(This is a preliminary summary of Urmas and Ülo's talk on Nov 17. The authors have not reviewed it yet - lack of time - so please be prepared for corrections!)
Ülo Väli and Urmas Sellis talked about use of trail cameras and web cameras, and experiences and facts learnt about the cameras and raptor nest life, with illustrations from a number of raptor nests, in a nearly 2-hour presentation in the Estonian Ornithological Society (EOÜ) lecture series; talk in Estonian, video at http://www.eoy.ee/node/417
.NEST CAMERAS IN RAPTOR STUDIES
Translation of authors’ summing up:WHAT HAVE WE LEARNT?
1. More precise information on nesting phenology:
- Arrival, egg-laying time, hatching time, fledging time, departure time
Result: better strategies for nesting territory protection regulations possible
Studies of annual variations needed
2. More precise information on nesting biology:
- Number of eggs, prey objects; nest-building, robbing and other behaviour
Result: better planning of species protection
Studies of annual variations needed
3. Determining nest status is not always simple
- Raptors may build and decorate several nests
- Breeding nest can be built very scantily or late
Removing a protected species nest from protection register must be supported by thorough study
4. Several species may inhabit and use one nest
- Prudence needed in deciding on the resident species
Removing a protected species nest from register must be supported by thorough study
5. Individual birds can be recognised
- Sex-related differences in behaviour can be studied
- Possible to read rings, observe other individual characteristics
- Mobility of birds, survival of individuals etc can be estimatedMore about the talk
Of our known “forum birds” Urmas showed several sequences of Sulev and Linda; Padis and Remo and Tuuli competing for Padis’s nest 2010; some sequences on Eha and Koit (LSEs, 2009). Ülo introduced a new possible camera star pair, LSEs Karin and Kaarel, first Estonian LSEs with transmitters whose migration 2011 can be followed on Birdmap. http://birdmap.5dvision.ee/index.php?lang=en
.Trail or web cameras?
Strong points for web cameras are constant monitoring, viewable on-line, inclusion of sound, detailed records, no storage space limit. Trail cameras (automatic cameras), with motion-initiated recording, are cheaper and easier to install and handle, so allowing more cameras to be used which makes e g estimates of annual variations or individual traits versus average species behaviour feasible. A team can set up 4-5 trail cameras per day in the field. Initial cost of one installed web camera with communication lines, solar power panels and other appendages may equal 30 trail cameras. Major technical limitations of trail cameras at present are battery life (standard, some days; special batteries, whole season used prudently) and memory space (16 GB, allowing ca 20 000 images; 32 GB introduced). 2011 was the first season of trail cameras at raptor nests. Authors agreed that the two camera types complement each other. Raptor nests: Musical chairs or Owners, residents, occupants, sub-tenants, visitors …
The trail cameras were mainly used at lesser spotted eagle (LSE ) nests, a few for goshawks. LSEs frequently build and maintain several nests. To determine which nest might be used for breeding in a particular year is problematic. Raptor nests in general were often used by other birds, raptors as well as others: temporarily, for short-time residence, breeding.
An LSE nest was claimed in turns by buzzards, long-eared owls and two different LSE pairs and inspected by several other species. Some LSE nests appeared to have been taken over by buzzards, one by a honey buzzard; conversely, a successful LSE nest was originally owned by goshawks. Other changes of nest residents were demonstrated, e g buzzard’s nest, with eggs, taken over by LSE pair, black stork ousted by LSEs; mallard breeding in white-tailed eagle nest.
“Best” strategies for protection regulations and nest classification depend on reliable data on aspects such as whose nest, for how long, for what (breeding? “spare”?).