scholarly journals Zanzibar's endemic red colobus Piliocolobus kirkii: first systematic and total assessment of population, demography and distribution

Oryx ◽  
2017 ◽  
Vol 53 (1) ◽  
pp. 36-44 ◽  
Author(s):  
Tim R.B. Davenport ◽  
Said A. Fakih ◽  
Sylvanos P. Kimiti ◽  
Lydia U. Kleine ◽  
Lara S. Foley ◽  
...  
Keyword(s):  
Protected Areas ◽  
Iucn Red List ◽  
Population Demography ◽  
Adult Males ◽  
Red Colobus ◽  
Systematic Assessment ◽  
Conservation Implications ◽  
Area Of Occupancy ◽  
Adult Females ◽  
Better Than

AbstractWe present the first systematic assessment of the population, demography and distribution of the Endangered Zanzibar red colobus Piliocolobus kirkii, in Unguja in the Zanzibar archipelago, based on a survey effort of 4,725 hours. We estimate the total population comprises 5,862 individuals in 342 groups (mean group size 17.12); 3.4 times the mean of all previous estimates. We calculated a total area of occupancy of 376 km2, with 4,042 individuals living within protected areas. Mean group sizes were significantly higher within protected areas (20.57) than outside (12.80). The number of adult females was 3,179 (54.21%), with a mean of 9.29 per group, and the number of adult males was 932 (15.89%), with a mean of 2.71 per group, giving a ratio of 3.31 adult females to adult males. This ratio was significantly lower outside protected areas. The total number of infants was 958 (16.34%), with a mean of 2.80 per group, and the number of subadults/juveniles was 793 (13.52%), with a mean of 2.32 per group, giving ratios of 0.30 infants to adult females, and 0.25 subadults/juveniles to adult females. The results indicate that P. kirkii is resilient and thriving far better than assumed. However, recruitment is low and the population may be in decline, with individuals outside protected areas most at risk. We tentatively support the categorization of P. kirkii as Endangered on the IUCN Red List, argue for greater protected area status for southern Uzi, Vundwe and Mchamgamle, and discuss conservation implications for this charismatic flagship species.

scholarly journals Conservation status and recovery of Podocarpus angustifolius: a threatened tree of Cuba

Oryx ◽  
2021 ◽  
pp. 1-3
Author(s):  
Ernesto Testé ◽  
Majela Hernández ◽  
Eldis R. Bécquer ◽  
Oliver Valle ◽  
Luis R. González-Torres
Keyword(s):  
Protected Areas ◽  
Size Structure ◽  
Conservation Status ◽  
Population Based ◽  
Iucn Red List ◽  
Small Population ◽  
Red List ◽  
Coffee Plantations ◽  
Area Of Occupancy ◽  
In The Wild

Abstract The recovery of species’ populations is one of the most challenging tasks in conservation, which is why species recovery is most likely to be successful if it involves as many stakeholders as possible. Podocarpus angustifolius, a tree endemic to Cuba, is potentially threatened by overexploitation, deforestation and expansion of exotic species. In December of 2017, in two protected areas containing the only known subpopulations of this species, we recorded the geographical position, height, and diameter at breast height of each individual, and calculated the extent of occurrence (EOO) and area of occupancy (AOO). We recorded a total of 575 individuals, 174 of which were adult (defined as ≥ 6 m height on the basis of the occurrence of reproductive structures), and most of which occurred in Lomas de Banao Ecological Reserve. The EOO and AOO were 125.8 km2 and 6.0 km2, respectively. All P. angustifolius that remain in the wild are within two protected areas, either in rainforest relicts or in coffee plantations. The size structure indicates a growing population. Based on our findings we recommend that P. angustifolius should be recategorized from Vulnerable (on the IUCN Red List) and Critically Endangered (on the national Red List) to Endangered, based on criterion D (small population size). We recommend the continued reinforcement of the population at Topes de Collantes Natural Protected Landscape and the continued engagement of local stakeholders for the long-term conservation of this species.

scholarly journals Impact of botfly parasitism on Microtus townsendii populations

1980 ◽  
Vol 58 (9) ◽  
pp. 1683-1692 ◽  
Author(s):  
Rudy Boonstra ◽  
Charles J. Krebs ◽  
Terry D. Beacham
Keyword(s):  
Negative Relationship ◽  
Adult Males ◽  
Adult Females ◽  
Significant Negative Relationship ◽  
Breeding Condition ◽  
Survival Differences ◽  
The Impact ◽  
Large Adult ◽  
Microtus Townsendii ◽  
Better Than

The impact of botfly (Cuterebra grisea) parasitism on populations of Microtus townsendii was studied on four areas near Vancouver, British Columbia, from 1971 to 1978. Botfly larvae were found in voles during the period from late June to late November, with a peak occurring from mid-August to mid-September. There was a significant negative relationship between vole density and the proportion of the population infested. The percentage of voles infested changed in the following manner in the three weight classes: juveniles (18.5%) > adults (16.5%) > subadults (13.0%), with the sexes showing no differences between them. Overall, noninfested voles always survived better than infested ones did in the three classes. In both adults and juveniles, survival declined as botfly larvae number increased; subadults did not show this relationship. Infested adult male voles survived more poorly at high densities (r = 0.62); adult females did not. Infested large adult males (≥ 55 g) survived better than small adults did (40–54 g), but the two size classes in females showed no survival differences. Infested adult voles had significantly lower rates of reproduction: 8% fewer males were in breeding condition, 10% fewer females were lactating, and 4% fewer females were pregnant. Parasitism significantly depressed growth rates in all weight classes above 40 g. We conclude that botflies had a significant detrimental influence on vole survival, reproduction, and growth.

scholarly journals Assessment of the rarity and conservation status of the Colombian endemic brown hairy dwarf porcupine Coendou vestitus

Oryx ◽  
2020 ◽  
pp. 1-6
Author(s):  
María M. Torres-Martínez ◽  
Héctor E. Ramírez-Chaves ◽  
Elkin A. Noguera-Urbano ◽  
Fernando C. Passos
Keyword(s):  
Small Body ◽  
Conservation Status ◽  
Natural Habitat ◽  
Habitat Type ◽  
Iucn Red List ◽  
Red List ◽  
Small Range ◽  
Minimum Convex Polygon ◽  
Area Of Occupancy ◽  
Species Rarity

Abstract The brown hairy dwarf porcupine Coendou vestitus is a poorly studied Andean species endemic to Colombia. Its current Red List category is contradictory: globally it is categorized as Data Deficient but in Colombia it is categorized as Vulnerable. This contradiction has limited the implementation of conservation programmes. We evaluate the level of rarity of the species and provide consolidated information for a new assessment of its Red List status. We reviewed literature, photographs, and voucher specimens in natural history collections. Using the confirmed records, we estimated the extent of occurrence (EOO) based on the minimum convex polygon and the area of occupancy (AOO) summing the area of grid squares occupied by the species. We found that C. vestitus is very rare, with a small range, low estimated population density, occurrence in only one habitat type and small body size. The species has an EOO of 3,323 km2 and an AOO of 24 km2, based on six confirmed localities, all on the western slopes of the Eastern Cordillera, in the central Andean region of Colombia. Based on the species' rarity, restricted distribution, and threats to its natural habitat, we recommend its categorization as Endangered on the IUCN Red List. This will help delineate research and conservation efforts for this porcupine, which has a highly restricted range and inhabits the threatened Andean forest.

Two new species and taxonomic notes on the Neotropical spiny orb-weaving spi-ders Micrathena and Chaetacis (Araneae: Araneidae), with remarks on the development of Micrathena excavata IVAN L. F. MAGALHÃES & ADALBERTO J. SANTOS (Brazil)

Zootaxa ◽  
2011 ◽  
Vol 2983 (1) ◽  
pp. 39 ◽  
Author(s):  
IVAN L. F. MAGALHÃES ◽  
ADALBERTO J. SANTOS
Keyword(s):  
New Species ◽  
Junior Synonym ◽  
Adult Males ◽  
Development Stages ◽  
Brazilian Amazonia ◽  
Central Brazil ◽  
Adult Females ◽  
Two New Species ◽  
Senior Synonym ◽  
First Time

In this paper, M. yanomami n. sp., from Brazilian Amazonia, Chaetacis bandeirante n. sp., from Central Brazil, and the males of M. gaujoni Simon, 1897 and M. ruschii (Mello-Leitão, 1945) n. comb. , respectively from Ecuador and Brazil, are described and illustrated for the first time. An ontogenetic series of the last development stages of both sexes of Micrathena excavata (C. L. Koch, 1836) is illustrated and briefly described. Adult females are larger and have longer legs and larger abdomens than adult males. Probably females undergo at least one additional moult before adulthood, compared to males. Micrathena ornata Mello-Leitão, 1932 is considered a junior synonym of M. plana (C. L. Koch, 1836), and M. mastonota Mello-Leitão 1940 is synonymized with M. horrida (Taczanowski, 1873). Acrosoma ruschii Mello-Leitão, 1945 is revalidated, transferred to Micrathena and considered a senior synonym of M. cicuta Gonzaga & Santos, 2004. Chaetacis necopinata (Chickering, 1960) is recorded for Brazil for the first time. Chaetacis incisa (Walckenaer, 1841) is considered a nomen dubium.

Spacing, movements, and habitat selection of the river otter in boreal Alberta

1994 ◽  
Vol 72 (7) ◽  
pp. 1314-1324 ◽  
Author(s):  
D. G. Reid ◽  
T. E. Code ◽  
A. C. H. Reid ◽  
S. M. Herrero
Keyword(s):  
Lontra Canadensis ◽  
Home Ranges ◽  
Adult Males ◽  
Movement Rates ◽  
River Otters ◽  
Aquatic Mammal ◽  
Adult Females ◽  
Two Factors ◽  
Bog Lakes ◽  
Selection Of

Seasonal spacing patterns, home ranges, and movements of river otters (Lontra canadensis) were studied in boreal Alberta by means of radiotelemetry. Adult males occupied significantly larger annual home ranges than adult females. Males' ranges overlapped those of females and also each other's. In winter, home ranges of males shrank and showed less overlap. Otters often associated in groups, the core members typically being adult females with young, or adult males. Otters tended to be more solitary in winter. In winter, movement rates of all sex and age classes were similar, and much reduced for males compared with those in other seasons. These data indicated a strong limiting effect of winter ice on behaviour and dispersion. We tested the hypothesis that otters select water bodies in winter on the basis of the suitability of shoreline substrate and morphology for dens with access both to air and to water under ice. Intensity of selection was greatest in winter, with avoidance of gradually sloping shorelines of sand or gravel. Adults selected bog lakes with banked shores containing semi-aquatic mammal burrows, and lakes with beaver lodges. Subadults selected beaver-impounded streams. Apart from human harvest, winter habitats and food availability in such habitats are likely the two factors most strongly limiting otter density in boreal Alberta.

scholarly journals Estimating change in the geographical range and population size of Hinde's Babbler Turdoides hindei

2003 ◽  
Vol 13 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Philip Shaw ◽  
John Musina ◽  
Patrick Gichuki
Keyword(s):  
Protected Areas ◽  
Population Size ◽  
Geographical Range ◽  
Population Estimates ◽  
Extent Of Occurrence ◽  
Area Of Occupancy ◽  
Species Area ◽  
Gains And Losses ◽  
Global Population

Hinde's Babbler Turdoides hindei is a globally threatened Kenyan endemic, which during the 1990s, was known from just seven localities. Based mainly on surveys undertaken in 2000–2001, we estimate the species's global population size and compare recent changes in its “extent of occurrence” and “area of occupancy”. Historically, Hinde's Babbler has been recorded from c. 40 10 × 10 km squares; 27 pre-1980 and 19 subsequently, suggesting that its area of occupancy has declined by about 30%. In contrast, its extent of occurrence has declined by only 8%, this measure being less sensitive to the balance of gains and losses occurring near the centre of its range. During surveys in 1994 and 2000–2001, 157 groups were located, containing 665 birds, 75% of which were found at two intensively cultivated sites. Some 97% of birds were located in, or adjacent to, five Important Bird Areas, but only 8% were found within legally protected areas. Two extrapolated population estimates are presented, based on the number of birds likely to have been missed at survey sites, and the species' area of occupancy. These suggest that the global population of Hinde's Babbler is likely to fall within the range of 1,500–5,600 birds.

Time-Budgets of Camargue Horses Ii. Time-Budgets of Adult Horses and Weaned Sub-Adults

Behaviour ◽  
1980 ◽  
Vol 72 (1-2) ◽  
pp. 26-48 ◽  
Author(s):  
Patrick Duncan
Keyword(s):  
Social Structure ◽  
Social System ◽  
General Trend ◽  
Small Population ◽  
Time Budgets ◽  
Adult Males ◽  
Adult Females ◽  
Young Horses

AbstractTime-budgets of adult and weaned sub-adult horses were studied in a small population of Camargue horses living in semi-liberty. The categories of activities used were: Standing resting, Lying flat, Lying up, Standing alert, Walking, Trotting, Galloping, Rolling and Foraging. The main differences in time-budgets were related to age and to sex : young horses spent more time lying (sleeping), males spent more time standing alert and in rapid movements (trot, gallop), while usually foraging less than did the adult females. During the three years of the study the population increased from 20 to 54 horses and there were considerable changes in social structure as the number of adult males increased. Associated with these developments there were some changes between years in the time-budgets: the most striking of which was a general trend for all horses to spend less time lying. Nonetheless the time-budgets showed a considerable constancy across years and age/sex-classes, especially with regard to time spent foraging. This conclusion may provide a clue as to why horses have an unusual social system based on long term relationships between a male and the females of his harem.

scholarly journals Habitat associations and conservation status of an endemic forest dwarf chameleon (Bradypodion sp.) from South Africa

Oryx ◽  
2006 ◽  
Vol 40 (2) ◽  
pp. 183-188 ◽  
Author(s):  
Walter J. Reisinger ◽  
Devi M. Stuart-Fox ◽  
Barend F.N. Erasmus
Keyword(s):  
South Africa ◽  
Conservation Status ◽  
Canopy Cover ◽  
Iucn Red List ◽  
Habitat Associations ◽  
Suitable Habitat ◽  
Area Of Occupancy ◽  
Forest Interior ◽  
Forest Remnants ◽  
Iucn Red List Criteria

We quantified habitat associations and evaluated the conservation status of a recently identified, undescribed species of dwarf chameleon, Bradypodion sp. nov. Dhlinza, endemic to scarp forest remnants in KwaZulu-Natal Province, South Africa. At the microhabitat scale the Dhlinza dwarf chameleon was found more often in forest gaps and near paths than highly disturbed edges or forest interior. Chameleon presence was not explained by forest physiognomic variables such as vine cover, shrub and tree density, or canopy cover. Presence near gaps may be better explained by the combined effects of the thermal microenvironment and food availability. The species is moderately common where it occurs, with estimated densities of 4.7, 8.7 and 29.7 individuals per ha within forest interior, edges and gaps respectively. At the landscape scale, the chameleon occurs only in three remnant forests: the Dhlinza, Entumeni and Ongoye Forests. The species' extent of occurrence was estimated to be 88 km2 and its area of occupancy 49 km2. Based on the small area of remaining suitable habitat, this species meets the requirements for categorization as Endangered according to IUCN Red List criteria.

Extrinsic Inter- and Intra-specific Competition in Parasitoid Wasps

2021 ◽  
Vol 67 (1) ◽  
Author(s):  
Paul J. Ode ◽  
Dhaval K. Vyas ◽  
Jeffrey A. Harvey
Keyword(s):  
Developmental Stages ◽  
Interference Competition ◽  
Apparent Competition ◽  
Annual Review ◽  
Publication Date ◽  
Natural Ecosystem ◽  
Adult Males ◽  
Alternate Host ◽  
Adult Females ◽  
Behavioral Mechanisms

The diverse ecology of parasitoids is shaped by extrinsic competition, i.e., exploitative or interference competition among adult females and males for hosts and mates. Adult females use an array of morphological, chemical, and behavioral mechanisms to engage in competition that may be either intra- or interspecific. Weaker competitors are often excluded or, if they persist, use alternate host habitats, host developmental stages, or host species. Competition among adult males for mates is almost exclusively intraspecific and involves visual displays, chemical signals, and even physical combat. Extrinsic competition influences community structure through its role in competitive displacement and apparent competition. Finally, anthropogenic changes such as habitat loss and fragmentation, invasive species, pollutants, and climate change result in phenological mismatches and range expansions within host–parasitoid communities with consequent changes to the strength of competitive interactions. Such changes have important ramifications not only for the success of managed agroecosystems, but also for natural ecosystem functioning. Expected final online publication date for the Annual Review of Entomology, Volume 67 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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