Population Ecology   I. Attributes II.Distribution III. Population Growth – changes in size through time IV. Species Interactions

IV. Species Interactions A. Types Effect on Species 2 Effect on species 1 Positive Neutral Negative mutualism commensal consumer - amensal competition

IV. Species Interactions A. Types

IV. Species Interactions B. Consumer-Resource 1. Types

IV. Species Interactions B. Consumer-Resource 1. Types 2. Responses - Structural, morphological

IV. Species Interactions B. Consumer-Resource 1. Types 2. Responses - Behavioral Sit-and-wait, crypsis pursuit

Tadpole responses

IV. Species Interactions B. Consumer-Resource 1. Types 2. Responses - Chemical

IV. Species Interactions B. Consumer-Resource 1. Types 2. Responses - Chemical

IV. Species Interactions B. Consumer-Resource 1. Types 2. Responses 3. Novel Aspects of Parasitism Complex life cycle Multiple hosts (definitive host is where sex. Rep. occurs) Evade immune system Reduction in structural complexity

IV. Species Interactions B. Consumer-Resource 1. Types 2. Responses 3. Novel Aspects of Parasitism Complex life cycle Multiple hosts (definitive host is where sex. Rep. occurs) Evade immune system Reduction in structural complexity 214 million cases in 2015 Between 2000 and 2015, malaria incidence among populations at risk (the rate of new cases) fell by 37% globally. In that same period, malaria death rates among populations at risk fell by 60% globally among all age groups, and by 65% among children under 5. Sub-Saharan Africa carries a disproportionately high share of the global malaria burden. In 2015, the region was home to 88% of malaria cases and 90% of malaria deaths. WHO (2016)

IV. Species Interactions B. Consumer-Resource C. Competition 1. Types: - exploitative/‘scramble’ – organisms remove what they can, and neither make get enough - territorial/ ‘contest’ – competition for access to the resource, with ‘winner take all’ 2. Responses - Competititve exclusion (one species wins) - Coexistence by resource partitioning

IV. Species Interactions B. Consumer-Resource C. Competition D. Mutualisms 1. Types: - trophic: involve species with complementary feeding relationships and they share food (mycorrhizae) - defensive: one species provides defense to another, in exchange for some service or food (ant-aciacia) - dispersive: one species disperses pollen or fruit in exchange for food 2. Responses - Increase frequency and intimacy - May increase the probability of extinction if an obligate relationship develops

IV. Species Interactions B. Consumer-Resource C. Competition D. Mutualisms

IV. Species Interactions B. Consumer-Resource C. Competition D. Mutualisms E. Interactions are not Static 1. Competition – Faciliation Continua

IV. Species Interactions B. Consumer-Resource C. Competition D. Mutualisms E. Interactions are not Static 2. Parasitism – Mutualism Continua

IV. Species Interactions B. Consumer-Resource C. Competition D. Mutualisms E. Interactions are not Static 2. Parasitism – Mutualism Continua Buchnera – bacterial endosymbiont that uses sugars from aphid but produces essential amino acids.