009b Marine Mammals & Birds.

009b Marine Mammals & Birds

Phylum Chordata Subphylum Vertebrata Class Reptilia Class Aves (birds) Class Mammalia

Class Aves

Birds Evolution

Warm blooded Feathers and wings Hollow bones Horny bill
Class Aves Characteristics Warm blooded Feathers and wings Hollow bones Horny bill Lungs have air sacks Hard egg shell

Marine Birds Only 3% of all bird species
Evolved from different groups of land birds Spend significant part of life at sea Feed on marine organisms

Marine Birds Must nest on land

Marine Birds Salt secreting glands Webbed feet for swimming (not all)

Marine Birds Dense waterproof plumage (except commorants and some terns)

Marine Birds Migrations (not all)
Arctic tern - 24,000 mi roundtrip between Arctic and Antarctica Sooty shearwaters - 40,000 mi/yr

17 species found in southern hemisphere
Penguins: 17 species found in southern hemisphere Spends 75% of lifetime in water Warm blooded animals in cold climates are pretty large, even the smallest Antarctic birds are on the large side and the smallest Antarctic penguin, the Rockhopper is a fairly hefty 2.5kg (5.5lb). The Adelie and Emperor penguins of the deep south are larger still. Adult weights are 5kg (11lb) for the Adelie and 30kg (66lb) for the Emperor - a similar size to an overweight 10 year old child, but with a man-sized chest measurement. The larger the animal, the smaller the surface-area : volume ratio and so the less relative area there is to lose heat. Take a 1cm cube: Volume = 1 x 1 x 1 = 1cm3 Surface area = 6 faces x (1 x 1) = 6cm2 So for 1cm3 of volume there are 6cm2 of surface area to lose heat from, 6 / 1 = 6cm2 per 1cm3. surface-area : volume ratio is 6:1 Now take a 3cm cube, identical shape: Volume = 3 x 3 x 3 = 27cm3 Surface area = 6 faces x (3 x 3) = 54cm2 So for 27cm3 of volume there are 54cm2 of surface area to lose heat from, 54 / 27 = 2cm2 per 1cm3. surface-area : volume ratio is 2:1 This means that for identically shaped animals of different sizes, the large one will keep its temperature more easily. Being big means being warmer. Wrap up warm Penguins have feathers to keep them warm right? - Well partly right, feathers work on land, but in the water where penguins spend quite a bit of their lives, they're not so valuable. What really keeps penguins warm in the sea is a sub-cutaneous (posh way of saying under-the-skin) layer of fat. This fat layer also serves as a valuable energy store as we will see later. This fat layer is the best form of internal insulation yet devised by mother nature - and therefore the best way to keep warm in water (external fur and feathers are better and thinner, but can be ruffled by wind and of course are useless when wet) and it keeps all warm blooded cold water animals operational down to -1.9°C (25.8°F). Why this temperature? - because that's when sea-water freezes, you can't get sea water colder than that without it being solid and then it would difficult for anything to swim in it! It's penguins fat layer that protects them against the cold more than anything while in the sea. On the land however their feathers have a very valuable function in keeping them warm. Penguin feathers aren't like the large flat feathers that flying birds have, they are short with an under-layer of fine woolly down. Penguin feathers are also very good at shedding water when the bird emerges from the sea. They overlap and give a good streamlined effect in the water and excellent wind-shedding abilities when on the land. When it gets very cold, penguins can puff their feathers out to trap more air for even better insulation. When it gets too hot (like as high as freezing point even!) they fluff their feathers out even more so that the trapped warm air can escape and enable the penguin to cool down. Penguins have two areas where their body is very poorly insulated and where they can lose a lot of heat, these are their flippers and their feet. These regions give penguins at the same time a problem and a solution. A problem because of the heat loss, and a solution because they can be used for cooling down. It's all well and good being brilliantly insulated, but when you use a lot of energy and so generate heat, or the temperature rises, not being able to lose that heat becomes a big disadvantage in itself. The solution is really quite elegant. The muscles that operate feet and flippers are not located in the feet and flippers, but deeper in the warmer regions of the penguins body. The feet and flippers are moved by tendons that pass through them and attach to toes etc. like a sort of remote operation by wire or string. This means that it doesn't matter if the feet and flippers get really cold as they can still be operated normally by regions that are fully functional and at normal body temperature. Penguins have a heat-exchange blood-flow to these regions. The warm blood entering the feet or flippers flows past cold blood leaving so warming it up in the process and cooling the blood entering at the same time. Blood in these parts is significantly colder than in the rest of the body. By the time the blood re-enters the rest of the body it has been warmed up and so doesn't have so great an effect on the core body temperature. Penguins feet are never allowed to get below freezing point, blood flow is finely adjusted so that they are kept just above. When it gets very cold, the feet are covered by the feathers and fat layer of the body so they are not exposed to cooling winds. So while a man standing barefoot on ice would quickly get frostbitten, penguins can do so all their lives with no damage at all. At low temperatures or when in the sea, the blood flow to feet and flippers is very low anyway so reducing heat loss further. When the penguin needs to lose heat quickly, the blood flow to these extremities is increased and so lots of warm blood enters them which cools quickly so dumping excess heat rapidly and efficiently. Don't touch unless necessary Ice and snow are cold. Lying on on snow, you would be really cold as there would be a large area of contact to lose body heat though conduction. Stand up and immediately your area of contact reduces enormously, stand on tip-toes and your area of contact is reduced to a minimum. This is what penguins do except they don't stand on tip-toes when it's really cold, they rock backwards on their heels, holding their toes up. How do they stop themselves from falling over backwards? They support themselves by their stiff tail feathers that have no blood flow and so lose no heat. So in the coldest conditions, penguins sit there supported on a tripod of two feet (heels) with reduced blood flow - see previous section - and a stiff tail through which they lose no heat at all. Hang around in gangs Emperor penguins live in probably the most extreme conditions endured by any warm-blooded animal on earth. They even breed in the depths of the Antarctic winter at temperatures of -30°C (-22°F) and below while putting up with winds of 200 kmh (125mph) and more which gives a wind chill factor that you don't even want to think about that would freeze exposed human flesh in seconds. Even worse, the emperors breed and overwinter on permanent ice shelf far from open sea where there isn't any chance of being able to feed so the penguins not only endure horrendously cold conditions, but do so with little or no shelter, without feeding - fasting for months - and in the darkness of the long Antarctic winter night. The males endure the worst conditions looking after the egg while the females build up their reserves. By the time they are relieved again, they may have lost 40% of their body weight. Relief is not even immediate as when the male hands over the egg to the female, he faces a march to the sea that is typically 50 to 100 km, but can be up to 200 km (125 miles). His total period sea to sea before he can catch any live food again living on stored fat can be 115 days or more. Despite these privations, the emperor penguin maintains a core body temperature at a steady 38°C (100.4°F). Scientists have worked out that even with the great weight loss of stored body fat, it cannot provide sufficient energy to allow the penguins to maintain their body temperature and so survive the winter, so how do they do it? The emperor penguins secret is huddling. Really just an extension of the "be big" method of surviving extreme cold. Emperor penguins have developed a social behaviour that when it gets cold, they huddle together in groups that may comprise several thousand penguins. That way for most of the group, where their feathers end, instead of all of them having to face the biting wind and relentless cold, most of them have another warm penguin blanket to shield them instead. The surface area of the group is greatly reduced and a great deal of warmth and body fat conserved. Of course it's not quite so great for the individuals on the outside of the group as they only have a part of their body protected and warmed by the other penguins. So there is a continual movement of penguins from the outside of the group to the centre so displacing the warmer and more protected penguins to the outside where they will take their turn in the worst places against the wind and raw cold. Calculations show that a solitary emperor penguin in these conditions could burn up 0.2kg of fat per day to stay warm and alive while huddling penguins need only about 0.1kg per day. Without huddling, emperor penguins just wouldn't be able to breed in the Antarctic winter at all. The young penguin chicks also huddle together for warmth when left behind on the sea-ice by the parents who have to go off fishing for food. More about emperor penguins Summary of how penguins Thermoregulate (keep their body temperature constant) 1/ Overlapping densely packed feathers make a surface almost impenetrable to wind or water. Feathers provide waterproofing in water that is critical to penguins survival in water, Antarctic seas may be as cold as -2.2°C (28°F) and rarely get above +2°C (35.6°F). Tufts of down on shafts below the feathers trap air. This trapped layer of air in the feathers provides 80% to 84% of the thermal insulation for penguins. The layer of trapped air is compressed during dives and can dissipate after prolonged diving, so leaving the insulation to the layer of fat. Penguins rearrange their feathers by preening. 2/ To retain heat, penguins may tuck in their flippers close to their bodies, this reduces the surface area available for heat loss. They also may shiver to generate additional heat. 3/ A fat layer improves insulation in cold water, but probably is not sufficient on its own to keep the body temperature stable at sea for long. Penguins must remain active while in water to generate body heat. Unlike other warm blooded Antarctic marine animals such as seals and whales, penguins are still relatively small, so the "be big" strategy is not taken as far as needed to remain warm at all times in the sea as in seals and whales. 4/ Cold climate penguin species usually have longer feathers and thicker fat than those in warmer climates. 5/ The dark colored feathers of a penguin's dorsal (back) surface absorb heat from the sun, so helping them to warm up. 6/ King and emperor penguins are able to tip up their feet, and rest their entire weight on a tripod of the heels and tail, reducing contact with the icy surface and so reducing heat loss. 7/ Emperor and king penguin chicks and adults huddle together to conserve heat. Up to 6,000 male emperor penguins will huddle together while incubating their eggs during the middle of the Antarctic winter. 8/ Emperor penguins can recapture up to 80% of the heat escaping through their breath thanks to a complex heat exchange system in their nasal passages. 9/ On land in warmer weather, overheating can be a problem. i) Penguins can cool down by moving to shaded areas and by panting (like dogs do when they're hot). ii) Penguins can ruffle their feathers, this breaks up the insulating air layer next to the skin, so releasing the warm air and cooling them down (like opening the front of a coat when you're too warm and waving it about a bit). iii) Penguins can increase their heat loss by holding the flippers away from the body, so both surfaces of the flippers are exposed to air, releasing heat. iv) warmer climate temperate species, such as the Humboldt and African penguins, don't have feathers on their legs and have bare patches on their faces where excess heat can be lost. 10/ Penguins circulatory systems can adjust conserving or releasing heat to keep the temperature constant. i) To conserve heat, blood flowing to the flippers and legs transfers its heat to blood that is leaving the flippers and legs. This is known as counter current heat exchange and enables the heat to remain in the body rather than ever actually reaching the legs or flippers. ii) If the body becomes too warm, blood vessels in the skin dilate (get wider), bringing heat from within the body to the surface, where it can be lost. This is a common response in warm blooded birds and mammals, you do it when you exercise and go red in the face or when you blush. Fairy (aka Little blue) penguins – up to 16 in (recovering from oil spill) Emperor penguins - up to 45 in

Penguins Southern hemisphere only (Galapagos south to Antarctica)

Penguin Adaptations Heavy, solid bones for diving
Watertight feathers (up to 70 per sq. in.) Blubber for insulation Oil gland for coating feathers Black & white counter shading Deep divers - 500 m, 15 min. Paddle-like feet Streamline, fusiform body - 15 mph Social

Penguin Adaptations Don’t fly in air, but swim very well (fly through the water) Wings act as flippers King penguin Adelie penguins Emperor penguins

Penguin Adaptations Eyes better adapted for underwater vision than air
Adapted for colder waters and air temps Black-footed penguin (aka African, Jackass) Gentoo penguin

Penguin Prey Larger penguins eat fish, squid
Smaller eat large plankton (krill) Mostly feed near surface Some dive to ft, 22 mins Galapagos penguin

Penguin Nesting Gentoo penguin Magellanic penguins King penguin
Adelie penguins make nests out of rock pebbles and sit on top. They steal each others pebbles constantly, leading to lots of braying and fights. The last ones to leave in autumn steal everybody else's pebbles and make a huge stack in prevision of their spring return. But then the early comers in spring transfer the pile to their own nest ! That is to say before they have to go back to the sea to feed at which point a free-for-all happens with lots of name calling. Magellanic penguins King penguin

Penguins Rockhopper penguin Macaroni penguins Yellow eyed penguins

Altruism

Nests on pack ice

Rookery

Marine Birds Tubenoses Albatrosses, shearwaters, and petrels
Storm petrel Shearwater Albatross – longest wingspan

Marine Birds Pelicans and web-footed birds
Cormorants, frigates, gannets Brown pelican Cormorant NOAA Gannet Frigate NOAA

Marine Birds Gulls Jaegers/skuas, terns, puffins, razorbills
Herring gull Least tern Horned puffin

Marine Birds Feeding strategies

Marine Birds Beak shapes:

Marine Birds Shorebirds – beak length

Marine Birds Shorebirds Sandpipers, plovers, coots Sandpiper Godwit
Hawaiian coot

Pacific Golden Plovers

Marine Birds Shorebirds Herons, egrets Black-crowned night heron
Great blue heron Black-crowned night heron Great egret

Marine Birds Shorebirds Swans, geese, loons
Ducks, coots, grebes, mergansers Common merganser Wood duck Mute swans

Marine Birds Birds of prey Eagles, ospreys

Human Impacts Pollution – pesticides, PCBs, metals Bioaccumulation,
biomagnification

Class Mammalia Whales & Dolphins Polar bear Sea otter Seals & sealions manatee Dugong

Mammals have returned to the oceans multiple times Adaptations
Return to the Oceans Mammals have returned to the oceans multiple times Adaptations vivipary suckling young thermoregulation feeding diving osmoregulation We’ll look at adaptation in marine mammals from the least to the most Osmoregulation in marine mammals has been investigated for over a century; however, a review of recent advances in our understanding of water and electrolyte balance and of renal function in marine mammals is warranted. The following topics are discussed: (i) kidney structure and urine concentrating ability, (ii) sources of water, (iii) the effects of feeding, fasting and diving, (iv) the renal responses to infusions of varying salinity and (v) hormonal regulation. The kidneys of pinnipeds and cetaceans are reniculate in structure, unlike those of terrestrial mammals (except bears), but this difference does not confer any greater concentrating ability. Pinnipeds, cetaceans, manatees and sea otters can concentrate their urine above the concentration of sea water, but only pinnipeds and otters have been shown to produce urine concentrations of Na+ and Cl-1 that are similar to those in sea water. This could afford them the capacity to drink sea water and not lose fresh water. However, with few exceptions, drinking is not a common behavior in pinnipeds and cetaceans. Water balance is maintained in these animals via metabolic and dietary water, while incidental ingestion and dietary salt may help maintain electrolyte homeostasis. Unlike most other aquatic mammals, sea otters commonly drink sea water and manatees frequently drink fresh water. Among the various taxonomic groups of marine mammals, the sensitivity of the renin–angiotensin–aldosterone system appears to be influenced by the availability of Na+. The antidiuretic role of vasopressin remains inconclusive in marine mammals, while the natriuretic function of atrial natriuretic peptide has yet to be examined. Ideas on the direction of future studies are presented.

Adaptations for diving
Exchange a large amount of air on each breath Up to 90% in each breath (humans exchange about 20%) Blood with more oxygen carrying capacity Heart rate slows Blood flow shunted Higher concentration of myoglobin in the muscles Collapsing lungs Dive with no air in contact with blood vessels to avoid problems of nitrogen being forced in

Fusiform Shape and Streamlining Evolutionary Convergence

Two basic bioenergetic strategies used by animals :
Endothermy “warm blooded” Ectothermy “cold blooded”

Thermoregulation Concurrent exchange Countercurrent exchange
Antarctic birds and mammals - penguins, whales and seals - are warm blooded animals and they maintain similar internal body temperatures to warm blooded animals in any other climate zone - that is about 35-42°C (95-107°F). They have to keep high body temperatures to remain active. Tropical animals with more variable body temperatures such as reptiles and amphibians can warm up by basking in the sun if they cool down - and they never cool down that much. A large (bigger than a small insect) Antarctic animal will never get enough energy from the surroundings to become active if it allows itself to cool (there are exceptions at the other end of the size scale amongst very small insects and mites and in the fish) so they have to stay warm to be active. Concurrent Flow - In this exchange system, the two fluids flow in the same direction. As the diagram shows, a concurrent exchange system has a variable gradient over the length of the exchanger. With equal flows in the two tubes, this method of exchange is only capable of moving half of the property from one flow to the other, no matter how long the exchanger is. If each stream changes its property to be 50% closer to that of the opposite stream's inlet condition, exchange will stop because at that point equilibrium is reached, and the gradient has declined to zero. In the case of unequal flows, the equilibrium condition will occur somewhat closer to the conditions of the stream with the higher flow. Countercurrent Flow - By contrast, when the two flows move in opposite directions, the system can maintain a nearly constant gradient between the two flows over their entire length. With a sufficiently long length and a sufficiently low flow rate this can result in almost all of the property being transferred. However, note that nearly complete transfer is only possible if the two flows are, in some sense, "equal". If we are talking about mass transfer, then this means equal flowrates of solvent or solution, depending on how the concentrations are expressed. For heat transfer, then the product of the average specific heat capacity (on a mass basis, averaged over the temperature range involved) and the mass flow rate must be the same for each stream. If the two flows are not equal (for example if heat is being transferred from water to air or vice-versa), then conservation of mass or energy requires that the streams leave with concentrations or temperatures that differ from those indicated in the diagram. [edit] Examples In a concurrent heat exchanger, the result is thermal equilibrium, with the hot fluid heating the cold, and the cold cooling the warm. Both fluids end up at around the same temperature, between the two original temperature. At the input end, we have a large temperature difference and lots of heat transfer; at the output end, we have a small temperature difference, and little heat transfer. In a countercurrent heat exchanger, the hot fluid becomes cold, and the cold fluid becomes hot. At the hot end, we have hot fluid coming in, warming further hot fluid which has been warmed through the length of the exchanger. Because the hot input is at its maximum temperature, it can warm the exiting fluid to near its own temperature. At the cold end, because the cold fluid entering is still cold, it can extract the last of the heat from the now-cooled hot fluid in the other section, bringing its temperature down nearly to the level of the cold input fluid. [edit] Countercurrent exchange in biological systems Rete mirabile = RM Countercurrent exchange is used extensively in biological systems for a wide variety of purposes. For example, fish use it in their gills to transfer oxygen from the surrounding water into their blood, and birds use a countercurrent heat exchanger between blood vessels in their legs to keep heat concentrated within their bodies. In biology this is referred to as a rete mirabile. Mammalian kidneys use countercurrent exchange to remove water from urine so the body can retain water used to move the nitrogenous waste products (see countercurrent multiplication). [edit] Countercurrent exchange of heat in organisms Countercurrent heat exchange (CCHE) is a highly efficient means of minimizing heat loss through the skin's surface because heat is recycled instead of being dissipated. This way, the heart does not have to pump blood as rapidly in order to maintain a constant body core temperature and thus, metabolic rate. When animals like the leatherback turtle and dolphins are in colder water to which they are not acclimatized, they use this CCHE mechanism. Such CCHE systems are made up of a complex network of peri-arterial venous plexuses that run from the heart and through the blubber to peripheral sites (i.e. the , dorsal fin and pectoral fins). Each plexus consists of a singular artery containing warm blood from the heart surrounded by a bundle of veins containing cool blood from the body surface. As these fluids flow past each other, they create a heat gradient in which heat is transferred. The warm arterial blood transfers most of its heat to the cool venous blood. This conserves heat by recirculating it back to the body core. Since the arteries give up a good deal of their heat in this exchange, there is less heat lost through convection at the periphery surface. [1] Another biological example, with separated fluid flow rather than a single channel flowing back and forth, is in the legs of an arctic fox treading on snow. The paws are necessarily cold, but blood can circulate to bring nutrients to the paws without losing much heat from the body. Proximity of arteries and veins results in heat exchange, so that as the blood flows down it becomes cooler, and doesn't lose much heat to the snow. As the blood flows back up through the veins, it picks up heat from the blood flowing in the opposite direction, so that it returns to the torso in a warm state, allowing the fox to maintain a comfortable temperature. [edit] Countercurrent exchange in seabirds to distill seawater If seabirds were drinking sea water without removing the salt it contains, they would be unable to control the osmotic balance of their organism. If the kidney alone would remove the excess of salt, these organisms would need even larger amount of fresh water to flush out the salt accumulated by drinking only saltwater. As freswater is not available in their environnement, seabirds like pelicans, petrels, albatrosses, gulls, terns possess special salt secreting glands which act as countercurrent exchangers. Tiny arteries carrying salty blood enter the gland and are very closely juxtaposed to the tubules of the gland. The gland concentrates the salt from the blood and the blood exiting the gland through the veinules contains a much lower amount of blood than in the artery. The salty liquid thus collected into the glands is periodically sneezed out from the nostrils. The glands remove the salt efficiently and thus allow the birds to drink the salty water from their environnement while they are hundreds miles away from land.

Marine mammals Characteristics of marine mammals: Warm-blooded
Breathe air Have hair (or fur) Bear live young Females have mammary glands that produce milk for their young

Marine mammals: Order Sirenia
Sirenian characteristics: Large body size Sparse hair all over body Vegetarians Toenails (on manatees only) Includes: Manatees Dugongs

Manatee & Dugong Most complete transition to marine life along with whales and dolphins Related to the elephant, but common ancestor didn’t look like either of them Once many more species around Large layer of blubber Origin of the mermaid myth Herbivores Nostrils on top of snout have valves to keep water out Both species have one calf at a time Tend to have a single calf every 3 years Description & Fascinating Facts The Dugong, Dugong dugon, range in length from m in length. Sexual dimorphism is either absent or females may slightly outsize males and can weigh over 270 kg. Dugongs are born a pale cream color, but they darken with age to a deep slate gray dorsally and laterally. Short hair is sparsely distributed over the body, save the bristles on the muzzle. The skin is thick, tough and smooth. The front-limbs have evolved into flippers that are cm long. These are used for propulsion by young, but the adults use the fluke-like tail for locomotion, using the flippers for steering. The muscular upper lip is cleft and protrudes over the down turned mouth. The premaxilla is enlarged and downturned, the nasal bones are absent, the braincase is small and the zygomatic arch is thick and deep. The bones of the skeleton are pachyostotic (extremely thickened and dense). Although superficially they resemble whales, sirenians have evolved independently. They are descended from the group of ancient land mammals that also gave rise to the elephants. World Range & Habitat Pacific Ocean, Indian Ocean: Found discontinuously in coastal waters of east Africa from the Red Sea to northernmost South, northeastern Indian, along the Malay peninsula, around the northern coast of Australia to New Guinea and many of the island groups of the South Pacific. Range was much greater in the past. Dugongs inhabit shallow, tropical marine coastal water mainly confined to sea grass beds, which occur in calm and shallow coastal areas, such as embayment and lagoons. Dugongs and are more strictly marine than manatees, it seldom enters rivers. Feeding Behavior Dugongs feed on the phanerogamous (having visible flowers containing distinct stamens and pistils) sea grasses of the families Potamogetonaceae and Hydrocharitaceae. Also reported to occasionally eat algae, and crabs have also been found in the stomachs of dugongs. Despite its diet, the dugong has a relatively simple stomach. The lower lip and distal parts of the palate have horny pads used to grasp vegetation, which is then uprooted with the strong upper lip. Dugongs have teeth in adults. The molars are rootless, circular in cross-section and lack enamel, males have long, tusklike incisor teeth. Reproduction The Dugong is a long-lived animal with a life span of up to 70 years, a minimum pre-reproductive period of 9-10 years, though it can occur as late as 15 years and an estimated mean calving interval of 3-7 years. Breeding occurs throughout the year and peak months for birth vary geographically. The exact length of gestation is unknown, but it is presumed to be about 1 year. Single calves are the norm and twins are rare. Parturition (the birth process)takes place in shallow water, and newborn calves are able to swim immediately to the surface for their first breath of air. Newborn calves are about cm long and weigh kg. Young may remain with the mother for a year. Warnings & Comments Dugongs are hunted throughout their range for meat, which has been likened to veal. They are also hunted for oil, hides for leather, and for their bones and teeth, which are made into ivory artifacts and charcoal for sugar refining. Some Asian cultures prize dugong products for medicinal purposes. Has been heavily exploited in the Philippines, almost to extinction. Endangered. Dugongs have a good fossil record going back to Eocene terrestrial ancestors.

Dugong Location: coastal and inland waters of the western Indo-Pacific region Dugongs are exclusively marine and have a dolphin-like tail Dugongs tend to dig seagrass rhizomes Predator includes tiger sharks

10,000 Dugong Range

Family Dugongidae Dugong dugong Steller's Sea Cow tHydrodamalis gigas
Discovered 1741, extinct 1768. 8.9 ft, lbs At one time, the Steller's sea cow was found in the cold waters of the Bering Sea, but it was hunted to extinction within 27 years of its discovery in The largest sirenian on record, the Steller's sea cow grew up to nine meters (30 feet) in length and weighed around four metric tons (approximately 4.4 tons). 30ft, 4.4 tons

Manatee Location: Florida, Central and South America
Manatees have paddle-like tails and frequent freshwater Manatees tend to crop and grab with prehensile lips Manatees are larger than dugongs Few predators Threats: Careless boaters Habitat loss

Manatee 9.8 ft, lbs 3,000 in U.S.

Relationship between Sirenians and elephants (mtDNA)
Asian elephant African elephant tmammoth tmastadon tStellar’s sea cow Dugong Ancestral mammals West Indian manatee Brazilian manatee West African manatee Other mammals 80 60 40 20 Million of years before present

Marine mammals: Order Carnivora
All members of order Carnivora have prominent canine teeth Includes: Sea otters Polar bears Pinnipeds (flipper-footed) Walrus Seals Sea lions/fur seals Hawaiian Monk Seal

Sea Otter

Sea Otter Enhydra lutris Native to north Pacific 394,000 hairs/cm2
No blubber Female 45 lbs; Male 65lbs Diet: Sea urchins, abalone, mussels, clams, crabs, snails and about 40 other marine species. Uses tools Dives to 330 ft Rests in coastal kelp forests STATUS: California, or southern, sea otters are listed as "threatened" under the federal Endangered Species Act (ESA) and "fully protected" under California state law. No other U.S. otter population is currently listed under the ESA. In 2003, there is a push to list a stock of the Alaskan sea otters, or northern sea otters, as "endangered" under the ESA. In Canada , the otter population in British Columbia is classified as "threatened" by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). All of the otters in the U.S. are protected under the U.S. Marine Mammal Protection Act (MMPA). DESCRIPTION: The sea otter has the thickest fur in the animal kingdom. Unlike other marine mammals, the sea otter does not have a layer of blubber (fat) to help keep it warm. If an otter's fur gets coated with oil or any other substance, it can easily die from cold and exposure. SIZE: The sea otter is the largest member of the weasel family. Southern sea otters typically reach about four feet in length. Females average 45 pounds, while males average 65 pounds. Northern sea otters can reach up to 100 pounds. POPULATION: Today there are about 2,500 southern sea otters off the coast of California. There are between 27,500 and 52,500 northern sea otters residing in Alaska, Canada and Washington. There are approximately 15,000 in Russia. Two hundred years ago, demand for the otter's pelt nearly led to its extinction. LIFESPAN: Male sea otters live an average of ten to 15 years, while female sea otters live an average of 15 to 20 years. RANGE: The sea otter?s historic range stretched from Japan, along the coast of Siberia and the Aleutian Chain and down the Alaska, British Columbia, Washington, Oregon and California coast to Baja California. HABITAT:Shallow coastal waters of the northern Pacific. FOOD:Sea urchins, abalone, mussels, clams, crabs, snails and about 40 other marine species. BEHAVIOR: Sea otters are the only mammals other than primates known to use tools. Otters use small rocks or other objects to pry prey from rocks and to hammer or pry open their food. They can dive up to 330 feet when foraging for food. Otters rest in coastal kelp forests, often draping the kelp over their bodies to keep from drifting away. OFFSPRING: Sea otters breed throughout the year. Females give birth to one pup after a gestation period of six to eight months. THREATS: Oil spills, habitat loss, disease, gill net entanglement and conflict with shellfish fisheries. PROTECTION: *CITES, Appendix I, Marine Mammal Protection Act, Endangered Species Act *Convention on International The Sea Otter (Enhydra lutris) is a large otter native to the North Pacific, from northern Japan and Kamchatka east across the Aleutian Islands south to California. The heaviest of the otters, Sea Otters are the only species within the genus Enhydra. Hunted extensively for their luxurious fur—the densest of all mammals with up to 394,000 hairs per square centimeter— from 1741 onwards, sea otter populations were greatly reduced to the point of extermination in many parts of their historic range. By 1911 the world population was estimated to be just 1,000-2,000 individuals in 13 colonies. Its estimated that a half million to a million otters were killed over time and over hunted and the population is thought to have been 150,000 to 300,000 historically before the years of the great hunt. Although several subspecies are still endangered, the otters have since been legally protected, and reintroduction efforts have shown positive results in some areas.

Polar Bear Pop size: 22,000 to 27,000 Weight: 550 to 1,700 pounds

Polar Bear Ursa maritimus
United States, Canada, Russia, Greenland and on the Arctic islands of Norway Male: 10 feet tall and weigh over 1400 lbs Female: seven feet and weigh 650 lbs wild polar bears live up to age 25. Not federally listed as endangered or threatened. The International Union for Conservation of Nature (IUCN), Polar Bear Specialist Group lists most populations as "stable." DESCRIPTION: The polar bear rivals the Kodiak bear as the largest four-footed carnivore on Earth and can live up to 25 years. Although the polar bear?s coat appears white, each individual hair is actually a clear hollow tube that channels the sun?s energy directly to the bear?s skin and helps it stay warm. The polar bear?s entire body is furred, even the bottom of its paws. That helps prevent bears from slipping on the ice. The polar bear is classified as a marine mammal. Its feet are partially webbed for swimming, and its fur is water-repellent. A formidable predator, it has extremely sharp claws. SIZE: Males are 8 to 11 feet long and weigh 500 to 1,100 pounds but can reach as much as 1,500 pounds. Females are smaller, measuring 6 to 8 feet long, and weigh from 350 to 600 pounds, occasionally reaching 700 pounds. POPULATION: Worldwide there are thought to be 22,000-27,000 polar bears in 19 separate populations. They can be found in the United States, Canada, Russia, Greenland and on the Arctic islands of Norway. There are estimated to be about 3,000 to 5,000 polar bears in Alaska. RANGE:Polar bears are found throughout the Arctic and are the most nomadic of all bear species. They travel an average of 5,500 miles a year or 15 miles a day. In the United States, polar bears are located in two Alaskan populations: the Chukchi/Bering Seas of western Alaska and the Beaufort Sea off northern Alaska. HABITAT: The entire circumpolar Arctic region is polar bear habitat. They are equally comfortable in the water and on land. Polar bears can be found on pack ice, coastal islands, coastlines and even out in Arctic waters. They are exceptional swimmers and have been observed in the sea more than 100 miles from the nearest land or pack ice. FOOD: Polar bears are strictly carnivores and feed or scavenge only meat. Their primary prey is the ringed seal though they also take bearded, harp and hooded seals and the occasional walrus youngster. They will also scavenge walrus and whale carcasses. That sometimes results in temporary aggregations of polar bears at such sites. Other species, such as the Arctic fox, rely entirely upon "polar bear left-overs" after the bears have eaten their fill of seal skin and blubber, leaving the remaining meat for such scavengers. BEHAVIOR: The two main focuses of this solitary creature's life are to conserve energy and to hunt. Only pregnant females dig dens and hibernate in the traditional sense for extended periods. The other bears may enter into what is referred to as "walking hibernation" where they remain active and continue to hunt and feed, even though some of their metabolic processes may slow (decreased heart rates, respiration, lowered temperatures, etc.). Polar bears depend mostly on their sense of smell to determine the location of prey. Their white coats make great camouflage for hunting seals, and they will wait patiently for hours next to a seal?s air hole waiting for the seal to take a breath. Once the seal arrives, the polar bear will use its immense strength and sharp claws to clutch the seal and drag it through the small blowhole. OFFSPRING: Females are able to breed at the age of five years. They dig dens either on the coastal mainland or out on the drifting pack ice in late October or early November, and then remain denned until the next spring. An average of two cubs are born, each weighing about 1 pound at birth and growing to about 15 pounds by the time they emerge in the spring. The cubs have much to learn and usually remain with their mothers for more than two years. THREATS: The primary threat facing polar bears today may be global warming. Scientists have already documented measurable effects in the body sizes and reproductive success of bears at Hudson?s Bay. This southern-most population of polar bears has adapted to an ice-free summer by moving onshore at Churchill, Manitoba, and fasting through the short summer season until freeze-up occurs, and the bears can return to the ice. Global warming has resulted in prolonged ice-free periods, and the polar bears are left stranded onshore for longer and longer periods. Break-up in the spring occurs an average of days earlier than 20 years ago and was four weeks earlier in Scientists estimate that for every week of delay in freeze-up, polar bears lose at least 22 pounds of critical fat reserves. Pregnant females are losing so much weight that they fail to produce enough milk for their cubs, which then suffer increased mortality. Once females fail to attain a minimum weight they won?t give birth at all, and scientists can already document a 15 percent drop in birth rates. Another globally produced impact to polar bears are chemical pollutants that find their way into the cold Arctic ecosystems and then never disappear. Such chemicals as PCB?s (polychlorinated biphenyls), banned from the U.S. plastics industry since the 1970s, concentrate in the blubber of prey species that are then eaten by the bears. Such concentrations of these and other toxins are linked to immune deficiencies and generally reduced fitness in some polar bears. The third threat of note is the proposed oil and gas development on the Arctic National Wildlife Refuge in northeastern Alaska. This is the most important onshore denning habitat for polar bears in the United States. About half of the bears from the Beaufort Sea population den onshore, and half of these select the refuge?s coastal plain. This is the very place proposed for oil exploration. Both the seismic exploration phase and an eventual oil extraction phase could introduce serious disturbances that may result in den abandonment and death of the offspring. PROTECTION: CITES* Appendix II, U.S. Marine Mammal Protection Act, Agreement on the Conservation of Polar Bears. Good swimmers Thick blubber Thick fur

Polar bears Polar bears are the least adapted to the marine lifestyle Land animals that are adapted to the cold Considered marine mammals because they feed almost exclusively on marine organisms Very good swimmers, but can’t dive below surface well Hunt seals and walruses, occasionally cetaceans

Range depends on sea ice
Circumpolar in Arctic Range depends on sea ice normal range occasional range over pack occasional range over permanent ice

Pinnipeds

Pinnipeds Hawaiian Monk Seal Family Phocidae Walrus Sea Lion
Family Odobenidae Family Otariidae

Biology and Natural History
Order Pinniped (seals, sea lions, & walruses) Family Phocidae- true, earless seals Family Otariidae- eared seals and sea lions Family Odobenidae- walruses 34 known species Evolved 20 mya from Order Carnivora (ancestors of dogs and bears) Differ in possession of external ears and mode of locomotion

Differences between seals and sea lions/fur seals

Hind flippers propel them while swimming Front flippers act as rudders
Hawaiian Monk Seal Family Phocidae Lack external ears Hind flippers propel them while swimming Front flippers act as rudders Travel on land is difficult (wiggle)

Front flippers propel animal when swimming
Sea Lion Family Otariidae Eared seals Front flippers propel animal when swimming Rear flippers act as rudders Fairly mobile on land

Paddle with front flippers Rear flippers act as a rudder
Walrus Family Odobenidae Found in Arctic region Lack external ears Paddle with front flippers Rear flippers act as a rudder Fairly mobile on land

Walrus Range Map Pacific walrus is in lavender, Atlantic walrus is in rose.

Walrus Facts Location:
Bering sea, Pacific Ocean, Atlantic Ocean, Arctic Ocean Pop Size: 250,000 Size: Weight: 2,000-3,500 lb. Breeding: Sexually mature late females, usually 6-7 years males, 15 years. Produce few offspring

Walrus Facts Lifestyle Habit: Gregarious, living mainly in herds.
Diet: Benthic suction feeders. Feed mainly on bivalve mollusks, but also other invertebrate marine animals, fish, sometimes seals and whales. Predators: polar bears, killer whales, and humans Lifespan: Up to 40 years.

Walrus Facts Swim speed: 7-35 kph Tusks: Both male & female
Used for dragging body across land or ice Symbolize age, sex, and social status Pharyngeal pockets: 2 found on either side of the esophagus that hold up to 50 liters of air ). For buoyancy; these pockets facilitate sleep in the water in an upright position May be used to amplify mating calls

Whales, Dolphins, & Porpoise

Pakicetus attocki Age: Early Eocene, 50 million years old
Location: Pakistan

Whale Evolution

Ambulocetus natans in action
Ambulocetus natans in action. A reconstruction of an early close cousin of whales.

Marine mammals: Order Cetacea

Marine mammals: Order Cetacea
Cetacean characteristics: Blowholes on top of skull Skull telescoped (streamlined shape) Very few hairs Includes: Whales, dolphins, and porpoises

Two suborders of order Cetacea
(55 mya- entered sea) Suborder Odontoceti (toothed whales) Echolocate (send sound through water) Includes killer whale, sperm whale, dolphins, porpoises, and many others Suborder Mysticeti (baleen whales) Have rows of baleen plates instead of teeth Includes blue whale, finback whale, humpback whale, gray whale, and many others

Differences between dolphins and porpoises
Dolphins have: An elongated snout (rostrum) A sickle-shaped (falcate) dorsal fin Conical-shaped teeth Killer whale jawbone

Differences between dolphins and porpoises
Porpoises have: A blunt snout (rostrum) A triangle-shaped dorsal fin Spade-shaped teeth

Echolcation - the location of objects by their echos - is a highly specialized faculty that enables dolphins to explore their environment and search out their prey in a watery world where sight is often of little use. As sound travels four and a half times faster in water than in air, the dolphin's brain must be extremely well adapted in order to make a rapid analysis of the complicated information provided by the echoes. Although the ability to echolcate has only been proven experimentally for a few odontocete species, the anatomical evidence - the presence of the melon, nasal sacs and specialized skull structures - suggests that all dolphins have this ability. The dolphin is able to generate sound in the form of clicks, within its nasal sacs, situated behind the melon. The frequency of this click is higher than that of the sounds used for communication and differs between species. The melon acts as a lens whi ch focuses the sound into a narrow beam that is projected in front of the animal. When the sound strikes an object, some of the energy of the soundwave is reflected back towards the dolphin. It would appear that the panbone in the dolphin's lower jaw receives the echo, and the fatty tissue behind it transmits the sound to the middle e ar and thence to the brain. It has recently been suggested that the teeth of the dolphin, and the mandibular nerve that runs through the jawbone may transmit additional information to the dolphin's brain. As soon as an echo is received, the dolphin generates another click. The time lapse between click and echo enables the dolphin to evaluate the distance between it and the object; the varying strength of the signal as it is received on the two sides of th e dolphin's head enable it to evaluate direction. By continuously emitting clicks and receiving echoes in theis way, the dolphin can track objects and home in on them. The echolocation system of the dolphin is extremely sensitive and complex. Using only its acoustic senses, a bottlenose dolphin can discriminate between practically identical objects which differ by ten per cent or less in volume or surface area. It can do this in a noisy environment, can whistle and echolocate at the same time, and echolocate on near and distant targets simultaneously - feats which leave human sonar experts gasping

Echolocation Sensing environment Produce clicks that travel out, hit objects and reflect back Produced by a structure in the airway called the “monkey lips” Sound received through the lower jaw Low frequency clicks travel further but can only be used for big objects High frequency clicks can discriminate small objects but don’t travel as far

Deepest Diver (3km~1.5 miles)

Mysticeti: The baleen whales
Mysticeti whales have baleen instead of teeth Baleen plates: Hang as parallel rows from the upper jaw Are made of keratin Are used as a strainer to capture zooplankton Allows baleen whales to eat krill and small fish by the ton

Baleen

Types of baleen whales Baleen whales include three families:
Gray whale (a bottom-feeder with short baleen) Rorqual whales (medium-sized baleen) Balaenopterids (blue whales, finback whales, and other large whales ) Megapterids (humpback whales) Right whales (surface skimmers with long baleen)

Whale Migration

Whale Carcass Removal http://perp.com/whale/video.nc.html
I am absolutely not making this incident up; in fact I have it all on videotape. The tape is from a local TV news show in Oregon, which sent a reporter out to cover the removal of 45-foot, eight-ton dead whale that washed up on the beach. The responsibility for getting rid of the carcass was placed with the Oregon State Highway Division, apparently on the theory that highways and whales are very similar in the sense that both are large objects. So anyway, the highway engineers hit upon a plan (remember, I am not making this up) to blow up the whale with dynamite. The thinking was that the whale would be blown into small pieces, which would then be eaten by seagulls and fish. That would be that--a textbook whale removal. So they moved the spectators back up the beach, put a half-ton of dynamite next to the whale and set it off. What follows, on the videotape, is one of the most priceless events in the history of the universe. First you see the whale carcass disappear in a huge blast of smoke and flame. Then you hear the happy spectators shouting "Yayy!" and "Whee!" Then, suddenly, the crowd's tone changes. You hear a new sound like "splud, splap," and you hear a woman's voice shouting "Here come pieces of...OH MY GOD!" Something smears the camera lens. Later, the reporter explains: "The humor of the entire situation suddenly gave way to a run for survival as huge chunks of whale blubber rained down everywhere.“ One piece caved in the roof of a car parked more than a quarter of a mile away!! Remaining on the beach were several large rotting whale sections the size of condominiums... Posted on: Saturday, June 15, 2002 Removal of carcass a whale of a task By Mike Gordon Advertiser Staff Writer State and city officials are used to removing things that wash up on island beaches, but two tons of smelly, decomposing whale carcass was a challenge yesterday. The dead sperm whale — what's left of it, anyway — floated in on Thursday night's high tide, coming to rest at Kualoa on a sliver of beach within sniffing distance of Kamehameha Highway, just north of the ruins of the sugar mill smoke stack at Kualoa Ranch. Normally, the city takes care of removing things that wash ashore but this was too much. "This thing is big," Jeff Walters of the Department of Land and Natural Resources' division of aquatic resources, said yesterday morning as the state weighed its options. "We need something big. We either have to have a crane to lift it up whole or something to cut it up into smaller pieces.“ At one point, he thought a backhoe could be used to chop it up, but anyone getting close to the carcass would have to wear protective clothing. "It is putrid," he said. So yesterday afternoon they hired a crane from Bob's Equipment. By 4 p.m. the biggest chunk had been removed and taken across the highway to Kualoa Ranch. DLNR spokesman Mike Markrich said four large chunks still remaining on on the beach will be taken away today by backhoe. The dead whale was first spotted Wednesday on a reef about 100 yards offshore, and signs were posted warning beachgoers to stay out of the water because of the possibility of sharks. The signs remained up today, but Walters said the carcass is so decomposed that even sharks probably don't want it.

Inquiry What characteristics distinguishes the three groups of pinnipeds? Why do whales migrate to Hawaii? What is echolocation? Which marine mammals lack blubber? Why are penguins black and white? What is the difference between an odontocete and mysticete? Why don’t whales get the bends? Why shouldn’t you load a dead whale with dynamite? Sea otters and polar bears lack blubber

009b Marine Mammals & Birds.

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