Field methods

Nest searching and incubation behavior protocol

 Daily nest searching will be conducted during the breeding season (August-December). Each field site will be divided into different areas.  The number and size of these areas will vary with the number of field assistants. Where there are fewer field assistants, there will be fewer and larger areas. Each field assistant will be assigned to one area for the entire breeding season, with the idea that he or she will become familiar with the area throughout the breeding season and will learn bird territories and any changes in the area (i.e., new nest in a tree, birds transporting materials, etc). Moreover, being in the same place allows that person to remember the exact location where a nesting behavior such as transporting material or food, new nests or repeated activities (i.e., close flushing) occurred. To have a better idea of specific techniques used to find nests, please read (Martin and Geupel 1993; PDF).  Once a new nest is found, it will be monitored.  The frequency that it is monitored will depend on the stage of each nest (e.g., construction, egg laying, full clutch, and nestling). Nests under construction will be monitored every day and direct observation on building behavior will be conducted for one hour every day until the clutch is completed. Similarly, nests found with incomplete clutch size will be monitored daily until clutch size completion. Once a nest is completed or is found with the full clutch, a data logger will be set up on the nest (and possibly video cameras depending on budget and availability). All nests will have three sensors  that will measure temperatures. One sensor will be located inside the egg (if the eggs are fresh and no embryonic development has taken place), one on the nest bottom and one externally close to the nest wall.  Sensors are connected to a U12-0006 4-Channel Hobo data logger (Onset Computer Corporation). Sensors will provide essential information for understanding incubation behavior. These sensors will provide information on nest microclimate, egg temperature, ambient temperature in the immediate vicinity of the nest and the time at which the incubating bird left or returned to the nest, as detected by rapid temperature shifts of at least 1.5oC (see, Londoño 2005 PDF for more details).  After egg hatching or when a nest is found with nestlings, a digital camera will be placed near the nest every three days to record continuous feeding-rate data during 24 hours, until the nestlings leave the nest or a predation event takes place.  

 Chlorospingus flavogularis, Nest. San Pedro 1500m.   Ampelion rubrocristatus, Egg. Wayquecha 2900m.

 Lanio versicolor, Eggs. Tono 1000m.  Henicorhina leucophrys, Eggs. San Pedro 1500m.

  Hylophylax naevius, Nest . Tono 1000m. Conopophaga ardesiaca , Nest . Tono 1000m.


I will measure rates of oxygen consumption (VO2) and carbon dioxide production (VCO2) in an open-flow, push-through respirometry system. External, naturally humid air (85-95% humidity, ~25 ºC) will be pumped through a mass flow controller (TR-FCI, 105 Sable Systems, Nevada, USA) and a multiplexer (V2-0, Sable Systems, Nevada, USA) into the metabolic and a reference chamber. Flow rate will be 1000 ml/min for birds and 50 ml/min for eggs, and the flow controller will be calibrated prior to use via a bubble meter. I will design different sized chambers for birds and eggs.  The oxygen consumption measurements will be conducted under different temperatures ranging from 35 ºC to 10 ºC.

Other measurements

Female body mass. As soon as eggs hatch and at 11 days during the nestling stage, females will be captured with mist-nest. Each female will be banded with an aluminum band and a unique combination of color bands, many measurements including: mass to the nearest 0.05g, tarsus, wing, bill and tail length to the nearest 0.1mm will be recorded. Nest predation: For each nest, I will record the day in which any nest is lost to predation. I will use two metrics of nest predation: the total number of nests lost to predation and the average daily survival rate. Egg properties: I will collect at least five fresh eggs from each species per elevation to evaluate initial investment on the egg (e.g., lipid and protein content) and egg properties (e.g., shell thickness and pore size and density, using an electronic microscope). Nest mass and thermal properties: After nest become inactive, I will collect every nest and dry them at slow temperatures until no change in mass is detected. Then I will use these nests to estimate thermal properties of the entire nest and each of the materials. I will heat up quail eggs and measure heat loss of the egg when in the nest and in each of the nest materials. Heat loss on each quail egg will be recorded every second with an internal sensor attached to a data logger. After the heat loss experiment is completed, I will weigh each of the nest layers to estimate the amount of different materials used by different species and individuals.

 Buff-Throated Saltator Nest (Saltator maximus). San Pedro 1500m.  Blue-Naped Chlorophonia Eggs (Chlorophonia cyanea). San Pedro 1500m.

 Orange-Bellied Euphonia Nest (Euphonia xantogaster). Tono 1000m.  Orange-Bellied Euphonia Nestlings (Euphonia xantogaster). Tono 1000m.

 Sooty Antbird Nest (Myrmeciza fortis). Tono 1000m.  White-Backed Fire-Eye Eggs (Pyriglena leuconota). San Pedro 1500m.


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