Pharaoh Eagle-owl

When Arnoud’s airline cancelled a flight home from Morocco in early 2013, this joined a long list of frustrations. The main goal of his trip had been to improve and diversify our recordings of Pharaoh Eagle-Owl Bubo ascalaphus, but they had been resolutely silent. By text message, we debated whether strong wind, timing of incubation, or food supply was the cause. The flight cancellation would give him two more nights. 

On the second, just as Arnoud was leaving his recording gear under some cliffs, a 4 x 4 vehicle appeared in the distance. Slowly, it made its way towards the gully. Arnoud guessed who would be inside. Some years ago when he and Dick had been drinking coffee at Oued Massa, a photographer had recognised them and shown them some stunning shots of Pharaoh Eagle-Owls. When Arnoud emailed him a few years later to ask where they had been taken, he mentioned Goulimine. It was only after promising secrecy that Arnoud had learned the exact location. He was not even supposed to tell Cecilia, who was travelling with him as usual. That was why the two of them had to sneak out of the gully, creeping from bush to bush so that whoever was in the vehicle would not see them.

In the morning, Arnoud returned alone to pick up his equip­ment before the local herdsmen appeared. Sure enough it was Torsten the photographer and his wife Kathrin who had arrived for a short holiday the evening before. They had camped and were now preparing a picnic breakfast. Arnoud was invited to join them by their fire for a cup of tea. Torsten told him that the Pharaoh Eagle-Owls had at least two nests to choose from, and changed every other year or so. He thought that the low level of activity this year was down to unusually dry conditions. The gully looked sandier than in previous years, and the usual Long-legged Buzzards Buteo rufinus and Lanner Falcons Falco biarmicus were not nesting, suggesting that food was scarce. Torsten and Kathrin reported that the wind had died down and they had heard the male Pharaoh from their sleeping bags before dawn. Fortunately, Arnoud’s equipment had not let him down (CD3-19).

Pharaoh Eagle-Owl has a very distinctive hoot consisting of a single, rapidly descending and diminishing note. The pitch levels out towards the end, sometimes creating a suggestion of a low final ‘syllable’, although it is never cleanly separated from the first. CD3-20 and CD3-21 were recorded near Rissani, also in Morocco, in different years and territories. Both are typically monosyllabic, although they differ slightly in how quickly the pitch levels out. 

Pharaoh Eagle-Owl breeds all the way from the Atlantic coast of Africa to the eastern limits of Arabia, although densities are low over much of this vast range. The name ‘desertorum’ is sometimes used for Pharaoh in the eastern part of its range (eg, Mikkola 1983). This subspecies is said to be smaller and paler than western birds, but has no basis in sounds. I once recorded a male at Wadi Dana in Jordan and the British Library Sound Archive has recordings from the United Arab Emirates but all sound indistinguishable from Arnoud’s Moroccan examples. 

At the other extreme of the breeding range, in Western Sahara, Arnoud did record one slightly different sounding Pharaoh Eagle-Owl. The hooting in CD3-22 sounds higher-pitched and slightly longer, as if wanting to draw attention to the high pitch, before descending as rapidly as in the other examples. In a weaker recording from the same location (CD3-23), this individual is joined briefly by a second one, whose hooting is closer to the other examples you have heard. Although faint, you can hear the second owl several times, eg, at 0:02. Both birds hoot from the same direction, and they seem likely to be a pair in the same territory, with the closer, higher-pitched one being the female. To the best of our knowledge, however, nobody has ever sound recorded hooting of a female Pharaoh Eagle-Owl with certainty, so there is nothing for comparison. According to König et al (2008), females do have a higher-pitched hoot, which would support the provisional sexing of the two individuals in CD3-23. 

Scouring the internet, I found one call type that was certainly given by a female Pharaoh Eagle-Owl. In a video of a public demonstration at the Centre for Birds of Prey, Charleston, South Carolina (sccontaindergarden 2012), a female demands morsels of food with a very coarse, rising rrrèh. This is similar to the soliciting call of female Eurasian Eagle-Owl B bubo but noticeably higher-pitched. 

We know what sort of prey male Pharaoh Eagle-Owls bring to females, because there have been many studies of the pellets of this species. They clearly prefer small desert mammals, especially jerboas Jaculus, gerbils Gerbillus and jirds Meriones, while invertebrates, especially scorpions and ‘camel spiders’ Solifugae, are probably their second choice (Boukhamza et al 1994, Rifai et al 2000, Sándor & Orbán 2008, Saint-Girons et al 1974, Shehab & Ciach 2008, Thévenot 2006, Vein & Thévenot 1978). The exact choice depends very much on rare episodes of rainfall. When it comes, the rain can be torrential. Annual plants react by growing new foliage almost immediately, and this in turn provides rodents with the minerals and water necessary to reproduce and lactate (Shenbrot et al 2010). Owls that live in the desert vary the exact timing of their breeding attempts according to rodent numbers. Perhaps this is why our visits never quite seem to coincide with the main courtship period. In Portugal a few 100 km to the north, Eurasian Eagle-Owls are at their most vocal in January and February. At the same time of year, the Pharaohs of Morocco seem to be much, much quieter.

Once Arnoud, Håkan and Killian were guided to a breeding cliff close to a village. Arnoud positioned his microphones before the male emerged, and as expected it hooted briefly before flying off. Not wanting to leave his equipment overnight for curious villagers to find, Arnoud climbed back up the slope. He was very surprised when the male started hooting again very close by, just as he was rolling up the cables. While Arnoud pressed record and held his breath, Killian accidentally knocked over a tripod some distance away. At this, the owl flew out, giving ‘devil’s cackles’ as it went (CD3-24). In the original recording there were three calls in sequence, then Arnoud lost his balance, spoiling the more distant calls.

Rissani, where CD3-24 was recorded, is perhaps the best-known area in Morocco for Pharaoh Eagle-Owls. It is right on the edge of the Sahara. Although there are cultivations around the town, the area is essentially flat desert with high, table-like rocky outcrops. Because of its outstanding beauty, several famous international films have been shot there. Rissani’s other claim to fame is that the ground is rich in fossils from the Devonian era, many of which are dug up from dangerous 10 m deep pits. 

Years ago, Arnoud made friends with a fossil seller named Lahcen Ouacha, who has a stall at a cave entrance on the road out of Rissani towards Alnif. When Lahcen saw tourists striking out into the desert to visit beauty spots they had seen in films, he would cycle after them with his fossils. Arnoud was one of the first birders to visit the area, which has since become popular. When Lahcen and one or two of his colleagues saw birders with binoculars, they offered to show them a Pharaoh Eagle-Owl. In the end, Lahcen got to know the owls rather well. Later, when Arnoud brought birding tour groups to Rissani, Lahcen kept an even closer eye on the owls, and went to look for other territories in the area. In return for up to date information, Arnoud brought customers to Lahcen’s cave and made him known to as many birders as possible.

One year, Lahcen told Arnoud about a breeding pair in a natural amphitheatre with beautiful acoustics, surrounded by a vast stretch of open rocky desert. Many centuries ago the Portuguese turned it into a fortress by putting a wall across the opening. The site became famous as a movie set for several films, including The Mummy in 1999. When Arnoud and Cecilia arrived to spend the night at this desolate site in mid-June 2010, two young Pharaoh Eagle-Owls haunted the fortress virtually all night long. In CD3-25, you can hear one of these fledged juveniles begging persistently at fairly close range. In CD3-26, both young are calling at shorter intervals, due to the arrival of a parent. The single hoot towards the end was the only adult call recorded during the entire night.

Pharaoh Eagle-Owl’s modern links with Egypt go back to 1809, when Savigny described ‘Bubo ascalaphus’ based on a specimen from Upper Egypt, in a 23-volume work on Egypt commissioned by Napoleon. Savigny was well versed in ancient literature, and the scientific name of his owl was based on Askalaphos, a figure from Greek mythology. Askalaphos was the custodian of the orchard of Hades, god of the underworld. After he told the other gods that Persephone had eaten a pomegranate in the underworld, they punished him by turning him into an owl (Ovid, Metamorphoses V, 534).

Although Savigny originally described Pharaoh Eagle-Owl as a species, for most of the following two centuries it was considered a subspecies of Eurasian Eagle-Owl. With a body length of 45-50 cm, it is around 75% of the size of Eurasian. The plumage of Pharaoh is much paler, and its ground colour is sandy-pinkish. The eyes are larger in proportion to the head. Diagnostic features include dark streaking on the upper breast but not the rest of the underparts, and a much more strongly marked black outline to the facial disc. Pharaoh is an extremely beautiful owl.

According to Wink et al (2009), Pharaoh Eagle-Owl and Eurasian Eagle-Owl differ by 3.5% in mtDNA, a level typical of species, not subspecies. In fact, Pharaoh is apparently not even the closest relative of Eurasian. That position belongs to Cape Eagle-Owl B capensis, an intermediate-sized predator of the Rift Valley, occurring from Eritrea and Ethiopia to South Africa. 

What happens when Pharaoh Eagle-Owl meets one of its larger northern relatives? Vaurie (1960) studied museum specimens from the contact zone between ascalaphus and the interpositus subspecies of Eurasian Eagle-Owl in Israel, and concluded that hybridisation was taking place. There has not been any molecular research to back up this view. Vaurie (1960) also suggested that Pharaoh and Eurasian occurred together on the southern slopes of the Atlas mountains in Algeria, based mainly upon the labels of two museum specimens. There have been no subsequent records and there is no proof that Eurasian ever bred there (Isenmann & Moali 2000), so it seems that only Pharaoh occurs in northern Africa, and that there is no opportunity to study interactions with Eurasian.

When we asked Håkan what he thought would happen when a Eurasian Eagle-Owl met a Pharaoh Eagle-Owl, he told us he had found remains of Ospreys Pandion haliaetus in three Eurasian nests. Håkan smiled and said that if they met, the Eurasian would eat the Pharaoh.

>>> Eurasian Eagle-Owl Bubo bubo >>>