted with flowers and the air filled with bees and butterflies.

Here are some of the bees and their antics on the cucumber flowers.

One of the first bees to arrive was the lovely Macrogalea bee, who also spent time sunning themselves on the flowers:

Macrogalea bee

Macrogalea Bee on Cucumber Flower

After warming themselves on the cucumber flowers, the Macrogalea bees dove into the flowers and as you can see were soon coated with pollen and moving it around the flowers:

Macrogalea bee hard at work

Macrogalea bee hard at work

They were also visiting the flowers of a different cucurbit (a butternut squash variety), nearby:

Macrogalea crawling out of Squash flower

Macrogalea crawling out of Squash flower loaded with pollen.

 

As the morning grew hotter, the next bee-shift appeared and these guys whizzed about the cucumber patch with dizzying speed. One of my favourite bees, known as Amegilla:

Amegilla Bee pollinating cucumber flower

Amegilla Bee pollinating cucumber flower

 

The Amegilla bees moved speedily between the different patches of cucumber plants, this makes them efficient pollinators as they transport pollen between different individual plants.

Busy Bees! Amegilla at work.

Busy Bees! Amegilla at work.

 

There were at least two different species of Amegilla present, the beige-grey one and this brightly coloured orange one visiting the cucumber flowers:

Another Amegilla bee hard at work!

Another Amegilla bee hard at work!

Bees were not the only insects visiting the flowers, a Grass Yellow butterfly (Eurema sp.) also stopped by. Although it was a faithful visitor, it didn’t seem to be carrying much pollen around.

Grass Yellow Butterfly sips nectar

Grass Yellow Butterfly sips nectar

 

The bees kept coming and going throughout the morning and we enjoyed some of the cucumbers at lunch!

Please click on image for larger version

Please click on image for larger version

More from the wonderful world (and work!) of insects soon…

 

Kerio Valley Bees (and a fly)

Hello – just spent a lovely day looking at bees in the Kerio Valley (one of my favourite parts of the world!). An extension of the Great Rift Valley in northwestern Kenya, the Kerio Valley is a beautiful and diverse landscape that is especially rich in bees.

The Kerio Valley is also home to a large number of small-scale farmers who rely on subsistence agriculture to support their families. Many of the crops grown in the region are dependent on pollinators and it is an area where I have been looking at pollinator diversity and the interface of agriculture and biodiversity for some years.

View from Iten looking down into the Kerio Valley

View from Iten looking down into the Kerio Valley

 

Here are a few of the bees that I encountered while walking around the farms on the floor of the valley near Biretwo.

Early in the morning the Morning Glories (Ipomoea) were in full bloom and peering into one of their deep dark hearts I found a Macrogalea bee hiding in the bottom of the floral tube.

Macrogalea bee in an Ipomoea flower

Macrogalea bee in an Ipomoea flower

The bee seemed to be struggling and as it emerged into the sunlight I could see why: it was overloaded with the flowers’ sticky pollen and could barely move!

Macrogalea_Ipomoea-LR12

 

Overloaded with pollen!

Overloaded with pollen!

 

Nearby there were some yellow flowers blooming and they were being thoroughly ‘worked’ by a small bee in the Leafcutter Bee family (Megachilidae). Each bee landed on the flower and then circled it in an anti-clockwise direction while packing pollen into the special ‘scopa’ (pollen carrying region) on the underside of its’ abdomen.

Combing pollen from its' face!

Combing pollen from its’ face!

 

Not to be outdone were the Amegilla bees who zipped about between the flowers. Here is one sizing some some Gynandropsis:

Amegilla bee in action

Amegilla bee in action

 

Some smaller bees were also working the Gynandropsis flowers. They clung to the anthers while simultaneously trying to pull off the pollen:

Collecting Gynandropsis pollen

Collecting Gynandropsis pollen

 

Sunning itself demurely on a leaf was a beautiful bee known as Crocisaspidia:

Handsome Crocisaspidia bee

Handsome Crocisaspidia bee

One of the most common bees visiting the flowers were the Seladonia, who are tiny but beautiful metallic bees that often look like they are made from gold:

Seladonia bee hard at work.

Seladonia bee hard at work.

 

Among all the different bees were some interesting flies, including this lovely Hoverfly (Syrphidae) that is an exquisite mimic of a wild bee.

Do I look like a bee?

Do I look like a bee?

More from the wonderful world of insects soon!

 

Some bees in the bush…

Dear All

Many greetings, the rains over the last couple of months have brought forth some wonderful flowers out on the plains. Now with the mix of sunshine and abundant flowers, it is a fantastic time for the bees who are out and about in large numbers. Many other insects are also making hay while the sun shines, imbibing nectar, gathering pollen and reproducing while the conditions are good.

Insects and plants have an ancient and beautiful relationship that spans hundreds of millions of years of co-evolution. For every single species of plant, there are many different kinds of insects that live on, in, around and off it.

There is incredible diversity even around just a single species of wildflower as you can see from this series of photos on the humble wildflower Leucas, that is currently flowering on the plains south of Nairobi…

A speedy Amegilla bee who zipped like a maniac between the flowers sipping up the abundant nectar...

A speedy Amegilla bee who zipped like a maniac between the flowers sipping up the abundant nectar…

 

This particular bee was so efficient that it just grabbed the flowers for a second stuck its long tongue in and sucked out the nectar then moved on to the next one...

This particular bee was so efficient that it just grabbed the flowers for a second stuck its long tongue in and sucked out the nectar then moved on to the next one…

The Amegilla bees are fairly diverse and this other species was much more methodical in exploiting the flowers. Notice how it bends the flowers in a special way and rubs against the orange ‘blobs’? Those are the flowers’ anthers that bear pollen which is what the flower expects the bees to transfer between different plants…

Amegilla bee efficiently pollinating the Leucas flower...

Amegilla bee efficiently pollinating the Leucas flower…

 

Amegilla hard at work!

Amegilla hard at work!

 

There were some leafcutter bees working this patch of flowers too:

Leafcutter bee visiting the Leucas flower...

Leafcutter bee visiting the Leucas flower…

 

A few delicate lycaenid butterflies stopped by to sip some nectar (though it didn’t seem like they carried much pollen, so they are basically free-loaders!)

The Pea Blue butterfly has a drink of nectar

The Pea Blue butterfly has a drink of nectar

While I was watching for bees, this gorgeous emerald green chafer beetle flew by distracting me:

"Am I cool or what!?"

“Am I cool or what!?”

Later in the evening the carpenter bees came out to visit the flowers:

Carpenter bee on Leucas flower

Carpenter bee on Leucas flower

 

Of course, not everyone visiting the flowers was behaving themselves. There were  a number of stink bugs and groove-winged flower beetles shamelessly feeding off the flowers and buds:

Stinkbug (on the left) and groove-winged flower beetle  with head buried in blossom.

Stinkbug (on the left) and groove-winged flower beetle with head buried in blossom.

 

My ‘field assistants’ Barabara and Zaza took a break in shade as I was watching the bees…

Barabara and Zaza (hidden lying down)...

Barabara and Zaza (hidden lying down)…

 

What an amazing world all taking place on just ONE species of wildflower. Imagine if we could quantify all of the interactions between insects and flowers in just one patch of natural habitat for one day – I find all these interactions a source of wonder and inspiration…

 

What other mysterious creatures dwell here?

What other mysterious creatures dwell here?

 

More from the wonderful world of insects soon!

Coriander (Cilantro) Pollinators…

Greetings from Turkana in Northern Kenya. I recently visited one of the farms that I work with up here and was very pleased to find the coriander (cilantro) flowering. This plant is a common and delicious herb that is widely used in the cuisines of many different parts of the world…

Coriander flowers close-up

Coriander flowers close-up

Many of us are aware of the role played by pollinators in producing fruits and other crops like beans, tomatoes, etc. However, even many of the spices that we grow are dependent on pollinators – and without them would not produce the seeds that are the basis of a valuable trade and make the food we eat much tastier and more nutritious!

The flowers of the coriander plant (called cilantro in America) are open and lay in flat heads called umbels. This means that they can be accessed by a wide range of pollinator species. Here are some of the insects that we found visiting and pollinating the cilantro flowers in Turkana.

A lycaenid butterfly and a cuckoo-wasp at the coriander flowers

A lycaenid butterfly and a cuckoo-wasp at the coriander flowers

The lycaenids are tiny butterflies, many of which are common in the drylands of Kenya. They can often be found visiting flowers where they sip nectar and check each other out…

Two lycaenid butterflies enjoying the cilantro flowers

Two lycaenid butterflies enjoying the cilantro flowers

Many different wasps were visiting the flowers. The Cuckoo Wasp was among the most striking with its bright green iridescent sheen…

Beautiful Cuckoo Wasp

Beautiful Cuckoo Wasp

Cuckoo wasps are named after their behaviour where (like the cuckoo birds) they lay their eggs in other wasps’ nests – they are parasites.

Of course the bees were among the most common and efficient pollinators visitors to the coriander flowers…

Braunsapis bee at the coriander flowers

Braunsapis bee at the coriander flowers

The Braunsapis bees were the most common visitors to the flowers among the bees. They moved about a lot and we found them carrying lots of pollen too.

Happy Braunsapis busy on the flowers

Happy Braunsapis busy on the flowers

A number of tiny Stingless Bees were also active – collecting pollen and nectar…

Stingless Bee at work...

Stingless Bee at work...

All the hard work by the pollinators produces these beautiful seeds that we can flavour our food with!

Yummy coriander seeds thanks to the pollinators

Yummy coriander seeds thanks to the pollinators

More from the world of insects soon!

Birds and bees in the Kerio Delta

Greetings from the remote reaches of Turkana in northern Kenya…

The Lake Turkana Basin, while being a hot and dry area, includes several river systems and the 6,000 km2 + Lake Turkana. Three rivers feed into the lake: The Turwel, Kerio and Omo. The Omo, from the highlands of Ethiopia contributes about 90 % of the lakes’ waters. The Kerio River comes from the south, from streams originating in parts of the Cherangani Hills and north-western Kenyan Highlands. The rivers and deltas close to the Turkana Basin Institute are home to a rich diversity of insect and bird life.

Pied Kingfisher preparing to dive into the water after a fish!

After a long journey through the dry country the Kerio reaches the lake. We visited the Kerio Delta to look at some of the freshwater ecology issues and biodiversity. To get to the water we had to walk through a thick green tangle of prickly Prosopis bushes.

A channel in the Kerio Delta where we took a boat ride

This is an invasive species that was first introduced to the area some 25-30 years ago. Prosopis, more commonly known as mesquite. A short tree/shrub, not striking in any aspect, has swiftly and silently colonized vast stands of Kenya, and indeed East Africa’s arid rangelands. Eight species are currently placed in the genus Prosopis, originating primarily from Central and South America (Prosopis alba, P. chilensis, P. glandulosa, P. juliflora, P. tamarugo), with P. africana native to the Sahelian margins and P. cineraria found in parts of Afghanistan, India, Iran and Pakistan. Several of the above species have been introduced and managed in different parts of Kenya over the last few decades. Of these, the main villain has proved to be Prosopis juliflora, originating in the drylands of the Americas. It is exceptionally drought tolerant, can live on the most marginal of soils, and tolerates strongly saline conditions as well as seasonal waterlogging. It is Prosopis juliflora that has taken over vast areas of the Kerio Delta at Lake Turkana.

Invasive Prosopis growing into the water

We found that the Prosopis is in the process of swamping the natural beds of Typha bulrushes and aquatic grasses that normally serve as nurseries for fish and help oxygenate the water. Beneath the Prosopis little survives as the trees rot and the bitter tannin-filled leaves fill the water. Managing the Prosopis will be a big challenge in the future especially as it spreads through larger and larger areas. Total eradication is not really feasible. Prosopis spreads rapidly into areas that have been overgrazed, a sad reality over much of Kenya’s drylands. Seed dispersal, an oft-overlooked aspect, is rapidly effected by browsing goats, other wild ruminants and hares. The thicket-forming growth habit and deep-roots make it extremely difficult to remove once established even over a few square metres.

Prosopis pods - seeds are dispersed by goats

The one thing that Prosopis does do is provide forage for many different bee species, including both wild bees and honeybees

Wild Ceratina bee visiting the Prosopis flowers

Where the Prosopis opened up to more natural rushes and reeds we started seeing interesting birds and insects. The most dramatic sighting was of a large, majestic Goliath Heron.

Goliath Heron, largest of the herons, takes to the air...

One of the most interesting insect behaviours that we were able to watch was mate-guarding by damselflies. We had discussed this in class and it was exciting to see how diligently the male Cherry-eyed Damselflies held on to their mates to keep them from taking off and mating with other males!

A pair of Cherry-eyed Damselflies - the male holds on to the female firmly!

More from the world of bugs soon, thanks to everyone for the kind comments!

Desert filled with bees

A recent rainstorm has brought out the flowers in the desert of northern Kenya where I am currently based at the Turkana Basin Institute (TBI). I am here teaching an ecology module for the Turkana Basin Field School. A single rainstorm that fell a few weeks ago has also brought out a large number of insects. Like many of the plants, the insects are active and taking opportunity of the greenery to forage and breed. And like the plants they are all under intense pressure to complete their life-cycles. For insects this often involves several stages as eggs, larvae, pupae and finally adults.

Deserts and drylands are often mistakenly thought to be places of low diversity. However, they are rich in insect life, but most of this is hidden away awaiting the brief periods of flowering. As this time is now upon us, it has been very exciting for the students to glimpse some of the incredible bee diversity in this habitat. One of the groups of insects that are more diverse in drylands, especially in Africa, are the bees. These are wild bee species. Many people are surprised to learn that there are more than just honeybees. Bee diversity in this area is largely unexplored and no doubt many exciting new species and biology remains to be discovered.

A tiny bee, Nomioides, visiting a Tribulus flower at TBI

We started out watching and collecting bees on the Indigofera spinosa bushes within the TBI compound. A number of bees have been frantically visiting the tiny pink flowers. The students have collected several different bee species on the Indigofera. These include some large leafcutter bees who carry pollen on their bellies, which turns them bright yellow. Another common bee visiting the flower was a Pseudapis. Also visiting the flowers was a striking parasitic cuckoo bee species (Coelioxys) that is a brood parasite of the leafcutter bees. Just like the cuckoo bird, it lays its eggs in the nests made by the hardworking leafcutter bees!

Pseudapis - one of the most efficient pollinators of the Indigofera bushes

Leafcutter bee with its belly covered in pollen!

Cuckoo Bee (Coelioxys) visiting the Indigofera flowers.

We then travelled to a site in the open desert plains where a carpet of miniature flowers pressed close to the ground was busy with bee activity.

Students search for bees on the open semi-desert plains

Here we found several different bees that we hadn’t seen nearer TBI. These included a beautiful halictid or sweat bee with a bright orange abdomen.

Tiny, gorgeous halictid Nomiine bee

We also spent time catching parasitic wasps and bees that were tiny. These are so tiny that we had to use small bags and slip them quickly over the bees as they were foraging, as they could wriggle through the holes in the nets! The students worked hard and learnt a lot about bee diversity and how much work it is to study them!

Students hard at work looking for tiny bees and wasps

Student Hui poised ready to catch one of the zippy bees...

The students also collected data on visitation rates to flowers on the Indigofera bushes. This species is really important as it is the main browse for goats and camels which are the livestock species that people depend on in the drylands of Turkana. We found that solitary wild bee species are both the most abundant and the most efficient pollinators as they carry pollen between many different individual plants resulting in effective cross-pollination. The Indigofera bushes establish new plants from the seeds that only come about as a result of pollination by the wild bee species. So the bees feed the goats and camels indirectly!

Camel browsing on Indigofera from seeds made by bees

More from the world of bees and bugs soon.

To learn more about the Turkana Basin Institute, please visit their website:

http://www.turkanabasin.org/