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Land-use practices can impact on bird populations. This study set out to explain why the helmeted guineafowl, Numida meleagris (Linnaeus 1766; Aves: Numididae) declined in the Midlands of KwaZulu-Natal, South Africa, an agricultural area where these birds were once abundant in savannas mixed with cultivation. Within the Midlands, the potential roles of land-use practices and pesticides were investigated. Using a grid cell approach, the distribution of 11 land-uses was mapped for 19 farms with different levels of guineafowl abundance. The edge distance between extensive and intensive agriculture was significantly associated with the presence of guineafowl. The presence of guineafowl was associated with greater land-use diversity, showing this species' preference for a mosaic of land-uses. Extensive agricultural areas were used for cover and intensive ones for food, but the adjacency of these land-uses affected access to these resources. Larger flocks (>=100 birds) were associated with pastures free of agro-chemicals, while smaller flocks (<100 birds) were associated with cereal lands where chemicals were used. The use of chemicals may reduce reproductive success by removing arthropods and weeds, which are critical food sources for female guineafowls and their keets during the breeding season. An inadequate grass cover for nesting may further reduce reproductive success. This study suggests that a combination of land-use spatial pattern and other factors, such as pesticide use, contributes to the decline in helmeted guineafowl populations in this intensively farmed area of South Africa.