Study Guide 2 Flashcards
Provide some descriptive traits for each of the following tropical plant families:
Annonaceae, Lauraceae, Myristicaceae, Orchidaceae.
Annonaceae: “custard apple fam” – cherimoya, soursop, pawpaw, lancewood, ylang-ylang — simple, flat, paired leaves w/ smooth margins — monolayered branches – radially symmetric flowers w/ 3 or 6 long petals —- big spiked, indehiscent, pulpy fruits (some cauliflorous) — flowers and fruits with fragrant oils — fruits and leaves with toxins
Lauraceae: “laurels” — trees, shrubs, and parasitic vines of Cassytha — top 5 in # of spp in single forest — cinnaomn, camphor, bay, avocado, rosewood — used in marine vessels — important for frugivores — thick, dark leaves with veins — small yellow/white/green flowers – big, single seeded drupe fruits that’re indehiscent — toxic sap or aromatic oils that’re resistant to insects
Myristicaceae: “nutmegs” — trees and shrubs — pantropical lowlands – medium sized trees – unknown origin, but maybe Africa/Madagascar 125-94 mya — glossy, dark green, simple leaves – almost no petals on flowers – fruits are big single seed with bright colors–aril — red sap and aromatic oils and hallucinogenics
Orchidaceae: epiphytes, lithophytes, hemiparasites, holoparasites —- biggest flowering plant fam — includes vanilla and is often cultivated as hybrids — monocots with variable growth forms – super modified resupinate flowers, bilaterally symmetric with one dif petal – tiny, wind dispersed seeds – symbiotic with fungi
What do we mean by a “megafaunal dispersal syndrome”? What plant families contain
species with this type of dispersal and in the absence of large, extinct animals, which
tropical birds or mammals contribute to dispersal in these species?
-big fruit grows on or close to trunk or on large branches –> inhediscent with thick or hard endocarp - hard to separate from pulp - drops on or before ripening —> bitter, peppery, nauseating chems –> seed benefit from or require physical/chemical abrasion to germinate
- Laurels, Anaceae
- oilbird, umbrellabird, pigeon, hornbill
Explain some differences in growth patterns or adaptations of early and late
successional tropical plants. Give examples of plants that you might find in early versus
late successional tropical forests.
Early
- Seeds: phytochrome pigment – photoblastic and thermoplastic – small, many, produced continuously – orthodox
- Seedlings: can’t survive in shade – grow fast with low branching
- Trees: often indeterminate (no resting buds or shoots and can make new brannches yr round) – leaves are short lived with high turnover and are soft with few chems
- Solanum and cecropia
Late
- Seeds: germinate below canopy – recalcitrant (non-dormant, no seed bank) – bigger and made less frequently
- Seedlings: shade tolerant; slow growth; lots of branches
- Trees: Determinate branching (resting buds and phases of growth) – leaves are tough and have chems – slow growth – long life
- pretty much everything from 1st notecard
Outline some of the differences in the traits that tropical fruits, seeds, and flower
possess that make them different from the types of fruits, seeds, and flowers that we
see in an average temperate forest plant. Summarize the differences in rates of growth
or length of lifespan between temperate and tropical trees.
Flowers: rely on animal pollination, have adaptations to promote outcrossign – vary from generalized w/ many pollinators to specialized w/ co-adaptations – big, conspicuous, nectar rich, away from leaves
Fruits: cauliflaury – strong flavors and aromas to attract animals
Seeds often inhedicent and need animals for physical or chemical breaking –> often big single seed
Tropical trees have faster growth rate (sunnier, warmer, wetter climate), but lower longevity
Describe the general characteristics of soils in an average lowland tropical rain forest.
What two types of soils occur in the majority of tropical rainforest regions?
Nutrient poor, highly weatherd , good for holding water bc clay-y, acidic bc of H ions in rain
Oxidols (35%)
- excessively weathered, clay soils w/ no more than 10% minerals – high phosphorus retention by oxides
- orange/yellow due to iron and aluminum oxides
- occur in forest with flood seasons
Utisols (28%)
- super leached, acidic soils w/ no more than 10% minerals (no Ca) – <35% base saturation, pH <5
- dark red/purple/orange due to iron oxides
- in aseasonal forests with consistant downward water flow
In what types of locations would you find inceptisols and andisols and how do these 2
additional tropical soil types differ from the average soil in a lowland tropical forest?
Andisols = very fertile, volcanic ash in Hawaii and Andes
Inceptisols = form quickly where plant biomass is decaying (floodplanes bring nutrients) in New Guinea
How do soils in peat forests in South East Asia differ from those mentioned above? Why
is it still difficult for plants to absorb nutrients from these soils?
Histosols are infertile peat areas that’re heavily organic with accumulated humus –> not available to plant roots because it’s held above the level of the water tables
What is meant by the phrase “paradox of tropical luxuriance” or the “paradox of the
plants”? Can you explain how highly diverse and dense tropical plant communities occur
on nutrient poor soils?
It references the seeming inconsistancy of the huge biomass and diversity of tropical rainforests despite the nutrient poor soil
Fertile soil is found in the canopy
plants can recapture dissolved nutrients as they’re released by decomposition
-Nutrients released from weathering of substrate (bedrock, volcanic eruptions, dust storms)
-Nutrients in water (throughfall, stemflow, capillary action, rain/humidity)
-Nutrients in biomass (greenfall)
-Nutrients in necromass (litterfall, waste, dead animals)
List and describe some adaptations that tropical plants in particular or tropical forests in
general exhibit for capturing nutrients before they are leached into the soil.
high shoot to root ratio
- apogeotropic roots grow up onto other plants (5-6 cm/ 72 hr)
- canopy roots = adventitious roots that grow into epiphyte layers and aerial soil
Leaves
- retain nutrients longer and use them efficiently
- thick leaves so don’t lose to herbivory
- waxy leaves/drip tips prevent leaching
- great at carbon fixation
- long life
- big, so catches rain
Throughfall and stemflow
Epiphytes, epiphylls, and phytotelmata contribute to arrested litter
How do animals contribute to rapid recycling of nutrients, soil mixing, or addition of
nutrients to soils?
- Lots of soil organisms
- Microflora (mycorrhizae) associated with 95% of plants –> fungi gives nutrients and gets prots, carbs, and fats –> increases surface area uptake, gives access to P and iron oxides and Ca and K
- Macrofauna: beetles, ants, caerpillars, millipedes, isopods, annelids, spiders, centipedes = litter transformers –> termites (isoptera) = 75% insect biomass and 10% of tropical animal biomass (eat 20-50% fallen leaves) (assist in N P Ca and K) (aerate soil)
herbivory leads to rapid recycling of nutrients
Outline some differences between temperate and tropical bird communities.
- Greater diversity bc of stratification
- less proportion of insectivores (60 vs 90% of breeding season birds) – unique ant birds though
- more diversity of canopy birds bc of fruit
- Migration: tropical birds don’t do this
- lower basal metabolic rate
- longer lived, fewer offspring
for each of the following taxa, list the major tropical region in which it occurs and provide a description and a unique characteristic that distinguishes it from other birds: Cassowary Hummingbirds Parrots Toucans & Hornbills Trogons Cotingas Antbirds Kingfishers Tyrant Flycatchers Oropendolas Vangas Motmots Leafbirds Sunbirds
Cassowary = Australia and New Guinea –> live up to 50 yrs –> ground dwelling –> long spike toe for defense –> bony crest on head – no camoflauged eggs (green) –> quills
Hummingbird = nectivores, Neotropical, related to swifts in Apodiforms –> small with thin bills and bright feathers –> feed by hovering –> can fly backward –> 90% nectar, but some isects –> territorial and trap-lining
Parrots = global distribution, but mostly in SA and Australia –> shork, thick, hooked upper bill –> 2 backwards claws –> nest in tree cavities and clffs –> seed predators and frugivors (a few nectivores) – parakeeets eat dipterocarp seeds
Toucans/Hornbills = long, dep bills for feeding, display, and defense –> cavity nester who seal nests –> mostly frugivres but will eat lizards, snakes, birds, and sometimes insects –> toucan is neotropical, but Hornbill is in Africa and Asia
Trogon = neotropical –> bright, compact, long tail, short notched beak with serrated mandible –> weak legs with backward claws –> frugivores, but also insectivores and eat lizards
Cotingas = Neotropical –> bigest range of body size –> short hooked beaks, round wings, strong legs–> terrestrial and courthsip behaviors –> extreme frugivores
Antbirds = Thamnophilidae, grallariidae, formicariidae –> neotropics and africa –> big variation in size –> strong bills with notch and small tooth, long claws, strong legs –> follow swarming ants and consume “flushed” insects
Kingfishers = “alcedines” –> origin in NA, but mostly Africa and Australia (a few SA) –> riparian habitats –> big heads, long beaks, egg-shaped eye –> burrow nesters –> insectivores and eat frogs/fish
Tyrant flycatchers = tyrannidae –> NA and SA –> small to medium with dull gray to yellow color –> hawking= catch insects in flight
Oropendolas = Icteridae = neotropical –> big, yellow tail, dark color with contrasting bill –> colonial breeders (10-50 nests) –> make long woven basket nests in high open canopies –> insectivores, frugivores, granivores, nectivores
Vangas = Madegascar –> super diverse –> look like a bunch of different birds to fill all the niches in Madegascar
Motmots = neotropical –> fused outer and middle toes –> serrated bills, long racquet tails –> burrow nestrs in groups of 20 couples –> insectivores, faculatative frugivory, predators on snakes and lizards
Leafbirds = Chloropseiae = 1 spp in SE asia –> sexually dimorphic w/ green feathers –> protect flowering trees –> song mimicry, insectivore and nectivore
Sunbirds = Africa, asia, new guinea, australia –> Nectariniidae (Africa and se asia) w/ elongated, curved bills, split tongues, and strong legs –> meliphagidae (new guinea and australia) w/ thick bills, boring color, hang upsidedown –> nectivores and frugivores
Compare and contrast nectivory, frugivory, folivory, carnivory, and insectivory in birds,
bats, and mammals. Specifically, explain some of the benefits or downsides of each
mode of feeding and some morphological adaptations relevant to each.
Nectivory: nectar is easily difestible, but doesn’t have lipids or prots –> most nectivores eat insects too and will feed on sap in lieu of flowers –> have to hover sometimes
Frugivory: fruit is abundant and easily collected –> prolonged nesting time for fledglings –> bird adaptations to fruit eating = increased olfactory senses, above ground nesting, reduced clutch size, and extensive courtship displays –> mostly bi-parental care and feed insects to young –> extreme nest builders
Insectivores: Insects are high in fat and protein –> abundant, but difficult to catch –> can increase tree growth by 30% (more for canopy than understory)
carnivory: gape-limited –> require adaptations for catching, gripping, and shredding prey –> forward facing eyes for binocular vision –> sharp, hooked beaks (tomial tooth = uper notch on beak that assists in ripping prey) –> sharp talons (hallux = longer than other claws)
. How do the differences in feeding behavior (hovering vs. perching) between
hummingbirds and sunbirds & honeyeaters, as well as in the fruit feeding and pollinating
bats, contribute to difference in flower morphology between Africa and South America?
In neotropics, flowers are outside foliage –> trap-lining and territoriality reduce cross pollination –> hummingbirds pollinate small herbs, lianas, epiphytes
In Africa + Australia flowers are inside foliage –> generalist feeding and greater omnivory increase cross pollination –> sunbirds and honeyeaters pollinate bigger herbs, lianas, and epiphytes and trees
Describe some of the behaviors involved in courtship in frugivorous birds. What
hypothesis have biologists proposed to explain why these behaviors are unique to
extreme frugivores?
they have a high level of resources and are not strained energetically
fruit = high energy resource that’s available year-round
Sometimes dance by themselves, but also do lekking where a group of males go to specific dance location to attract females
. How do birds and bats differ in the ways in which they evolved flight? Describe some
flight adaptations that are unique to each group.
Birds developed flight from ground dwelling creatures 160 mya -forelimbs modified for flight -epidermal covering of feathers and leg scales -hollow bones -air sacs and constant volume lung -four chambered heart -endothermic oviparous
Bats evolved from arboreal gliding species 51 mya
-icaronycteris was earliest aerial
mammal (bat)
-thinner, elongated digits along wings
-skin membrane
-big scapula
-modified hip joint reorienting femoral-acetabular joint to provide 90 degree hindlimb rotation
What two main families within the Yangochiroptera and the Yinpterochiroptera make
up the majority of New World and Old World bats, respectively?
Phyllostomidae (leaf-nosed, vampire, fruit, and white bats) and Pteropodidae (fruit bats)
Compare and contrast the morphology of an insectivorous and a frugivorous bat.
Specifically, what additional physical features do insectivorous bats have that assist in
prey capture? What information do bat collect during echolocation?
frugivorous: pteropodidae and phyllostomidae –> 1/3 of bats –> eat canopy fruits that extend beyond edge of leaves and branches –> feed on cauliflorous fruits or easily accessible understory fruits while clinging –> old world are wasteful, poor seed dispersers
Insectivores: mostly yangochiroptera –> nocturnal echolocators –> enlarged ears with tragus or antitragus – pinna often ridged –> well developed uroptagium –> can eat 1000 mosquitos/day
So, for each of the following taxa, list the major tropical region in which it occurs and provide a description and a unique characteristic that distinguishes it from other bats: Pteropodidae Phyllostomidae Desmodontinae Noctilionidae Rhinolophidae
Pteropodidae: Africa, Asia, Madagascar, Australia –> size ranges –> can live 30 yrs –> no facial ornaments –> big, bulging eyes, simple ears, brush tip tongues –> sexually dimorphic –> communal tree roosting –> frugivores (94%) and florivores
Phyllostomidae: 1/2 fruigivorous –> mostly in Stenodermatinae –> 30-50% Neotropical bats –> nocturnal and crepuscular feeders –> short, flat faces with some ornamentation –> no tail, high wing aspect ratio –> roost in leaves in small gps –> 5-100g –> frugivores that supplement with insects
Desmodontinae = vampire bats = New world phyllostomidae –> use echolocation –> smell and heat sensors in nose –> saliva contains anti-coagulants and anesthetic –> blood feeders - need 60% of body weight in blood each day
Noctillonidae: New world fisherman bats –> carnivores –> nocturnal echolocators with extensive pinna –> strong sagittal crest in more exclusively carnivorous spp –> eat small vertebrates (fish/frogs/lizards/birds/mice/bats) –> fishing bats might eat 30 fish/night –> insects are minor part of diet
rhinolophidae: horseshoe bat –> insectivore –> nocturnal echolocator with big ears with tragus or antitragus and pinna often ridged –> well developed uropatagium (one of them isn’t nocturnal in Malaysia)
How do bat pollinated and hummingbird pollinated flowers differ in structure? What
feature of bats contributes to their being better pollinators than hummingbirds?
hummingbird-pollinated flowers are often tubular while bat-pollinated flowers are more open, commonly bell- or bowl-shaped.
tongues are super long
have hairy tongues to bring out nectar
have compensatory feeding, allowing them to live off nectar with varying sugar volume
Bats pick up a huge amount of pollen and disperse it
Compare and contrast the major continental differences between Old World and
Neotropical bat faunas. How do tropical forests differ from temperate forests in the
diversity or feeding modes of bats?
Yinpterochiroptera
- africa, asia, india, australia
- wide ranging generalists, tongue feeding frugivory
- bigger with limited departure from ancestor skull
- can travel over 50 km
- just one genus echolocates
- feed while clinging
Yangochiroptera
- pantropical and neotropical
- more fruit specialization
- variety in skull shape
- may search 3 km^2 and travel <10 km
- more often feed while flying
More diversity in tropical area
Diverse feeding habits in tropics –> almost all insectivores in temperate areas
What have recent analyses of mammalian groups revealed about the sister groups of
bats and of colugos? What makes it difficult to resolve the relationships among
mammal taxa, such as among the Afrotheria, Xenarthra, and Laurasiatheria?
calugos are with humans, rodents, and shrews in a monophyletic group, but bats are within their own offshoot from that group.
During long fuses, there are back mutations that can occur which makes it difficult to determine the phylogenetic tree –> Afrotheria was first, then xenarthra and laurasiatheria
. With respect to diversity, how do rodents differ from most other animal groups in terms
of their species numbers within tropical forests?
rodents are the biggest taxonomic group overall, making up 40% of all mammal species (2200), but when we’re just talking about the tropics, theyre second to bats in terms of number of species
list the major tropical region in which it occurs and provide a description and a unique characteristic that distinguishes it from other rodent groups: Echimyidae Anomalures Capybara Porcupines Muridae Dasyproctidae and Cuniculidae (Agouti, Acouchi, Pacas)
Echimyidae = spiny rats = neotropics –> quill-like fur and has tails
Anomalures = Africa = “African scaly-tailed squirrels” – gliders (250 m) – litters of at least 3 offspring – precocial young – sometimes eat bark – no foraging
Capybara = neotropical — 75-200 lbs – partially webbed toes – jaw hinge moves back and forth – small social groups– semiaquatic, diurnal and crepuscular foraging – herbivores (grasses and aquatic vegetation) but also eat feces – bacteria help with digestion
Porcupines = Americas, Asia, India, Africa – in drier forests – 2 to 60 lbs – tropical ones have prehensile tails – arboreal and night time foragers – eat fruits, roots, bark, plowers, liverwarts, and small insects
Muridae = mostly in SE Asia, but also in Africa, Australia, and New Guinea – small to medium size – long tail, prominent nose, and whiskers – insectivores and omnivores (Australia/New Guinea water rats eat small arthropods, snails, fish, and frogs)
Agouti, acouchi, pacas = neotropical– under 2 lbs to 10 lbs– arched hindquarters and reduced tails – frugivores, but also eat roots and sugarcane – form lifelang pair bonds — Dasyproctidae = Agouti and Acouchi —- Cuniculidae = paca
. How do squirrel diversity, foraging, or behavior differ in temperate versus tropical
forests?
No ground squirrels, marmots, or chipmunks, but there are ratufinae, callosciurinae, sciurillinae
Don’t come to the ground
Group feeding and communal nesting is what really sets them apart
More color and size variation
Describe some unique features of sloths. Which of the tropical mammals that we have
discussed fall into this taxon (Xenarthra)?
peg teeth --> lost incisors -elongated forelimbs can turn head 270 degrees heterothermic mutualists: body hair hosts 2 spp of cyanobacteria eat leaves, shoots, flowers, and fruits long, slow digestion
two fingered and three fingered sloths anteaters
Which mammals fall into the Afrotheria?
elephants, aardvark, tenrecs
What behaviors do folivorous (leaf feeding) sloths and elephants share and how do they
differ in foraging behavior or gut morphology?
Elephants have hindgut digestion with short, broad guts –> compensatory feeding = they eat a lot but don’t digest well –> 3/4 diet is leaves or bark, but fruit too
Sloths have foregut digestion with large, compartmentalized stomach –> long digestion, can take a month – void feces every 7-8 days – forage for leaves, shoots, flowers, and fruit –> some sloths are omnivores
Why do scientists hypothesize that omnivory leads to less speciation than does
herbivory or frugivory? Which groups of mammals that we have discussed are
omnivores?
omnivory is a compromise strategy protein from scarce animal prey is supplemented with energy from abundant plants
Omnivores have intermediate phenotypes: teeth and guts have herbivore and carnivore qualities
They’re not specialized, so there’s not as much diversification
porcupines, muridae, two toed sloths
Why do scientists believe that speciation rates in large fruited/seeded plants are lower
in African and Asian forests compared to neotropical locations?
. Anteaters, echidnas, pangolins, and aardvarks are all tropical organisms that specialize
on ants and termites as food. For each group, provide the location in which it occurs
(Africa, South America, Asia, or Australia-New Guinea) and some features unique to the
taxon. What are some evolutionarily convergent features that all ant and termite
specialists share?
Anteaters: Neotropical – 5 to 7 ft long including 2 to 3 ft tail – 2 ft tongues attached to sternum – poor eyesight
Pangolins = Africa and Asia (dry tropical savannas) – burrowers and ground nesters – armored keratin scales – no teeth, long tongue – “skunk” glands – nocturnal ground and arboreal forager
Echidna: Australia and New Guinea – monotreme – birdlike skull with elongated snout, small toothless mouth, and long tongue – claws for digging – coarse hair and pines – nocturnal ground foragers
Aardvark: 1 spp in Africa –> tunnels – teeth at birth, but don’t regrow – shovel-like feet– crepuscular and nocturnal ground forager
