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

Bat diversity and abundance in Omo Forest Reserve, Nigeria

Bats are yet to be incorporated in management plans in Nigeria. This is attributed to dearth in information as well as social stigma. This study was designed to determine bat species diversity, abundance and the relation of both indices to habitat structure. The survey was carried out in Omo forest reserve between May and June. Mist nets were deployed using stratified sampling method to place nets at 20 points. Netted points were set to be at least 200m apart. Total length of net averaged at 60 m, height ranged between 2-4m and set up after sunset from 1800-2300 hrs and before sunrise from 0400-0630 hrs. Sixty-four individuals were trapped belonging to 14 species in 8 genera and 6 families. Two other species were observed but not captured Eidolon helvum (Straw coloured fruit Bat) and Hypsignathus monstrosus (Hammer headed Fruit bat). Identification was based on Mammals of Nigeria and Mammals of Africa. Bat species diversity and bat abundance were higher in the forest compared to plantation but not significantly different. Bat species diversity decreased significantly as density of trees and litter cover increased while bat abundance decreased with increase in tree density but the relationship was not significant. Difference in diversity and abundance of bats is attributed to relative short distance between farmland and forest habitat types which provides easy access to bats for foraging. Habitat type and land usage influences the level of diversity and abundance of wildlife species for which bats are good indicators of habitat suitability.Keywords: Bats, diversity, Omo forest reserve, deforestation, density of tree

Large Mammals and Wetland utilization: a case study in Yankari Game Reserve Nigeria

The African plain harbours high abundance and diversity of mammals, most of which are confined to protected areas (PAs) due to anthro‐ pogenic threats (Craigie et al., 2010; Dirzo et al., 2014; Estes, 1999; Kingdon, 1997). Also, PAs face problems of hunting, logging and live‐ stock grazing, conflict of interest and poor management (Caro, 2001; Dharmaratne, Sang, &Walling, 2000; Gardner et al., 2009; Geldmann et al., 2015; Geldmann et al., 2015; Hall, Harris, Medjibe, & Ashton, 2003; Pressey, 1994; Salum, Eustace, Malata, & Mbangwa, 2017; Thuiller, 2007), consequently disrupting conservation goals, effective monitor‐ ing and understanding of habitat utilisation dynamics of mammals. Although wetlands are important habitats for sustaining animal populations, there is a widespread trend of increasing degradation of these habitats (Fynn, Chase, & Rӧder, 2014) and dearth of infor‐ mation pertaining to wetland utilisation in most PAs. While this is integral for effective conservation practice, few studies focus on this area in Africa (Arzamendia, Cassini, & Vila, 2006; Kumar, Mudappa, & Raman, 2010; Rahman et al., 2017). Here, we investigated the wet‐ land utilisation dynamics of large mammals in Yankari Game Reserve (YGR). The objective was to determine abundance, density and di‐ versity of large mammals and whether these variables were associ‐ ated with wetland size and time of da

Circannual variation in blood parasitism in a sub-Saharan migrant passerine bird, the garden warbler

Knowing the natural dynamics of pathogens in migratory birds is important, for example, to understand the factors that influence the transport of pathogens to and their transmission in new geographical areas, whereas the transmission of other pathogens might be restricted to a specific area. We studied haemosporidian blood parasites of the genera Plasmodium, Haemoproteus and Leucocytozoon in a migratory bird, the garden warbler Sylvia borin. Birds were sampled in spring, summer and early autumn at breeding grounds in Sweden, on migration at Capri, Italy and on arrival and departure from wintering staging areas in West Africa: mapping recoveries of garden warblers ringed in Fennoscandia and Capri showed that these sites are most probably on the migratory flyway of garden warblers breeding at Kvismaren. Overall, haemosporidian prevalence was 39%, involving 24 different parasite lineages. Prevalence varied significantly over the migratory cycle, with relatively high prevalence of blood parasites in the population on breeding grounds and at the onset of autumn migration, followed by marked declines in prevalence during migration both on spring and autumn passage. Importantly, we found that when examining circannual variation in the different lineages, significantly different prevalence profiles emerged both between and within genera. Our results suggest that differences in prevalence profiles are the result of either different parasite transmission strategies or coevolution between the host and the various parasite lineages. When separating parasites into common vs. rare lineages, we found that two peaks in the prevalence of rare parasites occur; on arrival at Swedish breeding grounds, and after the wintering period in Africa. Our results stress the importance of appropriate taxonomic resolution when examining host-parasite interactions, as variation in prevalence both between and within parasite genera can show markedly different patterns