Determinants and consequences of territory quality in the Bar-throated Apalis Apalis thoracica

Includes bibliographical references.The underlying principles of territoriality propose that competition for resources compels individuals to defend areas (territories) that give them exclusive access to critical resources. The theory suggests that only high-quality individuals succeed in occupying areas rich in these resources with consequent benefits in terms of higher reproductive success and/or chances of survival. The main aims of this study were: i) to determine the ecological factors influencing variation in territory size and quality among Bar-throated Apalises Apalis thoracica; ii) to investigate the consequences of these factors for reproductive effort and reward, pair stability and survival; and iii) to investigate the signalling properties of the species' black breast band (a prominent 'badge' emblazoned across the white underparts) in relation to both male and territory quality

Implications of flower developmental stage, plant isolation and microclimatic condition on a hemiparasitic plant–avian pollinator interaction

The pollination success of bird pollinated plants is determined by avian visits and duration of foraging which in turn have been shown to be regulated by several plant features. However, very few of these factors have been demonstrated on hemiparasitic plants under tropical African climate. This study, determined how three flower developmental stages (ripe, unripe and open flowers), plant isolation and microclimatic conditions (temperature and wind speed) influenced frequency of visits and duration of foraging by avian pollinators on the Loranthaceae mistletoe T. sessilifolius in a tropical savanna habitat in Nigeria, West Africa. One hour focal observations across 40 individuals of the study plant species was used to collect information on avian visits and duration of foraging. While numbers of flowers for the three flower developmental stages were obtained through direct counts. Results showed that increased number of closed ripe flowers on the study plant significantly attracted avian pollinators. This relationship between avian visitors and ripe flowers may be connected with the high nectar content of such flowers as reported in previous studies. Increased intensity of microclimatic factors; temperature (°C) and wind speed (m/s) however, negatively affected avian pollinators. This could be linked to their established effects of increasing avian thermoregulatory costs and mechanical inhibition of flight. These observations could potentially limit pollen deposition at stigma with consequences on plant fitness as shown in previous studies. The observations also give a picture of the potential effects of increasing temperatures in the face of global warming. Keywords: flower, avian, plant-isolation, microclimate, hemiparasitic-plant, interactio

Avian Utilization of the Fruits of Carissa Edulis Vahl and Jasminum Dichotomum Vahl in A Central Nigerian Reserve

This study determined the avian fruit utilizers of the plants Carissa edulis and Jasminium dichotomum both related in the colour and size of their fruits. Furthermore, the study also compared the two plant species in terms of the diversity of avian fruit utilizers, their frequency and duration of visits and activities performed during visits to the plant species. Data was collected in the Amurum Forest Reserve, north central Nigeria, between June and July 2011 through focal observations. A total of 107 individual birds comprising 22 species were recorded during the study. C. edulis had the highest diversity and abundance of bird species as compared to J. dichotomum. Seven bird species were exclusively found on C. edulis while 5 bird species were exclusive to J. dichotomum. The Common bulbul (Pycnonotus barbatus) and Speckled mousebird (Colius stratus) were the most common bird species observed on the two plants. Mean time spent foraging differed significantly across bird species foraging on C. edulis but not on J. dichotomum with the Western grey plantain-eater (Crinifer piscator) spending the highest time foraging on the former. Activities performed by bird species on the two study plants include foraging and perching which did not differ significantly between plants. These observations highlights the ecological importance of the two plants within the reserve particularly in enhancing the survival of other animal groups within the reserve. Keywords: Carissa edulis, Jasminum dichotomum, Bird species, Fruit, Frugivores

Variation in Avian Visits on Two Host Plants of the Mistletoe Tapinanthus sesselifolius Depended on Habitat Type and Presence of Matured Flowers

This study investigated avian foraging behaviour on the Mistletoe, Tapinanthus sesselifolius with a view to determine whether avian visits to the stem parasitic plant significantly differ between its two common host plant species in the Amurum Forest Reserve, Nigeria namely; Dichrostachys cinerea and Ochna afzelii. Also the study determined whether habitat type and abundnace of the three flower developmental stages of T. sesselifolius (i.e.closed unripe, closed ripe and open flowers) influenced avian visits to T. sesselifolius. Data was obtained using focal observations; 22 individuals of each of the two plant species hosting the Mistletoe T. sesselifolius were selected through stratified sampling. Focal observations to determine avian visits were conducted over a period of 1-hour per individual plant. Flower developmental stages were sampled through direct counts on three randomly selected branches of the parasitic plant. A significant difference was observed in avian visits to T. sesselifolius on the two study host plants with higher mean visits per hour to T. sesselifolius on D. Cinerea. While T. sesselifolius around the gallery forest habitat received significantly more avian visitors than those located in the savannah scrub and rocky outcrop. Also closed ripe flowers had significant effect on avian visits with avian visits increasing significantly to T. sesselifolius having higher numbers of closed ripe flowers. The complex structure of D. cinerea and the dense vegetation structure of the gallery forest could act as buffer against birds of prey and may have encouraged more visits to T. sesselifolius based on these factors. Also, the tamper proof nature of ripe flowers and its high nectar content as observed in previous studies is speculated as reasons for its significant positive effect on avian visits in the study. These observations may have implications on the reproductive potential of the stem parasitic plant since reduced pollinator visits is known to limit pollen deposition and eventual fruit set in plants. Keywords: avian visits, Tapinanthus sesselifolius, host plant, habitat type DOI: 10.7176/JNSR/12-8-01 Publication date: April 30th 202

POND SIZE AFFECTS ABUNDANCE AND DIVERSITY OF AVIAN SPECIES

Wetlands provide great important ecosystem services and serve as refugia for biodiversity. Birds are bio-indicators of environmental health and utilize the wetland ecosystems. Wetlands and birds face many threats from anthropogenic activities in the forms of degradation and habitat loss. This research aimed at assessing the effects of pond size on avian abundance and diversity in a wetland in Jos south Local Government Area of Plateau state, ten (10) ponds were sampled using point count method. Each pond had two (2) points which were visited twice daily (morning and afternoon) each. A total of three thousand, four hundred and forty-eight (3448) individual birds consisting of 97 species belonging to fifty- one (51) families were recorded. Intra-African migrants such as Didric cuckoo (Chrysococcyx caprius) and yellow-billed kite (Milvus aegyptius) were recorded. Species diversity and abundance were tested against the size of the pond, depth of the pond and vegetation cover on and around the pond to determine the factors that best depicts the diversity and abundance of avian species at the Rennajj fish farm. Pond size was a significant predictor of bird abundance (P< 0.01) and had a slight positive effect on the diversity of avian species which was not statistically significant at (P>0.05). Depth of the pond had no significant effect on both bird abundance and species diversity (p>0.05). Vegetation parameters such as shrubs and saplings had positive effect while vegetation on water and number of trees had negative relationship at (p<0.001) on the abundance of birds, vegetation on the water had a negative relationship at (p<0.001) with the diversity of bird species. Wetland ecosystems should be protected from excessive human activities as they host wealth of biodiversity

Managing human disturbance : factors influencing flight-initiation distance of birds in a West African nature reserve

Thanks to the Leventis Conservation Foundation for providing full funding for this study.Escape behaviour in response to perceived predators can be employed as a guide when designating protected areas around sensitive bird species to minimize the impact of human disturbance. A key measure of escape response is flight–initiation distance (FID), the distance at which a prey animal initiates its escape when approached by a potential predator. We tested the predictions of optimal escape theory by determining the factors that influence FID of bird species in a Nigerian reserved area and its surrounding habitats and so the potential utility of FID in managing human disturbance on birds, for the first time within a West African context. We tested how FID varied with group size, proximity to vegetation acting as protective cover, levels of human use, and survival rate, and whether these relationships varied by species. We collected 504 FIDs for seven bird species in Amurum Forest Reserve and its surrounding habitats (Jos, Nigeria). FID was lower in larger groups and when species were closer to protective cover. FID was lower outside of the protected area because animals in sites with higher levels of human presence and use may become habituated. FID was higher for species with higher survival, being consistent with predictions from life history theory. Overall, birds perceived humans as a potential threat and responded in accordance to the predictions of optimal escape theory, with FID increasing with increased cost of staying. Reserve managers in Africa could use species and context specific FIDs to designate buffer distances for the protection of wildlife from human disturbance.PostprintPeer reviewe

Bird tolerance to humans in open tropical ecosystems

AbstractAnimal tolerance towards humans can be a key factor facilitating wildlife–human coexistence, yet traits predicting its direction and magnitude across tropical animals are poorly known. Using 10,249 observations for 842 bird species inhabiting open tropical ecosystems in Africa, South America, and Australia, we find that avian tolerance towards humans was lower (i.e., escape distance was longer) in rural rather than urban populations and in populations exposed to lower human disturbance (measured as human footprint index). In addition, larger species and species with larger clutches and enhanced flight ability are less tolerant to human approaches and escape distances increase when birds were approached during the wet season compared to the dry season and from longer starting distances. Identification of key factors affecting animal tolerance towards humans across large spatial and taxonomic scales may help us to better understand and predict the patterns of species distributions in the Anthropocene.</jats:p

Assessment of potential sources of protozoan contamination between two avian feeding guilds in a conservation area

Occasional screening of food and water quality available to organisms in protected areas could be beneficial to their successful conservation. This is important for areas receiving regular human visitors and exhibiting activities that may be detrimental to ecosystem health. This study determined the intestinal protozoan species harboured by insectivorous and granivorous birds within the Jos Wildlife Park, Nigeria and whether the two avian feeding guilds are more susceptible to protozoan infection through water or food (grass seeds and insects). Special boxes were used to collect faecal samples from trapped birds. Samples were later analysed in the laboratory for protozoans. Both food and water utilised by the birds in the area were microscopically screened. The composition and abundance of intestinal protozoans between the two feeding guilds did not show significant differences. However, considering parasite species individually, the degree of infection by protozoans such as Giardia lamblia was highly related to the range of infection sources that a feeding guild was exposed to. The composition of parasites observed in the two feeding guilds was strongly linked to both water bodies and avian diet obtainable in the Park. These observations showed that birds in the Park are orally susceptible to infection with protozoans, some of which have been reported to cause health implications in birds. Thus, any measure to curtail environmental contamination by the parasites may improve ecosystem health and survival of avian species in the Park

Bird tolerance to humans in open tropical ecosystems

Animal tolerance towards humans can be a key factor facilitating wildlife–human coexistence, yet traits predicting its direction and magnitude across tropical animals are poorly known. Using 10,249 observations for 842 bird species inhabiting open tropical ecosystems in Africa, South America, and Australia, we find that avian tolerance towards humans was lower (i.e., escape distance was longer) in rural rather than urban populations and in populations exposed to lower human disturbance (measured as human footprint index). In addition, larger species and species with larger clutches and enhanced flight ability are less tolerant to human approaches and escape distances increase when birds were approached during the wet season compared to the dry season and from longer starting distances. Identification of key factors affecting animal tolerance towards humans across large spatial and taxonomic scales may help us to better understand and predict the patterns of species distributions in the Anthropocene