--- title: "Ecology & Conservation" description: "13 topics in Science, in the order they build on each other." canonical: https://lightmysky.com/learn/science/areas/ecology-and-conservation source: https://lightmysky.com/learn/science/areas/ecology-and-conservation.md retrieved: 2026-09-02 --- > **Agent view.** This is the Markdown twin of the page, for tools and assistants. > When to use this site, and the call that answers each job: https://lightmysky.com/agent-instructions.md > API description (OpenAPI 3.1): https://lightmysky.com/openapi.json · Authentication: https://lightmysky.com/auth.md > Pricing: https://lightmysky.com/pricing.md · Catalog: https://lightmysky.com/llms.txt · Full catalog: https://lightmysky.com/llms-full.txt > Every machine-readable file on this domain: https://lightmysky.com/.well-known/ai-catalog.json > Ask for Markdown with `Accept: text/markdown`, a `.md` address, or `?mode=agent`. # Ecology & Conservation 13 topics in Science, in the order they build on each other. Page: https://lightmysky.com/learn/science/areas/ecology-and-conservation - [Optimal Foraging and the Currency of a Behavioural Decision](https://lightmysky.com/learn/science/optimal-foraging-and-the-currency-of-a-behavioural-decision-mt_9iNYB7d1Rh): Foraging decisions can be modelled as maximising energy gained per unit of time, once handling time and travel time are counted. Predictions from that currency can be tested, and where they fail the failure usually names a cost the model left out. - [Sexual Selection, Mate Choice and Parental Investment](https://lightmysky.com/learn/science/sexual-selection-mate-choice-and-parental-investment-mt_6oTPGFw_p5): When one sex invests more per offspring, that sex becomes the limiting resource and the other competes for access. Traits that lower survival can still spread if they raise mating success by more than they cost. - [Kin Selection, Relatedness and When Helping Pays](https://lightmysky.com/learn/science/kin-selection-relatedness-and-when-helping-pays-mt_scVf8G34WI): Helping a relative passes on shared alleles indirectly, so a costly act can spread when the benefit to the recipient, weighted by relatedness, exceeds the cost to the helper. Working out relatedness turns an argument about altruism into a calculation. - [Life-History Trade-offs and How Reproduction Is Allocated](https://lightmysky.com/learn/science/life-history-trade-offs-and-how-reproduction-is-allocated-mt_eGwlydfDWO): An organism cannot grow, survive and reproduce at full rate at once, so life histories are compromises: few large offspring or many small ones, early breeding or late. Where a species sits is predicted by how risky its environment is for juveniles and adults. - [Competition, Niches and What Allows Coexistence](https://lightmysky.com/learn/science/competition-niches-and-what-allows-coexistence-mt_VS9Yud3rCQ): Two species using the same limiting resource cannot both persist unless something separates them, such as different resource use in space, in time or in what limits each one. Modelling competition shows that coexistence needs each species to limit itself more than it limits the other. - [Predation, Herbivory and Trophic Cascades](https://lightmysky.com/learn/science/predation-herbivory-and-trophic-cascades-mt_T0jG4YImZp): Predators and prey drive each other's numbers in cycles, and removing a top predator can change vegetation several links away. Whether a community is controlled from the top or the bottom is a question that field manipulation can answer. - [Measuring Diversity: Richness, Evenness and Turnover Between Sites](https://lightmysky.com/learn/science/measuring-diversity-richness-evenness-and-turnover-between-sites-mt_d_iIiIArWZ): Counting species is not enough, because two communities with the same number of species can differ in how evenly individuals are spread. Indices combine richness and evenness, and a separate measure compares which species differ between sites. - [Productivity, Nutrient Limitation and Ecosystem Stoichiometry](https://lightmysky.com/learn/science/productivity-nutrient-limitation-and-ecosystem-stoichiometry-mt_QWdZj1G9iT): How much an ecosystem produces is usually set by whichever nutrient is scarcest relative to what organisms need, not by energy alone. Because tissues hold elements in fairly fixed ratios, adding one nutrient can shift what limits the system rather than raising production without end. - [Biomes and What Draws Their Boundaries](https://lightmysky.com/learn/science/biomes-and-what-draws-their-boundaries-mt_LpO2gwRYHd): Vegetation across the world falls into a modest number of types, and where each one occurs is predicted well by temperature and rainfall alone. The exceptions are as informative as the rule, because they point at fire, grazing or soil doing the work instead of climate. - [Biogeography: Why a Species Is Here and Not There](https://lightmysky.com/learn/science/biogeography-why-a-species-is-here-and-not-there-mt_sRi0FPcK8r): A species range is set by tolerance, by dispersal and by history, and the three explanations make different predictions. Island patterns, where richness tracks area and isolation, are the cleanest place to test them. - [Demography: Life Tables, Age Structure and What They Predict](https://lightmysky.com/learn/science/demography-life-tables-age-structure-and-what-they-predict-mt_raWfdLLACU): A life table turns survival and reproduction at each age into a single growth rate, and the age structure of a population says whether that rate will hold. It is the tool behind fishery quotas, pension forecasts and every claim that a population is recovering. - [Conservation: Small Populations, Fragmentation and Reserve Design](https://lightmysky.com/learn/science/conservation-small-populations-fragmentation-and-reserve-design-mt_yOl2NGoLeb): Small populations face genetic and demographic risks that feed on each other, so viability analysis asks what size and connection a population needs to persist. Reserve design turns that into choices about area, edge and the corridors between patches. - [Global Change Ecology: Ranges, Phenology and Regime Shifts](https://lightmysky.com/learn/science/global-change-ecology-ranges-phenology-and-regime-shifts-mt_tJ7XpAADMF): Warming moves species and shifts the timing of their life events, and because the shifts are not equal the partners in an interaction can pull apart. Some systems then change abruptly rather than gradually, which is why a slow forcing can produce a sudden result.