Birds have a wide range of sensory adaptations that enable them to survive and thrive in the diverse landscape of Londolozi. While their sense of smell may not be as developed as in mammals, many bird species possess a remarkable ability to detect and interpret odours. Although the specifics vary among species, their olfactory capabilities play a crucial role in hunting, locating food, communication and overall survival.

The striking Purple Crested Turaco feeds on fruit in the canopy of a tree.

Many classical textbooks of zoology used to report that birds are anosmic, with a few possible exceptions.

Anosmic | a-ˈnäz-mik |

adjective

loss or impairment of the sense of smell, either total or partial.

The bird olfactory system primarily involves the size of the olfactory bulb and the associated brain regions. Some birds, such as vultures, waders and seabirds have a highly developed sense of smell, allowing them to detect and locate food sources over vast distances and, even below the ground. Whereas other bird species rely more on using touch and sight to locate food and detect danger.

A Southern Ground Hornbill perches atop a termite mound during a foraging mission through the grassy marula crests.

So of all the birds we see at Londolozi, let’s break it down into a few different groups of birds that we believe a strong sense of smell is vital for their survival.

Firstly, almost self-explanatory yet somewhat counterintuitive.

Vultures

It must be said that the size of the nostril is not a reliable indicator of smelling ability but rather the size of the olfactory bulb located on the front side of the brain which allows birds to have an enhanced ability to detect smells.

So one would imagine that if your sole diet consists of meat, carrion or a decomposing carcass, having a strong sense of smell is of utmost importance. Well, this is not necessarily true, for the vultures that we see here at Londolozi. However, the “New World Vultures” located in the Americas and Oceanic islands, for instance, possess a heightened sense of smell, which enables them to locate carrion from great heights, even when it is not visible. They rely on the scent of decay to find food, displaying impressive olfactory navigation skills.

Three White-backed Vultures perch on a dead tree near a carcass as the sun begins to set.

However, the “Old World” Vultures found in Southern Africa can be observed at a carcass long before the smell of decaying meat is detected indicating that sight is the principal scent used to locate food and these types of vultures don’t have a developed olfactory bulb. One could imagine that having a strong sense of smell might be unpleasant when your head is buried in the throws of a putrid rotting carcass, but I guess maybe they might enjoy that smell.

A number of White-backed Vultures descend to a carcass to feed on decaying meat and clean up the remains of a hippo.

Waders

The Three-banded Plover is a tiny wader that often goes unnoticed on the water’s edge due to its size. However, when viewed through Binoculars or a long lens its beautiful details and distinctive three bands can be admired.

The ability to detect scent is also highly developed and important to birds that probe into sandy or muddy substrates to detect food. Ibises, Hoopoes and plovers are just a few species found at Londolozi in this category of waders. The nostrils of these birds link to the bill-tip and are crammed with chemo-receptors. The sense of smell is often aided in these birds by touch and the bill tip has many tactile sensors which assist in locating prey.

The Glossy Ibis uses its long, curved beak to probe the sandy substrate below the water to detect any movement of prey.

Seabirds and Navigation

Similarly, some seabirds, like petrels and shearwaters, rely on their olfactory abilities to locate patches of fish and squid in the vast oceans. They will also use their strong sense of smell to return to their roosting or nesting spot on land, which can be a challenge trying to find again once flying many miles out to sea.

Migratory birds will use their memories along with geographical features, winds and celestial bodies to navigate their way to and from their breeding grounds. The sense of smell may play a critical role in the memory of some species that would have travelled the same path a season before.

Smaller birds will usually group together during their migrations, this is no different with Amur Falcons.

The Amur Falcon takes one of the longest migratory flights of any Londolozi bird of prey. They fly +/- 15 000km (9300 miles) from China to Southern Africa. It will require to utilise many cues to make this trip successfully and smell will aid in them crossing the Indian Ocean and South over the African Continent.

Other Reasons

Birds also use their sense of smell for social interactions and for navigating their surroundings. Pigeons, renowned for their homing abilities, are known to navigate using a combination of visual landmarks and olfactory cues. They can detect and remember specific odours associated with their home location and use this information to navigate back over long distances.

The African Green Pigeon feeds primarily on fruit and is pictured here perched on a Natal Guarri Tree.

Greater Honey Guides relish honeycomb and are thought to be attracted by the smell of wax. This was first noticed in the 16th century by a Dominican missionary in Mozambique, who noticed that the honeyguides were eating wax from the altar candles.

It is worth noting that not all bird species rely heavily on their sense of smell. Some, like raptors, excel in visual acuity and use their keen eyesight to locate and hunt prey. And fruit-eating birds like African Green Pigeons and Sunbirds will use colour to locate their food. However, for those birds that do possess a well-developed sense of smell, it serves as an additional tool for their survival.

A White-bellied Sunbird feeds on the sweet nectar from an Aloe. Most fruit and nectar-eating birds rely more on the colour of the fruit or flower, using eyesight to find these sources of food rather than smell.

We watched a Yellow-billed Hornbill catch and kill a caterpillar. It took some time to thrash the prey against the hard wood of a Leadwood tree before swallowing the caterpillar whole.

In conclusion, while birds may not possess the same level of olfactory acuity as mammals, many species rely on their sense of smell to hunt, locate food, navigate, and engage in social behaviours. From scavengers detecting carrion to seabirds pinpointing patches of fish in the vast oceans, the olfactory abilities of birds contribute significantly to their survival and adaptation to various environments. The intricate interplay between visual and olfactory senses enhances their overall sensory repertoire, enabling them to thrive in diverse ecosystems.