Field Protocols
FINDING NEW NESTS
Plots should be searched for new nests every 2 days. This protocol will not describe the basic techniques used for finding nests; Martin and Geupel (1993) provides information on these techniques. When a new nest is found, the first priority is to insure that the nest can be found again. Ideally, a nest's location can be described using a distance and compass bearing from one of the stakes used to mark the study plot, coupled with some obvious local landmarks (e.g. distinctively shaped live tree or snag, fallen log). Do not use flagging to mark nests unless absolutely necessary! Always place flagging as far from the nest as possible (20 m or more if possible). In dense vegetation, 20 m may be too far to be useful for relocating the nest. Use your own judgment in placing flagging, but remember, predators can learn to associate flagging with nests. We suggest you have assistants label any flagging used to mark nests with year, species, and bearing and distance to nest. Flagging should be removed at the end of each field season. Record location information on a nest card immediately after finding a nest.
There will be occasions on which you are reasonably certain that there is a nest in the vicinity, but you have not been able to find the nest on that day. On these occasions, we have found it useful to fill out preliminary and unofficial information on a nest card: a description of the probable area of a nest. Additionally, search effort on your unsuccessful attempt to find the nest should also be recorded (see next section).
Once you have completed recording all of the information required in this section of the protocol, treat the new nest as you would any other nest, and follow the instructions for routine monitoring of nests found under MONITORING NESTS.
Filling Out The Nest Card
After you have ascertained how to describe the location of a new nest, the next step is to record on a nest card this description and initial information regarding the nest. We have assistants keep 2 sets of nest record cards for all of the nests that they monitor: field cards, which are updated while nest searching and monitoring, and a duplicate set of cards that remains at the field camp and is updated daily. The cards that we use in Arizona are color-coded in order to avoid confusing the two sets. Only assign a nest identification number and fill out the duplicate nest cards for nests that you are absolutely certain are active!
In the description of methods that follows, we have coded the individual data items to indicate their purpose. UNDERLINED VARIABLES IN LARGE BOLD LETTERS are included in the BBIRD database. The variable codes in parentheses after each variable are the exact names that should be used in data files contributed to the national database. Underlined Variables in italics and mixed case are needed to determine nest fate and/or provide useful information. Italicized variables are not reported directly to the central data repository but some are needed to calculate BBIRD reporting variables. In the figure below we show a sample nest card:
FIGURE: BASIC NEST DATA -- FRONT OF NEST CARD
The first information to record is that which is required to re-locate a nest, as well as identify the species of bird and the person who found the nest. This information should be recorded while you are in the vicinity of the nest:
- YEAR (YR)
- 2 digit number for year (e.g. 94).
- SPECIES (SPECIES)
- bird species. We use 4-letter codes from the Fish & Wildlife Service Bird Banding Lab for reporting data to national database, but have field assistants use the entire species name on the nest cards to eliminate confusion and errors. Note that recognizable forms within a species have their own codes (e.g., Myrtle and Audubon's Warbers). Codes can be obtained as a dBase file as part of the DOS banding data entry program used by the Fish & Wildlife Service, available on the World Wide Web for downloading
- OBSERVER (OBS)
- person or persons that found the nest (first 2 initials followed by last name e.g., TEMartin).
- NEST ID# (NST_ID)
- unique, individual nest ID number or code. This can be assigned in the field or after the field season (in AZ we use the last 2 digits of the year, the observer's 3 initials, and a sequential number that represents the order in which that observer found that nest in that year, e.g. 96TEM28 is the 28th nest that TEM found in 1996). Please choose a system for NEST ID# that will uniquely identify one specific nest in a given study area! Only assign a NEST ID# for nests that you are absolutely certain exist.
- NEST ATTEMPT# (ATTEMPT)
- the number of nests attempted in a season by an individual pair, up to and including the current attempt. If you do not know which attempt in a season this nest is for a pair, leave ATTEMPT blank. A new card should be filled out for each nest attempt.
- PLOT (PLOT)
- unique plot identification code (Number or letter codes are fine. Keep them short).
- STATION (STN)
- STATION is an identifier used to indicate location within a plot. Nests found outside of plot boundaries should be monitored and assistants should record OFFPLOT for the station for these nests to indicate that they were outside plot boundaries.
- DIRECTION: STATION TO NEST (DIRSTN_D)
- direction from station to nest in degrees.
- DISTANCE: STATION TO NEST (DSTSTN_M)
- distance from station to nest in meters.
- Location description
- give a complete description. Include bearing and distance from STN to nest or other landmark; sketching a detailed map works well for refinding nests, especially when nests occur in high densities or a nest is far from a station marker. Someone else should be able to find the nest from your description. Example: From STN #1, go 50m, 233° up slope to 27cm DBH snag in center of group of 3. Nest under bark on east side, 7m up.
- Estimated nest height
- useful for relocating the nest if height is not measured on finding.
The next step in keeping records is to describe the process that led you to find the nest. BBIRD is compiling this information in order to gain an idea of whether parental behavior or nest concealment affect the success of nests. I.e. if it took you a long time to locate a nest, it might indicate that such a nest would also be difficult for a predator to locate. We will compare success and vegetative characteristics of nests found by techniques that should be relatively unaffected by nest concealment (parents behavior leads us to the nest) and those extremely likely to be affected by nest concealment (chance observation of a nest). We will also use measures of Parental Elusiveness gathered at each nest visit in the same manner. We are also recording additional measures of search effort in Arizona (search time, systematic search radius, # of parent visits, and # of previous attempts to find the nest). These variables are not required but may turn out to be useful measures of nest concealment. Here is the information that you should record each time you have attempted to search for a nest:
- CUES USED TO FIND NESTS (FMETH1 -- FMETH5)
- These "finding methods" are recorded each time a nest is searched for, even if the attempt was unsuccessful, and several visits were required to finally locate the nest. The information should be recorded in a format similar to this figure:
FIGURE: SEARCH METHOD INFORMATION ON NEST CARD
Individual nests are frequently located using more than one technique. All of the methods used to find the nest should be recorded in sequence of use (see example, above). Recording of finding methods (FMETH1 up to FMETH5 if needed) is required. Search time, Search radius, # of parent visits, and # previous attempts to find nest are optional. The following are the possible methods used find nests, and their codes:
Name Code Description Parent behavior PB saw a parent bird and followed it to the nest or area around the nest. If the parent gets you within approximately 50 cm of the nest then parental behavior is considered the only cue used (but see systematic search notes). If you must systemically search an area around the nest larger than a 50 cm radius circle, then systematic searching is considered the second step in nest location. Parent flushed from nest F you flush a bird off its nest while walking past. This differs from luck because behavior of the bird is important to location of the nest. Systematic search SS nests found during a systematic search of possible nest sites. This may occur without previous observations of other cues, or after parental behavior or non-behavioral cues suggest a nest is present nearby. Example 1: some types of nests are most easily located by regularly checking certain habitat features (e.g., regularly checking small firs for Hermit Thrush nests or regularly checking snags you pass for fresh cavities). Example 2: Even after observation of a parental cue that narrows down the nest location, it is often necessary to systematically search the area to find the nest (e.g., you observe a Red-faced Warbler going down to a small area on the ground then flying away. After several observations of the adult you narrow the nest location to an area 1 meter in radius. You then systematically search the area for the nest). If parent behavior gets you within approximately 50 cm of the nest then the nest is considered to have been located by purely behavioral cues. However, use your own judgement when deciding whether systematic searching was part of the nest location process. The 50 cm cut-off is intended as a guideline and may be too large an area in some cases, and too small in others. For example, considerable searching may be necessary to find the exact position of a nest located in a thick shrub, even after localizing with 50 cm. Non-behavioral cue NBC a non-behavioral cue suggests a nest is nearby. The nest is then located by systematic searching or waiting for parents. Example: you notice fresh wood chips on the ground near a group of trees. You then locate the nest by searching nearby snags. Another example of a non-behavioral cue would be bird droppings on the ground or leaves under a nest. NOTE: if you were systematically searching under trees for wood chips then SS would be the first method recorded, followed by NBC, then SS or PB depending on the cues you used. Luck L came across a nest by chance without actively searching for it or seeing parental cues. Previous year PY found nest based on knowledge of nest location from previous year. Young behavior YB young's behavior led observer to nest. For example, noisy or begging young often can lead you to find nests of cavity nesting birds.
- Time (STIME1 -- STIME5)
- record the time in minutes spent searching for the nest within each cue type (when applicable). If using parental
- # Parent visits (NPARVIS1 -- NPARVIS5)
- for parent behavioral cues only - record the number of parent visits to the nest during an attempt to locate the nest using parental behavior. Record a separate value for each PB search method line you fill out.
- Search radius (SRAD1_M -- SRAD5_M)
- record a search radius in meters for systematic searches initiated by some other cue (PB, F, NBC). For searches initiated by PB or F record a search radius if it is necessary to systematically search an area larger than a 50 cm radius circle around the nest.
- # of Previous attempts to find the nest (NTRIES)
- number of previous days you have spent time trying to find this nest.
Field Protocols
Last modified: Tuesday, 25-March-97 10:32:14 MST