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Visar resultat 1 - 5 av 56 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Stopover Ecology of Mallards : Where, when and how to do what?

   Författare :Daniel Bengtsson; Jonas Waldenström; W. Michael Eichholtz; Linnéuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Age characters; body condition; departure decision; effects of influenza A virus; habitat selection; mallard; movement; Ottenby Bird Observatory; stopover ecology; weather; wild birds; Ecology; Ekologi;

   Sammanfattning : The mallard (Anas platyrhynchos) is the most numerous and widespread duck in the northern hemisphere and a model species in ecology and harvest management. Migration is a crucial life stage for many birds and understanding the drivers of migration has important implications for conservation biology and assessment of animal population responses to global changes. LÄS MER

3. 2. Movement patterns and displacement of a soil insect

   Författare :Elna Nilsson; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; attraction; repellence; fatty acid; Ecology; Ekologi; alarm; autoregressive model; autocorrelation; random walk; Protaphorura armata; Collembola; migration; dispersal; movement; displacement;

   Sammanfattning : Movement and dispersal are important determinants of the spatial distribution and persistence of animal populations in a heterogeneous environment. I studied the small-scale movement pattern of a soil-living insect, Protaphorura armata (Collembola) by using a video-equipment. LÄS MER

4. 3. Ecology across Boundaries : Food web coupling among and within ecosystems

   Författare :Pia Bartels; Peter Eklöv; Lars J. Tranvik; Daniel E. Schindler; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; cross-ecosystem; food web; habitat coupling; terrestrial-aquatic linkages; subsidy; allochthonous; lake ecosystem; population divergence; trait variation; Terrestrial; freshwater and marine ecology; Terrestrisk; limnisk och marin ekologi; Freshwater ecology; Limnisk ekologi; Biology; Biologi; Biologi med inriktning mot limnologi; Biology with specialization in Limnology;

   Sammanfattning : Cross-boundary movements of energy and material are ubiquitous. Freshwater ecosystems receive nutrients, dissolved, and particulate organic matter from adjacent terrestrial ecosystems, whereas terrestrial ecosystems mainly receive prey organisms and detritus deposited by physical processes such as floods from freshwater ecosystems. LÄS MER

5. 4. Benthic diatoms in the Gulf of Bothnia : Community analysis and diversity

   Författare :Svenja Busse; Michael Sullivan; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ecology; Baltic Sea; Biodiversity; Biomass; Community ecology; Diatoms; Multivariate analysis; Navicula; Phytobenthos; Salinity gradient; Scale; Size; Water movement; Ekologi; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi; Ecological Botany; Ekologisk botanik;

   Sammanfattning : Benthic diatoms are valuable tools for biological monitoring and paleo-ecological reconstruction of past environmental conditions. This thesis aims at describing size-related properties of benthic diatoms and suggests that data assessment for community analysis can be improved by considering the importance of scale. LÄS MER

7. 5. Behavioural ecology of Indo-Pacific bottlenose and humpback dolphins

   Författare :Eva Stensland; Per Berggren; Anders Angerbjörn; Elisabeth Slooten; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Behaviour; ecology; dolphins; Zanzibar; abundance; distribution; tourism; mixed-species groups; interspecific association; social interaction; swim-with-dolphin; Terrestrial; freshwater and marine ecology; Terrestisk; limnisk och marin ekologi;

   Sammanfattning : Dolphins in East Africa face various threats, such as direct hunt, bycatch and habitat degradation. It is therefore important to undertake research that can facilitate necessary conservation and management actions to minimize these threats. LÄS MER