Question

You have become concerned about the practice of setting up feeding stations for feral cats. You really like cats, out research links large populations of feral cats to high mortality of songbirds, small reptiles and amphibian, as Teral cats often utilize these as a food source Community advocates for the feeding stations insist that the cal populations are stable and not a problem. You find a researcher who has been collecting data on populations of teral cats (often called community cats). They recorded data on the populations on a regular basis for many years, and recorded the number of kittens produced each year, and recorded that at the end of the year. The data are summarized in 3-year increments, and the kittens represent any kittens recorded in the previous 3 years. Please use the data collected to construct a life table. What type of life table will this be? How do you know? Start of study (year 0): 96 kittens were monitored. 3rd year of study: 25 of the cats remained. There were 115 kittens. 6th year of study: 18 of the cats remained. There were 74 kittens. 9th year of study: 12 of the cats remained. There were 53 kittens. 12th year of study: 6 of the cats remained. There were 36 kittens. 15 year of study: 1 of the cats remained. There were 6 kittens *Note, individual cats in a cohort were counted at the beginning of the timespan, while the total number of kittens produced during that entire timespan was recorded at the end of that timespan 1. Use the data collected to fill in the cohort, H. and be values in the life table below. Cohort (x) b m 2. Calculate survivorship (1) for each cohort and input this on the table. (review the equation list if you can't recall how to calculate 1) 3. Graph survivorship below (remember, graph on a log scale) 1.0 suvivorship (log10 lx) 0.0 0 3 9 12 15 6 Age

Answer 1

cohort	nx	d(death)	lx= nx/n0	bx	mx=d/nx
0 year	96	96-25= 71	1	0	0.739
3year	25	25-18= 7	0.026	115	0.28
6year	18	18-12= 6	0.187	74	0.33
9year	12	12-6= 6	0.125	53	0.5
12year	6	6-1= 5	0.0625	36	0.83
15year	1	1	0.0104	6	1

answer of the question 1 and 2 is in the table .

lx is calculated and is in the table

answer no 3: type iii survivorship curve

  

type iii survivor ship curve ploted according to the value of the lx y-axis= 1x X-axis = age 9 12 15

answer no 4: mortality rate is higher in the early age after birth hence survival will be very low in the early age and with age mortality decreases or no of death reduces.

and the birth rate also reduces with age .

the reproduction rate decreases