Predicting distributions, habitat preferences and associated conservation implications for a genus of rare fishes, seahorses (Hippocampusspp.)

Washington, D.C. is home to a remarkable assemblage of troglomorphic amphipods and isopods living in shallow groundwater habitats, the hypotelminorheic. Groundwater from the hypotelminorheic emerges on the surface into low-flowing seepage springs, or “seeps”, which are categorized as having blackened leaves, an underlain layer of clay, a drainage area of less than 10,000 m2, and are situated in slight topographical depressions. Stygobiotic species found in D.C.’s seeps include Crangonyx and Stygobromus amphipods and Caecidotea isopods. One species, Stygobromus hayi, is on the endangered species list and is endemic to the district; however, little is known about their habitat preferences or their distribution. All small water bodies, including rainwater puddles and seepage springs were sampled in national park lands in Southeast D.C. for hypotelminorheic fauna, soil morphology, and water quality indicators such as nitrates, phosphates, radon, pH, DO, and conductivity. Comparing sites with and without stygobionts, all phsysico-chemical parameters were statistically insignificant except for conductivity, which was able to distinguish between stygobiont-rich and stygobiont-poor seeps using logistic regression. Spatially, Crangonyx and Stygobromus amphipods rarely inhabit the same seepage spring, with only three occasions of cohabitation and an expected occurrence of ten. Caecidotea, however, is found in habitats with both amphipods. These results can be explained by either competitive exclusion or the presence of chemical differences in their habitats; however, even if there were some slight differences in their habitats, that still does not exclude competitive exclusion as an explanation. This study highlights new and important findings into the environmental preferences of D.C.’s most cryptic and rare species, and the importance of continued exploration of D.C.’s lesser known park lands.

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From numbers to ecosystems and biodiversity: A mechanistic approach to monitoring

Koedoe ◽

10.4102/koedoe.v53i2.998 ◽

2011 ◽

Vol 53 (2) ◽

Cited By ~ 12

Author(s):

Sam Ferreira ◽

Andrew Deacon ◽

Hendrik Sithole ◽

Hugo Bezuidenhout ◽

Mahlomola Daemane ◽

...

Keyword(s):

National Parks ◽

Information Needs ◽

Biological Diversity ◽

Habitat Preferences ◽

Management Strategies ◽

Conservation Implications ◽

Trade Offs ◽

Population Sizes ◽

Underlying Mechanisms ◽

Analytical Approaches

Diverse political, cultural and biological needs epitomise the contrasting demands impacting on the mandate of the South African National Parks (SANParks) to maintain biological diversity. Systems-based approaches and strategic adaptive management (learn by doing) enable SANParks to accommodate these demands. However, such a management strategy creates new information needs, which require an appropriate analytical approach. We use conceptual links between objectives, indicators, mechanisms and modulators to identify key concerns in the context of and related to management objectives. Although our suggested monitoring designs are based mostly on defined or predicted underlying mechanisms of a concern, SANParks requires inventory monitoring to evaluate its key mandate. We therefore propose a predictive inventory approach based on species assemblages related to habitat preferences. Inventories alone may not always adequately serve unpacking of mechanisms: in some cases population size needs to be estimated to meet the information needs of management strategies, but actual population sizes may indirectly affect how the species impact on other values. In addition, ecosystem objectives require multivariate assessments of key communities, which can be used in trend analysis. SANParks therefore needs to know how to detect and define trends efficiently, which, in turn, requires precision of measures of variables. Conservation implications: Current research needs with regard to monitoring should focus on defining designs to yield optimal precision whilst taking methodology, survey trade-offs and analytical approaches into account. Use of these directives and research will guide monitoring during evaluation of SANParks objectives at various scales.

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Macro-habitat preferences by the African manatee and crocodiles – ecological and conservation implications

Web Ecology ◽

10.5194/we-12-39-2012 ◽

2012 ◽

Vol 12 (1) ◽

pp. 39-48 ◽

Cited By ~ 1

Author(s):

L. Luiselli ◽

G. C. Akani ◽

N. Ebere ◽

F. M. Angelici ◽

G. Amori ◽

...

Keyword(s):

Habitat Selection ◽

Coastal Lagoons ◽

Habitat Preferences ◽

Habitat Type ◽

Null Model ◽

Niche Overlap ◽

West African ◽

Conservation Implications ◽

Type Selection ◽

Selection Of

Abstract. African manatees (Trichechus senegalensis) and crocodiles are threatened species in parts of their range. In West Africa, crocodiles may constitute the main predators for manatees apart from humans. Here, we explore the macro-habitat selection of manatees and two species of crocodiles (West African crocodiles Crocodylus suchus and dwarf crocodile Osteolaemus tetraspis) in the Niger Delta (Nigeria), testing the hypotheses that (i) manatees may avoid crocodiles in order to minimize risks of predation, and (ii) the two crocodile species do compete. The study was carried out between 1994 and 2010 with a suite of different field techniques. We observed that the main macro-habitat types were freshwater rivers and coastal lagoons for manatees, mangroves for West African crocodiles, and rivers and creeks for dwarf crocodiles, with (i) the three species differing significantly in terms of their macro-habitat type selection, and (ii) significant seasonal influence on habitat selection of each species. Null models for niche overlap showed a significantly lower overlap in macro-habitat type use between manatee and crocodiles, whereas the two crocodiles were relatively similar. Null model analyses did not indicate any competitive interactions between crocodiles. On the other hand, manatees avoided macro-habitats where crocodiles, and especially West African crocodiles, are abundant.

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Habitat Preferences of the Grey Parrot in Heterogeneous Vegetation Landscapes and Their Conservation Implications

International Journal of Biodiversity ◽

10.1155/2016/7287563 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 6

Author(s):

Simon A. Tamungang ◽

Mathias A. Onabid ◽

Taku Awa ◽

Victor S. Balinga

Keyword(s):

Habitat Preferences ◽

Bird Species ◽

Conservation Strategies ◽

Vegetation Types ◽

Activity Intensity ◽

Conservation Implications ◽

Grey Parrot ◽

In The Wild ◽

Sustainable Conservation ◽

Heterogeneous Vegetation

The wild Grey Parrot Psittacus erithacus Linnaeus suffers from many habitat use challenges in the wake of extensive deforestation in its endemic range of West and Central African rainforests. To determine effects of these challenges on the bird species, seasonal densities of the Grey Parrot were determined using line transects in major heterogeneous vegetation types in the Korup Rainforest, south-western Cameroon. Results of the study highlight habitat preferences of this species on a seasonal base and under different situations of human activity intensity in the landscape. This information can be used to understand the causes of changes in the distribution and abundance of endangered species and also to determine sustainable conservation strategies. It is concluded that the parrot needs diverse vegetation types for survival in the wild state, as it depends on specific tree species for specific habitat resources such as food, roosts, security, and nests at specific periods of the year. Hence, the continuous survival of the Grey Parrot in the range states is not certain, if sustainable measures are not taken to conserve the parrot and its habitat resources both in and outside protected areas.

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Conservation status and biology of the Ultramarine Lorikeet Vini ultramarina in the Marquesas Islands, French Polynesia

Bird Conservation International ◽

10.1017/s0959270921000022 ◽

2021 ◽

pp. 1-16

Author(s):

TAMMY DOUKAS ◽

MARK ZIEMBICKI

Keyword(s):

Conservation Status ◽

Habitat Preferences ◽

Rattus Rattus ◽

French Polynesia ◽

Population Estimates ◽

Population Status ◽

Marquesas Islands ◽

Conservation Implications ◽

Over Exploitation ◽

Black Rats

Summary Classified as Critically Endangered, the Ultramarine Lorikeet Vini ultramarina is one of the world’s most threatened lorikeet species. Endemic to the Marquesas Islands in French Polynesia, the species was formerly distributed over most islands in the archipelago, but is today found primarily on the island of Ua Huka, its range having contracted significantly in recent decades. Habitat alteration and loss, and over-exploitation of natural resources, are cited as impacting the Ultramarine Lorikeet, but the influence of introduced black rats Rattus rattus as predators has been implicated as the primary threat to the species. To assess population status and document aspects of the species biology, including habitat preferences and diet, we conducted the first systematic surveys of the species during two independent surveys spaced seven years apart (2002 and 2009). Population estimates of 2,011 ± 284 (in 2002) and 1,922 (in 2009) individuals on Ua Huka suggest the population was relatively healthy and stable between these periods. However, surveys and searches of other islands in the species’ contemporary range, where black rats occur, either failed to document the species or noted very few individuals. These findings highlight the critical importance of Ua Huka as a rat-free refuge and the value of our surveys as baseline estimates of the population status of the species. We discuss the conservation implications of our findings and propose recommendations to secure the species’ future survival.

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GIS-models work well, but are not enough: Habitat preferences of Lanius collurio at multiple levels and conservation implications

Biological Conservation ◽

10.1016/j.biocon.2009.03.033 ◽

2009 ◽

Vol 142 (10) ◽

pp. 2033-2042 ◽

Cited By ~ 74

Author(s):

Mattia Brambilla ◽

Fabio Casale ◽

Valentina Bergero ◽

G. Matteo Crovetto ◽

Riccardo Falco ◽

...

Keyword(s):

Habitat Preferences ◽

Lanius Collurio ◽

Conservation Implications ◽

Multiple Levels

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Habitat alteration enables hybridisation between Lesser Spotted and Greater Spotted Eagles in north-east Poland

Bird Conservation International ◽

10.1017/s0959270913000348 ◽

2013 ◽

Vol 24 (2) ◽

pp. 152-161 ◽

Cited By ~ 9

Author(s):

GRZEGORZ MACIOROWSKI ◽

PAWEŁ MIRSKI

Keyword(s):

Environmental Factors ◽

Habitat Preferences ◽

Arable Land ◽

Habitat Requirements ◽

Habitat Alteration ◽

Landscape Changes ◽

Human Settlements ◽

North East ◽

Conservation Implications ◽

Several Variables

SummaryWetlands in the Biebrza Valley, north-east Poland, are inhabited by two closely related Aquila species: the more numerous Lesser Spotted Eagle A. pomarina prefers human-transformed landscapes, whereas the very rare Greater Spotted Eagle A. clanga is associated with natural marshy landscapes. At least since the last decade of the 20th century, these two species have been known to hybridise in the broad zone of their sympatric occurrence in Europe. The aim of the present study was to compare habitat preferences of both spotted eagle species in order to detect which environmental factors could increase the probability of hybridisation. We analysed nesting and hunting habitats for 148 breeding territories (61 of A. pomarina, 56 of A. clanga and 31 of mixed pairs). As expected, the presence of breeding Greater Spotted Eagles was associated with non-transformed marshy landscapes, whereas Lesser Spotted Eagles clearly preferred human-transformed areas. We hypothesised that mixed pairs should occur in intermediate habitat, confirming this assumption by analysing several variables: distance to human settlements, distance to open areas, and proportion of wetlands, shrublands, grasslands, agricultural mosaic and arable land. Results of this study suggest that some landscape changes can enable two species with different habitat requirements to inhabit the same area and hybridise. This scenario has potential conservation implications for the rarer species, Greater Spotted Eagle, which has narrower habitat preferences.

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