Two warbler species nest in the same tree holes, and both produce fewer young where the other species is abundant. What interaction is occurring?

A bobcat captures and eats a rabbit in a suburban habitat. How should the bobcat-rabbit interaction be classified?

White-tailed deer browse newly planted oak seedlings in a restored forest. What interaction do the deer have with the seedlings?

Two invasive mussel species filter the same plankton from a lake, and each grows more slowly when the other is present. What is the relationship?

A ladybug consumes aphids that are feeding on vegetable crops. What interaction occurs between the ladybug and the aphids?

Grasshoppers eat leaves of corn plants in an agricultural field. Which species interaction is this?

Coyotes and foxes in the same grassland both hunt the same small rodents, reducing prey available to each other. What interaction is shown?

A great horned owl catches a rat near a grain-storage facility and eats it. What term describes the owl's effect on the rat?

Sea urchins graze heavily on kelp in a coastal marine reserve. What interaction is occurring between the urchins and kelp?

Two desert rodent species eat the same seeds during a drought, and seed scarcity lowers survival in both populations. What interaction is occurring?

In a laboratory, two Paramecium species are grown together with one bacterial food source. One species persists while the other disappears, although each grows alone. What does this show?

After an invasive plant arrives, a native grass using the same shallow soil water declines until it is absent from the site. Which principle best explains this result?

Two beetle species need the same type of decaying log for egg laying. In long-term plots, only one species remains in each plot where logs are scarce. What outcome is illustrated?

A fish farm releases a nonnative fish that consumes the same zooplankton as a native fish. Over several years, the native fish is no longer found in the reservoir. What process most likely occurred?

Two yeast strains grown in one container rely on the same limited sugar. One strain eventually reaches zero population while the other persists. What does this result demonstrate?

A native bumblebee and an introduced bee visit the same flowers. Where the introduced bee is common, the native bee disappears despite suitable habitat remaining. Which concept fits?

In greenhouse trials, two aphid species feed on the same part of a bean plant. When raised together, one species has no surviving population after several generations. What is the best explanation?

A lake's two plankton species require the same dissolved nutrient. Following nutrient reduction, one species remains and the other is extirpated from the lake. What interaction outcome is indicated?

Two lizard species use identical sunny rocks for basking. On a small island with few rocks, one species is absent after several breeding seasons. What ecological principle is supported?

A crop field contains two weed species that need the same nitrogen, light, and soil space. Repeated surveys show one species replacing the other. What explains the replacement?

Five warbler species feed in one spruce tree, but each concentrates on a different branch height or branch zone. What allows the species to coexist?

Two lizard species live on the same desert outcrop. One hunts insects by day and the other hunts them at night. Which mechanism reduces competition?

In a lake, one fish species eats zooplankton near the surface while another feeds near the bottom. What does this difference illustrate?

Two pollinator species visit the same meadow, but one feeds mainly from deep tubular flowers and the other from open flowers. Why can both persist?

Three shorebird species forage along one beach: one probes mud, one picks insects from wrack, and one catches small crabs in shallow water. What pattern is present?

Two squirrel species occupy the same forest. One stores and eats large acorns, while the other specializes on small pine seeds. What ecological process is shown?

Native and introduced bees share a field, but native bees forage in spring while the introduced bees forage mostly in late summer. What most directly reduces competition?

In a coastal marsh, one crab species burrows above the high-tide line and another below it, although both eat detritus. What permits coexistence?

Two owl species hunt the same woodland. The larger owl takes rodents in open fields, while the smaller owl hunts insects beneath the canopy. What does this demonstrate?

On a coral reef, one damselfish eats algae from exposed rocks while another feeds in sheltered crevices. Which term describes their differing use of habitat?

A barnacle species survives from the low shore to the high shore when raised alone. When a competitor is present, it occurs only on the upper shore. What is its upper-shore distribution with the competitor?

In a greenhouse without competitors or predators, a plant can grow in soils with pH 5 through pH 8. What does this full pH range represent?

A mussel can attach throughout a rocky shore in cages that exclude a competing mussel. Outside cages, it remains only in the lower intertidal zone. What does the lower zone outside cages represent?

A rodent species can survive at temperatures from 5 °C to 35 °C in laboratory enclosures with abundant food and no predators. What does this potential temperature range describe?

A native trout can live in both cool upstream reaches and warmer downstream reaches in separate tanks. In the river, it is found only upstream because an introduced fish dominates downstream. What is the upstream river area for the trout?

A grass species grows under both full sun and partial shade when cultivated alone. In an intact prairie, it grows only in full sun because taller grasses shade it. The full sun-to-partial-shade range is what?

A small predator can use forest edges and grasslands when alone, but it occupies only forest edges where a larger predator is present. What term describes the forest-edge area it occupies there?

In controlled ponds with no fish, a frog species breeds in water from 10 °C to 25 °C. This breeding range is the frog's what?

A flowering plant is capable of growing across an entire meadow, but herbivores consume it everywhere except near thorny shrubs. The area near shrubs is the plant's what?

A crab survives in salinities from 15 to 35 ppt in laboratory tanks. Predation prevents it from occupying the shallowest estuary sites, although salinity is suitable there. Which term names the laboratory salinity range?