Where to live?

1. Where to live? BIOL 3100

2. Mid-term • Will cover everything up until Monday (21st), including papers we discussed on Fridays up to Week 5 (meerkats) • ~15-20% fill in the blank/multiple choice/one-word-answer • ~60% short answer • ~20% essay

3. Example Questions Fill in the blank: ________ is a signal from one individual to another; also referred to as a releaser Short Answer: Work on satin bowerbirds by Nicholls and Goldizen suggested that elements of vocal signals (songs) can be influenced by the environment. Explain the evidence provided to support that claim. Example of a previous essay question: Essay: How do corticosterone levels (both baseline and acute response) in American redstarts during the non-breeding season in Jamaica ultimately relate to reproductive success in Canada during the subsequent breeding season?

5. Least Terns have specific breeding requirements – namely, open, sandy beaches

7. By understanding the species’ habitat requirements, we can create new beaches or cordon off parts of beaches. The result: increased nesting success.

8. Caspian Tern relocation on the Columbia River - Management decision to reduce the number of juvenile salmonids being consumed

9. How do animals figure out where a “good” place to breed is?

11. Nelson’s sharp tail sparrow Bobolink

12. Nelson’s sharp-tailed sparrow – promiscuous, less social Bobolink – polygynous and gregarious Hayfield & Rough Cover

13. Definitions • Inadvertent social information (ISI) 2 Types: 1)Public information (PI) – number of young produced 2)Location cues (LC) – animals present • PI only works if breeding is asynchronous

14. Objectives and Hypothesis Objective: To determine whether location cues (and when those location cues are present) affect breeding site selection. If so, can poor location cues cause birds to choose unsuitable breeding sites. Hypothesis: Bobolinks (the more social bird) will be more affected by inadvertent social information (ISI) than Nelson’s Sharp Tails (the less social bird) in breeding site selection.

15. Methods Set up decoys and speakers in plots in unoccupied rough cover and hayfields (Location Cues) At the end of the first breeding season At the beginning of the subsequent breeding season

16. Bobolink, but not sparrow settlement influenced by ISI

18. Difference between first time breeding males and experienced males • First time breeders were “tricked” into settling on poor quality sites (rough cover) • Adult males used previous experience to select their breeding ground • Implies use of past experience/memory in adults • Highlights importance of social interaction for first time males

19. When to stay and when to go?

20. When a honey bee colony gets too large, the colony will split in two. The old queen will eventually leave with half her worker force, fly off in a swarm, and leave the old hive and remaining workers to a daughter queen. Question: How do they find and decide upon a new place to live? In this picture, half a colony huddles in a swarm on a tree branch waiting for scouts to bring back information on new nest sites

21. Over several days, scout workers search for chambers in the ground, cliffs, or hollow trees. When sites with a 30-60L capacity are discovered, the bees return and perform a dance back at the swarm, communicating information about the location of a potential new home. Other workers may be sufficiently stimulated to fly out and see the spot themselves. If it is also attractive to them, they will dance upon their return and send still more workers out to the area. Typically, only make a few trips out to a spot and dance for shorter periods each time before giving up. So, for a site to be attractive enough to build up a population of advertisers, it must have a recruitment rate that exceeds the drop-out rate.

22. Eventually, many (or all) of the recruiters will be advertising the same location, leading to tons scouts going to the same location. When bees encounter several dozen others coming from the same site, they begin piping, initiating dispersal to the new site

23. Are there costs to dispersal?

24. Lots of variation in amount of movement exhibited by ruffed grouse

25. Some birds spent months in the same location (A), while others moved around substantially). Alas, being in a new, unfamiliar location boosted the risk of being killed by a hawk or mammal at least threefold. So, why disperse?

26. One possibility is avoidance of inbreeding depression. Many taxa exhibit similar patterns with differences in dispersal distances between males and females (e.g., in most birds females generally disperse further than males)

27. There are clear costs to inbreeding. In oldfield mice, inbred mice survival is about half that of outbred mice. Even if they survive, reproduction is much lower in inbred motheers.

28. -Another potential reason for male dispersal in mammals: avoiding getting beaten up. -When new mature males move into a pride, subadults are evicted or disperse on their own -Advantage to females being sedentary: familiarity with hunting grounds, assistance from their mothers -Advantage to males dispersing: mating with non-relatives

29. Sometimes you really want to get away…. Migration involves breeding site selection, stopover site selection, and non-breeding site selection