Suspended from the tiny tip of a twig at the attenuated top of a branch extending from an itself slender limb of a bristling thorn tree, an African weaver bird’s nest bobs.
"No uninvited guest, dinner guest at that, much bigger than a butterfly is likely to lite on that nest," I thought, marking a quick entry in my notebook. Africa, I read later in my apartment in Gaborone, capital city of Botswana, is home to more than fifty types of weaver birds, and India hosts a dozen or so more.
IN SPITE OF FREQUENT SIMILARITIES WEAVER BIRDS SHOW FASCINATING VARIETY
In spite of frequent similarities, these birds are prone to fascinating variety. Weavers are active "anters," for one thing. They will clutch up an ant and apply it vigorously to their plumage. No one is exactly sure why. Still, as a group, they are probably most famous for weaving their chicks a good, solid nest.
Weavers are active "anters," . . . They will clutch up an ant and apply it vigorously to their plumage. No one is exactly sure why . . .
With an agile flick, a bright yellow, black-faced Masked weaver, Ploceus velatus, swoops in to cling upside down to the woven nest I've been watching. Near by, a handful of other small nests, all about the size of large grapefruit, are similarly sited with offspring security in mind.
Immediately his caterwauling begins, an insistent call, demanding the attention of females. Distinctive parts of the call sound to my ear like the rapid metal-to-metal tapping of a tack hammer on the end of a dangling steel rod. Although sometimes they just hang while calling or perhaps sway a bit, the suitors also frequently snap their black and yellow, narrow wings open and shut adding visuals to their audio display.
As with all his brethren, as mentioned above, this weaver knits up a lavish home for his potential spouse. Carefully building a tough yet airy nest by skillfully "weaving" fresh, flexible grass or palm fibers. At first bright green, his construction dries rapidly in the dry desert air, like a sphere of tiny steam-bent canoe ribs, into a resilient yet wonderfully light habitation.
. . . as with all his brethren, as mentioned above, this weaver knits up a lavish home for his potential spouse. Carefully building a tough yet airy nest by skillfully "weaving" fresh, flexible grass or palm fibers . . .
Some weaver birds choose to create their baskety nests above standing water to thwart predators. Others set up housekeeping near protective neighbors: wasp nests or roosts of bigger, aggressive birds. Really nervy weavers have taken up residence dangling beneath eagle eyries.
In Botswana, and indeed generally in Southern Africa, the weavers often have a place analogous to cardinals or robins in the United States. Their presence is enjoyed by many members of the regular population, entirely outside birders and biologists. Homeowners try to attract them, and conversation may be about the changing locations of the remarkable nests.
According to common information, as a gaggle “. . . weavers are seed-eating birds with rounded conical bills, most of which breed in sub-Saharan Africa, with fewer species in tropical Asia and also in Australia. The weaver group is divided into the buffalo-weavers, sparrow-weavers and typical weavers.
The males of many species are brightly coloured, usually in red or yellow and black, some species show variation in color only in the breeding season. Weavers get their name because of their elaborately woven nests. The nests vary in size, shape, material used, and construction techniques from species to species.” The small, quick-flitting weavers I watched in Botswana certainly exhibited character typical of their family ties!
. . . the weaver group is divided into the buffalo-weavers, sparrow-weavers and typical weavers. The males of many species are brightly coloured, usually in red or yellow and black, some species show variation in color only in the breeding season . . .
THE RED BILLED WEAVER OR DREAD QUELEA: A SCOURGE OF EAST AFRICA
Not all nominal weavers—those cone-billed, generally seed eating birds including sparrows and their allies in the family Ploceidae--are welcome because they can become enormously numerous. The so-called red-billed weaver or dread quelea has been a scourge in East Africa. When food is fairly plentiful, usually from well into until the end of the rainy season, the attractive little birds travel in large flocks. In times of scarcity, these communities coalesce into cities on the wing with populations sometimes, terrifyingly for the farmers, into the millions.
And, just as the benefit of agriculture, with its routinized cultivation and its irrigation practices, is the maximization of food productivity for human consumers, this benefit exists for the quelea to the farmer's detriment. Quelea, settling like smoke on millet and sorghum fields, can denude them of food in an hour.
Such ruthless avian reaping has stimulated the human victims of quelea infestation to reply equally ruthlessly. The pest species has been fire bombed, air assaulted with powerful toxins, net trapped, and suffered roost after roost put to the torch. None of these brutal methods serve the desired end: the vast hordes still arrive to chow down on hundreds of tons of agricultural produce.
. . . such ruthless avian reaping has stimulated the human victims of quelea infestation to reply equally ruthlessly. The pest species has been fire bombed, air assaulted with powerful toxins, net trapped, and suffered roost after roost put to the torch . . .
Sometimes all "weavers" are painted with the same brush. At issue here, of course, is the curious complexity of the nests among true weavers.
VARIETY IN WEAVER BIRD NESTS
Buffalo weavers of East Africa use press-gang tactics, adolescent non-breeding males helping build group nests from thorny acacia twigs. Each member of the dominant bird's harem gets an individual brood chamber. In Kenya, the communal nests of the white-browed weaver are reportedly fashioned with two openings in order to frustrate would-be predators.
Obviously, among many weavers, nests have taken on deeply social and physiological implications. Once the male masked weaver has selected a site--and unlike some cold climes when the short breeding season demands quick action, the climate in Botswana allows great indulgence--he turns out a nest. Then he literally hangs around whistling at the girls.
It's generally assumed that females, who certainly scope out the guys in the fashion of teenagers around a poolside, use the color of the nest as an indicator of competence. Young males must devote a meaningful period to practicing nest construction before entering the mating fray. In any event, a complete nest finished and still green may signal quickness, health, and dexterity--to say nothing of enthusiasm. Golden brown, drying nests are scorned.
Written sources sometimes say the female weavers will unweave nests they particularly don't like (because these things are tight, this is a real chore, involving undoing the labor which went into the original weaving). I never saw this among the many Masked Weavers and far fewer Spotted backed Weavers, Ploceus cucullatus, I observed while in Botswana. But nests were certainly torn up, abandoned, or apparently duplicated. Some weavers did seem to strip leaves from the twigs they intended to use, and perhaps just stripped leaves as a nervous habit.
. . . written sources sometimes say the female weavers will unweave nests they particularly don't like (because these things are tight, this is a real chore . . .
With so many species in Africa it’s easy enough to find the nests. Often sociable, weavers frequently cluster in colonies making the nests yet more prominent. Within the nominal weavers, there's lots of variation in method, strategy, and behavior. For example, if the Masked Weavers lean toward architecture to impress mates, the exotic Red Bishop, Euplectes orix, relies on what looks like a fuzzy, bright-red balaclava and distinctive, attention-getting fancy flights.
Although forming in colonies might be viewed as risky, advertising the bird's presence to predators, some benefits are clear. Once the hen is brooding, the nest entry may be extended, tube-like. Then, if a wily serpent stops in for a bite, its dangerous fore end is sheathed in woven grass while its end hindermost is all too vulnerable to colony-strong pecking. Usually it gets the mob's message and heads off for a less troublesome repast.
Also, the general brouhaha of a colonial group helps vivify reproduction while the many adults provide excellent role models for chicks. The sites I visited in Botswana routinely ranged from a handful of nests, some of which were invariably disused, to many dozens. In South Africa colonies of many hundreds were said to be fairly common.
BIRDLIFE IN BOTSWANA
Although Southern Africa is considered to embrace the area south of the Okavango-Zambesi Rivers, it shares much with the general sub-Sahara avifauna. Thus, the region is lush with bird life. Botswana is rich with representative examples within its habitat zones and with seasonal and rare vagrants. Its 582,000 square-mile area is thinly populated with a bare 1.5 million people leaving enormous expanses unburdened by human presence on a regular basis.
[Botswana's] . . . 582,000 square-mile area is thinly populated with a bare 1.5 million people . . .
Back at a weaver bird colony, the individual birds tap out their calls and noisily fan their wings unless they see me. Discovered, my proximity would bring about an immediate change: they drop off and flutter to a near-by bush. Curiously, they tend to move down to somewhat lower, leafy branches, keeping an eye on me.
In twos, threes, fives they would shoot out from the thorny bush veld, and with the characteristic rise-and-thrust, arrow toward other thickets. Later, they zooned back, regained their hanging positions at the lips of their basket-like nests, and began again the timeless, enduring calls to potential mates.