The Survey Findings of the Fox’s Weaver in North-Eastern Uganda

The Survey Findings of the Fox’s Weaver in North-Eastern Uganda” Uganda’s only endemic bird species is the Fox’s Weaver, Ploceus spekeoides (Carswell et al., 2005). The species was initially collected in July and August of 1913 in the Katakwi district near Usuk and Ngarium by an English zoologist called Harold Munro Fox, after whom the species was named. A female Fox’s Weaver was taken at Usuk on August 14, 1913, while a male specimen was collected on July 30, 1913, at Ngarium. Once Grant and Mackworth-Praed completed their comprehensive description of the species in 1947, the specimens that had been sent to the British Museum in 1923 were kept there.

Physical Characteristics and Survey findings of the Fox’s Weaver

With its huge head, substantial bill, and short tail, the Fox’s Weaver is a rare weaver. The male’s black mask finishes in a point on his breast, and he has a yellow rump and crimson eyes. The species is often confused for several other weavers that have a similar appearance because to its similarities to other species. Similarities exist between the species and Ploceus spekei, the Speke’s Weaver, except that the latter has a pale eye and a distinct range. Ploceus heuglini, the Heuglin’s Masked Weaver, has a short bill, pale eyes, and a simple green back. Ploceus intermedius, the Lesser Masked Weaver, has a black fore-crown and a white eye, whereas Ploceus vitellinus, the Vitelline Masked Weaver, has a distinctive chestnut crown and black mask curving around the throat. According to Keith and Fry (2004), the female Fox’s Weaver has light-colored underparts and a yellow rump, along with thick, dark stripes across her back and crown.

Diet and Foraging habits

Although little is known about the species’ eating habits, it is known that it consumes seeds and ants (Keith & Fry, 2004). The bird’s breeding ecology has been fairly thoroughly investigated, and it is believed to take place from May to August. According to the Fox’s Weaver Expedition Report (2018), the species’ preferred place to build nests is on standing Whistling-thorn acacia trees. Nests measure 140 mm in length and 80 mm in height. There is no entrance tunnel and the opening is 45 mm by 50 mm (Keith and Fry, 2004).

Distribution and Survey findings of the Fox’s Weaver

Only the northeastern region of Uganda is home to the species. In the former Teso district, where the species is highly prevalent during the wet seasons, the majority of records have been made at Aketa, Usuk, Ngarium, and Katakwi (Pitman 1948, Mann 1976). In August 1996, forty-seven nests of the species were recorded around Lake Bisina. Additionally, unverified records of the species were obtained from Rhino camp in Arua and from south of Lake Kyoga near Nakasongola (Byaruhanga et al., 2001). Though the species’ range is mainly unknown, it is believed to be limited to an estimated 33,300 km2 in northeastern Uganda (BirdLife International 2017).

Threats and challenges

On the National Red List (WCS, 2016), the species is listed as Endangered and is considered Near-threatened both globally and regionally (BirdLife, 2017). Changes to and destruction of the species’ habitat pose a threat. Every dry season, from October to February, more than 20,000 cattle heads migrate to the Opeta region in search of pasture and water, which damages the woodland grasslands that the species depends on for reproduction (Byaruhanga et al. 2001).

Observations and Survey findings of the Fox’s Weaver

The first recorded rediscovery of the species occurred in July 2018 during a reconnaissance visit by the Nature Uganda team to the recently found habitats of the species, despite the fact that the population of this bird species is unknown. After that, in August 2019, a more thorough survey was conducted in the region, encompassing four districts and large ecosystems. At that time, the majority of the species’ recordings were made on nests, suggesting the height of the mating season. The ecology and behaviour of the species have not received much attention, with the exception of the breeding season, which is known to take place between May and August. Although the species is classified as endangered locally, it is considered near-threatened globally and regionally.

Only a small region of periodically flooded wetlands in northern Uganda has been known to harbour Fox’s Weaver, Ploceus spekeoides (Collar and Stuart, 1985; Byaruhanga et al., 2001). The species is found in the marshy habitat that stretches between Lake Bisina and Lake Opeta, two Important Bird Areas (IBAs) where it has been documented. According to Byaruhanga et al. (2001), there are records from as far north as Rhino Camp in Arua, the area south of Lake Kyoga close to Nakasongola, and the area surrounding Lake Bisina.

Since 1996, the species’ existence in the nation has not been officially recorded for more than 20 years, with the exception of a few sporadic, unverified sightings. Despite thoroughly examining the habitat in northeastern Uganda, no individuals of the species were found during a survey carried out by Nature Uganda in 2015 (Nalwanga et al., 2015). In August 2018, Nature Uganda carried out another survey that proved to be more fruitful. Twelve (12) individuals and thirty-two (32) nests of the species were found in Magoro, Katakwi District. The 2018 survey verified the Fox’s Weaver’s existence in northeastern Uganda. Several observers have reported seeing the animal multiple times since then.

Despite being proven to exist in northeastern Uganda, it is unknown where the species is distributed within its occurrence range. To map the distribution and breadth of the species’ occurrence in northeastern Uganda, Nature Uganda and the Uganda Bird Guides Club (UBGC) performed a survey of the Fox’s Weaver and Karamoja Apalis.

Objectives of the study

The study’s main objectives were to:

• Determine the Fox’s Weaver’s range of occurrence in northeastern Uganda.

• To compile information on the two species’ preferred habitats, Karamoja Apalis and Fox’s Weaver.

Study area and methods

The investigation was conducted between May and August, during the Fox’s Weaver breeding season (Keith and Fry, 2004). A total of roughly 13,000 square kilometres, or fourteen locations spread across six districts, were surveyed. districts of Katakwi, Soroti, Kumi, Amuria, Ngora, and Napak were included in the study.

The investigation was carried out by four groups made up of volunteers from Uganda Bird Guides Club and employees of Nature Uganda. Based on prior records, line transects were methodically created in seasonally flooded wooded grassland habitats, which were thought to have a high possibility of species presence (Fox’s Weaver Expedition Report, 2018). We also conducted surveys in other possible habitats, particularly in wetlands that were periodically submerged.

Survey Methods and Survey findings of the Fox’s Weaver

The number, sex, and activity of each individual of the two species was recorded along each transect, as were the GPS coordinates of all nesting trees and bird sightings, nest count, nesting tree characteristics (such as species name and tree height), the dominant vegetation, and the predominant human activity.

Results of Fox’s Weaver Sightings

A total of Six (6) districts were surveyed, with records for the Fox’s Weaver coming from four (4) of those districts (Soroti, Katakwi, Amuria and Napak). Despite the whistling thorn’s favourable habitat, Ngora and Kumi did not record any individuals of the species in the area where the bird species appeared to have been reported. Additionally, a total of sixty-six (66) respondents were identified for the survey. Of these, men made up the majority (74%), followed by women (23%), and juveniles (3%). The majority of them (50) were found in Katakwi, followed by seven in Napak, six in Amuria, and three in Soroti.

Breeding Records

Eight (8) locations in the Districts of Amuria and Katakwi yielded a total of 168 nests that were recorded. Of the nests, the majority (51%) were inactive, while the remainder were active. As seen in Figure 8 below, every nest that has been documented was built on Whistling-thorn Acacia Vachellia drepanolobium. The majority of the nests were built on trees near or in water. It was noted in the field that although females search and select the best nests, males appear to construct the majority of the nests.

Two important districts, Amuria and Katakwi, were found to have active nests. 42 active nests were found at the sites in Magoro, Katakwi, the most of any place (Figure 9), indicating the locations’ significance for weaver reproduction.

Nesting Materials

African bristle grass, or Setaria sphacelata, is the main material that Fox’s Weavers use to build their nests. The stalks and inflorescences of this grass are used by the weaver to construct the nest. Guinea grass, Megathyrsus maximus, is typically used to line the inside of the nests. Based on this data, it appears that the species chooses which materials to use to create its nests.

Bird activity and survey findings of the Fox’s Weaver

Of the records, 51% were of birds that were observed feeding. The Whistling-thorn Acacia (seen below) and the ant Crematogaster mimosae are symbiotic, and the Fox’s Weaver has been seen to feed on both. Other behaviours, such perching and building nests, were closely linked to this Whistling-thorn Acacia.

Habitat Characteristics

Just 3% of Fox’s Weaver sightings were reported in arid regions, but the majority of sightings and nesting records (97%) were documented in seasonal wetlands. It is interesting to note that Karamoja Apalis and Fox’s weaver were frequently observed feeding at the same locations. Seasonally flooded forested grasslands with a predominant Acacia plantation are the hallmark of northeastern Uganda’s seasonal wetlands.

Evaluating Possible Routes for the Distribution of Fox’s Weaver

Dominant Vegetation

In the regions where Fox’s Weaver was found, the predominant tree species was the Whistling-thorn Acacia. For the species, this Acacia is the preferred species of nesting tree. The species of bird was observed consuming food made by ants (Crematogaster mimosae), which live in harmony with Whistling-thorn Acacia. Hyparrhenia rufa was the predominant herbaceous species; it was frequently seen in mixed stands with Setaria sphacelate, Sporobolus pyramidalis, and occasionally Megathyrsus maximus.

Human Activities

The majority of human activity at all Fox’s Weaver locations (93%) was grazing. The Iteso people who reside in the area mostly depend on cattle for their livelihood, and the forested grasslands in the area offer suitable pasture for their animals. Farming and fishing are typically combined with cattle rearing.

Altitude of the Fox’s Weaver

The seven sites’ individual and nest records of Fox’s Weaver sightings varied in altitude from 1044 to 1262 metres above sea level. The highest point at Iriiri, which was 1262 metres above sea level, was higher than any other site in the Napak district, whereas the average elevation at Lorengecora was 1160 metres. The lowest point was 1046 metres above sea level at Gweri in the Soroti District. With the exception of those in Napak District, all Fox’s Weaver sightings occur between 1022 and 1099m.

Soils and vegetation of the Fox’s Weaver

It is evident from the vegetation map created for the study area that the species was observed in the Edaphic Wooded grassland vegetation type. These woodland grasslands are found in soils affected by drainage and are primarily composed of Acacias (Bruegel et al., 2015). Given that the Fox’s Weaver nests atop V. drepanolobium and feeds on ants that live there, this is hardly a coincidence. These results support the theory that the species may be limited to grasslands that are periodically flooded and are mostly dominated by V. drepanolobium.

Additionally, sightings of Fox’s Weaver were discovered in soil types classified as vertisols. While soil type has a significant impact on vegetation type, it does not directly affect bird dispersion. The majority of sightings were reported in Vertisols, indicating the importance of these soil types’ vegetation for the species. According to an ecological study and characterization of acacia species in Kenya, soils rich in black cotton support the growth of Vachellia drepanolobium (Oginosako et al., 2005).

Recommendations:         

In conclusion, despite the Survey findings of the Fox’s Weaver, it is more widespread in the nation than previously believed based on historical data. The weaver’s range has expanded northward, reaching the Napak District’s Iriri. Four districts, primarily in the northeastern region of the nation, have records for this bird species.

To determine the true extent of species coverage, more research on the distribution of this bird species needs to be done in new, potentially suitable habitat areas. Since the majority of research, including this one, have been conducted during the breeding season, it is also unknown where this bird species is found during the non-breeding season. Therefore, surveys must be conducted throughout the non-breeding season as well in order to determine the Fox’s Weaver’s distribution during that time.