scholarly journals Effect of a major highway on the spatial and temporal variation in the structure and diversity of the avifauna of a tropical premontane rain forest

2016 ◽  
Vol 64 (4) ◽  
Author(s):  
Gerardo Ávalos ◽  
Esteban Bermúdez

Roads immersed in conservation areas will increase in number, size, and traffic over the next decade, and thus, understanding their effects on forest-dependent wildlife is crucial for improving current management practices and reducing the negative impacts of roads on sensitive species. We examined the influence of route 32 (a.k.a. Guápiles Highway) on temporal and spatial changes in the structure of the avifauna of Braulio Carrillo National Park, Costa Rica, a site crossed by this road along 25 km. The highway connects the capital city of San José with the Harbor of Limón in the Caribbean Sea (142 km). Although the road is narrow (12 m in width and comprised by two lanes along most of the route) it services over 1.5 million motor vehicles per year, 12 % are heavy trucks and trailers. We expected the highway to divide the avifauna, and thus to observe significant differences in species structure on opposite sides of the road. We described changes in bird diversity between wet and dry seasons at Las Palmas and Ceibo trails located on opposite sides of the highway (14 point counts per trail), and evaluated how abundance and diversity varied with road distance. Censuses took place during wet and dry seasons from 2002 to 2005. We listed 245 species and 6 035 observations during the 4-yr survey. Rare species dominated the avifauna (65 % of species < 5 observations), and species overlap between trails was high (Sorensen= 71 %; Morisita= 0.96). Species accumulation curves varied little among trails, yielding 190 species. Resident species represented 70 % of observations, followed by elevational (15 %) and long-distance migrants (1-2 %). Understory species were the most abundant (60 %) followed by canopy birds (30 %). Species turnover rate was 55 % between seasons, but species composition between trails remained homogeneous. Overall, birds were avoiding the road (abundance increased away from the road) although other diversity parameters (richness, dominance, Shannon index, and equitability) were not influenced by road proximity. Although the avifauna remained homogeneous on both sides of the road, which did not support the fragmentation hypothesis, the highway reduced the abundance and diversity of specialized understory insectivores associated with primary forests near the road. This highway will expand outside the National Park (from 2 to 4 lanes along 107 km from Río Frío to Limón) in the next years, which will increase traffic volume and road impacts within the Park. Roads are increasing across highly diverse tropical areas justifying the need for management practices based on the identification of sensitive groups.

1998 ◽  
Vol 8 (3) ◽  
pp. 297-308 ◽  
Author(s):  
Lorena Calvo ◽  
John Blake

SummaryMany studies have examined differences in bird communities between shade and sun coffee plantations but less is known about how different management practices within shade coffee plantations affect bird populations. This study compares diversity and abundance of resident and migrant birds in two shade coffee plantations located in Palajunoj, Quetzaltenango, Guatemala, that differ in their farming practices (e.g. pruning schedules and fertilizer regimes) and, consequently, in vegetation structure. One plantation represents a traditional, polyculture shade system whereas the second represents a more modernized, monoculture shade system. Both plantations supported many resident and migrant birds. Bird abundance and diversity were significantly greater during both wet and dry seasons on the traditional farm, due largely to the vegetation structure resulting from the different management practices. All plantations typically classified as ‘shade coffee’ are not equivalent, much of their conservation value coming from the more diverse and structurally complex traditional polycultures rather than from the newer, monocultural systems. Coffee production techniques that affect the structural and floristic diversity of the vegetation (e.g. pruning, application of chemicals) have important consequences for birds.


2021 ◽  
Vol 13 (5) ◽  
pp. 18132-18140
Author(s):  
D. Ejigu ◽  
A. Bekele ◽  
L. Powell

Walia Ibex Capra walie is an endemic and endangered species residing in Simien Mountains National Park, Ethiopia.  It has shifted its range within the Park in the last decade, and in this study our main objective was to provide information on their feeding ecology to inform recovery goals.  We used a scan sampling method to collect foraging information during October 2009 to November 2011.  Our observations suggest a diverse diet of more than 28 species of grasses, forbs, and shrubs.  The most commonly used plants were Festuca sp., Lobelia rhynchopetalum, Helichrysum citrispinum, and Helichrysum horridum.  Walia Ibex were active in feeding before and after mid-day, and time spent feeding was the highest compared with other diurnal activities.  The percentage of time spent feeding on major plant species did not differ between wet and dry seasons (p> 0.05).  Walia Ibex, however, tended to spend more time browsing than grazing.  The generalist nature of foraging behaviour in Walia Ibex most likely contributes to complaints from the local people who witness Walia Ibex raiding crops cultivated in and around the Park.  Thus, the contribution of crop raiding to the shifts in the species’ range towards higher altitudes at Sebatminch within Simien Mountains National Park emphasizes the need to consider foraging ecology as community-based conservation efforts are developed to support Walia Ibex in the Park. 


2020 ◽  
Vol 2020 ◽  
pp. 1-5
Author(s):  
Adanech Lemma ◽  
Wondimagegnehu Tekalign

This study was undertaken with the intention of assessing abundance, species diversity, and distribution of medium and large diurnal mammals at the Humbo Community Based Forest Area, Ethiopia. The study area was stratified into three major habitats based on the vegetation cover of the area, such as riverine forest, bushland, and open grassland. The study in each vegetation type was surveyed using the transect method. It was conducted on foot along a randomly selected transect line. A total of eight large and medium mammalian species were recorded. The species recorded were Papio anubis, Sylvicapra grimmia, Tragelaphus scriptus, Chlorocebus pygerythrus, Tragelaphus strepsiceros, Lepus fagani, Phacochorus ethiopicus, and Panthera leo. During the survey, the leading order recorded was Artiodactyla followed by Primates. In terms of relative abundance, Anubis baboon (28.4% and 28.1%) and common duiker (19.4% and 11.4%) were the most abundant species, while warthog (12.1% and 8.9%) and lion (0.7% and 0.4%) were the least abundant during the wet and dry seasons, respectively. The highest number of mammalian species were distributed in bushland habitat during both wet (n = 7) and dry (n = 7) seasons. The highest Shannon-winner diversity index and evenness were obtained in the bushland habitat (1.70 and 2.21) during wet and dry seasons, respectively. Though the forest is the living place for various wild mammalian species, the conservation measures of the local community should also consider those species in line with the efforts that have been done on forest management practices.


Author(s):  
William O'Dell ◽  
Raychel Watkins ◽  
Aelita Pinter

The long-range objectives of this research on the biological cost of parasitism to small mammals are: 1) to document the incidence and prevalence of Giardia and other parasites in Microtus and other sympatric small mammals of Grand Teton National Park: 2) to compare parasite loads for these animals during wet and dry seasons: 3) to determine the incidence of intestinal parasites in Microtus during a growth cycle that ranges from years of lowest to years of highest population densities of the hosts, 4) to investigate the relationship of parasite infection to reproductive success in Microtus, and 5) to investigate small mammals as potential reservoirs of human parasites such as Giardia.


Author(s):  
William O'Dell ◽  
Aelita Pinter

The objectives of this research are: 1. To document the occurrence of Giardia and other protozoan parasites in Microtus and other sympatric small mammals of Grand Teton National Park; 2. To compare parasite loads for these animals during wet and dry seasons; 3. To determine the occurrence of intestinal parasites in Microtus during a growth cycle that ranges from years of lowest to years of highest population densities of the hosts; and 4. To investigate the relationship of infection to reproductive success in Microtus.


Author(s):  
O. O. Ogunyemi

A study was carried out to evaluate the species composition and relative abundance of bird species of the natural and plantation forest of Ogbese Forest Rserve, Ekiti State. The study was conducted from April, 2010 to February, 2011 covering both wet and dry seasons. Sample sites were stratified based on the vegetation types and transect count techniques was employed for the evaluation. A total of 52 bird species consisting of 47 resident and 5 immigrant species was recorded. The species composition of birds during the wet and dry seasons was not significantly different. The natural forest vegetation had the highest species diversity and evenness. The relative abundance score of species during the Wet and dry seasons was variable in both habitats. The result of this study has shown that the natural and plantation vegetation types of Ogbese Forest Reserve, Ekiti State. The heterogeneity of flora species in the natural forest compared to the plantation forest might be responsible for the variation. The management of birds in the reserve should take cognisance of the vegetation types for effective conservation of bird species which are resident in the reserve.


2015 ◽  
Vol 38 (1) ◽  
pp. 1-10
Author(s):  
D. Ejigu ◽  
◽  
A. Bekele ◽  
L. Powell ◽  
J.-M. Lernould ◽  
...  

Walia ibex (Capra walie) is an endangered and endemic species restricted to the Simien Mountains National Park, Ethiopia. Recent expansion of human populations and livestock grazing in the park has prompted concerns that the range and habitats used by walia ibex have changed. We performed observations of walia ibex, conducted pellet counts of walia ibex and livestock, and measured vegetation and classified habitat characteristics at sample points during wet and dry seasons from October 2009 to November 2011. We assessed the effect of habitat characteristics on the presence of pellets of walia ibex, and then used a spatial model to create a predictive map to determine areas of high potential to support walia ibex. Rocky and shrubby habitats were more preferred than herbaceous habitats. Pellet distribution indicated that livestock and walia ibex were not usually found at the same sample point (i.e. 70% of quadrats with walia pellets were without livestock droppings; 73% of quadrats with livestock droppings did not have walia pellets). The best model to describe probability of presence of walia pellets included effects of herb cover (β = 0.047), shrub cover (β = 0.030), distance to cliff (β = –0.001), distance to road (β = 0.001), and altitude (β = 0.004). Walia ibexes have shifted to the eastern, steeper areas of the park, appearing to coincide with the occurrence of more intense, human–related activities in lowlands. Our study shows the complexities of managing areas that support human populations while also serving as a critical habitat for species of conservation concern.


2021 ◽  
Author(s):  
GEORGE N. GATHUKU ◽  
David O. Chiawo ◽  
Charles M. Warui ◽  
Cecilia M. Gichuki ◽  
Innocent O. Ngare

The Rothschilds giraffe is currently listed as vulnerable by the International Union for Conservation of Nature (IUCN). This is attributed to the loss of habitat due to human activities. This study examined the effect of habitat type on population structure and distribution of Rothschilds giraffe in Ruma National Park (RNP) and Mwea National Reserve (MNR) in Kenya. The study employed road transects to collect data on the number, age class and sex distribution in three habitat types, open, medium and closed. Data was collected along three road transects of equal lengths measuring 14.2 km in each site (RNP and MNR) for comparison. A driving speed of 20 km per hour was maintained along each transect for standardization of survey effort and a maximum giraffe detection rate. Photographic capture of the coat patterns of the right side of all the giraffes sighted within 500 m from the transect was done for identification of age classes. The field visits were replicated 12 times for each transect giving 36 replications for each site spread equally through wet and dry seasons from March 2017 to November 2018. The effect of habitat type on population structure and distribution was analysed using ANOVA and Tukey HSD to test for significant differences. T-test was used to compare the mean population size of giraffe across the wet and dry seasons. Coat pattern analysis for age class identification was done using WildID software. The findings indicated that MNR had more males to females compared to RNP that registered more females and calves. Habitat type had a significant effect on the distribution of giraffes. The giraffe population showed a preference for medium habitat types. The findings are key for the management of habitat quality for giraffe populations at the interface where conservation areas overlap with human land use.


2019 ◽  
Vol 11 (6) ◽  
pp. 13680-13689 ◽  
Author(s):  
Alembrhan Assefa ◽  
Chelmala Srinivasulu

An ecological survey was conducted to assess the species composition and abundance of rodents in Kafta-Sheraro National Park, Ethiopia from June 2017 to April 2018 covering wet and dry seasons.  Rodents were trapped using Sherman live traps from five selected habitat types—natural forest, bushland, grassland, farmland, and human settlement.  A total of 209 individuals of rodents belonging to seven species were captured over 2940 trap nights, and three species of rodents were only observed.  The trapped rodent species include Mastomys natalensis, Stenocephalemys albipes, Rattus rattus, Mastomys awashensis, Acomys cahirinus, Arvicanthis niloticus dembeensis, and Mastomys erythroleucus.  Lemniscomys striatus, Hystrix cristata, and Xerus rutilus were only sighted during the study.  Mastomys natalensis was the most abundant species (41.1%), followed by Stenocephalemys albipes (26.3%) and Rattus rattus (18.2%), whereas Mastomys erythroleucus (1.4%) was the least abundant species.  The abundance of female (59.8%) was higher than male (40.2%).  Of the total trapped rodents, 52.2% were adults, 32% sub-adult and 15.8% young.  The abundance of rodents was varied among habitat types and between seasons.  The results of the study revealed that the park has diverse species of fauna including rodents.


2021 ◽  
Author(s):  
Abraham Tolcha ◽  
Simon Shibru ◽  
Belayneh Ayechew

We investigated the population status and habitat association of the endemic Swayne’s Hartebeest (Alcelaphus buselaphus swaynei (Sclater, 1892)) in the Maze National Park, Southern Ethiopia, in 2018 and 2019. Sample count method line-transect was used for the population estimation, while habitat association was made based on the abundance of individuals counted in each habitat. Data were analyzed using descriptive statistics and comparisons with χ2 test. The total estimated populations of Swayne’s Hartebeest (SHB) in the study period were 1456 and 1492 during wet and dry seasons, respectively showing no seasonal variation. Among the total estimated population, 31% were adult males, 38.46% adult females, 13.97% sub adult males, 15.94% sub adult females and 1.07% young. The number of adult females was higher than the other age groups followed by adult males in both seasons. Significant differences were reported  among age and sex structure of population size during both seasons (wet season: χ2= 58.423, df =3, P < 0.05; dry season: χ2=534.079, df= 4, P < 0.05). The maximum group size was 36 and the minimum was 1. The ratio of adult males to adult females was 1:1.24 and 1:1.24, sub-adult males to sub adult females was 1:1.16 and 1:1.12, adult males to sub-adult males was 1:0.36 and 1:0.56, adult females to sub-adult females was 1:0.33 and 1:0.49 in the wet and dry seasons, respectively. The male to female ratio was 1:1.22 and 1:1.19 during wet and dry seasons as well. The population trend among ten years were significantly differed (χ 2 = 1.708, df= 9, P< 0.05). The SHB was distributed into three types of habitat (riverine forest, open grassland and scattered tree) with significant differences (χ2=1109.937, df = 3, P < 0.05). The savannah grass land was most preferable habitat followed by scattered tree habitat. Maintaining its critical habitat was highly recommended for sustainability of current population status.


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