Balancing Human Demands and Conservation in Natural Resource Harvesting

1. Human demands versus conservation in the harvesting of natural resourcesAbalone poaching is illegal

2. Human demands versus conservation in the harvesting of natural resources Oysters need to be a specific size before it may be harvested

3. Human demands versus conservation in the harvesting of natural resources During 2010 more than 300 rhino’s have been pouched and killed for their horns in South Africa. The sad truth is that a rhino is worth more dead than alive. A rhino horn is valued at $20 000 (R140 000) per kg and a rhino horn weigh up to 5 kg. Currently a live rhino is sold at R130 000 – R300 000. 678 rhino’s were killed in SA since 2000

4. Social organisation enhance survival of species Animals that live in herds, schools, swarms, and flocks typically give up on their individual defences because they pursue another survival strategy. If you are a member of a herd, you do not need to run faster than your predator; you only need to run faster than the slowest member of your herd. The individual defence IS forming the herd where the weak are daily sacrificed to earn the others one more day of untroubled life, until it is their turn. It is creepy to watch video footage of lion hunting the antelopes: after a brief chase, the herd is standing still and staring at their member being eaten alive, chewing their cud. That's what herd is about.

5. Herds of wildebeest

6. School of fish

7. Some Predators form packs as an efficient hunting strategy like wild dogs

8. African wild dogs form packs of up to 40 members, each with a dominant breeding pair that remain monogamous for life. These gregarious animals are co-operative hunters, relying on sight rather than smell to pinpoint their prey. Hunts tend to occur at dawn and dusk, but on occasion the dogs will venture out if there is a full moon.

9. They chase until their prey tires, reaching speeds up to 55 kmph, and sometimes disembowelling prey while it is still running

10. African wild dogs live in packs of 6 to 20. The aggression exhibited towards prey is completely nonexistent between members of the pack and there is little intimidation among the social hierarchy. Their large range of vocalizations includes a short bark of alarm, a rallying howl and a bell-like contact call that can be heard over long distances. Elaborate greeting rituals are accompanied by twittering and whining. The entire pack is involved in the welfare of the pups, which are born in thick brush or in a den.

11. Sharks also hunt in groups

12. Group hunting improves efficiency. By hunting in groups a predator can kill larger animals than a single animal can kill

13. Animals with dominant breeding pairs- the giant otter Giant otters live in groups with one breeding pair. There is one dominant female in the group She has many offspring and is also the top fish catcher and the leader of the hunt.

14. Animals with dominant breeding pairs – Lions The advantages of dominant breeding pairs are: - offspring are cared for by many members of the group - dominant males and females are usually the strongest and most efficient members of the group, their genetic material will be carried to the next generation

15. The Southern ground hornbill The Southern ground-hornbill occurs from Kenya to southern Africa, living in a wide range of grassland, savannah woodland habitats. In South Africa, it is listed as Vulnerable, with an estimated population of just 1500-2000. It eats a wide range of food, especially animals, such as grasshoppers, frogs, mongooses and bird nestlings. It is a monogamous, cooperative breeder, with a group consisting of a dominant breeding pair and 0-9 helpers, who are usually either adult males, or juveniles from previous breeding seasons. It lays 1-2 eggs, which hatch in the sequence laid, meaning that the one chick is 3-14 days older than the other chick. The younger chick is unable to compete for food with its older sibling, and dies of starvation when it is rarely 3-4 weeks old. Current conservation measures include hand-rearing of the otherwise redundant second born chicks, captive breeding and reintroduction.

16. Dominant breeding pairs - meerkat Meerkats are facultative monogamous, which means that they breed with only one other member of the opposite sex. The female does not depend on the male for help raising the pups. She depends instead on kin and non-kin helpers. Cooperation in meerkat breeding is obligate because the breeding female cannot reproduce and raise offspring without help. Subordinate meerkats occasionally breed, but the dominant pair is always responsible for the majority of reproduction.

17. The alpha pair mates for life, though life span is limited by predation. Turnover in the dominant male position is higher than in females because males are more likely to leave the territory, and meerkats off of their territory are likely to be preyed upon. The mating pair shares little or no relatedness Availability of resources limits meerkat breeding. Rainfall triggers breeding because rain increases plant life which in turn increases the population of arthropods that serve as meerkats’ prey. In fact, reproductive success for a band as a whole depends directly on the amount of rain during the rainy season Because rainfall is unpredictable, breeding meerkats must have a mate at all times so that they don’t miss any breeding opportunities. If they had to spend part of the rainy period wooing a mate, they would run the risk of breeding too late into the season. The rain and the corresponding increase in arthropod abundance would end before the critical period of offspring growth, or even before the birth of the offspring. Reproduction also depends on the presence of helpers. Meerkats are monogamous because there are only enough helpers for one litter. With only one litter, there can be only one breeding female, and competition for the position results. The breeding female has her choice of males, and she chooses the one with the best genes. He proves himself to her by competing for and attaining the alpha male position.

18. Bees live in a colony with division of labour There is one queen to each colony, and she is much larger in size than the other bees. Her main task is to lay eggs. Reproduction can take place only by means of the queen, and no other females are able to mate with the drone males. In addition to laying eggs, the queen also secretes important communicative substances that maintain the unity of the colony Honey bee eggs hatch regardless of whether they are fertilized. Drones develop only from unfertilized eggs. Unfertilized eggs are haploid in origin, which means that they contain only 16 chromosomes from their mother. Honey bees are a haplo-diploid species, in which drones have haploid cells and workers and queens have diploid cells

19. The drones are larger than the female workers, though they lack stings and the necessary organs to collect food for themselves. Their only function is to fertilize the queen. The worker bees perform all such other tasks that you might imagine, including making the waxen combs in the hive, gathering food, producing royal jelly, regulating the temperature in the hive, cleaning it of debris and defending it

20. The workers (females) collect pollen and nectar every day

21. Some pollen collect in a packet around their legs

22. Honey is stored to feed the developing embryos

23. Workers have a special wagging dance with which they communicate with other workers on the distance and direction of food sources

24. Division of labour among members of a colony, e.g. an ant colony Sociality is more advanced in bees, ants, and termites. As a rule, only one female (a queen) lays eggs in a colony, and numerous workers are sterile. Workers are involved in other functions like construction, defence and taking care of juveniles. They often have a division of labour and corresponding morphological differences.

25. Termites with different members and division of labour This picture shows some forms (casts) of termites. Social insects have very complicated behaviour. Their success largely depends on coordinated actions of many individuals. For example, leaf-cutting ants have underground fungus gardens. Ants bring foliage to this garden and collect fungus for food. This is insect agriculture!