Species Interactions - Vocabulary Flashcards
Niche and specialization
Within an ecosystem, there are multiple interactions between species.
A species' role in an ecosystem is its niche, which can be very specific.
Generalists (e.g., raccoons) can exploit a wide variety of resources.
Specialists (e.g., koalas) have a very narrow niche.
Slide fragments show emphasis on niche breadth as a key organizing concept.
Interspecific vs. Intraspecific Competition
Interspecific competition: species use similar resources (-/- interaction).
Intraspecific competition: individuals within the same species compete for resources.
Intraspecific competition is a powerful evolutionary driver.
Specialist vs. Generalist traits (slides with fill-in options)
Slides present statements about specialists:
Have narrowly specific habitat requirements.
Tend to have higher reproductive rates than generalists.
Are tolerant of environmental change.
Do not have narrowly specific habitat requirements.
Note: The conventional ecological understanding often finds specialists have narrow habitat needs and can be more vulnerable to environmental change; reproduction rates can vary by taxa, and generalists typically tolerate a broader range of conditions. The slide content includes multiple-choice style assertions; treat them as presented content with potential need for clarification in class.
Practical takeaway: Specialists have narrow habitat needs and can be more sensitive to change; generalists exploit diverse resources.
Herbivory (Plant consumption by animals)
Definition: Herbivory is the consumption of plants by animals.
Interaction type: typically considered as (+/−) from the consumer’s perspective and prey/plant’s perspective respectively; hosts may evolve adaptive defenses.
Mention of adaptive defenses against herbivory (context implied): structural, chemical, and behavioral defenses.
A light, informal aside in slides: “Temptation of my youth” appears as a note or aside, not a core concept.
Predation
Predation is a (+/−) interaction for predator and prey.
Question posed: What has been an adaptive response to predation? (implies discussion of defenses and strategies)
Coevolution and Predator–Prey Dynamics
Coevolution can occur between predators and prey.
Predator defenses discussed: chemical defenses, cryptic coloration, flashing coloration.
Implication: predator and prey traits can influence each other’s evolution over time.
Prey Defenses and Warning Coloration
Aposematism: warning coloration used by toxic or chemically defended prey.
Conceptual idea: coloration signals to predators that the prey is unpalatable or dangerous.
Mimicry and Coloration (Are all brightly colored animals toxic?)
Mimicry allows non-toxic or less dangerous species to imitate warning signals.
Batesian mimicry: harmless species mimics a poisonous or dangerous species.
Müllerian mimicry: multiple unpalatable species share similar warning signals.
Examples cited in slides: ant-mimicking jumping spider, Viceroy butterfly, Monarch butterfly.
Parasitism
Parasitism is a (+/−) interaction where a parasite obtains nourishment from a host.
Examples listed: mites, lice, dog heartworm.
New York parasitism context provided via Lyme disease material (parasite–host dynamics and public health relevance).
Lyme Disease Data and Parasitism in New York (case study in slides)
Slide presents U.S. Lyme disease data across states (1990–2021) with a total of 758{,}912 reported cases (the CDC case definition changed in 2008; total includes confirmed plus probable cases since then).
2019–2020 data caveat: CDC notes incomplete jurisdiction reporting due to the COVID-19 pandemic.
2011 case definition added positive CSF antibody tests; 2017 update to CDC case definition used for reported totals.
2021 estimate (Lyme Disease Association): approximately 476{,}000 Americans diagnosed and treated for Lyme disease annually (insurance-based estimate).
Geographic distribution: map shows state-by-state totals with top-ranked states for reported cases; notables include NY and surrounding states; a state-by-state table lists county-level cases and rates per 100{,}000 (e.g., Albany: 153 cases; 49.5 per 100,000; Allegany: 8.4; Broome: 294; 149.6; etc.).
Important caveat: the map notes reporting criteria changes and that only a fraction of actual cases are reported under surveillance definitions.
Parasitism and Host Fitness (Does parasitism kill the host?)
Parasitism can reduce host fitness; not all parasites kill hosts but they often impair fitness.
Example study prompt: Reed Warbler and Common Cuckoo (YouTube link provided) illustrating parasite impacts in larger vertebrates.
Conceptual takeaway: parasitism may reduce host performance and survival, potentially influencing host evolution.
Host Defense Mechanisms to Parasites
Hosts have evolved defenses to counter parasites, including:
Grooming
Inflammatory response
Scabs
Cysts in muscle or skin to isolate the parasite
Symbiosis and Mutualism (+/+)
Symbiotic relationship with mutual benefits is also known as mutualism (positive for both partners).
Example focus: Coral reef symbiosis (see next section).
Coral Reef Symbiosis and Coral Bleaching
Coral–algae mutualism: corals depend on microscopic algae (zooxanthellae) living in their tissues; these algae provide major food sources and color.
Bleaching context: When symbiosis is stressed (temperature rise, pollution, etc.), algae leave coral tissue, causing bleaching.
Consequences: bleached corals lose their main food source and become more vulnerable to disease.
Primary driver of bleaching: increased ocean temperature due to climate change; other contributing factors include runoff, pollution, storm runoff, and excessive sunlight exposure.
NOAA Coral Reef Conservation Program referenced as a resource.
Commensalism (+/0)
Definition: interaction where one species benefits and the other is unaffected.
Example: Hermit crabs use trash or discarded shells as shells; a small species benefits from the resource while the large host is largely unaffected.
Interactive Quiz: Mutualism Recognition
Question: Which interaction involves both species benefiting?
Correct answer (as presented): Mutualism.
Other options listed: Commensalism, Predation, Competition, Herbivory.
Repeated prompts indicate in-class polling content from pollev.com.
Keystone Species and Ecosystem Engineers
Keystone species have a disproportionate impact on ecosystem structure and function.
Classic examples include wolves and sea otters (predator control of prey and ecosystem cascades).
Ecosystem engineers are organisms that create, modify, or maintain habitats, often considered a subset of keystone species (e.g., beavers, prairie dogs, earthworms).
Biodiversity Metrics: Richness and Diversity
Species richness: total count of species within a given area; does not account for distribution among species.
Species diversity: considers relative abundance and proportions of each species (evenness alongside richness).
Key distinction: richness vs. diversity.
Species Changes with Environmental Conditions: Ecological Succession
Ecological succession overview: changes in community structure over time in response to disturbance or new colonization.
Primary succession: occurs where no biotic community previously existed (e.g., bare rock, lava fields).
Secondary succession: occurs in areas that were previously occupied by a community but experienced disturbance.
Word bank in slides includes: Primary succession, Secondary succession.
Primary Succession: Pioneer to Climax Sequence (example sequence)
Typical progression on exposed rock:
Lichens
Mosses
Grasses
Herbs
Shrubs
Tree seedlings
White spruce, Balsam fir, Paper birch, Aspen, Black spruce, Jack pine (species in sequence toward a climax community)
Concept: a pioneer community establishes first, followed by later successional stages leading toward a climax community.
Secondary Succession after Disturbance: Phases and Pathways
Disturbances include natural and anthropogenic events (e.g., fire, deforestation, agriculture, cattle farming).
Described as Phase I through Phase IV toward a secondary forest.
Emphasizes that disturbance initiates a successional trajectory toward recovery and potential new stable states.
Yellowstone 1988 Wildfires: Case Study of Disturbance and Recovery
Event: large-scale wildfires burned roughly 36% of the park to varying degrees.
Post-fire response: Fireweed (Chamerion angustifolium) emerged soon after; Aspen became more common after fires, displacing some conifer stands.
Lodgepole pine cones: some open when exposed to fire, enabling seed dispersal; crown fires can enhance seed release in some areas.
Overall implication: disturbances can reset successional timelines and alter species composition through altered seed dispersal and establishment patterns.