Population Abundance is at any point in time t is a direct result of the 4 primary population parameters or processes
Fecundity
Mortality
Immigration
Emigration
The elementary equation that describes this relationship is:
Fecundity: Average number of offspring (usually female) born per individual (usually female)
Natality: Average number of live offspring born to individuals that reproduce
Fecundity = Natality x proportion of population that gives birth
Estimate of Fecundity
Mark-recapture: Jolly-Seber open population method can be used if we assume no immigration
Estimates number of individual 'added' to the population
Estimates of Natality
Direct methods: Based on number of young observed. In some cases, this may be based on in utero counts.
Remember: the timing of counts may necessitate incorporation of survival
Counts in utero:
Counts after birth:
Indirect methods: Natality is inferred from some component of reproduction (e.g., clutch size and nest success)
Estimates of Proportion of Population Likely to Breed
Direct methods: Most methods for estimating proportion of breeders are based on field data and are often species specific (e.g., fecal hormones, lactation, etc.).
Survival rate = (1 - Mortality rate)
**Survival estimators generally arise from 3 types of data:
All animals can be relocated (known fate) and determined to have survived or died
Only survivors are encountered (e.g., capture-mark-recapture)
Only deaths are recorded (e.g., band recovery)
Known-fate Models
Kaplan-Meier method:
- Individuals in the population are monitored (e.g., via telemetry) over time
- Accommodates 'staggered' entry into the known population
- Animals may be 'censored' (i.e., leave the known population)
- Survival can change over time (due to harvest, seasons, etc.)
Survival is estimated as:
Capture-mark-recapture
Jolly-Seber method:
- Open population model (see Mark-recapture estimate of abundance)
- Accommodates 'staggered' entry into the known population
- Animals may be 'censored' (i.e., leave the known population)
- Survival can change over time (due to harvest, seasons, etc.)
- Assume NO emigration...
Survival is estimated as:
Band recovery
- Based on CMR methods
- Recaptured individuals are dead individuals recovered
Other methods:
Migration: A periodic mass movement of individuals from one place and climate to another.
Dispersal: The spreading or movement of individuals away from others.
Natal dispersal - dispersal from place of birth
Successful dispersal - dispersal that results in successful breeding in another population
Immigration: Dispersal into a population
Emigration: Dispersal out of a population
Important questions for population ecology:
Sources and Sinks in MetapopulationsDispersal and consequent establishment are often essential for metapopulation persistence
Population Sources: Net exporter of individuals.
Population Sinks: Net importer of individuals.
What is the effect of immigration and emigration on local population parameters (e.g., abundance, population structure)?
What effect does dispersal rates have on metapopulation dynamics (e.g., persistence)?
What are the genetic consequences of dispersal among metapopulations, subspecies, and species?
Because of difficulties in measuring dispersal, analyses of populations typically ignore dispersal, assume that it does not exist or hope that immigration and emigration cancel out.
Three approaches have been used including:
Observations of marked animals (e.g., telemetry, intensive observations, trapping) that can then be fit to a parametric model
Mark-recapture studies that can estimate losses or gains to the population between trapping occasions
Recent genetic techniques that can be used to infer rates of successful dispersal between populations
Open population models (e.g., Cormak-Jolly-Seber)
Tag-recovery studies: common in fisheries and ornithology
Genetic Approaches:
Fst: Method for estimating gene flow among populations
Assumption: The more genetic differentiation there is among populations, the less successful dispersal occurs among the populations
Assignment Tests:
Important
General Reviews:
Dublin, L. I., and A. J. Lotka. 1935. Length of life. A study of the life table. New York.
Farner, D. S. 1955. Birdbanding in the study of population dynamics. pp. 397-449 in A. Wolfson (ed.). Recent studies in avian biology. Univ. Ill. Press, Urbana.
Hickey, J. J. 1952. Survival studies of banded birds. U.S. Fish and Wildlife Serv. Spec. Scient. Rep., Wildlife No. 15:II + 177 pp.
Hill, J. A. 1936. United States life tables. U.S. Bureau of Census. VI + 57 pp.
Lack, D. 1954. The natural regulation of animal numbers (chapters 8 and 9). London.
Pearl, R. 1941. An introduction to medical biometry and statistics. 3rd ed. Philadelphia.
Trenerry, C. F. 1926. The origin and early history of insurance, including the contract of bottomry. London.
Some Studies on Mammals:
Eberhardt, L. 1960. Estimation of vital characteristics of Michigan deer herds. Mich. Dept. Cons. Game Div. Rep. 2282:192 pp.
Green, R. G., and C. A. Evans. 1940. Studies on a population cycle on the Lake Alexander area. J. Wildl. Manage. 4:220-238, 347-358.
Leslie, P. H., and R. M. Ranson. 1940. The mortality, fertility, and rate of natural increase of the vole (Microtus agrestic) as observed in the laboratory. J. Anim. Ecology 9:27-52.
Lord, R. D., Jr. 1958. Mortality rates of cottontail rabbits. J. Wildl. Manage. 25:33-40.
Murie, A. 1944. The wolves of Mount McKinley. Fauna of the U.S. Nat. Parks Series No. 5:XX + 238pp.
Pearl, R. and J. R. Miner. 1935. Experimental studies on the duration of life. XIV. The comparative mortality of certain lower organisms. Quart. Rev. Bio. 10:60-79.
Southern, H. N. 1940. The ecology and population dynamics of the wild rabbit (Oryctolagus cuniculus). Ann. Appl. Biol. 27:509-526.
Tyndale-Biscoe, C. H. and R. M. Williams. 1955. A study of natural mortality in a wild population of the rabbit, Oryctolagus cuniculus (L.). N. Zealand Jour. Sci. and Tech. B 36:561-580.
Some
Studies on Birds:
Austin, O. L. 1942. The life span of the common tern. Bird Banding 13:159-176.
Austin, O. L., Jr. 1951. The mourning dove on Cape Cod. Bird Banding 22:149-174.
Bellrose, F. C., and E. B. Chase. 1950. Population losses in the mallard, black duck and blue-winged teal. Ill. Nat. Hist. Surv. Bull. 57:56-74.
Farner, D. S. 1945. Age groups and longevity in the American robin. Wilson Bull. 57:56-74.
Hickey, J. J. 1952. Survival studies of banded birds. U.S. Fish and Wildlife Serv. Spec. Scient. Rep., Wildlife No. 15:II + 177pp.
Lack, D. 1943. The life of the robin. London.
_____. 1943a. The age of some British birds. Brit. Birds 36:193-197, 214-221.
_____. 1946. Do juvenile birds survive less well than adults?
Leopold, A., T. M. Sperry, W. S. Feeney, and J. S. Coterhusen. 1943. Population turnover on a Wisconsin pheasant refuge. J. Wildl. Manage. 7:383-394.
Nice, M. M. 1937. Studies on the life history of the song sparrow. Trans. Linn. Soc. N. Y. 4:VI + 247pp.
Paynter, R. A. 1947. The fate of Kent Island herring gulls. Bird Banding 18:156-170.
Fish
and Aquatic Mammals:
Barnaby, J. T. 1944. Fluctuations in abundance of red salmon, Oncorhynchus nerka (Walbaum) of the Karluk River, Alaska. U.S. Fish and Wildl. Serv., Fishery Bull. 50(39):235-295.
Eschmeyer, R. W. 1939. Analysis of the complete fish population from Howe Lake, Crawford County, Michigan. Papers Mich. Acad. Sci., Arts, Lett., 24(II):117-137.
Jensen, A. J. C. 1939. On the laws of decreases in fish stocks. Cons. Per. Intern. Explor. Mer., Rapp. Proc.-Verb. 110(8):85-96.
Laurie, A. H. 1937. The age of female blue whales and the effect of whaling on the stock. Discov. Rep. 15:223-284.
Raitt, D. S. 1939. The rate of mortality of the haddock of the North Sea stock. cons. Per. Intern. Explor. Mer., Rapp. Proc.-Verb. 110(6):65-79.
Ricker, W. E. 1945. Natural mortality among Indiana bluegill sunfish. Ecol. 26:111-121.
_____. 1949. Mortality rates in some little-exploited populations of freshwater fishes. Trans. Amer. Fish. Soc. 77:114-128.
_____. 1958. Handbook of computations for biological statics of fish populations. Fisheries Res. Bd. Canada Bull. No. 119:300pp.
Russell, E. S. 1942. The overfishing problem. Cambridge.
Wheeler, J. F. G. 1934. On the stock of whales at South Georgia. Discov. Rep. 9:351-372.
Invertebrates:
Corbat, P. S. 1952. An adult population study of Pyrrhosoma nymphula (Sulzer): (Odonata:Coenagrionidae). J. Anim. Ecol. 21:206-222.
Deevey, G. B., and E. S. Deevey. 1945. A life table for the black widow. Trans. Conn. Acad. Arts Sci. 36:115-134.
Dowdeswell, W. H., R. A. Fisher, and E. B. Ford. 1949. The qualitative study of populations in the Lepidoptera. 2. Maniola jurtina L. Heredity 3:67-84.
Edmundson, W. T. 1945. Ecological studies of sessile Rotatoria, Part II. Dynamics of populations and social structures. Ecol. Monogr. 15:141-172.
Jackson, C. H. N. 1939. The analysis of an animal population. J. Anim. Ecol. 8:238-246.
Moore, H. B. 1934. The biology of Balanus balanoides I. Growth rate and its relation to size, season, and tidal level. J. Mar. Biol. Assn., n.s. 19:851-868.
Pearl, R., J. R. Miner, and S. L. Parker. 1927. Experimental studies on the duration of life. XI. Density of population and life duration in Drosophila. Amer. Nat. 61:289-318.
Pearl, R., T. Park, and J. R. Miner. 1941. Experimental studies on the duration of life. XVI. Life tables for the flour beetle Tribolium confusum Duval. Amer. Nat. 75:5-19.
Analyzing
Banding Recovery Data:
Brownie, C., D. R. Anderson, K. P. Burnham, and D. S. Robson. 1985. Statistical inference from band recovery data -- a handbook. U. S. Dept. Interior, Fish and Wildlife Service Resource Publ. No. 156. Wash., D.C. 305pp.
Seber, G. A. F. 1973. The estimation of animal abundance and related parameters. Griffin, London. 506pp.
Anderson, D. R., and K. P. Burnham. 1980. Effect of delayed reporting of band recoveries on survival estimates. J. Field Ornithol. 51(3):244-247.
Anderson, D. R., A. P. Wywialowski, and K. P. Burnham. 1981. Tests of the assumptions underlying life table methods for estimating parameters from cohort data. Ecology 62(4):1121-1124.
Anderson, D. R., K. P. Burnham, and G. C. White. 1985. Problems in estimating age-specific survival rates from recovery data of birds ringed as young. J. Anim. Ecol. 54:89-98.
Burnham, K. P., and D. R. Anderson. 1979. The composite dynamic method as evidence for age-specific waterfowl mortality. J. Wildl. Manage. 43(2):356-366.
Conroy, M. J., and B. K. Williams. 1984. A general methodology for maximum likelihood inference from band-recovery data. Biometrics 40(3):739-748.
Mardekian, S. Z., and L. McDonald. 1981. Simultaneous analysis of band-recovery and live-capture data. J. Wildl. Manage. 45(2):484-488.
Nelson, L. J., D. R. Anderson, and K. P. Burnham. 1980. The effect of band loss on estimates of annual survival. J. Field Ornithol. 51(1):30-38.
Nichols, J. D., S. L. Stokes, J. E. Hines, and M. J. Conroy. 1982. Additional comments on the assumptions of homogeneous survival rates in modern bird banding estimation models. J. Wildl. Manage. 46(4):953-962.
Pollock, K. H., and D. G. Raveling. 1982. Assumptions of modern band-recovery models, with emphasis on heterogeneous survival rates. J. Wildl. Manage. 46(1):88-98.
White, G. C. 1983. Numerical estimation of survival rates from band-recovery and biotelemetry data. J. Wildl. Manage. 47(3):716-728.
Revised: November 08, 2010