Food and Feeding Behaviour of Kingfishers (Family: Alcedinidae) in Selected Water Bodies in Osun State, Nigeria

Study Area

This research was carried out within Osun State which has a total area of 9251km2 and coordinates latitude and longitude 7°00′N 4°00′ E and 8°14′ N,5°00′ E [11]. The state experiences a tropical climate while the local vegetation is the lowland rain forest type that favour agriculture. The sampling locations (Opa Reservoir in Ile - Ife, Akinrinade Reservoir in Moro, Osinmo Reservoir in Ejigbo and Osu Reservoir in Osu) were randomly selected for the research.

Opa Reservoir

Opa Reservoir was established in 1978 by the impoundment of Opa River which took its source from Oke Opa Hills. The climate of the area is characterized by two distinct seasons, dry and wet seasons. The wet season extends from April to October and is marked with high rainfall; while dry season on the other hand extends from November to March [12]. It has a mean annual precipitation of 1000-1250 mm and a mean annual temperature of about 27°C [13, 14].

Osinmo Reservoir

It was created in 2005 by the impoundment of Ataro River which took its source from Iware in Oyo State. It has a catchment area of about 102 km2. The reservoir basin extends from Longitude 04°21.2' E to 04°21.7' E and from Latitude 07°52.8' N to 07°53.2' N. It occupies an undulating terrain with the highest altitude of 365.76 m above the sea level. The vegetation of the area is a lowland rain forest with some areas of derived grassland. There is heavy rainfall between July and September of each year and an annual rainfall of 130.88 mm has been recorded [15].

Akinrinade Reservoir

Akinrinade Reservoir located in Moro, Ife North Local Government of Osun State was constructed in 1980, primarily for fishing and it is characterized by dense forest around the Reservoir.

Osu Reservoir

Osu Reservoir is situated in Osu, Atakumosa West Local Government area of Osun State, Nigeria. This reservoir was impounded in the year 2005 by Osun state government in conjunction with Osun State Water Corporation. The surface area of the reservoir is about 0.118km2.

Sampling Technique

In each of the sampling sites, observation and data collection were done for a period of twelve months April to October, 2017 for the rainy season while November to March, 2018 for the dry season. Following local informants and personal observations of brightly coloured plumage, various sizes of kingfishers and perching characteristics were used in identifying various species. Confirmatory identification was done using a (Borrow Nik and Ron Demey 2014) on the field [16]. Observations were limited to morning, afternoon and evening at selected periods based on the information got from the preliminary observations because they were present nearly throughout the day. Identified kingfishers were counted singly in numerical order to give more information about their pattern of feeding. The observations took place once in all the sampling sites on different dates. Where there were large populations and at long distances binoculars was used in getting a clearer picture of the way they feed and their counts. Nest and roosting places of kingfishers were located and visited to collect their faecal samples which were used to determine remnants of food, i.e. the undigested food left in the faecal pellets to ascertain the food they consume. Collections took place every second week of the month for the period of twelve months at the entire study site. A reference collection of representative and distinctive body of insects, fishes and plant seeds collected from the study site were compared with the hard parts from the faecal samples. The insects collected were identified in Museum of Natural History (O.A.U), fishes were identified in fishery section in Zoology Department (O.A.U) while the seeds of some plants were identified in Ife Herbarium in the Botany Department (O.A.U). Fresh faecal samples collected at each sampling site were sorted in the laboratory. Water was used to soften the faecal samples before sorting to prevent the hard parts from breaking after which all of the hard parts were sorted and examined at 40x under the microscope or magnifying lens through comparing of hard part with the reference collection and then identified up to order level.

Data Analysis

Data were subjected to one-way analysis of variance (ANOVA), Mean separation was done using Duncan’s New Multiple Range. The statistical package used for analysis was statistical package for social scientists (SPSS) version 17.0.Graphs were plotted using Excel and Graph pad prism version 5. The excel descriptive statistical packages such as frequency of distribution, means, percentages and charts were also used in the presentation of findings from this work.

Mean Comparison of Species Abundance across Sites

The mean comparison of the species across the sites

$$ \text{revealed that Opa Reservoir had the highest} (63.83 \pm 12.90) \text{ abundance of species, followed by} $$

of species, followed by

Akinrinade Reservoir with (57.5±11.18) while Osu

Reservoir had the lowest (11.33±6.12) abundance of

species (Table 5). The species abundance in Opa and

Akinrinade Reservoirs were not significantly (p>0.05)

different from each other but significantly (p<0.05) different from Osu Reservoir. Also, species abundance in Osinmo and Akinrinade Reservoirs were not significantly (p>0.05) different from each other but significantly (p<0.05) different from Osu Reservoir (Table 5).

Mean Comparison between Numbers of Species of Kingfishers Observed across the Study Sites

There were significant differences in the mean comparison of kingfisher recorded for the period of twelve months across study sites. The number of kingfisher recorded in Opa, Akinrinade and Osinmo Reservoirs were not significantly different (p>0.05) from each other but significantly different from Osu Reservoir (0.36±0.81) in the month of June and July (Table 6). Also, the number of kingfisher recorded in Akinrinade Reservoir had the highest mean (2.84±1.65) value in the month of August and was highly significantly different (p<0.05) from other sampling sites. However, across most of the months, numbers of kingfishers observed in Osu Reservoir was significantly different (p<0.05) from Opa, Akinrinade and Osinmo Reservoirs (Table 6).

The preference of different food items preyed upon by kingfisher at Opa Reservoir revealed that barbus had the highest preference by pied kingfisher, followed by grasshopper fed on by Woodland Kingfisher while butterfly and ants had lowest preference fed on by woodland (Figure 1). In Osu Reservoir, dragonfly had the highest preference, followed by damselfly, praying mantis and grasshopper with equal preference while butterfly and ants had the lowest preference (Figure 2).

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Preference of Different Food Items Preyed by Kingfisher Across the Sites Using their Faecal Sample

The faecal analysis revealed different food items preyed upon by kingfisher at all the studied sites identified to their species level though not all the food items were found in their faecal samples. In Opa Reservoir, the ants had the highest percentage of occurrence followed by grasshopper and seeds of Mimosa pudica for woodland kingfisher species (Table 7), while faecal samples of pied kingfishers and giant kingfisher had tilapia as its highest percentage occurrence. Also in Osu Reservoir, dragonfly had the highest percentage while butterfly had the lowest percentage (Table 8).

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occurrence, African dwarf kingfisher had ant as the highest occurrence and least was grasshopper (Table 10).

One of the most important features of waterways is the biodiversity that they support and many are designated as the bird’s habitats [17]. A number of bird species of significance in Nigeria occur in the waterways including the Kingfisher Alcedinidae. Protection of waterways was fundamental to the success of this species, and many other flora and fauna that depend on riparian habitats the majority of the birds observed during the study were resident species. The species include the Woodland, Giant, Pied, Blue breasted and the African

environment and quantity of food which was in agreement with the findings of Lameed, et al. [19] who observed low abundance of birds (kingfisher) due to quality of the vegetation in the study of species diversity and abundance of wild birds in Dagona-Waterfowl Sanctuary Borno State, Nigeria. In Nigeria, the dry season is categorized by the drying out of small water bodies, which causes a congregation of water-birds at larger stable water bodies. The lower numbers of kingfishers observed in some of the sampling sites during the wet season were due to the dispersal of kingfishers to breed. They move away from large lakes into smaller pans that form seasonally and are likely to have lower risks of predation and disturbance than the larger water [20]. Food habits were observed for all the months throughout the study period. The birds were watched from dawn to dusk as most of the species are diurnal. During preying, the prey items especially fishes were observed and identified immediately by a pair of binoculars. It was observed that kingfishers preyed on several species of insects (dragonfly, grasshopper, damselfly, butterfly, praying mantis and ants), fish (tilapia, fry of tilipia and barbus) and also snail. This result was in line with the findings of Islam and Kamruzzaman, et al. who reported that kingfishers fed largely on insects such as grasshoppers, crickets, mantises, scarabs and other beetles, ants, winged termites, locusts and dragonflies. Wikipedia [11] also confirmed that kingfishers mainly hunt large crustaceans, insects, earthworms, rodents, snakes, fish, and frogs. The diversity of prey item consumed during this study suggested that kingfishers were voracious and take different types of prey that comes their ways particularly invertebrates. Soud, et al. [21] also buttressed the statement that the main cause of diet selection might be due to the opportunistic feeding habit of kingfishers to maintain their daily food needs.

Faecal samples that were used to ascertain the food items picked by various kingfishers only reviewed the hard undigested parts of the prey items according to Pierce, et al_. [22] who reported that faecal samples only review the hard parts in the faecal samples. The faecal samples from their roosting and nesting sites were collected. The noninvasive method of faecal samples examined revealed that woodland kingfishers fed on insects and also seeds of _Mimosa pudica which also were found in their faecal samples in the reservoirs where Mimosa pudica was present [23]. Conclusively, Blue breasted kingfisher in this study was revealed to be insectivorous, African dwarf kingfisher fed on both insects and water snail while pied kingfishers was found to be piscivorous with what was reviewed in their faecal sample. It was however noted that soft bodied preys were never observed in the faecal samples due to their lack of hard parts. Kingfishers observed occupied a wide range of areas around the water bodies and its surrounding and also pick diversity of food materials including seed of Mimosa pudica plant thereby limiting interrelationship among the species of kingfishers observed within the reservoirs. Perch height and foraging areas differed among the species of kingfishers observed which revealed that they occupied different foraging niche within the reservoirs.