1. Group : 10
Conservation Biology
Bsc 2076-2080 (A)
Group members
Byanjana Sharma
Biva Singh
Gaurav Rimal
Kishor Kumar Mahat
2. Reproduction
It is a process by which living organism give rise to new
offspring.
Reproduction is the only process for continuity of life on
earth.
Types of Reproduction
Sexual Asexual
3. Asexual reproduction
It involves the production of offspring without the
fusion of gametes from two parents.
It produces genetically identical offsprings.
Binary fission, Budding, Fragmentation etc. are
common among simpler organisms like bacteria, fungi
etc.
Parthenogenesis can be found in some reptiles, fishes,
birds, wasps etc.
4. Parthenogenesis
Parthenogenesis is the type of asexual reproduction
involving the development of embryo from an
unfertilized egg.
It is not common in isogamous species.
Types :
Arrhenotoky : produces male
Thelytoky: produces female
Deuterotoky: produces male without fertilization and
produces female by fertilization
5. Parthenogenesis in bees
Honey bees usually maintain
colonies by sexual reproduction
but parthenogenesis is also
found to occur under special
circumstances.
Male are haploid and females
are diploid. So, males can be
produced by parthenogenesis
whereas the female is produced
by mating.
Queen bees produce a
pheromone which activates the
Anarchy gene (plays to
deactivate ovaries) in worker
bees. So as long as there's a
queen in the colony, worker
bees will remain sterile.
6. Parthenogenesis in Komodo
dragon
Komodo Dragons perform sexual as well as asexual(
parthenogenesis) reproduction depending on the
environment ( habitat with or without opposite sex
individuals).
7. Parthenogenesis in Crocodile (
recent case)
Scientists have discovered that female American
crocodiles can reproduce by parthenogenesis.
The newest case was found in an 18-year-old crocodile
at Parque Reptilandia in Costa Rica.
8. Sexual reproduction
It involves the production of offspring with the fusion
of gametes from two parents.
It produces genetically unidentical offsprings and is
basis of gradual evolution.
9. Mating System
A mating system is a pattern of
male–female pairings
• The mating system is an
important component of the
social system in that it
influences the size,
composition, and kin structure
of groups of interacting
individuals.
- Males and females differ
greatly in the investment each
makes to reproduce, and may
therefore approach mating
with differing strategies.
11. Monogamy
Monogamy refers to the pair bond between two
individuals of same species, typically of opposite sex,
who mate and reproduce only with eachother.
It occurs in canids like wolves, in eagles, gibbons, etc.
Serial monogamy is when an individual mates with
only one partner in one breeding season but changes
partner in another season.
12. Monogamy
From a conservation point of view monogamous
parents both take part in raising offsprings. Hence
they have higher chances of raising young ones
successfully.
For example in cases of birds like eagles, both parents
hunt and search for food to feed their young ones.
14. Polygyny
Polygyny in animals is a mating system in which one
male lives and mates with multiple females, but each
female only mates with that male.
It is most common in mammals and occurs when there
is abundance of resources and females can raise young
ones without male parents.
Types: Resource Defense polygyny, Harem, Leks
15. Resource Defence Polygyny
In resource defence polygyny, individual males
compete and form territories centered around
resources that are necessary for successful mating. And
group of females are attracted towards the resources.
16. Harem
In harem a group of females is defended by a single
male.
Males compete to take control of a group.
Initially females my associate in a group for group
defense, or they may be herded together by a male.
17. Leks
A lek is a mating system where a male (or a few males)
tries to attract female mates.
Males form leks because they attract more females
than isolated males.
Males compete to be in the centre of lek while females
choose dominant male i.e. Male at the centre.
Eg: Sage Grouse, Birds of paradise.
19. Polygyny
Polygyny can help improve genetic quality by allowing
females to choose males with good genes and high
resources.
Males benefit by increase in reproductive success due
to access to number of mates. Females also benefit by
association and mating with a strong male.
But polygyny may have negative effects due to
inbreeding depression, infanticides, etc.
21. Polyandry
It is a mating system in which a single female mates
with multiple males.
It helps female ensure reproductive success by
providing her with multiple mating options.
For eg: Honey Bees, Crickets, Emu etc.
Types: resource defence polyandry, cooperative
polyandry.
22. Resource Defence Polyandry
In Spotted Sandpiper, female controls resources which
in turn controls male mating associations.
23. Cooperative Polyandry
In this case all males in the group copulate with the
female and also take part in brood provisioning.
Galapagos Hawks exhibit cooperative polyandry.
In Saddle Backed Tamarin, the father (male) invites
another male to join the group and after the offspring
are established one of the males gets kicked out of the
group.
24. Polygynandry
Some mating system have bonding between loseer
males and females. It allows them to live together and
be less concerned about mate compititions.
Multiple females and males mate with eachother and
multiple males may take part in brooding offsprings of
a single female.
It is advantageous from female perspective as it creates
parental confusion and decreases infanticides and also
multiple male take part in brooding of offsprings.
25. Promiscuity
There is no pair bonds.
Males and females, although sometimes choosy, often
seem to mate randomly.
It occurs in species whose environmental conditions
are unpredictable.
It is beneficial to one or both sexes as it increases their
chance of successful reproduction.
Eg: Penguins, Hyenas, Sloths, etc.
27. Courtship displays
It is a set of display behaviour, in which an individual,
usually male, tries to attract a mate, and the mate
exercises choice based on the display.
It includes ritual movement (dances), vocalization,
mechanical sound production, display of beauty,
strength, etc.
28. Territory defense
Male establish and defend territories to attract
females.
They may display aggressive behaviours towards rival
males to protect their territory and prevent them from
mating with females.
This behavious is observed in various animals,
including birds, fish and mammals.
29. Nupital Gifts
It is a material presentation ( food offerings, male body
parts, salivary gland secretions, etc) from donor to
recepient during sexual intercourse in order to
improve reproductive fitness of donor and even
recepient.
31. Lekking
Aggregrate of males gathered to engage in compititive
displays and courtship rituals.
32. Sexual dimorphism
In many species, males and females exhibit distinct
physical differences known as sexual dimorphism.
It could be difference in size, colour or presence of
special features. It is associated with attracting mates
or competing for mates.
Eg: antlers of male deer.
34. Mating Systems and conservation
Mating systems are variety of strategies to achieve
reproductive success developed as solutions to
complex evolutionary problems.
35. References
Krasnec, M. O., Cook, C. N. & Breed, M. D. (2012)
Mating Systems in Sexual Animals. Nature
Education Knowledge 3(10):72
Watts, P., Buley, K., Sanderson, S. et
al. Parthenogenesis in Komodo dragons. Nature 444,
1021–1022 (2006). https://doi.org/10.1038/4441021a
