Wildlife Photographer of the Year: The small world of bees wins big

Karine was on a routine drive around a ranch in Texas, USA, when something caught her eye. She recounts how 'the ground suddenly become pockmarked with hundreds of volcano-like turrets' and that her 'immediate thought was "what kind of ants are these?"' Pulling over for a closer look, Karine soon discovered that the 'ants' were in fact bees. 

The species she came across belongs to the genus Diadasia, which are considered solitary bees. This means that, unlike honeybees for example, they do not build hives and live as a collective. Instead, they nest individually in the ground, and the female has the sole responsibility of building her own nest.

The word solitary, however, can be misleading. these bees construct their nests close together and forage within a 50-2,000 metre radius of their nest site.

The concentration of so many nests in one area means that when the time comes for mating, the place seemingly comes alive with thousands of bees buzzing just a few inches above the ground.

Importantly, the species has a male bias, and there are many more males than females. As a result, competition to mate with the few existing females is fierce.

When it is time to mate, the males emerge first, explains Dr Joseph Monks, Curator of Hymenoptera at the Museum. 'Up to several thousand males emerge at the same time. They patrol the nesting area and then compete intensively for the females, which emerge periodically.'

'This is why they form the mating balls,' he continues, 'they are fighting for access to a newly emerged female'.

It is this dramatic moment that Karine captured so vividly. Her winning shot shows numerous males struggling with one another, competing for the opportunity to mate with the solitary female.

Following this intense fight, Joseph continues, 'The female will emerge from the ball with a single male clinging to her. After a few seconds or minutes, they will mate and then the female will start constructing and provisioning a nest.'

This mating behaviour is relatively rare, even among ground-nesting bees. In the UK it can be observed in the ivy bee, Colletes hederae.

For Karine, who'd visited the ranch for many years, the presence of the bees was quite a surprise. 'I'd never seen them before,' she explains, 'and I had no idea what I was looking at in the beginning'. This, along with the searing heat of the Texas sun, made photographing the bee's distinctive behaviour quite challenging.

In order to bring the viewer into their world, Karine got down to ground level, being careful not to step on any of the bees, then used a specialist lens and a strobe to take this winning photo.

She says, 'The small world of animals is one we often overlook and so often take for granted, and, ironically, it is the basis for the structure of all life'.

'What I love most about this image is that it shows most people something they have never seen before - it makes a small world big and puts the life of a tiny bee onto the word's stage.'

How can we protect bees?

Bees in Texas face many of the same challenges as others around the world, including habitat loss, overuse of pesticides, competition with invasive species and rising temperatures as a result of climate change.

In addition to these mounting threats, ground-nesting bees are further impacted by disruptive and industrial-scale farming practices. Joseph explains how, 'tilling the soil can destroy nesting sites while soil compaction and a build-up of chemicals in the ground can negatively impact the chances of successful development of larvae in ground-nesting bees'.

Texas is one of the most intensively farmed states in the USA, with around 248,000 farms and 127 million acres of land given over to ranches.

Additionally, many bee species are oligolectic, which means they are adapted to rely on only a single family or genus of flowering plant for their pollen. If the plant that a species depends on goes extinct, then so too will the bee species.

One example of this behaviour can be found in Cactus bees, so called as they are regular visitors to the prickly pear cactus, found across the southern United States of America and northern Mexico. 

Joseph explains that, 'Cactus bees were initially thought to be oligolectic. However, recent studies have shown them to be polylactic, relying on a wide range of plant families, including the prickly pear cactus. This ability to use different resources mitigates some of the risks associated to oligolectic species.'

'Nevertheless, their limited dispersal means preserving floral diversity is critical to protecting bee diversity.'

With there being a combination of threats facing bee species around the world, their survival requires a multi-faceted approach. Importantly, farming practices that consider the biology and reproduction cycles of pollinators need to be implemented.

Pollinators such as bees are vital to preserving ecosystems and pollinating our food crops. Some studies estimate that around one-third of all food crops rely on pollinators for their survival, meaning that without them global food security would be severely affected.

While there are changes that individuals can make such as supporting organic farmers, opting for a natural lawn and encouraging wildflowers, changes are needed at a governmental level. Pesticides that harm bees need to be restricted and farmers should be rewarded for working in a way that is harmonious with the lives of our pollinators.

Karine's winning image puts ground-nesting bees centre-stage. As competition judge and wildlife filmmaker Sugandhi Gadadhar, notes, 'In today's world, where we struggle to grab the attention of the policymakers towards even big mammals, this image helps in bringing the spotlight to one of nature's most important creatures - bees'.