The Hawaiian monk seal is one of the most endangered seal species in the world. The population overall had been declining for six decades and current numbers, though increasing, are only about one-third of historic population levels. Importantly, however, the current upward trend is in part due to NOAA Fisheries recovery efforts.

Hawaiian monk seals are found in the Hawaiian archipelago which includes both the main and Northwestern Hawaiian Islands and rarely at Johnston Atoll which lies nearly 1,000 miles southwest of Hawaii. These monk seals are endemic to these islands, occurring nowhere else in the world. Hawaiian monk seals are protected under the Endangered Species Act, the Marine Mammal Protection Act, and State of Hawaii law.

Rocky, the Famous Hawaiian Monk Seal

Rocky became famous in 2017 when she had a pup on a busy beach in Waikiki on the island of Oahu. She returned to Kauai on July 14, 2018, and two days later, she was observed with a new pup.

Population Status

The population is estimated to be around 1,600 seals—nearly 1,200 seals in the Northwestern Hawaiian Islands and 400 seals in the main Hawaiian Islands.

A prolonged decline of the Hawaiian monk seal population in the Northwestern Hawaiian Islands occurred after the late 1950s, lasting until very recently. While individual subpopulations increased or decreased during that time, the total number of seals in the Northwestern Hawaiian Islands declined. Although this decline means that a full recovery of the species is a long way off, there are relatively recent, encouraging developments, including:

Visible recolonization and significant growth of the main Hawaiian Islands monk seal subpopulation from low numbers to approximately 400 over the past 2 decades or more

Overall species population growth of 2 percent each year between 2013 to 2022—2021, marked the first time their population exceeded 1,570 in more than 2 decades

Promising advances in juvenile seal survival enhancement research, such as evaluating how translocation affects survival and continued efforts to improve medical treatments

The decline that occurred in the Northwestern Hawaiian Islands was attributed to a number of factors at various regions and time periods. However, low juvenile survival, likely related to limited food availability, was the primary driver of the decline during the past 25 years.

Appearance

Newborn monk seal pups are born black, while weaned pups and older seals are dark gray to brown on their back and light gray to yellowish brown on their belly.

Monk seals undergo a “catastrophic molt” about once per year, where they shed the top layer of their skin and fur (similar to elephant seals). Seals that spend a long time at sea foraging can grow algae on their fur. Those that look green haven’t molted recently and may be getting ready to shed into a new silvery coat.

Most Hawaiian monk seals have unique natural markings, such as scars or natural bleach marks (white spots), on their fur which help identify them. Personnel authorized by NOAA Fisheries often apply identification tags to their rear flippers. Tagging and tracking used in combination with identification of unique markings enable long-term monitoring of individuals.

Male and female monk seals are similar in size. The only way to confirm whether a seal is female or male is by looking at its belly.

Behavior and Diet

Hawaiian monk seals are “generalist” feeders, which means they eat a wide variety of foods depending on what’s available. They eat many types of common fishes, squids, octopuses, eels, and crustaceans (crabs, shrimps, and lobsters). Diet studies indicate that they forage at or near the seafloor and prefer prey that hide in the sand or under rocks. They do not target most of the locally popular gamefish species such as ulua (giant trevally), pāpio (baby ulua), and ‘ō‘io (bonefish).

Hawaiian monk seals can hold their breath for up to 20 minutes and dive more than 1,800 feet; however, they usually dive an average of 6 minutes to depths of less than 200 feet to forage at the seafloor.

Hawaiian monk seals are mostly solitary and don’t live in colonies like sea lions or other seals. But they do sometimes lie near each other—usually not close enough to make physical contact—in small groups. They usually sleep on beaches, sometimes for days at a time. They also occasionally sleep in small underwater caves.

Monk seals do not migrate seasonally, but some seals have traveled hundreds of miles in the open ocean. Individual seals often frequent the same beaches over and over, but they do not defend territories.

Where They Live

Hawaiian monk seals are found throughout the entire Hawaiian archipelago, a distance of 1,500 miles from Kure Atoll (Hōlanikū) in the northwest to Hawaii Island in the southeast. The majority of Hawaiian monk seals (about 1,200 individuals) live in the Northwestern Hawaiian Islands, and a much smaller number (about 400) live in the main Hawaiian Islands. There have also been rare sightings of Hawaiian monk seals, as well as a single birth, at Johnston Atoll, the closest atoll southwest of the Hawaiian Islands. Monk seals live in warm, subtropical waters and spend two-thirds of their time at sea. They use the waters surrounding atolls and islands and areas farther offshore on reefs and submerged banks; they also use deepwater coral beds as foraging habitat. When on land, monk seals haul-out to rest, molt, give birth and nurse on sand, coral rubble, and volcanic rock shorelines. They generally prefer sandy, protected beaches surrounded by shallow waters for pupping

Lifespan & Reproduction

Monk seals can live to over 30 years of age, but few live that long. Monk seals mate in the water. The youngest documented female to give birth was 4 years old, but typically females begin reproducing at age 5 to 6 in the main Hawaiian Islands and age 7 to 10 in the Northwestern Hawaiian Islands.

SOURCE: FISHERIES.NOOA.GOV

Appearance

The coat of the White-tailed deer is a reddish-brown in the spring and summer and turns to a grey-brown throughout the fall and winter. The deer can be recognized by the characteristic white underside to its tail. It raises its tail when it is alarmed to warn the predator that it has been detected. An indication of a deer age is the length of the snout and the color of the coat, with older deer tending to have longer snouts and grayer coats. A population of white-tailed deer in New York is entirely white (except for areas like their noses and toes) – not albino – in color. White-tailed deer’s horizontally slit pupils allow for good night vision and color vision during the day. Males regrow their antlers every year. Males without branching antlers are often termed “spikehorn”, “spiked bucks”, “spike bucks”, or simply “spikes/spikers”. The spikes can be quite long or very short. The length and branching of antlers are determined by nutrition, age, and genetics. Spiked bucks are different from “button bucks” or “nubbin’ bucks”, which are male fawns and are generally about 6 to 9 months of age during their first winter. They have skin-covered nobs on their heads. They can have bony protrusions up to a half inch in length, but that is very rare, and they are not the same as spikes. Males shed their antlers when all females have been bred, from late December to February.

Habits and Lifestyle

White-tailed deer are usually considered solitary, particularly in summer. Their basic social unit is mother and fawns, although sometimes they do graze together in herds that can number hundreds of individuals. Bucks and does remain separate from each other except during the mating season. Bucks usually live alone or within small groups alongside other bucks. Deer living in deserts often migrate from summertime elevations down to warmer areas where there is more food available. White-tailed deer are crepuscular, and mainly feed starting before dawn until a few hours after the sun has risen, and again in the late afternoon until dusk. They use a number of forms of communication, such as sound, odor, body language, and marking with scratches. When alarmed, a White-tailed deer will raise its tail to warn other deer.

Diet and Nutrition

Whitetails are herbivores and feed on twigs, bark, leaves, shrubs, the nuts and fruits of most vegetation, lichens, and other fungi. Plants such as yucca, huajillo brush, prickly pear cactus, ratama, comal, and a range of tough shrubs can be the mainstay of a whitetail’s diet if it lives in a desert area. Though almost entirely herbivorous, White-tailed deer may opportunistically feed on nesting songbirds, field mice, and birds trapped in mist nets, if the need arises

Mating

Whitetails are polygynous, and bucks fight fiercely during the mating season, with winners able to mate with does in the area. The season runs from October to December. The gestation period is about 6 months. A female usually gives birth to one fawn in her initial year of breeding but 2 are born subsequently. Fawns can walk as soon as they are born and only a few days later are able to nibble on vegetation. When seeking food, mothers leave their offspring hidden amongst vegetation. A fawn starts to follow its mother as she goes off to forage when it is about 4 weeks old. At 8 – 10 months old, they are weaned. At one-year-old, young males leave their mothers but young females will often stay with them for two years. Most of them (particularly males) will breed in their second year.

Fun Facts for Kids

When White-tailed deer gather together and trample down snow in a particular area, this is called a “deer yard.”

White-tailed deer can jump vertically more than 8.2 feet and horizontally 354 in, which is almost the length of a school bus.

White-tailed deer swim well and can escape from predators through large streams and lakes.

Only the males grow antlers, and they shed them each year.

White-tailed deer are the shyest and most nervous of deer. When they are startled and run away, their tails wave from side to side.

Deer can smell human odor on underbrush for days afterward. Bucks will stay away from areas that have been visited by humans for weeks afterward.

Bucks usually lie on their right side when they go to sleep, and they face downwind, enabling them to employ their nose, ears, and eyes to detect danger in any direction.

From the National Park Service website:

Once common throughout the southeastern United States, fewer than 100 Florida panthers (Puma concolor coryi) are estimated to live in the wilds of south Florida today. The current range of Florida panthers is less than five percent of their original range across Florida, Georgia, Alabama, Mississippi, Louisiana, Arkansas, and parts of Tennessee and South Carolina. Florida panthers were heavily hunted after 1832 when a bounty on panthers was created. Perceived as a threat to humans, livestock, and game animals, the species was nearly extinct by the mid-1950s.

Today, the primary threats to the remaining panther population are habitat loss, fragmentation, and degradation. Urban sprawl, the conversion of once-diversified agricultural lands into intensified industrial farming uses, and the loss of farmland to commercial development combine to reduce the amount of suitable panther habitat. Other factors include mortalities from collisions with automobiles, territorial disputes with other panthers, inbreeding, disease, and environmental toxins. All these other factors, however, also are related to habitat reduction.

 Like most animals, Florida panthers need food, water, shelter, and access to mates to survive. Panthers are strictly carnivores and eat only meat. About 90 percent of their diet is feral hog, white-tailed deer, raccoon, and armadillo. Occasionally they consume rabbits, rats, and birds, and occasionally even alligators. In south Florida, panthers prefer mature upland forests (hardwood hammocks and pinelands) over other habitat types. Upland forests provide dry ground for resting and denning, and prey density is higher than it is in lower habitats where flooding is more common. Much of the prime panther habitat is north of Interstate Highway 75, and panthers in that area weigh more, are healthier, and successfully raise more kittens than panthers that live primarily south of the highway and feed mostly on small prey. Panthers in Everglades National Park are smaller and fewer because much of the park consists of wetlands, while panthers need uplands in order to thrive. Although the Long Pine Key area within the park provides dry upland habitat, hogs are scarce in the park and deer are limited to dry or low water level areas. A panther has to kill and eat about 10 raccoons to equal the food value of 1 deer. To maintain their health and fitness, adult panthers need to consume the equivalent of about 1 deer or hog per week. Females with kittens may need twice this amount.

The recent history of the Florida panther documents the success of the genetic restoration program. Historically, natural gene exchange occurred between the Florida panther and other contiguous species of Puma concolor as individuals dispersed among populations and bred. This natural mechanism for gene exchange maintained genetic health within populations and minimized inbreeding. However, as the population declined, gene exchange between subspecies could no longer occur because the Florida panther had become isolated from neighboring subspecies such as the Texas panther. Inbreeding accelerated, resulting in genetic depression, declining health, reduced survivability, and low numbers. If action was not taken to address the loss of natural gene exchange, it was feared that the species would soon be extinct. In 1995 when the genetic restoration program began, the population of panthers had dwindled to only 20-30 individuals in the wild. In 1995, eight female Texas panthers were released in south Florida. Five of the eight Texas panthers produced litters and at least 20 kittens were born. By 2007, the Florida panther population had responded by tripling to about 100 animals. The genetic restoration program restored genetic variability and vitality for a healthier, more resilient population.

Mercury in Panthers

 Scientists first became aware of the potential threat of mercury to panthers in south Florida in 1989 when a female panther from the park died. An immediate cause of death could not be determined, but later tests revealed that her liver contained high levels of mercury. That same year, the State of Florida found high levels of mercury in fish from the Everglades. Air pollution from metals mining and smelting, coal-fired utilities and industry, and solid-waste incinerators was determined to be the major source of mercury contamination. Although some of this pollution was coming from utilities and industries within Florida, some originates in other countries and continents. Summer thunderstorms scour airborne mercury out of the upper atmosphere and deposit it in the Everglades. Mercury in rainfall is transformed to methylmercury by bacteria in sediments and algal mats. Zooplankton feed on algae, fish and crayfish feed on zooplankton, raccoons feed on fish and crayfish, and panthers feed on raccoons. In the 15 months before her death, the panther with high levels of mercury in her liver fed only on small prey, primarily raccoons. As mercury moves through the food chain, it accumulates in ever-greater quantities in the tissue of each predator. The tissues of predators at the top of the food chain, such as panthers, typically contain the most mercury.

Subsequent studies found that mercury concentrations in panther tissues were lowest north of Interstate Highway 75 where adequate deer and hogs were available and highest in the Everglades and the southern part of Big Cypress National Preserve where consumption of raccoons was highest. Raccoons are thought to have been the major source of mercury in Florida panthers at that time. Since 1989, mercury concentrations in fish and birds in the Everglades have dropped by 60 to 70 percent. The drastic reductions are directly linked to the installation of technology that reduced mercury in emissions from industries in south Florida. Although mercury levels in the natural environment are a worldwide concern and mercury likely will never be completely removed from the environment, mercury reductions are expected to continue into the future. Monitoring, modeling, and research demonstrate the relationship between mercury detected in the air, deposited in waterways and sediments through rainfall, and concentrated in fish and wildlife.

SOURCE: nps.gov.com