The dry riverbed of the Ribeira de Odelouca (São Marcos da Serra)

River reliance

I am lucky to live on the bank of the Ribeira de Odelouca, upstream from the Barragem de Odelouca which is a huge water resource for the Algarve region. However, here we are in February and the river is still dry.

Usually, the autumn rains kickstart the river in October or November and, even though we had some autumn/winter rains, the river remains dry except for pools in the deeper sections of the riverbed.

This may cause a problem for humans with both drinking water and agriculture supplies but, of course, there are many species of wildlife reliant on the river. As we head into spring, I sit here constantly checking the forecast for persistent rain which may give life to the river.

A similar situation occurred in 2017/18 when no rain during the autumn fell leaving the river dry until February 28 when it seemed to rain for six weeks. The rainfall was so heavy and persistent that the river changed from dry to flood overnight.

The wildlife flourished in 2018 so the late start of the river did not seem to impact and, hopefully, we will receive the downpours we require in the coming weeks.

Here is a selection of some of the local wildlife that rely on the river running. Wildlife is very resilient and resourceful when it comes to food and, therefore, I suspect currently there are no real concerns. The wildlife also has the option to search out the smaller private ‘barragens’ (reservoirs) for a food source whilst the river remains dry.

Common kingfisher
No river, no fish, no food for the kingfisher. It’s a simple as this. The Ribeira de Odelouca has a thriving common kingfisher population along the northern stretch, upstream of the barragem and you can often see and hear kingfishers.

When food sources become scarce, kingfishers will head further downstream in search of a food supply. I have even witnessed a kingfisher at a garden pond in Vale do Lobo in the winter months. Not only am I lucky to have the kingfishers on the stretch of the river I live on, but also they nest on my land too.

Thankfully, the river pools must be providing some food resources as I spotted one this morning at one of the pools. When looking for kingfishers along the riverbanks, you’ll often hear their high-pitched call before spotting a flash of blue as it flies low over the water.

Please be aware of your surroundings when spotting kingfishers as their nest sites are very vulnerable to abandonment if approached. So please stay clear if you spot a kingfisher at a hole in the bank.

Eurasian otters
These very shy creatures are present in many locations in the Algarve and none more so than the Ribeira de Odelouca. The first time I photographed otters, the locals in the village did not believe me.

Again, I am lucky to have them living on my land and, a few weeks ago, when there was sufficient rain to fill the pools, we could hear the otters at night seemingly partying at the sight of water. Otters hunt mainly in the water for anything aquatic, however, they will also catch anything they can overpower, so whilst the river may not provide a food resource, I suspect they become very inventive to catch their food.

The obvious sign of otter presence is their poop! Spraint, as it’s called, is nice, sweet smelling (try for yourself or take my word for it!) and is left to communicate to other otters the presence of a food source. They often contain shells of the Louisiana crayfish, which thrives in the river (they bury themselves in the mud and wait for water to return).

(Southwestern) water vole
Often mistaken as a brown rat, the water vole has a rounded face, flat nose and small ears, which makes it easy to differentiate between the two. As their name suggests, they burrow in riverbanks and are excellent swimmers.

Although they eat mainly vegetation, they can occasionally increase their protein intake by eating aquatic creatures. I only occasionally spot water voles, usually when I’m hiding, waiting patiently for kingfishers to photograph.

Viperine
The viperine snake is a very docile and harmless semi-aquatic snake that is very commonly found in rivers. Although the name may suggest otherwise, it is not venomous but is a description of the defence stance it takes when threatened by flattening its head and making it appear triangular like a viper. I often find them motionless in flowing water waiting to catch any aquatic creatures that wash past in the water flow.

So for now, we find ourselves constantly checking the weather forecast in the hope we are lucky to receive a few days of persistent rain before the start of the springtime breeding seasons for these and many other species reliant on the river.

By Craig Rogers
|| features@algarveresident.com

Craig Rogers is a wildlife and nature photographer from Wales now living in the Algarve, offering photography workshops. For more information, photographs and his blog visit www.craigrogers.photography

The dry riverbed of the Ribeira de Odelouca (São Marcos da Serra)
Water pool
Eurasian otter
(Southwestern) water vole
Viperine warming in the sun on the riverbank
Female common kingfisher