Answer: The larva of the carpenterworm moth (Prionoxystus robiniae) generally has more white-ish color on its back.

Question: Which one has more white-ish color on its back, the larval of carpenterworm moth (scientific name: Prionoxystus robiniae) or that of the goat moth (scientific name: Cossus cossus)?


Answer: The bulb surface of broadleaf wood sorrel (Oxalis latifolia) generally has a lighter color.

Question: Consider the bulb surface of broadleaf wood sorrel (scientific name: Oxalis latifolia) and purple woodsorrel (scientific name: Oxalis purpurea), which one has a lighter color?


Answer: The larva of the Urania swallowtail moth (Urania fulgens) typically has a darker head.

Question: The the larva northern pine sphinx (scientific name: Lapara bombycoides) and the larva urania swallowtail moth (scientific name: Urania fulgens), which one has a darker head?


Answer: Neither one has black dots on the underside of the tail feather.

Question: Mistle Thrush (scientific name: Turdus viscivorus) and Fieldfare (Turdus pilaris) which one has black dots on the underside of its tail feather?


Answer: The Thick-billed kingbird (Tyrannus crassirostris) has non-yellow feathers at the leading edge of their underwing

Question: Which one has non-yellow feathers at the leading edge of their underwing, Couch's Kingbird (scientific name: Tyrannus couchii) or Thick-billed kingbird (scientific name: Tyrannus crassirostris)?


Answer: The Willet (scientific name: Tringa semipalmata) has striped primary flight feathers.

Question: Which one has striped primary flight feathers, Willet (scientific name: Tringa semipalmata) or Grey-tailed tattler (scientific name: Tringa brevipes)?


Answer: The Giant Chickweed (scientific name: Stellaria aquatica) normally would not have red stamen tips.

Question: Consider the lesser stitchwort (scientific name: Stellaria graminea) and Giant Chickweed (scientific name: Stellaria aquatica). Which one of them normally would not have red stamen tips?


Answer: The matured fruit of the Virginia creeper (Parthenocissus quinquefolia) generally has less shiny surfaces.

Question: The matured fruit of which plant have less shiny surfaces, the Virginia creeper (scientific name: Parthenocissus quinquefolia) or the pepper vine (scientific name: Ampelopsis arborea)?

Ampelopsis arborea
Parthenocissus quinquefolia


Answer: No, both have the same number of petals (four).

Question: Do the flowers of Silver Dollar (scientific name: Lunaria annua) have fewer petals than those of Tower Mustard (scientific name: Turritis glabra)?'


Answer: No, mature sori (spore-producing organ) found on gully fern (scientific name: Pneumatopteris pennigera) have darker color.

Question: Does mature sori (spore-producing organ) found on narrow beech fern (scientific name: Phegopteris connectilis) have darker color than that found on gully fern (scientific name: Pneumatopteris pennigera)?

Pneumatopteris pennigera
Phegopteris connectilis


Answer: No, the ventral side (underside) of both are generally pale and unmarked.

Question: Does the Mountain Tree Frog (scientific name: Hyla eximia) have more distinctive patterns on the underside of its body compared to Green Tree Frog (scientific name: Hyla cinerea)?


Answer: Neither one has a red flower pistil.

Question: Black mustard (scientific name: Brassica nigra) and Ink Berry (scientific name: Dianella nigra), which one has a red flower pistil?


Answer: Yes, both are yellow.

Question: Do the stamen tips of Chocolate Lily (scientific name: Fritillaria biflora) and yellow fritillary (scientific name: Fritillaria pudica) have the same color?


Answer: Sparrow vetch (scientific name: Vicia tetrasperma) has more hairy seed pods.

Question: Sparrow vetch (scientific name: Vicia tetrasperma) and slender vetch (scientific name: Vicia ludoviciana), which one has more hairy seed pods?


Answer: The western maidenhair fern (Adiantum aleuticum) typically has more elongated sori.

Question: Common maidenhair fern (scientific name: Adiantum cunninghamii) and western maidenhair fern (scientific name: Adiantum aleuticum), which one has more elongated sori (spore-producing structures)?

Adiantum aleuticum
Adiantum cunninghamii


Answer: The theona checkerspot (scientific name: Chlosyne theona) caterpillar has less prominent color patterns.

Question: Which one has less prominent color patterns, silvery checkerspot (scientific name: Chlosyne nycteis) caterpillar or theona checkerspot (scientific name: Chlosyne theona) caterpillar?


Answer: No.

Question: Do the mottled duck (scientific name: Anas fulvigula) and grey teal (scientific name: Anas gracilis) both show a white underside of the primary flight feathers when their wings are spread?


Answer: The larva of mottled beauty (scientific name: Alcis repandata) has a more slender body.

Question: Which one has a more slender body, the larva of mottled beauty (scientific name: Alcis repandata) or the larva of the Showy Emerald moth (scientific name: Dichorda iridaria)


Answer: The larva of the marbled fritillary (scientific name: Brenthis daphne) has a more spiky body.

Question: Which one has a more spiky body, the larva of Tawny Rajah (scientific name: Charaxes bernardus) or the larva of the marbled fritillary (scientific name: Brenthis daphne)?


Answer: The bright spots on the back of the tawny rajah (Charaxes bernardus) larva generally appear farther apart.

Question: Comparing the pair of two bright spots on the back of tawny rajah (scientific name: Charaxes bernardus) larva and the two-tailed pasha (scientific name: Charaxes jasius) larva, which one appear farther from each other?


Answer: Yes.

Question: Do both Kentish Plover (scientific name: Charadrius alexandrinus) and semipalmated plover (scientific name: Charadrius semipalmatus) have white stripes above eyes?

Charadrius semipalmatus
Charadrius alexandrinus


Answer: No.

Question: Does the ripe fruit of Cornelian cherry (scientific name: Cornus mas) have a darker color than the ripe fruit of roundleaf dogwood (scientific name: Cornus rugosa)?


Answer: No, they have the same number of blocks of scute (12).

Question: Does the underside of an adult Meso-American slider (scientific name: Trachemys venusta) shell have more blocks of scute than that of an adult northern map turtle (scientific name: Graptemys geographica)?


Answer: No, only the mountain maple (scientific name: Acer spicatum) has upright flower clusters

Question: Do the mountain maple (scientific name: Acer spicatum) and the bigleaf maple (scientific name: Acer macrophyllum) both have upright flower clusters?


Answer: The Long-tailed Mockingbird (scientific name: Mimus longicaudatus) has darker feet.

Question: Brown Thrasher (scientific name: Toxostoma rufum) and Long-tailed Mockingbird (scientific name: Mimus longicaudatus), which one has darker feet?


Answer: The mole snake (scientific name: Pseudaspis cana) has darker-colored eyes.

Question: Common tree snake (scientific name: Dendrelaphis punctulatus) and the mole snake (scientific name: Pseudaspis cana), which one has darker-colored eyes?

Pseudaspis cana
Dendrelaphis punctulatus


Answer: Yes, both are yellow.

Question: Do the flower of pōhutukawa (scientific name: Metrosideros excelsa) and flower of Common Myrtle (scientific name: Myrtus communis) have similarly colored anthers?


Answer: No, only the flowers of common bilberry (scientific name: Vaccinium myrtillus) exhibit a color gradient on their petals

Question: Do the flowers of common bilberry (scientific name: Vaccinium myrtillus) and the flowers of sparkleberry (scientific name: Vaccinium arboreum) exhibit a distinct color gradient on their petals?


Answer: Yes (both black)

Question: Are the tongues of grass snake (scientific name: Natrix helvetica) and Chicken Snake (scientific name: Spilotes pullatus) the same color?


Answer: No.

Question: Is it true that both the giant heron (scientific name: Ardea goliath) and White-necked Heron (scientific name: Ardea pacifica) have clearly visible webbings on their feet?


Answer: The scarlet-chested sunbird (scientific name: Chalcomitra senegalensis) has a darker iris.

Question: Which on has a darker iris, the scarlet-chested sunbird (scientific name: Chalcomitra senegalensis) or the brown-throated Sunbird (scientific name: Anthreptes malacensis)?

Anthreptes malacensis
Chalcomitra senegalensis


Answer: Yes.

Question: Is it true that both the wings of white-necked jacobin (scientific name: Florisuga mellivora) and the wings of Booted Racket-tail (scientific name: Ocreatus underwoodii) display a dim pink color when they are flying or hovering?

Ocreatus underwoodii
Florisuga mellivora


Answer: The unopened flower buds of desert milkweed (scientific name: Asclepias erosa) tend to have a rounder structure.

Question: Comparing the unopened flower buds of Spider Milkweed (scientific name: Asclepias asperula) and those of desert milkweed (scientific name: Asclepias erosa), which tend to have a rounder structure?


Answer: No. Coastal cutthroat trout (scientific name: Oncorhynchus clarkii) has lighter color inside the mouth.

Question: Is it true that coastal cutthroat trout (scientific name: Oncorhynchus clarkii) has darker color inside the mouth compared to King Salmon (scientific name: Oncorhynchus tshawytscha)?

Oncorhynchus tshawytscha
Oncorhynchus clarkii


Answer: No. Both species can have blue colored throat scales for male individuals.

Question: Is it true that both the crevice swift (scientific name: Sceloporus torquatus) have blue colored throat scales and the mountain spiny lizard (scientific name: Sceloporus jarrovii) have brown colored throat scales?

Sceloporus jarrovii
Sceloporus torquatus


Answer: Common milkpea (scientific name: Galega officinalis) has a more slender legume.

Question: Which one has a more slender matured legume, common milkpea (scientific name: Galega officinalis) or narrowleaf lupin (scientific name: Lupinus angustifolius)?

Galega officinalis
Lupinus angustifolius


Answer: The Crested Honey Buzzard (Pernis ptilorhynchus) generally exhibits darker throat plumage compared to the Griffon Vulture (Gyps fulvus).

Question: The Griffon Vulture (scientific name: Gyps fulvus) and the crested honey buzzard (scientific name: Pernis ptilorhynchus), which one has more darker colored throat plumage?


Answer: No.

Question: Are the dorsal fin spines of Hardhead Catfish (scientific name: Ariopsis felis) more smooth along their posterior edge, compared to the channel catfish (scientific name: Ictalurus punctatus)?


Answer: The eastern chipmunk (scientific name: Tamias striatus) has lighter abdomen fur?

Question: Eastern chipmunk (scientific name: Tamias striatus) and plantain squirrel (scientific name: Callosciurus notatus), which one has lighter abdomen fur?


Answer: The larva of the Columbia silk moth (Hyalophora columbia) typically has more colorful sparse protuberances on its body.

Question: The larva of Columbia silk moth (scientific name: Hyalophora columbia) and that of tulip-tree silkmoth (scientific name: Callosamia angulifera), which one has more colorful sparse protuberance on its body?

Hyalophora columbia
Callosamia angulifera


Answer: The Stripe-headed Sparrow (Peucaea ruficauda) has warmer-colored feet scales.

Question: Which one has warmer colored feet scales, the Black-throated Sparrow (scientific name: Amphispiza bilineata) or the Stripe-headed Sparrow (scientific name: Peucaea ruficauda)?


Answer: The longnose gar (Lepisosteus osseus) generally has more densely arranged teeth.

Question: Comparing longnose gar (scientific name: Lepisosteus osseus) and spotted gar (scientific name: Lepisosteus oculatus), which one has more densely arranged teeth?


Answer: The fruit of the small-leaved milk tree is the one that generally has a bright red color.

Question: Comparing the fruit of Chinese Banyan (scientific name: Ficus microcarpa) and the fruit of small leaved milk tree (scientific name: Streblus heterophyllus), which one generally have a bright red color?


Answer: No, their unopened flower buds are uniformly colored.

Question: Is it true that both the tiger lily (scientific name: Lilium lancifolium) and the Michigan lily (Lilium michiganense) have dotted patterns on their unopened flower buds?


Answer: Yes.

Question: Is it true that both the crimson banded wrasse (scientific name: Notolabrus gymnogenis) and the sergeant baker (scientific name: Latropiscis purpurissatus) have obvious teeth?

Latropiscis purpurissatus
Notolabrus gymnogenis


Answer: No, both have black underside of tail when viewing from front.

Question: Is it true that both Black-vented Oriole (scientific name: Icterus wagleri) and Spot-breasted Oriole (scientific name: Icterus pectoralis) have yellow underside of tail when viewing from front?


Answer: The American Lady (Vanessa virginiensis) is the one with the eye-like pattern on the underside of the hindwings.

Question: The Western Painted Lady (scientific name: Vanessa carye) and the American Lady (scientific name: Vanessa virginiensis), which one has eye-like pattern on the underside of their hindwings?


Answer: The male garden sunbird (Cinnyris jugularis) does not exhibit split tail feathers when viewed from the front during perching.

Question: Male crimson sunbird (scientific name: Aethopyga siparaja) and male garden sunbird (scientific name: Cinnyris jugularis) , which does not exhibit split tail feathers when viewed from front during perching?


Answer: Yes, both are black.

Question: Is it true that the Mexican tiger moth (scientific name: Apantesis proxima) and the Parthenice tiger moth (scientific name: Apantesis parthenice) have the same tip color on their tail sections of abdomen when viewed from above?


Answer: The Latticed Heath (Chiasmia clathrata) typically has more prominent stripe patterns on its abdomen.

Question: Latticed heath (scientific name: Chiasmia clathrata) and juniper-twig geometer (scientific name: Patalene olyzonaria), which one has more prominent stripe patterns on its abdomen?