In order for a Male to be polygynous, it depends on the female’s temporal and spatial distribution. (Pg 1) 

• Temporal component: when females are fertile. All at once (harder to mate with all) or at different times.  

• Moderate asynchronous: not all females fertile at same time but close in time. Best strategy for males to reach the most females. 

• Synchronous if breeding and feeding grounds are separate in space. Females will be ready to mate once in mating grounds (therefore they’re all synchronous if they’re found there) (pg 3) 

Pinnipeds

• most synchronous. 

Sirenians

• least synchronous. Mostly in the warmer months but still will find some females fertile outside of “breeding season”. 

• Orca whales (killer whales) and sperm whales:

  • have long gestation periods so at lot of females are infertile because they’re taking care of a calf.

  • Some males will be unsuccessful for the breeding season but may still be successful later. 

• Mysticete:

  • cycles and migration routes are seasonal patterns. Therefore, their window for fertility is narrow (only fertile when traveling to breeding grounds). 

Spatial distribution (pg 4) 

• Spatial clustering: Females same place and at the same time  

• Pinnipeds birth on land (clustering) 

• Otariids: use foraging cycle. nurse pups and leave to forage then come back and so on (cycle).

• “Resource defense polygyny”  

  • Males are territorial, and other males try to take advantage and breed with some females.

    Territorial males try to defend borders so that all breeding rights are his. (Polygon shape are territories and dots are other males trying to intrude). 

• Otariids are more mobile and harder (more energy) for males to keep up with females (especially, multiple females) so territory guarding is more efficient. 

• Abrupt weaning:

  • Phocids: use fasting nursing strategies. Shorter window of time when females are clustered in space and then leave to eat and never come back.

• Female defense polygyny:

  • Males pick a cluster of females to mate with and move with the females (he will move to try to mate with her.)  

  • Phocids are bad at locomotion. (Both females and males) so its easy for males to keep up with females. 

• Scramble:

  • Mating sometimes happens in the ocean. Males wait just out of the beach and catch and mate as many females as he can. (This is after land breeding efforts have been exhausted). 

• Leks: miniature territory.

  • Do not have anything of value for females except the males. Males found close to each other, and all are displaying to attract the females. Females jump from lek to lek and mate with the best. (Pg 5) 

  • Walrus, males display at the surface of water and underneath. Also, use vocal display. 

• Resource defense (different to leks)

  • Sea otters: These territories have resources that females need. The quality of the kelp area that you control directly proportional to you mating success. (Rare in aquatic groups but sea otters are not fully aquatic). 

• Fully aquatic mating strategies: males do not use resource defense because resources are free moving (aka fish). 

Mysticete: 

• Humpback whales: use a variety of different strategies. Use strategies depending on age (experience) or body size. 

• May use lek strategies and it is hypothesized that their leks move. Males advertise by singing. 

• Females defense:

  • males (“escorts”) follow females that have a calf so that they form a relationship with the female and has first rights to her when the calf is weaned. He is not harming the calf. He just follows the female and calf. The male is not eating (fasting). 

• Contest (combat/conflict):

  • fast-paced chase with active combat. Inflate throat grooves before body slamming the other male. (Dangerous to be around the two males fighting).  

• NA right whales: use sperm competition. Have the largest testes about body size. Do not physically compete with other males. 

• Sirenians: manatees 

  • Scramble competition: travel from female to female to find female that are fertile. 

  • Contest (combat/conflict): males fight for access to females. Females tend to move towards shore to get away from males. 

Odontocete mating strategies: (pg 6) 

• Breeding asynchronous and have large ranges (move around a lot). So, for males it becomes hard to monopolize a single group of females. 

Female defense: 

• Mate guarding: since asynchronous, males can guard one female, mate, and then move to another and repeat the process.  

• Temporary coalitions: males work together to mate guard females. (Example lions). Usually males are closely related (inclusive fitness). Also, usually, the most dominant male gets mating rights. 

• Long-term alliances: males work together. With one female, one male gets to mate. With the next female, the next male 

Male mating strategies: bottlenose dolphins. (Pg 7) 

• Males test each other to understand what abilities the other male has. According to the outcomes of these tests, the males decide to form an alliance or not.  

• Alliance helps to coerce the female to mate by cornering into a beach. 

• Females can just reject the males by flipping upside down on the surface of the water. 

Different order alliance form: different alliances work with other alliances to form a larger number of alliances to work to mate or to fend off other alliances (second order alliance); 

• First-order alliance: a PAIR of males. 

• Herding females. Males defend females to have reproductive rights. 

• Bonds are stronger between first-order males (who spend more time together than apart) compared to second-order alliances.  

SJR alliance complexity: (pg 8) 

• 3 strategies:  

  • Only form a first-order alliance 

  • Thicker lines: stronger bonds (seen in second-order alliance) 

  • Example C: form Multiple second-order alliances (“more re-enforcement to call in to help” =more successful at mating and defense). Becomes complicated because who are your friends' friends with? So, you can’t be enemies with your friends’ friends. 

The potential for the male to mate with many females depends on the temporal (time when females are fertile) and spatial distribution of receptive females

• Polygynous male: Moderately synchronous females that are grouped together (spatially) are ideal for this strategy

• Temporal distribution

  • Pinnipeds: Most synchronous females (very tight window when all females are fertile)

    • Easy for males to monopolize females

    • Embryonic diapause contributes to the fact that the females are fertile within the same window.

  • Sirenians: Least synchronous

  • Odontocetes: More synchronous than sirenians, but less synchronous than pinnipeds

    • Lots of variation, but there is still a “peak” breeding time (when females are fertile)

    • Orcas

      • Long nursing periods (infertile when nursing consistently)

      • Can mate year round, but there are times in of the year where there are more receptive females (August-December)

    • Sperm whales:

      • Long nursing periods (infertile when nursing consistently)

      • 1 year, 4 month gestation period with no embryonic diapause. Possible this is a reason why there is a gap.

      • Gap in fertility between May-Jul. Fertile females mostly concentrated in fall and winter.

• Spatial distribution

  • Terrestrial birthing → Spatial clustering of breeding female pinnipeds

    • Easier for males to monopolize them

  • Resource defense polygyny: Males monopolize resources that females need to gain access to as many females as possible.

    • Otariids

    • Resource = beach

    • Females exhibit foraging cycle lactation strategy

    • Males defend sections of the beach against other rival males

    • Efficient at moving on land, making defending specific territories much easier for males.

  • Female Defense Polygyny: Males defend females against other rival males, moving with the females.

    • Utilized by land-mating Phocids (like northern elephant seal)

    • Females exhibit fasting lactation strategy

    • Phocids are poor at moving on land, so it’s difficult to patrol a territory to keep out rivals. Much easier to follow females (who are also moving slowly) around.

  • At-sea mating strategies

    • Phocids

      • Some ocean-mating species become fertile when they return to sea after finishing nursing their pup. Males wait for them offshore and try to mate with as many as possible (scramble competition strategy)

    • Walrus

      • Lek: Cluster of males in a certain area who advertise for mating partners (gives females a clustered group of males to choose from)

      • Males display on the surface and underwater. Will move cyclicaly from the surface to underwater (in an oval pattern) while making vocalizations to attract females.

    • Sea otters

      • Males use resource defense: Kelp beds

        • This strategy is relatively rare in sea-mating groups because a majority of resources are typically free-moving (like fish). Kelp is the exception because it is stationary.

      • Quality of kelp bed area correlates with male mating success. Male otters defend these territories against rival males.

  • Full aquatic mating strategies

    • Females are much more spread out

    • Mysticetes

      • Humpback whale strategies

        • Display (Lek?)

          • A traditional lek is a single area in space throughout the breeding period. Humpback whale “leks” move around day to day.

          • Females assess male songs 

        • Female defense

          • Males follow around a female(non-aggressively) prior to her fertile period likely as a means to form a “relationship” with her to strengthen his odds of mating with her when she is actually fertile. He will 

        • Contests (competition pods)

          • Multiple males are fighting each other while chasing a fertile female. Fast paced and aggressive strategy.

      • North atlantic right whales

        • Sperm competition

          • Largest testes to body size ratio in the animal kingdom

          • No aggression, just lots of mating. Males rely on health and quantity of sperm to increase reproductive success.

    • Sirenians

      • Range of strategies

        • Scramble competition - solitary roaming

          • Roaming around trying to find females that are fertile

        • Contests - periodic mating herds

    • Odontocetes

      • Breeding asynchrony + large ranges → difficult to monopolize a large number of females

      • Bottlenose dolphins

        • Female defense strategy

          • Mate-guarding

            • Mate-guard one female while she is fertile and then move to the next female

          • Temporary coalitions

            • Baboons: Solitary males mate guard a female

            • Lions: Multiple males (2-3) work together temporarily to mate-guard females. 

              • Males may take turns mating with the different females they guard

              • One may be dominant and mate with the females, but they could be related allowing for the other members to also have some indirect reproductive success

      • Long-term alliances

        • Seen in bottlenose dolphins

        • Multi-level alliances

          • First-order (pairs)

            • Used to mate-guard females, “herding” the females to locations where it will be easier to mate with her. Sometimes use aggression toward female to coerce her into mating, other times there is no aggression and it seems like a mutual agreement

          • Second-order 

            • Other first-order alliances may try to steal females that are being herded by other males. In this case, first-order alliances may call in another male alliance to help them defend their female.

            • Only seen in Shark Bay, Australia, and St Johns River, Florida

      • SJR Alliance complexity: bottlenose dolphins

        • 3 strategies

          • 1st order only

          • Exclusive 2nd order

            • Form 1st order and 2nd order alliances

          • Multiple 2nd order

            • Ex: SCTR and PLAT have multiple 2nd order alliances, so they have lots of males they can call in for help. 

            • Requires the need to know who your “friends” are “friends” with, which requires high cognitive abilities.