Prigogine's Greenbul

19-20 cm  

Golden-olive greenbul  

Pale grey lores and preorbital area  

Feathers are short, stiff, and pointed forward  

Pale grey eye ring that is broad and contrasting  

Rest of head and upperparts are yellowish olive-green  

Wing feathers are dark brown with yellowish olive-green outer webs  

Tail is olive-colored with yellowish olive-green margins  

White chin  

Yellow throat  

Greenish-yellow underparts  

Side of breast and flanks are darker and greener than rest of body  

Undertail-coverts are yellowish-brown  

Dark red iris  

Black bill  

Dull bluish-grey legs 

Prigogine’s Greenbul is similar in appearance to the Joyful Greenbul (Chlorocichla laetissima) 

This species differs from the Joyful Greenbul by being smaller, having a white (not yellow) chin, grey (not yellow) lores and preocular area, and a pale grey eye ring  

Based on the specimens collected, the females of the species tend to be smaller than the males 

Habitat 

This species’ range is known only to encompass the Albertine Rift in northeast Democratic Republic of the Congo (DR Congo) that includes the Lendu Plateau between Nioka and Djugu as well as other sites in the Beni-Butembo region northwest of Lake Edward (Birds of the World) 

The only specimens of the species were collected in dense understorey in isolated montane forest patches, thickets, and gallery forest along rivers at an altitudinal range of 1280-1800 m (IUCN Red List) 

Other Information 

Movement unknown  

Diet is unknown although the stomach of one specimen contained seeds, pulp, and a caterpillar 

Vocal behavior unknown  

Breeding behavior unknown (Birds of the World) 

Life span- 3.4 years 

Prigogine’s Greenbul is listed as Endangered by the IUCN that made its last assessment in 2016. The rate of habitat loss, the species’ small range, and the fact that most of the forests in the Lendu Plateau and the Beni-Butembo regions have been destroyed by logging and encroachment makes this species endangered if not critically endangered. It is difficult to gauge the state of this species since so much is still unknown about this bird’s behavior and range. It is possible that the species may still exist in suitable habitat outside the two regions where the only specimens were collected (i.e. Lendu Plateau and the Beni-Butembo region). The species’ extent of occurrence is 4300 km.² Experts believe that, given the rate of habitat loss, there may be only 40-50 individuals remaining at the Lendu Plateau with the total population numbering around 250 individuals (IUCN Red List). 

To see a distribution map for Prigogine’s Greenbul, click here.

Most of what is known about Prigogine’s Greenbul comes from specimens collected between the years 1948-1981. Most of these specimens (13) come from the Beni-Butembo region with only one originating from the Lendu Plateau that was collected in 1926. Both of these sites are in the northeast of the DR Congo. 

Even though specimens of Prigogine’s Greenbul were collected as early as 1948, the species would not be discovered until 1967 when the specimens were examined by Antoon de Roo. He named the bird after the specimens’ collector, the Russian-Belgian ornithologist Alexandre Prigogine.  

Other than these specimens, sightings of this rare greenbul have been scarce over the years. 

During the 1950s, J.M Vrijdagh reported seeing Joyful Greenbuls in the Lendu Plateau. Due to the fact that this species is similar to appearance to Prigogine’s Greenbuls, it is possible that some of the greenbuls Vrijdagh saw could have come from the latter species. If this was indeed the case, he does not state as such in his survey accounts. 

The only known expedition to search for Prigogine’s Greenbul was done from February 6-8, 1994. This expedition was led by Tommy Pedersen, Marc Languy, and Laurent Esselen. The three visited an isolated highland region west of Lake Albert in Lendu. Their mission was to find traces of Prigogine’s Greenbul and the Lendu Crombec (Sylvietta chapini). By flying over the area, they were able to identify two main forest patches that had not been razed due to logging and encroachment from neighboring villages. These areas were Djugu close to the village of Nioka and another area close to the plateau’s edge east of Nioka. Each area was the size of around 10 football pitches. After searching both areas, they did not find any Lendu Crombecs. However, they did not come back empty handed because they were able to find three Prigogine’s Greenbuls  

Pedersen et al., spent two days on the Lendu Plateau where they explored the Djugu Forest near Nioka between February 7 and 8. Within an hour of entering the forest on February 7, they saw a Prigogine’s Greenbul (the first sighting of the bird in 13 years). The bird was alone and silent in the understorey of a relatively damp forest. They observed the bird for one minute before she flew into the dense forest. It was not long before they found another member of the same species nearby. This greenbul followed a group of 12 noisy Joyful Greenbuls. The bird stayed with the flock of Joyful Greenbuls near a drivable forest path 1-3 m above the ground until they disappeared two minutes later. Pedersen et al., noticed that, in sharp contrast to the Joyful Greenbuls that called and flicked their wings frequently, the Prigogine’s Greenbul remained silent and perched on large leaves of a bush. On February 8, another Prigogine’s Greenbul was seen following Joyful Greenbuls near a small stream. The bird’s behavior was similar to that of the other Pedersen et al., had seen the previous day. After their encounters with the elusive greenbul, Pedersen et al., noted that the main difference between Prigogine’s Greenbul and the Joyful Greenbul is that the former has a clear grey area between the bill and eye as well as a distinct pale grey eye ring. These traits can help identify the bird in the field (Pedersen, 1997).  

The Prigogine’s Greenbuls encountered by Pedersen et al., marks the last time this species was sighted. Thirty years later, it is unclear whether the forest patches searched by Pedersen and his friends still remain due to the high rates of logging and encroachment in the Albertine Rift. Political instability in the region makes any surveys next to impossible.

A major concern is that most of the montane forest habitat in the Lendu Plateau and the Beni-Butembo region has been destroyed due to uncontrolled logging and encroachment from nearby villages. The Lendu Plateau is a large massif at the northern end of the Albertine Rift in northeastern DR Congo bordered in the north by Uganda. It is located between 1,700-2,000 m altitude with the main habitats being mostly grassland with isolated trees. Most of the montane forest above 1,500 m has been destroyed. In 1994, when Pedersen et al., conducted their survey, only 24 hectares of forest remained in the Lendu Plateau (Pedersen, 1997). Thirty years later, the amount of remaining forest is probably significantly lower if not completely gone. The forests remaining in the Beni-Butembo area is unknown. Some forest patches might still remain.   

The disappearance of the montane forests in the Albertine Rift is the biggest challenge facing the survival of Prigogine’s Greenbul. Most of the montane forest in the Lendu Plateau has vanished due to encroachment from surrounding villages and logging (Birds of the World). It is unclear how many patches of forest remain and if those patches are even sufficient enough to sustain a tiny population. One can only speculate since so much is still unknown about this bird. It is possible that this bird’s range could extend outside the Lendu Plateau and Beni-Butembo; increasing the species’ chances of survival. Some forests might still remain west of Lendu at Mt. Wago, around Mongbwalu, and Bondo Mabe that have not been explored. Without detailed surveys, it is unclear how the political instability in the DR Congo has affected the rates of habitat loss in these areas. 

Another challenge is the political instability that continues to plague the DR Congo that makes any assessment or survey of these areas almost impossible.

This habitat loss across the range of Prigogine's Greenbul is caused not only by encroachment and logging but also by the indirect and direct impacts continuous armed conflict has had on diverse ecosystems in the DR Congo. During a wartime situation, there are several ways an armed conflict can negatively affect wildlife. Animals can be accidentally killed by mines or shells. They can be hunted and overexploited to feed troops. If they are an endangered species, they can even be used by hostages or pawns to hamper government troops or gain international support. War can affect park institutions in a reserve where endangered and vulnerable species are protected. Rebels can occupy an area and chase park officials away. With park institutions absent, this not only opens the door for rebels and poachers but also refugees from neighboring regions affected by the conflict to come in and overexploit park resources and destroy natural environments (Gaynor et al., 2016). All of these factors either have happened or continue to happen on some level in the DR Congo ever since the country ceased to be a Belgian colony in the 1960s. The armed conflict that has ravaged the country does not show signs of ending anytime soon. While large mammals tend to be the center of attention for economic reasons such as poaching, birds can be the target of poaching and habitat loss as war forces many in the country to overexploit resources to survive. 

The DR Congo has among the richest and diverse ecosystems in the world. Ironically, these areas are also among the most poorly studied and ravaged by habitat loss as a result of the incessant warfare that has plagued the country since independence. Prigogine’s Greenbul is one of 13 rare species that are either only known from the DR Congo or are mainly known from this region. Other than Prigogine’s Greenbul, the list includes the Itombwe Nightjar, Itombwe Owl, Chestnut Owlet, Grauer’s Cuckooshrike, Lendu Crombec, Kabobo Apalis, Sassi’s Greenbul, Chapin’s Mountain Babbler, Prigogine’s Sunbird, Upemba Masked Weaver, Black-Lored Waxbill, and Yellow-Legged Weaver. It appears that more and more of their habitat is destroyed by agriculture and overexploitation and more and more of their members are captured or killed due to poaching and hunting with every passing year. If the armed conflict in the DR Congo does not cease, it is unsure how much longer these rare species can continue to cope with the direct and indirect impacts war has had on their survival.

When the political situation in the region becomes stabilized, detailed surveys should be done to see how much forest remains in Beni-Butembo, the Lendu Plateau, and the Albertine Rift as well as whether or not any Prigogine’s Greenbuls could possibly still be living in these areas despite the rampant habitat loss.

Order: Passeriformes 

Family: Pycnonotidae 

Genus: Chlorocichla 

Species: Chlorocichla prigoginei