Mindblowing Planet Earth

Saturday, 7 September 2019

The Snapping Turtle

Where Do Snapping Turtles Live

Snapping turtles are among the largest of the freshwater turtles. They are characterized by large heads with powerful hooked jaws. There are only two species of this family in North America. The snapping turtle, including both the common and Florida snapping turtles, and the alligator snapping turtle mostly found in lakes, streams, and freshwater where fish in abundance numbers.

The snapping turtle (Chelydra serpentina) is primarily aquatic, inhabiting freshwater and brackish environments, although they will travel overland. There are two subspecies recognized in North America that are primarily distinguished by range.

s. serpentine (the common snapping turtle, which is the largest subspecies, primarily occupies the United States east of the Rockies, except for the southern portions of Texas and Florida), and C.s. Osceola (the Florida snapping turtle, found in the Florida peninsula).

Snapping Turtle Size

An adult snapping turtle is large, 20 to 37 cm in carapace length. Although the male turtle attains larger sizes than females. In a large oligotrophic lake in Ontario Canada, adult males averaged more than 10 kg. Hence the female’s turtle is averaged 5.2 kg. In other populations, the difference in size between males and females often is less.

Snapping Turtles reach the sexual maturity at about 200 mm in carapace length. The cool, brief activity season in more northern areas results in slower growth rates and extended times to reach sexual maturity.

Snapping Turtle Habitat

In the east, snapping turtles are found in and near-permanent ponds, lakes, and marshes. However, in the arid west, the species is primarily found in larger rivers, because these are the only permanent water bodies.

They are often found in turbid waters with a slow current. They spend most of their time lying on the bottom of deep pools or buried in the mud in shallow water with only their eyes and nostrils exposed.

It is observed that young snapping turtles show a preference for areas with some obstructions that may provide cover or food. The turtle has the great ability to travel extremely long distances to find food or an appropriate area to lay their eggs.

What do Snapping Turtles Eat

Snapping turtles are omnivorous. In the early spring, when limited aquatic vegetation exists in lakes and ponds. They may eat mainly animal matter. Though, when aquatic vegetation becomes plentiful, they become more herbivorous. Also, young snapping turtles are chiefly carnivorous and like smaller streams where aquatic vegetation is less abundant.

Snapping turtles consume a wide variety of animal material. That is including insects, snails, crustaceans, clams, leeches, earthworms, tubificid worms, freshwater sponges, fish (adults, fry, and eggs), frogs, toads, salamanders, small snakes, small turtles, birds, small mammals, and carrion and plant material including several algae.

Snapping Turtle observed no difference between the diets of males and females who fed at the surface, mid pelagic, and benthic levels. The pharyngeal mechanism of feeding (i.e., drawing water with food objects into the mouth) prevents snapping turtles from ingesting food above the air-water interface.

Temperature Regulation and Daily Activities

Snappers are most active at night. During the day, they occasionally leave the water to bask onshore, but basking is probably restricted by intolerance to high temperatures and by rapid loss of moisture. It is found that the turtles were active in the early morning and early evening and basked in the afternoon but were rarely active at night.

Active turtles were found in deeper waters than inactive snappers. Cloacal temperatures of 18.7 to 32.6C were reported for snapping turtles captured in the water in Sarasota County, Florida, between May and October.

Snapping Turtle Hibernation

Snapping turtles habitually enter in the hibernation process at the end of October and emerge sometime between March and May. But it is all depending on latitude and temperature. Also, to hibernate, turtles burrow into the debris or mud bottom of ponds or lakes, settle beneath logs, or retreat into muskrat burrows or lodges.

The turtles have been seen moving on or below the ice in midwinter. Large congregations sometimes hibernate together. This turtle is incredible cold-tolerant; even remain active under the ice during the winter.

Snapping Turtle Breeding Activities

Mating occurs any time turtles are active from spring through fall, depending on latitude. Some investigators believe that male snapping turtles are territorial but doubt that males defend their home ranges against other males. Sperm may remain viable in the female for several years.

Nesting occurs from late spring to early fall, peaking in June. Snapping Turtles can travel long overland to reach a new destination. They do it because of pollution, food scarcity, destruction in habitat, overcrowding, and many other factors.

When do Snapping Turtles Lay Eggs

The older females nested earlier in the season than did smaller, younger ones. Females often move up small streams to lay eggs. The nest site may be in the soil of banks or in muskrat houses but more commonly is in the open on south-facing slopes and maybe several hundred meters from the water.

The turtle digs a 4-to 7-in cavity on dry land, preferably in sand, loam, or vegetable debris. The duration of incubation is inversely related to soil temperature. In more northerly populations, hatchlings may overwinter in the nest.

Home Range and Resources

Moreover, many turtles stay mainly within the same marsh or in one wide-ranging area from year to year. The summer home range includes a turtle’s aquatic foraging areas, but females may need to travel some distance outside of the foraging home range to find a suitable nest site.

The females tagged at their nesting site moved an average of 5.5 km from the nest site afterward. The 91.9 percent of the turtles in one population returned to the same nesting site a year after having been tagged there. Home ranges overlap both between and within sexes.

However, the young snapping turtles use different habitats than adults; they tend to remain in small streams until shortly before maturity when they migrate to habitats preferred by adults (e.g., ponds, marshes, lakes).

Population Density

The density of snapping turtles appears to be positively correlated with the productivity of the surface water body (e.g., density in a eutrophic surface water body is higher than in an oligotrophic lake). Specific habitat characteristics and intraspecific interactions contribute to the variability of observed population densities in snapping turtles.

Snapping Turtle Egg Incubation

Females do not begin laying eggs until age 6 to 19 year depending on latitude and when they reach an appropriate size (approximately 200 mm carapace). Males mature a few years earlier than females. However, females may lay 1 or 2 clutches per season.

Snapping turtle eggs incubation took around 90 days. However, it all depends on the average temperature during that time, hatch anywhere from 80 to 120 days after being laid. Clutch size increases with female body size calculated the relationship between clutch size and plastron length.

Clutch size has also been positively correlated with latitude the mammalian predators destroyed over 50 percent of the turtle nests. The undisturbed nests, hatchling success was less than 20 percent. Adult mortality is low, corresponding with the long lives exhibited by these turtles.

Snapping Turtles Predators

The eggs predators by crows, Foxes, mink, skunks, and raccoons. The hatch-lings and juveniles, most of the same predators will attack them as well as herons, as it is observed that mostly attacked by great blue herons, Yellow bitterns, fishers, hawks, owls, bullfrogs, large fish, and different snakes. The average lifespan is not known, but estimated life is more than a hundred years.

Similar Species

The alligator snapping turtle (Macroclemys temmincki) is much larger (16 to 68 kg; 38 to 66 cm carapace) than the common snapping turtle and is one of the largest turtles in the world. Its range is from northern Florida to east-central Texas and north in the Mississippi Valley.

Are Snapping Turtles Poisonous

Snapping Turtle biggest threat is to humans are their powerful bite and scratch. So be careful when you interact with him to avoid the danger of their bite and claws which are very sharp and lacerate the flesh of a person trying to calm them. The Snapping Turtle can also cause some serious bruise or even break the skin or break bones as well. CP

Read More – The Lesser Goldfinch (Spinus psaltria) / The Himalayan Cutia / The fire-tailed myzornis / Pando – The One Tree Forest

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Thursday, 5 September 2019

American Kestrel (falcons)

American Kestrel Facts

Order Falconiformes, Family Falconidae - Falcons are the more streamlined of the raptor species, with long pointed wings bent back at the wrists and large tails that taper at the tips. They consume numerous kinds of animals including insects, reptiles, small mammals, and birds. It is also called sparrow hawk, although birds are not the main prey item. Falcons, in general, have long, pointed wings and long tails, like mourning dove (Zenaida macroura).

Falcons are found in a variety of habitats, from cities to the most remote areas. Strong fliers that achieve high speeds, falcons’ range in size from the American kestrel 27 cm bill tip to tail tip to the peregrine falcon 41 to 51 cm. It is one of the smallest and most widely distributed falcons in North America. In the first sight, kestrels are often confused with other small birds such as mourning doves.

Nest of American Kestrel

The American Kestrel seek ready-made nests, such as wild woodpecker excavated holes or nest boxes provided by humans. Especially- ready-made nest boxes support kestrels throughout the areas where there are few natural cavities. They prefer cavities in large trees, crevices in rocks, nooks in structures.

Mainly surrounded by large open areas covered with short ground vegetation with adequate hunting perches close by. The Kestrel used nest boxes, but competition from non-native European Starlings is a real problem. Once the Kestrels pair select the site for nesting, then they use it for many years.

Selected species

The American kestrel (Falco sparverius), or sparrow hawk, is the most common falcon in open and semi-open areas throughout North America. There are three recognized subspecies.

1. F.s. paulus (This is a year-round resident from South Carolina to Florida and southern Alabama).

2. F.s. peninsularis (it is a year-round resident of southern Baja California).

3. F.s. sparverius (It is widespread and migratory).

The Predators of the kestrel include large raptors such as great horned owls, golden eagles, red-tailed hawks, coyotes, bobcats, skunks, raccoons, ravens, and crows.

Body size of American Kestrels

The bird weighing slightly over one-tenth of a kilogram, the kestrel is the smallest falcon native to the United States. As for most raptors, females are 10 to 20 percent larger than males. Kestrel body weights vary seasonally, with maximum weight (and fat deposits) being achieved in winter and minimum weights in summer.

American Kestrels Habitat

Kestrels inhabit open deserts, semi-open areas, the edges of groves and even cities. In several areas, investigators have found that male kestrels tend to use woodland openings and edges, while females tend to utilize more open areas characterized by short or sparse ground vegetation, particularly during the winter. In other areas, however, investigators have found no such differentiation.

In Florida, kestrels appear to prefer sandhill communities particularly pine/oak woodlands. These areas provide high-quality foraging habitat and most available nest sites. Kestrels are more likely to use habitats close to centers of human activities than are most other raptors.

Territory size of American Kestrels in relation to relatively small mammal abundance at the trap site probably reflects a reasonable estimate of prey availability at all nearby sites. American Kestrels may not alter territorial boundaries once established, particularly if the original territory maximizes rates of prey capture while minimizing costs associated with territorial defense.

American Kestrels Diet

Kestrels prey on a variety of small animals including invertebrates such as worms, spiders, scorpions, bats, and beetles. The other large insects, amphibians, and reptiles such as frogs, lizards, and snakes, and a wide variety of small-to-medium-sized birds and mammals.

Large insects, such as grasshoppers, are the kestrels' primary summer prey. Although in their absence kestrels will switch to small mammals and birds. In winter, small mammals and birds comprise most of the diet. Kestrels usually cache their vertebrate prey, often in clumps of grass or in tree limbs and holes, to be retrieved later.

Invertebrate prey usually is eaten immediately. In Florida, where small mammals are scarce, and reptiles are abundant, lizards are an important component of the diet. Kestrels forage by three different techniques: using open perches from which to spot and attack ground prey, hovering in the air to spot ground prey, and catching insects on the wing.

Also, some favorite prey, like voles and mice, leave urine trails that show up in ultra-violet light. They use these trails to track the hapless rodents. Hence, after a hearty meal, Kestrel stash leftovers in clumps of grass, bushes, fence posts, tree limbs or tree cavities.

Molt

Females begin their molt during incubation and complete it by the end of the breeding season. Males, who are responsible for capturing most of the prey for the family, do not begin their molt until near the end of the breeding season.

Migration

The American kestrel is a year-round resident over most of the United States but is migratory over the northern-most portions of its range (National Geographic Society. Because of their late molt, males migrate and arrive at the wintering grounds later than females or immatures.

Breeding activities and social organization

Adult kestrels are solitary, except during the breeding season, and maintain territories even in winter. Kestrels typically build their nests in tree cavities but have used holes in telephone poles, buildings, or stream banks when tree cavities are not available.

Both parents participate in incubation, but the female performs most of the incubation, while the male provides her with food. Following hatching, the male brings most of the prey to the nestlings. After fledging, young kestrels remain dependent on their parents for food for at least 2 to 4 additional weeks.

Fledglings often perch and socialize with their siblings prior to dispersal. In Florida, resident kestrels (Paulus subspecies) maintain year-round pair bonds and joint territories. The resident pairs have a competitive advantage over winter migrants (sparverius subspecies) in their territories.

Home range and resources

Although some investigators have not noted territorial defense demonstrated that kestrels defend territories by introducing captured birds into other birds' territories. Winter foraging territories range from a few hectares in productive areas to hundreds of hectares in less productive areas.

Summer breeding territories probably follow the same pattern. Population density although much smaller than red-tailed hawks and bald eagles, reported kestrel breeding population densities can be similarly low 0.0003 to 0.004 nests per hectare.

Population Dynamics

Kestrels are sexually mature in the first breeding season after their birth. Scarcity of suitable nesting cavities probably limits the size of kestrel populations in parts of the United States. Three to four young may fledge per nest per year, but the mortality of juveniles in the first year is high (60 to 90 percent). Adult mortality can below 12 % per year.

Similar species

from general references, the peregrine falcon (Falco peregrinus), a rare resident of woods, mountains, and coasts, preys almost exclusively on birds. Though uncommon, they can be found wintering in most states, but rarely breeding. These large falcons are 38 cm) have been reintroduced in some areas in the United States and have nested in urban environments.

The merlin (Falco columbarius), larger (30 cm) than the kestrel, can be found in a variety of habitats but nests in open woods or wooded prairies. Wintering along coasts and near cities of the Great Plains, it primarily eats birds.

The prairie falcon (Falco mexicanus) also is a larger bird 39 to 50 cm than the kestrel and inhabits dry, open country and prairies. A year-round resident of the western United States, prairie falcons prey chiefly on birds and small mammals.

American Kestrels Call

American Kestrel (falcons) are quite vocal and have a limited set of calls. However, the familiar one is a repeated loud, thrilled series of 3-6 klee or killy lasting just over a second. The Kestrels call is distinctive and an excellent way to find these birds. Moreover, they do not need to drink free-standing water, as they need from the moisture of their prey.

Kestrel Take-Off and Landing

During take-off, the forward speed of the bird being low, the primary requirement of lift to overcome gravity is essentially provided by a fast flapping rate which is higher than in normal forward flight. The amplitude of flapping is also greater.

Similarly, during landing, the speed being low, the bird's wings must generate the required lift to uphold the weight and break the forward motion. Therefore, the wings are spread wide and the flapping motion adjusted. Kestrel also used "reduced span" upstroke in fast flight. The bird is having the habit of pumping their tail feathers up and down when perched, particularly after landing.

Sexes

The male kestrel has a rusty back, blue-gray wings and crown with a rusty cap, and distinguishing black facial stripes, and lightly spotted underparts. However, the female is alike, with a rusty back, wings, and breast streaking, but it does not have the blue-gray markings of the male. Source: CP

Breeding activities and social organization of American Kestrel

Home range and resources of American Kestrel

American Kestrel (falcons) are quite vocal and have a limited set of calls.

The American kestrel is a year-round resident over most of the United

Read More – The Lesser Goldfinch (Spinus psaltria) / The Himalayan Cutia / The fire-tailed myzornis / Pando – The One Tree Forest

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Tuesday, 27 August 2019

American Goldfinch (Spinus tristis)

American Goldfinch Identification

The American Goldfinch (Carduelis tristis) is a favorite visitor of many backyard birdwatchers. The American Goldfinch is about five inches in length tail tip to bill tip. The American Goldfinch is a bird of edge and brush, preferring naturally open swamp and marsh vegetation, man-made clearing, road edges, orchards, and pasture forest, fringes and open uplands with their scattered shrubs and saplings.

The American Goldfinch is a common migrant resident in various states of United States, however variable in numbers from season to season. The American goldfinch is the state bird of “Iowa” and “New Jersey”, where it is known as "Eastern Goldfinch", and in Washington, it is called the "Willow Goldfinch". The bird is often victim to brood parasites, mainly brown-headed cowbirds. The lifespan of the American Goldfinch is around three to six years in the wild. So far, the oldest known American goldfinch was 10 years and 5 months old.

American Goldfinch Male and Female

The male bird has bright yellow body feathers with black wing and tail feathers are having black forehead patch. Also, a white rump patch and two white wings bars are also present. Hence, the female American Goldfinch has olive yellow body feathers with black wing feathers and two white wings bars. This is a diurnal bird, meaning it's most agile during the day.

American Goldfinch Habitats

It breeds in blue oak savannahs, digger pine-oak wood-lands, and particularly in low elevation riparian groves. In late summer and fall, some upslope movement, especially in chaparral type and along riparian corridors. The most amazing part of American goldfinch is displaying sexual dimorphism in its coloration.

The male bird is a vibrant yellow in the summer and an olive color during the winter. Thus, the female bird is a dull yellow-brown shade which brightens only slightly during the summer. The American Goldfinch is one of the most common and widespread birds, but it can seem to disappear during the winter.

During the fall, the bright yellow males molt into the same muted brown as the females and juveniles. While these “brown-finches” will remain all winter, casual observers don’t notice them, searching instead for the summer-attired male. As goldfinches are gregarious during all parts of the year, even feeding together during the breeding season, it’s easiest to find the flock.

The American Goldfinch truly deserves its name. It can be found in all the 48 contiguous states during some portion of the year. The population retreats from the southern third of Canada and expands into the southern U.S. and Mexico during the winter. The bird is also well-known for its susceptibility to mycoplasmal conjunctivitis, that has infected and killed many House Finches.

American Goldfinch Song

Normally male bird sings a long and different series of twitters and musical warbles lasted for several seconds long. The phrases and notes inconstant and repeated in a seemingly random order. The finch perpetually to learn song patterns throughout life.

American Goldfinch Sound

The bird most common call is its contact call, repeatedly given tsee-tsi-tsi-tsit in flight. It sounds just like saying po-ta-to-chip with a very even cadence, but sometimes give severe threat calls when in feeding flocks or at the nest. The male bird makes a tee-yee courtship call upon landing near a female followed by a burst of song.

Females brooding nestlings make a rapid sequence of high notes when they hear their mate approaching with food. Further, at nest both make a loud defense call, two-parted bay-bee when they feel threatened. The most common predators are snakes, squirrels, weasels, cats, hawks, and blue jays, normally destroy eggs or kill young, also pose a threat to both young and adults.

American Goldfinch Courtship Behavior.

In contrast to most songbirds the American Goldfinch may delay establishing territory up to two months following pair formation in May and June. Two distinctive courtship behavior of the American Goldfinch are the extended, canarylike warbling given by the male from prominent perches and the prolonged pursuit of a single female by several males.

American Goldfinch Breeding

Breeding Biology of American Goldfinch is unusual. Unlike more than 95% of other terrestrial birds, the goldfinch feeds its nestlings only seeds. Brown-headed Cowbird chicks, which thrive in the nests of insect-eating warblers, rarely survive past three days and never fledge from goldfinch nests. The goldfinch is also one of the latest nesting songbirds. The female bird chooses to mate with males that exhibit the brightest colors, and therefore, may obtain the most skilled foragers in doing so.

American Goldfinch Nest

The birds may pair up during the winter flock, but most nesting occurs July through September. Nests are placed in open areas with shrubs, fibrous matter from the bark of vines and the stems of milkweed that the female gathers and form into a supporting basket. Such as residential areas and old fields. The basket is cradled in the crotch of 3 to 4 upright slender branches of a tree shrub or herbaceous plant.

Females choose their mates based on the brightness of their plumage, using that as a signal of their overall health. First-time nesters raise a single brood; experienced females leave their first brood with their mate and attempt a second nest with a new male. Moreover, nest height above the ground varies according to the chosen habitats.

Whereas nest building in July may average 13 days, it requires less than half this time by late August. Incubation by the female bird of the 4 to 6 smooth shelled pale bullish, white eggs lasts from 12 to 14 days. During incubation the male is most attentive feeding the begging female a regurgitated supply of while milky seed cereal.

By the 8^th day after hatchling the nestlings are very active calling loudly and standing upright in anticipation of the parents’ arrivals. At this time juvenile begin defecating on the nest edge, where their excreta may cling and harden. Earlier the parents removed the fecal sacs.

American Goldfinch Population

American Goldfinch breeding populations have remained stable nationally and increased. Winter populations are also widespread and apparently stable with goldfinches consistently among the “top five” Winter Feeder Survey birds in both total numbers and percent of feeders visited.

Fewer breeding attempts were confirmed in part due to the late nesting season (many observers had turned in their records before young goldfinches left the nest). Furthermore, less emphasis was placed on “confirming” a species needs European settlement was beneficial for the American Goldfinch, increasing both edge habitat for nesting and “weedy” food sources. In the winter these finches make a group of up 40 or 50 birds, occasionally more. The flock of Goldfinches is called a real “charm”.

What Do American Goldfinch Eat?

The bird eats mainly Thistle or Nyjer seeds of trees, maple sap, alder & birch, forbs, especially of composites; sunflower seeds, bark of young twigs, and, some insects. Generally, feeds in flocks, picking and gleaning food from flower heads and foliage of forbs, shrubs, and trees. A peculiar behavior of goldfinches is that they feed upside-down to obtain seeds from thistles, and sunflowers.

The American Goldfinch is an agile species and may also be one reason this species will readily come to birdfeeders whether they must feed right-side up or upside-down. Though the Goldfinch will eat at both types of feeders, results show that feeding right-side up increases the number of feeding attempts and the amount of seed consumed by gold-finches.

The farm management plan that sets aside land for grassland-nesting species, has also benefitted goldfinches. While forest succession and the move towards “clean” farming both work to decrease appropriate habitat and food availability, this can be easily countered by thoughtful landscaping of urban and suburban yards.

Natural landscapes should be allowed to experience disturbances that produce the desired habitat. The American Goldfinch is a species that fits easily into the human-dominated landscape. The only subspecies of the American Goldfinch known from southern California is the one breeding locally, the Willow Goldfinch.

Backyard birders are not always able to watch the goldfinch because the larger House Finch usually crowds the goldfinch off the perches of conventional feeders. Some backyard birders do not like this competition and would like to have a feeder that can only be used by the goldfinch.

Trees Attract American Goldfinches

The Goldfinches attract with colorful flowers such as asters, Bolivian sunflower, , daisies, cosmos, marigolds, Mexican sunflower, poppies, purple coneflowers and zinnias. The seed heads of above plants are enjoyed by birds throughout their growing seasons. A special blooming favorite is the black oil sunflower.

Read More - The Lesser Goldfinch (Spinus psaltria) / The Himalayan Cutia / The fire-tailed myzornis