Breeding biology of the helmeted guineafowl (Numida meleagris meleagris, Linnaeus 1758) in Western Ethiopia

Abstract

The study investigated the breeding season, nest site selection, clutch size, egg morphometry, and breeding performance of wild helmeted guineafowl (Numida m. meleagris) in the Arjo-Didessa River Valley Area, Western Ethiopia. Breeding data were collected during the 2018 and 2019 breeding periods. Its breeding ecology was studied by active nest monitoring techniques. Nest searches were carried out through intensive ground surveys using behavioral cues and systematically structured searching plots across the four habitat categories: grassland, farmland, forest, and riverine habitats. Egg morphometry measurement was examined using a portable vernier caliper (range: 0–150 mm, accuracy: 0.001 mm) and a digital balance (range: 2000 g × 0.1 g). Breeding performance was estimated as the percentage proportion of nests and eggs in a population sample that was successful in producing hatchlings. The active breeding season of helmeted guineafowl was from early June through late September when intensive egg-laying was observed. A total of 17 active nests comprising 207 eggs were located and monitored throughout the study period. Nests were located at a mean altitude of 1565.50 ± 270.50 m a.s.l. (range: 1295–1836). Most of the nests were observed in grassland (41.18%), followed by farmland (35.29%) and woodland forest (23.53%) habitats. No nest was recorded in the riverine areas. The species nest on the ground and prefer breeding areas scantily lined with essential vegetation cover. There was a statistically significant difference between habitat vegetation features and nesting site preferences of the species (P < 0.05). Helmeted guineafowl build nests with grass (45.39%), leaves (27.82%), feathers (11.46%), straw (8.95%), and other nesting constituents (6.38%) including dry weeds and lianas. Poaceae and Combretaceae were the most commonly used plants to construct nests. The mean clutch size of the species was 12.18 ± 4.40 (range: 5–19). The eggs were white creamy and sharp-shaped, with a mean egg shape index value of 60.36 ± 0.83 mm. The mean egg length, egg width, and egg weight of the species were 27.33 ± 0.19 mm, 16.44 ± 0.11 mm, and 43.42 ± 0.34 g, respectively. Its mean egg volume was 37.67 mm³. The breeding performance of helmeted guineafowl in the area was moderate with overall breeding (64.71%) and hatching (66.67%) successes. Its mean incubation period was 28.50 ± 1.83 (range: 25–32) days. The breeding performances of helmeted guineafowl varied between nesting habitats, by which the highest (100%) and lowest (50%) breeding success were recorded in the woodland forests and farmland areas, respectively. The breeding and hatching success of the species in the study area were highly influenced by human disturbance, abandonment, predation, and illegal egg collection activities. Further research and conservation efforts are, therefore, essential to understanding the post-fledging successes and maintaining the breeding and foraging areas which could enhance the breeding performance of the species and hence its conservation.