Herp 2 essay questions

Explain the different foraging modes and their relationship

Animals mainly use two foraging modes: sit-and-wait or active foraging. Sit-and-wait predators rely on ambush, camouflage, and fast strike speed, while active foragers move constantly and require more energy and sensory input. These modes shape differences in body form, metabolism, and behavior. They also influence predator-prey interactions and energy use.

What are the 3 asexual reproduction types?

Hybridogenesis is a hemiclonal system where hybrid females mate with males of another species but pass on only the maternal genome, discarding the male's before egg formation.

-Kleptogenesis occurs when females "steal" sperm from another species to trigger development, sometimes incorporating parts of the male genome for added variation.

-Parthenogenesis is full asexual reproduction where females produce offspring from unfertilized eggs, creating genetically identical or nearly identical young.

Describe the differences in lifestyles between urbanophiles and urbanophobes and list an example of a herp in each group.

Urbanophiles tolerate or benefit from cities, using buildings, lights, and human resources—e.g., the Mediterranean House Gecko. Urbanophobes avoid urban areas and decline with noise, pollution, heat, and fragmentation—e.g., the Sonoran Desert Toad. These categories reflect behavioral flexibility and sensitivity to disturbance. Urbanization acts as a filter that only some species can pass through.

In the Southwestern US, what factors increase herpetofauna's vulnerability to climate change?

Extreme heat pushes many species near their thermal thresholds. Drought reduces breeding ponds and moist refuges, especially harming amphibians. Fragmented landscapes limit movement to cooler microhabitats. These combined pressures reduce survival, reproduction, and long-term persistence.

How are plethodontids able to achieve extreme tongue-protracting?

Being lungless frees the hyoid apparatus from breathing functions, allowing it to be specialized for feeding. Their direct development removes larval constraints that restrict tongue mechanics in other salamanders. They use elastic recoil rather than muscle contraction alone to propel the tongue. This creates high-speed, long-distance tongue projection.

Explain the four methods of limbless locomotion. Which is the most commonly used?

Snakes use lateral undulation, concertina, rectilinear, and sidewinding locomotion. Lateral undulation is the most common and uses body waves pushing against environmental resistance. Concertina is used in narrow tunnels where anchoring is needed. Sidewinding and rectilinear locomotion help on loose sand or for slow, straight movement.

Explain ecological mismatch and its significance.

Ecological mismatch happens when the timing of an organism's life events no longer aligns with environmental conditions. Climate change can shift breeding or emergence earlier while food availability stays the same. This lowers survival and reproductive success. Long-term mismatches can lead to population declines.

Explain how temperature-dependent sex determination works and describe the three types.

TSD occurs when nest temperature influences hormone pathways that determine gonad development. Small temperature shifts can dramatically change sex ratios. The three patterns are MF (male at cool, female at warm), FM (female at cool, male at warm), and FMF (female-male-female across a temperature gradient). This makes species highly vulnerable to warming climates.

What did Mrosovsky et al. (2009) find as to why many leatherback sea turtles ingested plastic?

Leatherbacks ingest plastic bags because they resemble jellyfish, their main prey. In open water, floating bags mimic the movement, translucence, and shape of jellyfish. Turtles rely heavily on silhouette detection, making them prone to this mistake. Rising plastic pollution increases the frequency of ingestion.

How precise do Müllerian and Batesian mimics have to be to prevent predation?

Batesian mimics must be fairly precise because predators only avoid them if they convincingly resemble a harmful model; otherwise, they risk being eaten. However, Brodie (1993) found that free-ranging birds avoided multiple coral snake-like banded patterns—even imperfect ones—because the high danger of attacking a true coral snake causes predators to generalize avoidance. This means deadly models protect a wider range of mimics than classical theory predicts. Some patterns were still attacked more than others, showing that mimic accuracy still influences protection.

Brodie 1993

What methods do reptiles and amphibians use to detect prey?

Herps use chemical, visual, and sometimes heat or vibration cues to detect prey. Snakes rely on tongue-flicking and the vomeronasal organ to follow chemical trails. Pit vipers use heat-sensing pits to detect warm prey. Amphibians often depend on motion vision and mechanosensation.

Define kleptogenesis and why it may be useful.

Kleptogenesis occurs when females of one species use sperm from another species to activate egg development. The sperm may or may not contribute genetically, allowing mostly clonal reproduction with occasional genetic input. This can boost genetic diversity while keeping a stable lineage. It helps these lineages persist in changing environments.

In geckos, what force allows them to climb walls with setae on their feet?

Geckos use van der Waals forces—weak molecular attractions between surfaces—created by millions of microscopic spatulae on their toe setae. These increase contact area and adhesion, allowing strong grip without suction or liquids. The forces are individually tiny but collectively powerful. This enables smooth-surface climbing.

What specializations do frogs have for jumping, and how do they work?

Frogs have long hindlimbs, a fused urostyle, strong pelvic muscles, and elastic tendons that store energy. When preparing to jump, their spine and pelvis flex to load the tendons like springs. Energy releases rapidly during takeoff, producing explosive power. These adaptations allow long, high-force leaps.

What are the differences between granular and keeled scales in lizards, what are their functions, and give an example species for each?

Granular scales are small, round, and smooth, giving lizards a soft, bead-like texture that helps with flexibility and maneuverability; an example is the Mediterranean House Gecko (Hemidactylus turcicus). Keeled scales have a raised ridge down the center, making them rougher and enhancing protection, camouflage, and water channeling. Many skinks and fence lizards, such as the Eastern Fence Lizard (Sceloporus undulatus), have keeled scales. These scale types reflect differences in habitat use and defensive strategies.

Briefly describe three distinct mechanisms of prey detection, and provide one example of a group of animals (or a specific animal) that primarily uses each mechanism

Many predators use chemosensory detection, such as snakes “tasting” the air with their tongues and Jacobson’s organ. Visual detection is common in diurnal species like anoles, which rely on sharp eyesight to spot moving insects. Vibrational/infrared detection occurs in animals like pit vipers, which sense heat signatures or ground vibrations to locate prey. Each mechanism suits the ecological niche and sensory strengths of the predator.

What shell adaptations have Galapagos Tortoises evolved to forage more efficiently on different islands? How might tortoise populations respond if vegetation type were to change rapidly

Galapagos Tortoises evolved two major shell morphologies: dome-shaped shells for grazing on ground vegetation, and saddleback shells with raised fronts that allow the neck to stretch upward to reach shrubs and cacti. These adaptations reflect available plant height on each island. If vegetation changed rapidly, tortoises may face mismatches between morphology and food accessibility, potentially shifting their foraging range, experiencing reduced fitness, or undergoing directional selection favoring forms better suited to the new vegetation. Over long timescales, new shell shapes could evolve.

Which survivorship category do lizards typically fall into: I, II, or III? What about amphibians and other reptiles? Are there any exceptions?

Most lizards display Type II survivorship, with a fairly constant mortality rate across life stages. Amphibians and many reptiles (like turtles and crocodilians) tend to show Type III, producing many offspring with high early mortality. Some species, such as large crocodilians or long-lived tortoises, approach Type I patterns later in life due to strong adult survival. Life-history strategies vary based on parental care, body size, and ecological pressures.

Why might reptiles be important organisms to study in the field of public health? Give at least one example.

Reptiles are important to study in public health because their immune systems and ecological roles can directly influence disease transmission. Some reptiles show natural resistance to parasites—for example, certain lizards can mount an immune response that kills attached ticks, causing them to drop off before they can spread pathogens like Lyme disease. By understanding these mechanisms, scientists can identify potential strategies for reducing vector-borne diseases in humans and wildlife. Reptiles also act as bioindicators, helping us detect emerging environmental health risks.

What is fecundity, and how does the trade-off between number and size of offspring manifest in amphibians and reptiles

-Fecundity refers to the number of offspring an organism can produce in a reproductive event or lifetime. Amphibians and reptiles show a classic trade-off: species producing many offspring typically invest little per individual, resulting in small, vulnerable young (e.g., frogs laying hundreds of eggs).

-Species producing fewer offspring, such as many lizards or some snakes, invest more energy into each, creating larger and more developed young. This trade-off reflects different survival strategies across environments.