Information

43.0: Prelude to Animal Reproduction and Development - Biology


Animal reproduction is necessary for the survival of a species. In the animal kingdom, there are innumerable ways that species reproduce. Asexual reproduction produces genetically identical organisms (clones), whereas in sexual reproduction, the genetic material of two individuals combines to produce offspring that are genetically different from their parents. During sexual reproduction the male gamete (sperm) may be placed inside the female’s body for internal fertilization, or the sperm and eggs may be released into the environment for external fertilization. Seahorses provide an example of the latter. Following a mating dance, the female lays eggs in the male seahorse’s abdominal brood pouch where they are fertilized. The eggs hatch and the offspring develop in the pouch for several weeks.


43.0: Prelude to Animal Reproduction and Development - Biology

Maternal malnutrition has important developmental consequences for the foetus. Indeed, adverse fetal ovarian development could have lifelong impact, with potentially reduced ovarian reserve and fertility of the offspring. This study investigated the effect of maternal protein restriction on germ cell and blood vessel development in the fetal sheep ovary. Ewes were fed control (n = 7) or low protein (n = 8) diets (17.0 g vs 8.7 g crude protein/MJ metabolizable energy) from conception to day 65 of gestation (gd65). On gd65, fetal ovaries were subjected to histological and immunohistochemical analysis to quantify germ cells (OCT4, VASA, DAZL), proliferation (Ki67), apoptosis (caspase 3) and vascularisation (CD31). Protein restriction reduced the fetal ovary weight (P < 0.05) but had no effect on fetal weight (P > 0.05). The density of germ cells was unaffected by maternal diet (P > 0.05). In the ovarian cortex, OCT4+ve cells were more abundant than DAZL+ve (P < 0.001) and VASA+ve cells (P < 0.001). The numbers, density and estimated total weight of OCT4, DAZL, and VASA+ve cells within the ovigerous cords were similar in both dietary groups (P > 0.05). Similarly, maternal protein restriction had no effect on germ cell proliferation or apoptotic indices (P > 0.05) and the number, area and perimeter of medullary blood vessels and degree of microvascularisation in the cortex (P > 0.05). In conclusion, maternal protein restriction decreased ovarian weight despite not affecting germ cell developmental progress, proliferation, apoptosis, or ovarian vascularity. This suggests that reduced maternal protein has the potential to regulate ovarian development in the offspring.

Lay summary

Variations in a mother’s diet during pregnancy can influence her offspring’s growth and might cause fertility problems in the offspring in later life. We investigated whether reducing the protein fed to sheep during early pregnancy affects their daughters’ ovaries. We then compared our findings to the offspring of sheep on a complete diet. We measured ovary size and estimated the number of germ cells (cells that become eggs) they contained. We used cell markers to assess potential changes in the pattern of germ cell growth, division, and death, and how the ovarian blood supply had developed. We found that protein restriction reduced ovary size. However, the pattern of germ cell development, growth, or death was not altered by poor diet and blood vessels were also unaffected. This suggests that maternal diet can change ovarian development by an unknown mechanism and might reduce future fertility in their offspring.


Animal Diversity Web

Appalachian cottontails inhabit forests and brushy areas at high elevations of the Appalachian Mountains, which stretch from the Hudson River in New York to northern Alabama. (Boyce and Barry, 2007 Russell, et al., 1999 Sharpe and Newman, 1996)

Habitat

Appalachian cottontails inhabit montane areas of high elevation coniferous forests as well as areas providing dense cover from mountain laurel (Kalmia latifolia), blueberry (Vaccinium spp.), rhododendron (Rhododendron spp.), blackberry vines (Rubus spp.), greenbriar (Smilax spp.), and cane (Arundinaria gigantea). Generally, Appalachian cottontails are found at elevations greater than 762 m, though this species has been reported below 610 m at the southern end of the Appalachian Mountains in Tennessee and Alabama. Appalachian cottontails are also found in high densities in clear cuts and ares of recent (5 to 25 years) disturbance. (Bunch, et al., 2006 Russell, et al., 1999 Sharpe and Newman, 1996)

  • Habitat Regions
  • temperate
  • terrestrial
  • Terrestrial Biomes
  • forest
  • scrub forest
  • mountains
  • Range elevation 762 (low) m 2500.00 (low) ft

Physical Description

Appalachian cottontails are yellowish brown mixed with black on the dorsal side and have a reddish brown patch over the neck. Their sides are lighter in color and their ventral side white. They also have a short fluffy tail, which is darker on the top and ventrally white. Appalachian cottontails are nearly indistinguishable from New England cottontails in the field. They, however, occur in different ranges cottontails found south or west of the Hudson River in New York are considered Appalachian cottontails. (Bunch, et al., 2006 Kurta, 1995 Russell, et al., 1999 Sharpe and Newman, 1996)

While Appalachian cottontails show great resemblance to Eastern cottontails, Appalachian cottontails are slightly smaller in size, have shorter, rounded ears with black along the edges, and have a black spot on the head between the ears. Also, Eastern cottontails usually have a white spot on their forehead, which Appalachian cottontails lack. Additionally, the skulls of Appalachian cottontails and Eastern cottontails are markedly different when viewed from above. Appalachian cottontails have a jagged and irregular suture line between the frontal and nasal bones, whereas this line is smooth in Eastern cottontails. Also, the postorbital process of Appalachian cottontails are thin and just barely join the skull at the posterior end. (Kurta, 1995 Sharpe and Newman, 1996)

  • Other Physical Features
  • endothermic
  • bilateral symmetry
  • Sexual Dimorphism
  • sexes alike
  • Range mass .8 to 1.0 kg 1.76 to 2.20 lb
  • Range length 38.6 to 43.0 cm 15.20 to 16.93 in
  • Average length 40.0 cm 15.75 in

Reproduction

Although little information is available regarding the mating systems of Appalachian cottontails, other members of g. Sylvilagus are polygynous. Males in this genus fight amongst themselves, determining a hierarchy that influences mating priority. Appalachian cottontails may squeal while mating. (Nowak, 1999)

Male Appalachian cottontails come into breeding condition at the end of winter due to lengthening daylight and increases in temperature. Breeding begins in warm weather, usually between late February and early October. A prolific species, adult female Appalachian cottontails can breed immediately after giving birth. An adult female breeds an average of 3 times during the season and can bare 3 to 4 young with each litter. Appalachian cottontails produce 2 to 8 young annually. Gestation lasts 28 days, and young are weaned after 3 to 4 weeks. Around 6 to 7 days of age, young Appalachian cottontails, which are born blind, open their eyes, and after 12 to 14 days, they leave the next. Sexual maturity is reached after 1 to 2 months of age. Although males do not reproduce until the following spring, some female Appalachian cottontails reproduce late in the breeding season of their first summer. (Kurta, 1995 Sharpe and Newman, 1996)

  • Key Reproductive Features
  • iteroparous
  • seasonal breeding
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • viviparous
  • Breeding interval Female adult Appalachian cottontails breed 3 times during the breeding season, and a female cottontail from the first litter will likely breed during that same summer.
  • Breeding season Appalachian cottontails breed between February to October.
  • Range number of offspring 2 to 8
  • Average number of offspring 3.5
  • Average gestation period 28 days
  • Range weaning age 3 to 4 weeks
  • Average time to independence 1 months
  • Average age at sexual or reproductive maturity (female) 2-3 months
  • Average age at sexual or reproductive maturity (male) 2-3 months

Expectant female Appalachian cottontails build a shallow nest composed of leaves, grass, and fur. Young cottontails are born naked, blind, and helpless, and the mother invests the month after birth to weaning and raising the litter. When she leaves for an extended period of time, the mother covers her nest and young with layers of fur, grass, leaves and twigs for camouflage and to keep the young warm. After 6 or 7 days, young Appalachian cottontails open their eyes, and after 12 to 14 days, they leave the nest. Lactation generally lasts for 16 days. After about one month, the young are completely independent from the mother. (Kurta, 1995 Sharpe and Newman, 1996)

  • Parental Investment
  • altricial
  • female parental care
  • pre-hatching/birth
    • provisioning
      • female
      • female
      • provisioning
        • female
        • female
        • provisioning
          • female
          • female

          Lifespan/Longevity

          Appalachian cottontails are very short-lived and are expected to live less than one year. Populations of this species are maintained because of their incredible productivity. (Sharpe and Newman, 1996)

          Behavior

          Appalachian cottontails are crepuscular or active at dawn and dusk. During the day, they tend to rest and groom under a log or in another area sheltered from predators. Cottontails are active year-round. Most species of g. Sylvilagus are considered solitary, and males are thought to create dominance hierarchies based on fighting that influence mating priority. (Kurta, 1995 Nowak, 1999 Russell, et al., 1999)

          • Key Behaviors
          • saltatorial
          • nocturnal
          • crepuscular
          • motile
          • daily torpor
          • solitary
          • dominance hierarchies
          • Range territory size 0.015 to 0.133 km^2

          Home Range

          Male Appalachian cottontails have a larger home range during the breeding season, up to 13.3 ha. Female home ranges remain fairly constant and can be as small as 1.5 ha. (Boyce and Barry, 2007 Nowak, 1999)

          Communication and Perception

          Similarly to other cottontails, Appalachian cottontails exercise a heightened sense of smell, hearing, and sight, aiding sending and receiving of signals, attracting mates, and allowing quick perception of and reaction to potential predators. Mothers may grunt if a predator is seen near the nest. Appalachian cottontails may also squeal while mating. (Kurta, 1995 Nowak, 1999 Wilson and Ruff, 1999)

          • Communication Channels
          • chemical
          • Perception Channels
          • visual
          • tactile
          • acoustic
          • chemical

          Food Habits

          The diet of Appalachian cottontails consists of grasses, forbs, and conifer needles in addition to leaves, twigs, and fruits from the mountainous shrubs in its habitat. In the winter, it is suspected that this species eats the buds and bark of trees and shrubs including red maple, aspen, choke cherry, black cherry, alders, and blueberry bushes. (Bowers, et al., 2007 Kurta, 1995)

          Like most Lagomorphs, Appalachian cottontails partakes of coprophagy, the eating of their own feces. This allows for the uptake of essential vitamins that were unabsorbed during the first pass through the digestive tract. (Kurta, 1995)

          • Primary Diet
          • herbivore
            • folivore
            • Plant Foods
            • leaves
            • wood, bark, or stems
            • fruit
            • Other Foods
            • dung

            Predation

            Appalachian cottontails have quick, saltatorial locomotion to escape potential predators. Often, cottontails dash in a zig-zag pattern to lose predators. A slinking form of movement, low to the ground with the ears back, may be used to avoid detection. Additionally, cottontails can remain almost completely still and quiet for up to 15 minutes, even when closely approached, to prevent detection from predators. Known predators include Owls, Hawks, Dogs, Foxes , and Humans. (Kurta, 1995 Nowak, 1999)

            • Known Predators
              • Owls Strigiformes
              • Hawks Accipitridae
              • Dogs Canidae
              • Foxes g. Vulpes
              • Humans Homo sapiens

              Ecosystem Roles

              Appalachian cottontails serve as prey for a wide variety of animals, including Owls, Hawks, Dogs, Foxes , and Humans. As consumers of fruits, this species may also act as seed dispersers. Appalachian cottontails also slow the regeneration of disturbed areas in the environment by feeding on low growing shrubs and grasses that colonize during early to mid succession. (Kurta, 1995 Sharpe and Newman, 1996)

              Economic Importance for Humans: Positive

              Appalachian cottontails and eastern cottontails are similar in appearance and both are hunted for their meat and fur. (Sharpe and Newman, 1996)

              Economic Importance for Humans: Negative

              Appalachian cottontails slow the regeneration of disturbed areas in the environment by feeding on low growing shrubs and grasses that colonize during early to mid succession. Appalachian cottontails can also transmit the bacterial infection, Tularemia, to humans. (Kurta, 1995 Wilson and Ruff, 1999)

              Conservation Status

              Appalachian cottontails are found only in high elevations and are considered to be "near threatened" by the IUCN Red List. Population sizes are decreasing, and it is unknown why this species is limited to high elevations. Conservation status on the US Federal List is under review. (Bunch, et al., 2006)

              • IUCN Red List Near Threatened
                More information
              • IUCN Red List Near Threatened
                More information
              • US Federal List No special status
              • CITES No special status
              • State of Michigan List No special status

              Contributors

              Jeremy Cook (author), Northern Michigan University, John Bruggink (editor), Northern Michigan University, Gail McCormick (editor), Animal Diversity Web Staff.

              Glossary

              living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

              uses sound to communicate

              young are born in a relatively underdeveloped state they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

              having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

              an animal which directly causes disease in humans. For example, diseases caused by infection of filarial nematodes (elephantiasis and river blindness).

              uses smells or other chemicals to communicate

              an animal that mainly eats the dung of other animals

              ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates

              animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor the fossil record does not distinguish these possibilities. Convergent in birds.

              parental care is carried out by females

              an animal that mainly eats leaves.

              A substance that provides both nutrients and energy to a living thing.

              forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

              An animal that eats mainly plants or parts of plants.

              offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

              having the capacity to move from one place to another.

              This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

              the area in which the animal is naturally found, the region in which it is endemic.

              having more than one female as a mate at one time

              specialized for leaping or bounding locomotion jumps or hops.

              scrub forests develop in areas that experience dry seasons.

              breeding is confined to a particular season

              reproduction that includes combining the genetic contribution of two individuals, a male and a female

              uses touch to communicate

              that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

              uses sight to communicate

              reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

              References

              Bunch, M., R. Davis, S. Miller, R. Harrison. 2006. "Appalachian Cottontail" (On-line). Comprehensive Wildlife Conservation Strategy (South Carolina Department of Natural Resources). Accessed January 23, 2011 at http://www.dnr.sc.gov/cwcs/pdf/AppalachianCottontail.pdf.

              Kurta, A. 1995. Mammals of the Great Lakes Region . Ann Arbor, Michigan: The University of Michigan Press.


              Animal Diversity Web

              Caprimulgus vociferus is primarily found in North America, reaching from central and southeast Canada to parts of southern Mexico. Caprimulgus vociferus is not found in the western United States except for small, disjunct populations found in Arizona, Texas, and New Mexico. Whip-poor-wills are also found in Mexico and Central America during migration and winter. (Cink, 2002)

              Habitat

              Whip-poor-wills are usually found in dry deciduous or mixed woodlands and some pine-oak woodlands. They prefer to live in young second growth forests, especially dry woods near fields and other open areas. The degree of openness in the forest seems to be more important than the type of trees that make up the inhabited forest. Shade and sparse ground cover are also key elements of whip-poor-will habitat. During migration, they can be found in low canopy levels of their migratory forest. They have a tendency to inhabit lowlands but can be found at elevations ranging from sea level to 3,600 meters. ("Nighthawks and Nightjars", 2001 Cink, 2002 Ehrlich, et al., 1988)

              Whip-poor-wills are usually found in dry deciduous or mixed woodlands and some pine-oak woodlands. They prefer to live in young second growth forests, especially dry woods near fields and other open areas. The amount of openness in the forest seems to be more important than the type of trees that make up the forest. Shade and small amounts of ground cover are also important in whip-poor-will habitat. During migration they are also found in forested habitats. They are usually found in lowlands but can be found from sea level to 3,600 meters elevation.

              • Habitat Regions
              • temperate
              • tropical
              • terrestrial
              • Terrestrial Biomes
              • forest
              • scrub forest
              • Other Habitat Features
              • agricultural
              • Range elevation 0 to 3600 m 0.00 to 11811.02 ft

              Physical Description

              Whip-poor-wills are medium-sized nightjars. They range from 22 to 26 cm in length and from 43.0 to 63.7 g in mass. They have a large, flattened head, large eyes, small bill with enormous gape, and rounded tail and wings. The bill and iris are dark brown while the legs and feet are also brownish. Plumage is grayish brown with darker streaks and broad black stripes on the crown. There is a white stripe across the lower throat. The wings are covered in grayish brown feathers with tawny and buff colored spots and speckles. There is no seasonal plumage change. Females are almost identical to males with the exception of a thinner stripe on their throat and a more pale, clay color with brown for the outermost tail feathers, instead of white. Females are also slightly browner in general color. There is no known information on basal metabolic rates of whip-poor-wills. (Cink, 2002)

              Whip-poor-will hatchlings are completely downy with yellowish brown color. Juvenile males are similar in appearance to adult males, except the crown has black spotting instead of streaking. Outer primaries and outer tail feathers are also narrower and more tapered compared to adults. Juvenile females are similar to juvenile males except their outer tail feathers don't contain white. (Cink, 2002)

              In general, C. vociferus can be distinguished from other members of the Caprimulgidae family by the white band on its throat, its relatively small size, and its brownish color. Whip-poor-wills can be distinguished from Chuck-will's-widows by their smaller size, less reddish color, and smaller white markings on the tails of males. They are distinguished from common pauraques and common poorwills, which are larger, have longer tails, and have a broad white band across the primaries. Whip-poor-wills are separated from other nightjars by their paler, less reddish color. They are distinguished from other nighthawks by the lack of a white wing-stripe and smaller wings with white or buff tips on outer tail feathers. (Cink, 2002)

              Subspecies such as C. v. arizonae are larger, have longer tail feathers with more white on males, and darker tail tips on females. Caprimulgus vociferus oaxacae individuals are darker than the arizonae group with black spots on their crown and spotted breast. Caprimulgus vociferus chiapensis individuals are much darker and redder on top and bottom. Caprimulgus vociferus vermincularis individuals are paler, more reddish, smaller, and have fewer black spots on the scapulars. (Cink, 2002 Cink, 2002 Cink, 2002 Cink, 2002)

              • Other Physical Features
              • endothermic
              • homoiothermic
              • bilateral symmetry
              • Sexual Dimorphism
              • sexes alike
              • Range mass 43 to 63.7 g 1.52 to 2.24 oz
              • Range length 22 to 26 cm 8.66 to 10.24 in
              • Average length 25 cm 9.84 in

              Reproduction

              Caprimulgus vociferus is thought to be monogamous. There is little known about whip-poor-will courtship displays. Females may try to solicit the attention of males by strutting on the ground with a lowered head and outspread wings and tail. Females circle in different directions while producing a guttural chuckle. The male will respond by approaching the female and undulating his body up and down. The male may circle the female and she then undulates her body up and down and quivers her wings. If the female flies away, the male may not follow. The male may also try to approach the female by using a tail-flashing display. (Cink, 2002 Ehrlich, et al., 1988)

              Whip-poor-wills breed twice per year, from May through June, usually laying 2 eggs per clutch. They lay eggs on the ground usually beneath trees, bushes, or fallen trees branches near open areas. Most nests are depressions in leaves, pine needles, or bare ground. Eggs hatch after about 19 days. Time to fledging is about 17 days. Little is known about the age of reproductive maturity for whip-poor-wills but it is assumed that it one year of age, which is the average for the nighthawk and nightjar family. Whip-poor-will reproductive cycles are synchronized with lunar cycles to result in better moonlit nights when foraging to feed their young. ("Nighthawks and Nightjars", 2001 Cink, 2002 Ehrlich, et al., 1988)

              • Key Reproductive Features
              • iteroparous
              • seasonal breeding
              • gonochoric/gonochoristic/dioecious (sexes separate)
              • sexual
              • oviparous
              • Breeding interval Whip-poor-wills breed twice per year.
              • Breeding season Whip-poor-wills breed from May through June.
              • Average eggs per season 4
              • Average eggs per season 2 AnAge
              • Range time to hatching 17 to 20 days
              • Average time to hatching 19 days
              • Range fledging age 14 to 20 days
              • Average age at sexual or reproductive maturity (female) 1 years
              • Average age at sexual or reproductive maturity (male) 1 years

              Both male and female whip-poor-will adults incubate the eggs, starting with the laying of the first egg. Both sexes trade incubation duties from dusk until dawn. Both parents feed their young, beginning right after hatching. While one parent is finding food, the other is protecting the nest. Whenever the returning adult comes back to the nest, it regurgitates insects to both young. Young whip-poor-wills have been known to accept food from parents at 30 days of age. Whip-poor-wills are semi-precocial birds and have the ability to avoid predators without parental care. (Cink, 2002)

              • Parental Investment
              • precocial
              • pre-fertilization
                • provisioning
                • protecting
                  • female
                  • provisioning
                    • female
                    • male
                    • female
                    • provisioning
                      • male
                      • female
                      • male
                      • female
                      • provisioning
                        • male
                        • female
                        • male
                        • female

                        Lifespan/Longevity

                        Little information is known about the lifespan of whip-poor-wills. Tagged wild whip-poor-wills have been known to live up to 15 years. Most causes of mortality occur when birds are very young or as eggs. There is some competition with related species, such as Chuck-will's-widows for territorial space and for food that might impact their longevity. (Cink, 2002)

                        Behavior

                        Whip-poor-wills fly slowly and noiselessly. They usually glide and can take off nearly vertically. They waddle when they walk and can make short hops. They are nocturnal animals that move very little at dusk or dawn. They typically roost in tree branches close to the ground. Whip-poor-wills are generally solitary but may form small flocks during migration. (Cink, 2002)

                        Caprimulgus vociferus is a medium-distance complete migrant. Whip-poor-wills migrate to the southern tip of Florida, Mexico, and Central America in early September and October. They return to breeding sites from late March through May.

                        • Key Behaviors
                        • flies
                        • nocturnal
                        • motile
                        • migratory
                        • solitary
                        • territorial
                        • Range territory size 18000 to 111000 m^2
                        • Average territory size 51000 m^2

                        Home Range

                        Little is known about the home range but some have been known to have territory sizes up to 111,000 square meters. (Cink, 2002)

                        Communication and Perception

                        Caprimulgus vociferus is known for its three tone call, sounding like "whip-poor-will", for which it is named. The primary whip-poor-will call is usually given by males to establish territories. The "quirt" is a soft call that increases as the individual becomes more and more excited. It is usually used by wintering, territorial birds. A "growl" is a fluttering sound used when two territorial individuals aggressively meet. The "hiss" is a repeated loud call given in response to predators. The "cur" is a guttural chuckle, often given during courtship, or for nest exchanges and when moving to new sites. (Cink, 2002)

                        • Communication Channels
                        • visual
                        • acoustic
                        • Perception Channels
                        • visual
                        • ultraviolet
                        • tactile
                        • acoustic
                        • vibrations
                        • chemical

                        Food Habits

                        Whip-poor-wills use aerial foraging techniques to catch their prey and primarily feed on night flying insects. They also feed on some non-flying insects. Known diets consist of moths, mosquitoes, flying beetles, ants, grasshoppers, and crickets. They especially prey on moths. (Cink, 2002 Ehrlich, et al., 1988)

                        Predation

                        Most losses through predation are of eggs and young birds because ground nests are extremely vulnerable. Predators such as skunks, raccoons, coyotes, red foxes and snakes prey on the eggs and young. To protect their young, adult whip-poor-wills fake an injury by flopping on the ground several meters away from the nest in full view of the predator, called the "Broken Wing" display. This is performed until the predator is not in view of the eggs or young and the adult then displays on a perch above the ground. Whip-poor-wills are cryptically colored and nocturnal, protecting them from some predation. (Cink, 2002)

                        • Anti-predator Adaptations
                        • cryptic
                        • Known Predators
                          • skunks (Mephitis mephitis)
                          • raccoons (Procyon lotor)
                          • red foxes (Vulpes vulpes)
                          • coyotes (Canis latrans)
                          • snakes ( Serpentes )

                          Ecosystem Roles

                          Whip-poor-wills help to control populations of insects that they prey on. They also compete with other nightjars and nighthawks for habitat and food resources. (Cink, 2002)

                          Economic Importance for Humans: Positive

                          Caprimulgus vociferus is an insect eater, usually living near open, agricultural areas. It is likely that they help control insect populations that affect humans. Because whip-poor-wills are cryptic, nocturnal creatures they have no other known interactions with humans.

                          Economic Importance for Humans: Negative

                          There are no known adverse effects of whip-poor-wills on humans.

                          Conservation Status

                          Whip-poor-wills have a large global population, estimated at 2,100,000 individuals. Although the population seems to be declining, it is not expected to reach the threshold for population decline that would put it on the IUCN Red List of Threatened Species. This species has an IUCN Red List status of least concern. (Ekstrom and Butchart, 2004 Ekstrom and Butchart, 2004)

                          • IUCN Red List Least Concern
                            More information
                          • IUCN Red List Least Concern
                            More information
                          • US Migratory Bird Act Protected
                          • US Federal List No special status
                          • CITES No special status
                          • State of Michigan List No special status

                          Other Comments

                          Contributors

                          Tanya Dewey (editor), Animal Diversity Web.

                          Robert Duszynski (author), Kalamazoo College, Ann Fraser (editor, instructor), Kalamazoo College.

                          Glossary

                          living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

                          uses sound to communicate

                          living in landscapes dominated by human agriculture.

                          having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

                          an animal that mainly eats meat

                          uses smells or other chemicals to communicate

                          having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment being difficult to see or otherwise detect.

                          animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor the fossil record does not distinguish these possibilities. Convergent in birds.

                          forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

                          An animal that eats mainly insects or spiders.

                          offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

                          makes seasonal movements between breeding and wintering grounds

                          Having one mate at a time.

                          having the capacity to move from one place to another.

                          the area in which the animal is naturally found, the region in which it is endemic.

                          reproduction in which eggs are released by the female development of offspring occurs outside the mother's body.

                          scrub forests develop in areas that experience dry seasons.

                          breeding is confined to a particular season

                          reproduction that includes combining the genetic contribution of two individuals, a male and a female

                          uses touch to communicate

                          that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

                          defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

                          the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

                          movements of a hard surface that are produced by animals as signals to others

                          uses sight to communicate

                          young are relatively well-developed when born

                          References

                          2000. "Goatsuckers Whip-poor-will, Caprimulgus vociferus" (On-line). Georgia Wildlife Web. Accessed October 11, 2006 at http://museum.nhm.uga.edu/gawildlife/birds/caprimulgiformes/cvociferus.html.

                          2001. Nighthawks and Nightjars. Pp. 348-351 in C Elphick, J Dunning, D Sibley, eds. The Sibley Guide to Bird Life and Behavior . New York: Alfred A. Knopf, Inc.

                          Cink, C. 2002. Whip-poor-will (Caprimulgus vociferus). Pp. 1-20 in A Poole, F Gill, eds. The Birds of North America , Vol. 16 No. 620. Philadelphia, PA: The Birds of North America, Inc.

                          Ehrlich, P., D. Dobkin, D. Wheye. 1988. The Birder's Handbook . New York: Simon and Schuster Inc.

                          Ekstrom, J., S. Butchart. 2004. "The IUCN Red List of Threatened Species" (On-line). Accessed November 05, 2006 at http://www.iucnredlist.org/search/details.php/48656/summ.

                          Peck, G., R. James. 1983. Breeding Birds of Ontario Nidiology and Distribution Volume 1: Nonpasserines . Toronto, Canada: The Royal Ontario Museum.


                          A brief history of desiccation tolerance

                          The most ancient record recognizing the importance of the dry state in biology is probably that of Theophrastus of Lesbos around 370 BC. The Father of Botany taught in the Athenian school and described in details the conditions necessary to keep dry seeds alive and for how long they can be stored. The narrative translated by Sir Arthur Hort (1916) is as follows:

                          “[…] It appears that soil and climate make a difference as to whether the seed gets worm-eaten or not, at least they say that at Apollonia on the Ionian Sea beans do not get eaten in this way at all, and therefore they are put away and stored and about Cyzicus they keep an even longer time. It also makes a great difference to keeping that the seed should be gathered dry, for then, there is less moisture in it. […].

                          […] For propagation and sowing generally seeds one year old seem to be best those two or three years old are inferior, while those kept a still longer time are infertile, though they are still available as food. For each kind as a definite period of life in regard to reproduction. However, these seeds too differ in their capacity according to the place in which they are stored. For instance, in Cappadocia at a place called Petra they say that seed remains even for forty years fertile and fit for sowing, whole as food it is available for sixty or seventy years for that it does not get worm-eaten at all like clothes and other stored-up articles, for that the region is, apart from this, elevated and always exposed to fair winds and breezes […].”

                          Another example illustrating that plant desiccation tolerance was part of common knowledge comes from the use of Myrothamnus flabellifolia, a resurrection plant used in traditional medicine in Southern Africa (reviewed in Moore et al. 2007). In Zulu language and folklore, this bush is called ‘uvukwabafile’, which means “wakes from the dead”. This plant, probably the largest known desiccation-tolerant organism, was rediscovered in the early 1900 by FE Weiss. He was amazed by the so-called “miraculous” reviviscence upon rehydration of what appeared to be a dried, dead branch (Weiss 1906). FE Weiss was probably unaware that the first annotated desiccation-tolerant organisms were dried rotifers that resurrected in the presence of water (Keilin 1959 Tunnacliffe and Lapinski 2003), as observed by van Leeuwenhoek in 1702 using his invention of the microscope. Initially, however, van Leeuwenhoek did not think that they were alive in the dry state and was surprised that within an hour of them being wetted they were active (quoted by Alpert and Oliver 2002 Tunnacliffe and Lapinski 2003). The next 150 years after van Leeuwenhoek’s observation saw a vigorous debate between zoologists and philosophers who disputed each other findings—or beliefs—as to whether some organisms are able to survive desiccation and resurrect upon rehydration. This debate was fierce and is well documented in the literature (see references in Keilin 1959 Crowe 1971 Tunnacliffe and Lapinski 2003).

                          Perhaps, the first scientist to experimentally establish that life can exist in the dry state was Spallanzani who confirmed in 1776 that rotifers are desiccation tolerant following slow drying and can revive after 4 years in dry storage (quoted by Leopold 1986 Tunnacliffe and Lapinski 2003). Duchartre (1852) demonstrated that is was possible to dry immature seeds to a water content equivalent to that of mature seeds without killing them. He saw in this discovery a technological breakthrough to speed up the plant life cycle, but did not address the mechanisms of tolerance. The extraordinary stability of dry seeds started to be documented around 1850 (reviewed by Keilin 1959 Priestley 1986), although there was little understanding of the conditions necessary to keep them alive in the dry state. These first accounts of longevity led a visionary botanist, William Beal, to launch in 1879 a seed storage experiment with the intent of determining the length of time that seeds of some common plants would remain alive during storage in sealed vials. This study, which is still in progress, is probably the longest continuously monitored viability experiment (see the latest viability data in Telewski and Zeevaar 2002). An important milestone in the recognition of desiccation tolerance was the publication by Bernard (1878), the first scientist who noticed that desiccation tolerance was widespread among plants and animals. He demonstrated that removing water is an important factor in bringing the organism into a state of so-called “chemical indifference” and considered that desiccation-tolerant organisms belong to a different category of living things. Throughout the second half of the 19th century, experiments on desiccation tolerance were aimed at addressing one main question: whether or not life is a discontinuous process since no signs of life or metabolism could be observed in the dry state. Dry seeds were used, probably because they were a convenient material to obtain and survival was easy to monitor: if they survived, they germinated. The rationale of these experiments was to subject dry seeds to conditions known to arrest metabolism or to kill living organisms such as incubating them in pure oxygen or noxious gases (Romanes 1893) or at low temperatures (at −53 °C for several weeks De Candolle 1895) or by plunging them in liquid nitrogen whose method of production had just been invented (Brown and Escombe 1897). None of these treatments were effective in killing those seeds, which led to the suggestion that dry organisms truly represented a discontinuity in life.

                          The review by Keilin (1959) on anhydrobiosis stimulated the first studies aimed at unraveling the mechanisms of desiccation tolerance by leading researchers such SJ Webb, JS Clegg, JH Crowe and LM Crowe, mainly working on the brine shrimp Artemia. Using biochemical and biophysical approaches, these authors posited the role of polyols as a means to replace water molecules in the dry state (Crowe 1971 Crowe et al. 1992). In animals, yeasts and some resurrection plants (Fernandez et al. 2010), this was attributed to the disaccharide trehalose. Recent evidence obtained in anhydrobiotic nematodes shows that trehalose is absolutely required for their survival in the dry state (Erkut et al. 2011). Correlations between sugar content and desiccation tolerance in plants—first in pollens, and then seeds and additional resurrection plants (Hoekstra et al. 2001)—led to suggestion that sucrose and oligosaccharides were acting as surrogates of trehalose. The role of trehalose in particular received much attention in the popular press and even led to fantastic allegations (reviewed in Crowe 2007). Indeed, the sugar alone has proven to be remarkably useful in preserving biomolecules and even intact cells in vitro (Crowe 2007). From these observations and the publicity around the amazing protective effects in vitro, it was extrapolated in the literature that trehalose alone could confer desiccation tolerance. However, trehalose or non-reducing sugars alone are not sufficient to preserve whole, intact organisms in vivo (Ooms et al. 1993 Tunnacliffe and Lapinski 2003 Ma et al. 2005 Dinakar and Bartels 2013), suggesting the need of non-based disaccharide mechanisms.

                          Among non-based disaccharide mechanisms, the contribution of antioxidants to desiccation tolerance had already been suggested in the 60s by Heckly and collaborators, following studies on lyophilized bacteria that exhibited an oxygen-dependent accumulation of free radicals during dry storage (Heckly and Dimmick 1968). In the 70s, Bewley and collaborators, working on the desiccation-tolerant moss Tortula ruralis, suggested that repair mechanisms are important during rehydration from the dry state (Bewley 1979). Late embryogenesis abundant proteins (LEA) were discovered during the molecular characterization of cotton seed development by Dure et al. (1981) and their role in desiccation tolerance was first proposed by McCubbin et al. (1985) based on the physico-chemical characterization of the purified LEA Em protein from wheat germ. With the progress of sequencing technologies, LEA homologues were discovered in other desiccation-tolerant organisms, first in resurrection plants and pollens, then in microbes and more recently in animals. Finally, an important step forward in our understanding of survival in the dry state occurred in the mid-80s when Burke (1986) suggested that glasses could be formed from cell solutes like sugars in dry anhydrous organisms. “Biological glasses” was a concept borrowed from physics and physical chemistry where it was used to explain unusual thermodynamical properties of supercooled liquids. It was, therefore, proposed that glasses might act to fill spaces in a cell during dehydration and that their high viscosity prevents chemical reactions that require molecular diffusion (Buitink and Leprince 2008 Walters 2015).


                          10 TIMED ARTIFICIAL INSEMINATION PROTOCOLS TO SYNCHRONIZATION OF OVULATION IN BOS TAURUS TAURUS SUCKLING BEEF COWS

                          The aim of this study was to compare 3 methods for synchronization of ovulation in anestrous beef cows. The hypothesis of this study was to determine whether low doses of hCG has superior efficacy to cypionate to induce ovulation in anestrous cows and provide higher pregnancy rate in oestrus-synchronization programs. Synchronization of ovulation and conception rate to timed AI (TAI) were evaluated in anestrus Bos taurus taurus suckling beef cows 45 ± 15 days postpartum and with body condition score of 2.9 (1 to 5) maintained in a native pastured system in the south of Brazil. Females were evaluated with ultrasound on the Day 0 (D0) of the protocol (Day 0), day 8 (D8), immediately before TAI (D10), and 7 days after TAI (Day 17). All cows were synchronized with an intravaginal progesterone-releasing device (IPRD 0.75 g of progesterone, Prociclar®, Hertape Calier Animal Health, Juatuba, Brazil) and 2 mg IM of oestradiol benzoate (EB Benzoato HC®) on D0. On Day 8, the IPRD was removed and 150 μg of D (+) cloprostenol (Veteglan Luteolytic®), and 25 IU IM FSH/LH (Pluset®) were administered. Females of the EC (n = 84) group received 1 mg IM of oestradiol cypionate (EC Cipionato HC®). Females on D8 of the hCG (n = 81) group received 500 IU IM of hCG (Vetecor®, Hertape Calier) at the time of TAI. The females of the EC + hCG group (n = 83) received both treatments. All cows were submitted to TAI 54 h after withdrawal of IPRD. A part of the cows (n = 102) had the ovulation evaluated every 12 h from the withdrawal of IPRD [EC (n = 34), hCG (n = 34), and hCG + EC (n = 33)]. Statistical analysis was performed using SAS PROC GLIMMIX. The dominant follicle diameter (FD) on Day 8 (8.7 ± 0.2, 8.8 ± 0.2, 8.6 ± 0.2) did not differ between treatments EC, EC + hCG, or hCG (P = 0.79). However, the FD on D10 was higher (P = 0.001) for cows treated with hCG (12.9 ± 0.3) compared with cows from the EC (11.3 ± 0.2) or EC + hCG group (11.8 ± 0.2). The interval (h) between the withdrawal of IPRD and ovulation was lower (P = 0.01) for the hCG group, (71.2 ± 1.7) compared with the groups treated with EC or EC + hCG (76.6 ± 2.18 and 74.2 ± 1.65), respectively. The ovulation rate did not differ (P = 0.61) among the EC (85.2%, 29/34), hCG (91.1%, 31/34), or EC + hCG groups (90.9%, 30/33). Corpus luteum diameter (mm) was higher (P = 0.04) on D17 for the hCG-treated group (21.4 ± 0.3) compared with others treatments (EC = 19.1 ± 0.8 or EC + hCG = 20.4 ± 0.8). However, the plasma progesterone levels on D17 were EC = 2.0 ± 0.1, hCG = 2.4 ± 0.1, and EC + hCG = 2.3 ± 0.1 ng mL –1 (P = 0.19), and the conception rate on the 28th day after TAI (EC = 43.0% hCG = 47.0%, and EC + hCG = 48.8% P = 0.76) was also similar. The hCG determined smallest ovulation interval, but similar rates of pregnancy were observed with both treatments.


                          Abstract

                          To inhibit fertilisation by more than one sperm (a condition known as polyspermy), eggs have developed preventative mechanisms known as blocks to polyspermy. The block at the level of the egg extracellular coat (the zona pellucida in mammals, the vitelline envelope in non-mammals) has been well characterised in many different animal species and the block at the level of the egg plasma membrane is understood in some non-mammalian species. However, virtually nothing is known about the membrane block to polyspermy in mammalian eggs, despite data dating back 50–90 years that provide evidence for its existence. In the present review, we will discuss the background on blocks to polyspermy used by animal eggs and then focus on the membrane block to polyspermy in mammalian eggs. This will include a summary of classical studies that provide evidence for this block in mammalian eggs, assays used to study the mammalian membrane block and what has been elucidated from recent experimental studies about the cellular signalling events that lead to membrane block establishment and the mechanism of how the membrane block may prevent additional fertilisation.


                          Assorted References

                          …organ for habitat selection and mating, using the snout to make deliberate contact with the object being investigated. These animals have a narrow groove close to each nostril that connects the upper lip with the nostril. During nose tapping, fluid moves along the grooves by capillary action and is driven,…

                          …that is characteristic of the mating pattern of the species.

                          …off onto the female during mating, and this changes her wax chemistry so that she is no longer attractive. Females of the vinegar fly, Drosophila, lose their attractiveness after mating by secreting wax with a different chemical profile.

                          …different from their own thus, mating tends to occur between individuals with different MHCs. In order to detect different MHCs, an individual must be aware that a potential partner has a distinct smell. In mice the odour of the family in which they are reared becomes imprinted early in development.…

                          …also serve to coordinate the mating act. The range of a courtship signal should be small not only because the sender and receiver are close but also because the mating couple does not want to attract interlopers or predators. Therefore, in most cases, sounds, movements, and scents are low in…

                          Small populations suffer from inbreeding, an inevitable tendency of mating individuals in a small isolated population to be more closely related than they would be in a larger one. When population size is severely reduced, inbreeding may be the final insult that will…

                          …animals, behaviour that results in mating and eventual reproduction. Courtship may be rather simple, involving a small number of chemical, visual, or auditory stimuli or it may be a highly complex series of acts by two or more individuals, using several modes of communication.

                          Some mating displays evolve from food-giving behaviours the male bobwhite quail gives a food call and offers a tidbit to his potential mate. In many birds the food-giving behaviour is completely ritualized and proceeds without any exchange of food domestic cocks, for example, call and peck…

                          …engage in alternatives to random mating as normal parts of their cycle of sexual reproduction. An important exception is sexual selection, in which an individual chooses a mate on the basis of some aspect of the mate’s phenotype. The selection can be based on some display feature such as bright…

                          The total act of copulation is organized in the anterior part of the hypothalamus and the neighbouring septal region. In the male, erection of the penis and the ejaculation of semen are organized in this area, which is adjacent to the area that controls…

                          activity directed toward perpetuation of a species. The enormous range of animal reproductive modes is matched by the variety of reproductive behaviour.

                          …in pairs, nor is such mating practiced.

                          …this, the time of the mating season is clearly regulated, both with regard to the physiological condition of the animal and to the environmental conditions. The urge and capacity to mate depends on the ripeness of the gonads, male or female. In most animals, the reproductive glands wax and wane…

                          …acts as a breeding and mating cue, since it is produced in greater amounts in response to the longer nights of winter and less so during summer. Animals who time their mating or breeding to coincide with favourable seasons (such as spring) may depend on melatonin production as a kind…

                          …are best thought of as mating effort (that is, effort directed at increasing the number of offspring a male sires), because they are usually not available at the time of birth or hatching to benefit the offspring sired by the male presenting the gift. The male’s paternity and the number…

                          Animal behaviour

                          …when these fish defend their mating territories in the springtime against intrusions from rival male sticklebacks. The males differ from all other objects and forms of life in their environment in a special way: they possess an intensely red throat and belly, which serve as signals to females and other…

                          …to study the diversity of mating systems, specifically among various species of African antelope. In some species, such as the dik-dik (Madoqua), individuals are solitary and cryptic however, during mating season, they form conspicuous monogamous pairs. Others, such as the black wildebeest (Connochaetes taurinus), form enormous herds. During the breeding

                          …secondary sexual characteristics and female mating preferences in several taxa, such as Central American frogs (Physalaemus) and swordtail fishes (Xiphophorus). In the frogs, electrophysiological studies of present-day species indicate that females have identical auditory preferences regardless of the acoustic characteristics of the mating calls of the males. The most parsimonious…

                          …are fundamentally promiscuous, though such mating behaviour is heavily proscribed by the cultures into which individuals are born and reside. Indeed, theorists who wish to construct models of the emergence of hominin societies on the basis of extant ape societies seldom tackle the overriding fact that humans utilize a wide…

                          Arachnid

                          In most cases the male does not transfer spermatozoa directly to the female but rather initiates courtship rituals in which the female is induced to accept the gelatinous sperm capsule (spermatophore). During mating the sperm are transferred to a sac (spermatheca)…

                          The sexes occur separately in acarids i.e., there are both males and females. Most species lay eggs (oviparity), but in some parasitic ones the eggs hatch within the female, and the young are born alive. Many species also can reproduce by…

                          Mating in scorpions is preceded by a complicated and characteristic courtship initiated by the male. He first faces and grasps the female, using his pincers (pedipalps). Then the pair, directed by the male, moves sideways and backward in a dancelike motion called promenade à deux.…

                          In most groups, after a male has successfully approached a female and mounted her, he inserts his left pedipalp into the left opening of her genital structure and the right pedipalp into the right opening. In some primitive spiders (e.g., haplogynes, mygalomorphs) and a…

                          Insect

                          …elaborate of these experiments, 1,600 sexually receptive females were released around the periphery of a large enclosed area in the middle of which had been placed a cage containing one or more chirping males. Precise data concerning the frequency with which the females moved toward the cage were obtained by…

                          In some species mating is preceded by elaborate courtship by the male. In two families the male hovers in front of the female while displaying his brightly coloured wings, abdomen, or legs, sometimes in combination. To mate, damselflies join together in the “wheel” position and commonly fly in…

                          Dragonflies, like damselflies, exhibit a mating posture unique to the Odonata. The male and female contort themselves into the “wheel” position before sperm is transferred. Before and after mating, dragonflies often fly in tandem, with the male towing the female in flight using claspers at the tip of his abdomen…

                          …and finds the female for mating. For the male yellow fever mosquito, the most effective (i.e., apparently best heard) frequency has been found to be 384 hertz, or cycles per second, which is in the middle of the frequency range of the hum of females of this species. The antennae…

                          …functions that combine to control mating and egg production. Frequently, dorsal abdominal glands of the male aid in attracting the female to a mating position. In several cases, once a female has mated and an ootheca is being carried, mechanical pressure of the ootheca causes a stimulation to be transmitted…

                          To increase mating opportunities, males counterevolved a strategy of vibrational signaling that attracts both females and predators. During copulation the female floats on the water’s surface with the male mounted on her back this leaves the female more susceptible to predators than the male. The males’ strategy…

                          Mammal

                          Courtship is relatively simple among the social equids. The true ass is apparently exceptional. The partners are strangers when the first approaches are made and the female requires violent subjugation by the male, which bites, kicks, and chases her before she will stand for…

                          This is necessary if mating with closely related and coexisting species is to be avoided. Swans and geese cement the pair bond by a “triumph ceremony,” with mutual head waving and calling, typically when the male has driven off an intruder. Male sheldgeese have a puffing, strutting display. Their…

                          …predators, but ewes prefer to mate with dominant rams. Young rams cannot compete until their horns have reached full curl at seven or eight years of age. Bighorns can live 20 years or more, but life expectancy may be only six or seven years in populations that are reproducing rapidly.

                          …and females, old and young, mate and use a variety of sexual behaviours to promote social bonding. Female bonobos are sexually active for more of the time than their chimpanzee counterparts they bear offspring at roughly five-year intervals and resume copulating with males within a year of giving birth. Bonobos…

                          Whether the mating system is territorial or based on a male dominance hierarchy may be linked to phylogeny. The members of the subfamilies Caprinae and Bovinae, which appear to have separated from the main bovid line very early, are virtually all nonterritorial. For the rest, the Antilopinae…

                          Sexual behaviour starts early in cetaceans. Young dolphins engage in exploratory sexual behaviour involving their mothers and other members of the school. Self-stimulation is common in both sexes. Male cetaceans perhaps use their penises as a manipulation organ in much the same way that…

                          …however, initiate most of the mating.

                          Both sexes are polygamous and breed throughout the year, but females are usually restricted to the one or two adult males of their pride. In captivity lions often breed every year, but in the wild they usually breed no more than once in two years. Females are receptive to mating…

                          …to prevent other males from mating. There is also a dominant female that produces more litters than other females. Meerkats are unusual among carnivores in that the pups are raised with the assistance of adults other than the parents. In the wild, a female bears one or occasionally two litters…

                          Moose mate in September so that the calves may be born in June to take advantage of spring vegetation. The antlers are shed of the blood-engorged skin called velvet in late August, and the bulls are in rut by the first week of September. Rutting bulls…

                          Most mating takes place in the context of consortships that last 3 to 10 days and are correlated with ovulation. Subadult males often forcibly copulate with females at times other than during ovulation.

                          Courtship and mating take place in the water from late winter through spring timing varies with latitude, mating occurring earlier in the more northern parts of the range and later in the more southerly regions. Mating is a strenuous affair in one recorded session the male was…

                          …are both solitary except for breeding associations lasting one to six days. Pumas are usually silent, but during this time they emit long, frightening screams intermittently for several hours. Pumas breed throughout the year, with a summer peak in births at higher latitudes. The interval between births is about two…

                          …readiness of a tigress to mate is announced through vocalization and scent production. There is no fixed breeding season, though the preponderance of mating appears to occur in winter, with striped cubs being born after a gestation period of more than three months. The normal litter size is two to…

                          Two types of mating systems are observed in zebras. Like the horse, the mountain and the plains zebras live in small family groups consisting of a stallion and several mares with their foals. The females that form the harem are unrelated. The harem remains intact even when the…

                          Mating behaviour in animals includes the signaling of intent to mate, the attraction of mates, courtship, copulation, postcopulatory behaviours that protect a male’s paternity, and parental behaviour. Parental behaviour ranges from none to vigilant care by both parents and even by additional group members. Biologists…

                          Mating behaviour describes the social interactions involved in joining gametes (that is, eggs and sperm) in the process of fertilization. In most marine organisms, planktonic gametes are shed (or broadcast) into the sea where they float on the tides and have a small but finite…

                          As a result, mating is not a simple cooperative endeavour. On the contrary, male and female interests often conflict each step of the way, from mating to allocation of parental effort. The end result of these conflicts has been an extraordinary diversity of sexual ornaments, sexual signals, genital…

                          …is highly modified and in mating is autotomized (self-amputated) and left within the mantle cavity of the female. In the squids a much larger section of the arm may be modified often the suckers are degenerate and the distal half of the arm bears rows of slender papillae, although special…

                          …noted for an exceptionally flexible mating and territorial system that reflects food density. They may be monogamous, polygamous, or polyandrous. Where food is plentiful, one male may overlap the territories of two or more females. When it is scarce, females have larger territories that overlap with two or more males.

                          Mating (copulation) is very brief, often completed in a few seconds and usually following the reproductive molt of the female, when her exoskeleton is still soft. The eggs are fertilized as they are extruded from the oviductal opening on the sternum of the sixth thoracic…

                          …to different habitats or find mates by swimming when visual predators find it hard to see them. In some cases only one sex will emerge at night, and often that sex is morphologically better suited for swimming.

                          …whereas in some cephalopod species mating or egg laying appears to be rapidly followed by death effected by hormones.

                          …year and generally rejoins its mate of the previous year, unless the death of the latter forces it to choose another partner. This applies even to the emperor penguin, which is capable of finding its mate despite the absence of a nest and the large size of the colony.

                          …of the fairy prion, the mating season for the tuatara occurs. During this period, social interactions between tuatara increase. A male defends his territory by inflating his body, erecting the crest on his head and neck, and shaking his head. Close encounters between males result in a sequence of mouth-gaping…


                          In vitro fertilization as a tool for investigating sexual reproduction of angiosperms

                          In vitro fertilization (IVF) of isolated male and female gametes of flowering plants was first accomplished in the last decade. Successful isolation of male and female gametes, and culturing of in vitro zygotes to form new plants, is a prelude to the use of IVF for research into the cellular and molecular control of fertilization in higher plants and its application as a tool in biotechnology. Genes unique to male and female gametes and zygotes of higher plants, although currently incompletely characterized, are expected to permit direct molecular dissection of fertilization. By applying IVF and microculture to zygotes and endosperm obtained by both in vivo and in vitro methods, newly activated fusion products may be observed and manipulated in media where they are directly accessible to the techniques of molecular cell biology. IVF and zygote culture may also offer potential for creating new hybrid plants by fusing isolated gametes from different species to produce unique zygotes and ultimately plants that would be impossible to obtain using typical crossing techniques. Transformation and regeneration frequencies using IVF may also be high enough to avoid the necessity of adding controversial antibiotic and herbicide resistant genes to screen transformed products. This review describes advances using IVF in plant sexual reproduction and discusses its potential in the genetic improvement of flowering plants.

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