The White-browed Sparrow-weavers (Plocepasser mahali; Afrikaans: Koringvoël) is a predominantly brown, sparrow-sized weaver found throughout central and northern southern Africa.
It is found in groups of two to eleven individuals consisting of one breeding pair and nonreproductive individuals.
Description
It ranges from 17 to 19 centimeters (6.7 to 7.5 inches) in length and is characterized by a broad, white eyebrow stripe and white rump visible in flight.
While the male White-browed Sparrow-weaver sports a black bill, the female’s bill is horn-colored; that of the juvenile is pinkish-brown.
In Zimbabwe, the White-browed Sparrow-weaver shows faint brown spotting across its white breast.
Similar Species
The Yellow-throated Petronia has a pinkish brown (not black) bill, a buff (not white) eyebrow stripe, black (not pink) feet, and yellow shading at the bottom of a white throat.
Additionally, the White-browed Sparrow-weaver is larger than the Yellow-throated Petronia. Unlike the White-browed Sparrow-weaver, the Yellow-throated Petronia may be found in broad-leaved woodland.
Distribution, Habitat, and Migration
The White-browed Sparrow-weaver is found in greatest numbers in north-central southern Africa. While this species most densely populates dry regions with woodland or wooded grassland in northern South Africa, its range includes Botswana, northern and central Namibia, and western Zimbabwe. Populations may be found as far north as Ethiopia.
This species nests along thornveld and scrubby, dry riverbanks.
Because the White-browed Sparrow-weaver nests in colonies, populations are sedentary.
Subspecies
There are four recognized subspecies of the White-browed Sparrow-weaver.
- P. m. Mahali is found in the eastern part of the Northern Cape Province of South Africa.
- P. m. Stentor is found in the western part of the Northern Cape Province northwards along the Namibian escarpment.
- P. m. terricolor is found towards the center of the White-Browed Sparrow-weaver’s range, occurring predominantly in eastern Botswana.
- P. m. pectoralis is found in northeastern Zimbabwe along the lower Zambezi River.
Nesting
Year-round, groups of the White-browed Sparrow-weavers are active and nest-building. Groups of ten to sixty inverted-U-shaped nests of dry grass appear in the outside limbs of trees, although only several are used for breeding or roosting.
While breeding nests have only one entrance, roosting nests have an entrance located at each of the two nest extremities.
Research has shown that, throughout a region, nests are located at the leeward side of a tree. According to Bug Guide, this species is well documented.
This behavior preserves a greater number of intact nests for breeding and roosting. White-browed Sparrow-weaver nests are sometimes used by other birds, such as the Red-headed Finch and Ashy Tit. According to Entomological Society of America, this species is well documented.
Breeding
Breeding has been observed year-round, but occurs mainly in warmer months.
Voice and Vocal Behavior
The White-browed Sparrow Weaver is a fairly vocal bird, using a variety of songs and calls in various social and environmental situations. Their voices include brief “chik-chick” calls as well as longer, more elaborate whistles described in literature as things like “cheoop-preeoo-chop.” The calls are sharp, carrying, and designed to be heard over some distance–often in early morning or around dawn when many birds are most vocally active.
Their duetting behavior is an interesting characteristic. Mated pairs sing in choruses or duets, and sometimes they have their own duet train where the partners alternate vocal elements or overlap them. Each pair has its own rules. Duets and choruses tend to be more prevalent at certain times (early morning), and are often linked with territorial or breeding behaviour. The studies have shown that couples adhere to certain rules of answering. Each individual responds to others in predictable manners, contributing to an organized vocal interaction.
The density of the groups around you also influences song variation: those groups that are closer together tend to have more choruses and duets. The vocal repertoire is vast: males and women share many “elements”, or syllables. However, certain parts of the repertoire are sex or pair-specific.
Alarm calls and group calls are used to alert group members when predators are nearby or when they need to coordinate. Vocal coordination is also important for group cohesion and territory defense when you live in a group.
Feeding
The White-browed Sparrow Weaver’s feeding behavior is flexible and opportunistic. Omnivores, they forage on the ground primarily in small groups of 4-10 birds (sometimes more), often near nesting trees and colony areas. They eat insects such as beetles, ants, termites, and other bugs. In some regions, seeds are important, particularly grasses and grains like wheat or maize. Fruits and leaves with flesh are eaten whenever they are available, particularly in seasons where insects are not as abundant.
Foraging is done by jumping or running, scratching the soil to reveal insects. They may also dig small holes in the soil or move small stones. Also, they eat fallen debris and lower vegetation. They tend to forage in shaded areas when it is hotter or during the day. Because of the nature of their habitat, which is dry with scattered trees, ground foraging can be efficient, but it depends on the availability of insects and seeds, both of which are dependent on weather/rainfall.
After the rains, the abundance of insects increases, increasing feeding opportunities. In seasons of drought, the diet shifts to seeds and plant material. It appears that their ability to use different food sources helps them to survive in a variable environment.
Conservation
The IUCN Red List rates the White-browed Sparrowweaver as Least Concern. The species’ range is very large (Extent Of Occurrence approximately 9,610,000km2), and its population seems to be stable. It does not meet the thresholds of Vulnerable for range, population, size, or trend criteria. Although the exact number of mature individuals is not known, it is believed that this species does not appear to be declining rapidly. BirdLife DataZone
The species is not as threatened by deforestation as other birds. This may be because the species lives in semi-arid habitats and open areas that are less affected than those of forest specialists. There are still pressures. Overgrazing, agricultural conversions, the removal of vegetation (especially mopane trees, acacia, and thorn trees), and changes in land use can cause habitat degradation. This may reduce nesting sites or alter foraging grounds. Sometimes, predators bear irds of prey, ssnakend monkeys. Prey on chicks or eggs. Climate change can also pose a risk. Changes in rainfall patterns could affect the food supply, especially insects, and breeding timing. Extremely hot or dry years can reduce the reproductive success of animals or threaten their survival.
Conclusion
In many ways, the White-browed Sparrow Weaver is a success. This bird has managed to survive despite arid climates and unpredictable rain, as well as seasonal food shortages and predators. The bird’s cooperative nature, its flexible feeding habits and multiple nests, both breeding and roosting, and its wide geographic range are all factors that contribute to its being resilient.
But that doesn’t mean there aren’t challenges. The pace of environmental change is increasing: land use changes, the loss of forest cover, climate shifts, and extreme weather. This species, while not threatened at the moment, lives in a constantly changing landscape. What’s stable today could be fragile tomorrow.
The White-browed Sparrow Weaver isn’t just interesting because of its color or song, but also for its social life. It breeds cooperatively, with its nest-building and group-defence, its vocal duets that bind together groups, and its survival depends on group structure and the environment.
