A method widely used in order to measure populations of species is that of mark, release and recapture. Species that are small such as insects and mammals are often difficult to count therefore population numbers of such species are hard to establish. Due to the difficulty in this population estimates are made through what is known as the Lincoln Index (Chapman and Reiss, 2009). The method is carried out through capturing a number of individuals which are then marked so that they can be recognised again if they are recaptured after the initial release. The original marked individuals may be recaptured whereby the proportion of marked to unmarked individuals can then be calculated to estimate the population size through the following equation (Chapman and Reiss, 2009). N= CM R Whereby N refers to the whole population, C is the number of individuals captured, M is the number of individuals marked and R is the number of individuals released. 2.6.4 Counting Individual Species There are generally three different methods for counting individual species, with these being direct and indirect counting, along with look-see counting (Bibby et al, 1993). Direct counting involves the counting of all visible birds from a suitable vantage point whereby the birds are easily distinguished; for example waders breeding on a small island (Bibby et al, 1993). Factors can influence the results of this method which may impact upon the quality of the results. As Bibby et al (1993) examines accuracy can be affected by those undertaking counts with the naked eye or with binoculars. Indirect counting differs from direct as it relies upon counting signs of bird activity such as droppings, this however may only be useful where species live in burrows (Bibby et al, 1993). An example of this would be that of the Manx Shearwater whereby on the Island of Rum in the Inner Hebrides of Scotland they make their burrows in order to raise their young (Butt, 2012). It can however be argued that the number of droppings only indicates bird usage rather than population numbers (Owen, 1971).
Nest Number Number of chicks predated Un-hatched eggs Number of dead chicks found Number of chicks ringed 1 2 - - 2 - - -- 2 3 - 1 1 - 4 2 - - - 5 2 - - - 6 - 1 - 1 7 - - - 2 8 2 - - - 9 - - - 2 10 2 - - - 11 - 1* - - * Nest 11 was not found however only one juvenile was witnessed in flight; it is presumed that the second
when inspecting. Turtle Dove Risk of desertion when laying. Owl Risk of desertion when laying. Also, eggs can also chill when female off, so visits best in late afternoon. Owl Sensitive to disturbance during site selection and early incubation. Grasshopper Warbler Risk of trampling when searching nest site. Wood Warbler Risk of trampling when searching nest site.
Chiffchaff Risk of trampling when searching nest site. Willow Warbler Risk of trampling when searching nest site. Jay Sensitive to disturbance when laying and incubating. House Sparrow Risk of desertion when laying. Tree Sparrow Risk of desertion when lying. Bullfinch Sensitive to disturbance when building. Hawfinch Sensitive to disturbance when
and original signature 2.2 Co-workers: names and positions [e.g. student] Forestry Commission: Jim Stewart (Wildlife Ranger) 3 External collaborators 3.1 List external collaborating bodies 3.2 Provide evidence of any ethical approvals obtained [or needed] by external collaborators 3.3 Indicate whether confidentiality agreements have been or will be completed Read any associated procedures and guidance or follow any associated checklist, and delete, Yes or No, for each characteristic in A) to F) below. If you respond No, then in your judgment you believe that the characteristic is irrelevant to the activity. If you respond Yes, then you should provide relevant documentation [including ] with the application, and cross-reference to it, e.g. A2 or B9. Use reference numbers of standard forms, protocols and approaches and risk assessments where they exist. Does the activity involve or to unfamiliar places? If Yes: Does the activity involve field work or leaving the campus [e.g. ]? Does the work involve a ‘party’ of participants or ? Does the activity involve children visiting from A) Yes Yes Yes No B) Does the activity involve humans other than the investigators? If Yes: Will the activity involve any external organisation for which separate and specific ethics clearance is required (e.g. NHS; school; any criminal justice agencies including the Police, CPS, and Prison Service)? – start this now [CRB clearance process at ; Carole Knight] Does the activity involve participants who are unable to give their informed consent (e.g. children, people with severe learning disabilities, unconscious patients etc.) or who may not be able to give valid consent (e.g. people experiencing mental health difficulties)? B) Yes No No