Graphs

I went through each day of observation for each pair and added all of the observations together to create some graphs to show the breakdown of the behaviors for the individual birds in each pair.

Parasitic Jaeger Pair 1 was observed for a total of 166 minutes and this is the graph below.

I also made a scatter plot for the distances I recorded for when each pair began defending against me as I approached their nests.  You can see that the distance increases as incubation length (the date) increases. If I had a better idea of when they actually initiated their nests, and was able to record more points, the X-axis would look differently, but for these purposes it is just the date the distances were recorded. The date is valued as the day of the year; for example June 16th is day 167 of the year. I appreciate questions and suggestions for changing any of these graphs, so please share if you have them.

Parasitic Jaeger Pair 2 was observed for a total of 241 minutes and this is the graph below.

I already stated before, that based on these observations and information from other studies by Martin and Barry from 1978, the female primarily attends the brood, so the female is likely the Light Morph of PAJA Pair 2. Below is the chart for the distance an observer could be from the nest before the pair began defending.

There is another study by Maher from 1974 that states, "repeated visits by humans to a nest result in reduced aggression." However, based off my observations I would say that they increase aggression, at least by increasing the distance a potential predator can approach before they defend against that predator.

Well, that is it for these observations and this blog. Thanks for reading and please leave comments, questions, and whatever you want to share with me!

July 4th 2013, PAJA Pair 2

This might be the final time I am able to observe either pair. Both chicks of PAJA Pair 2 have hatched and as far as I can tell the single egg of PAJA Pair 1 has also hatched. I observed Pair 1 today, and they were defensive but not much when I was close to the nest. When I checked the nest there was no egg so they likely have a chick in the area but I did not see it. Since the chicks will now be able to move around, it will not be easy to observe them, even though they will stay close to the nest for 2-3 weeks. In my observations of PAJA Pair 2 yesterday, I have added a new behavior. Although I have Brood defined as attending brood/young, I did not include in the definition the act of feeding the young. So I added Feeding which is defined as bringing food to young and feeding them. I was too far away to tell what was being given to the chicks, or which was receiving the food.

PAJA Pair 2              Date: 7/4/14        Time spent observing: 13:14 – 14:34

Temperature: 56 F     Wind 11 mph      30% Cloud Cover

Type of Behavior	Total Time Dark Morph	Percent time spent doing behavior	Total Time Light Morph	Percent time spent doing behavior
Defending	8	10	6	7.5
Incubating	0	0	0	0
Hunting/Foraging	34	42.5	0	0
Preening	4	5	1	1.25
Loafing	27	33.75	8	10
In flight	3	3.75	0	0
Altercation	2*	2.5	1*	1.25
Brood	1	1.25	64	80
Feeding	1	1.25	0	0

Total time spent observing: 80 minutes

* = Altercation with King Eider pair. They were dive-bombing them and the eiders were fighting back.

With these observations, I can conclude that the female of the pair is in fact the light-morph. I was hoping to get that down for Pair 1 as well, but am unlikely to figure it out. 

Pretty freshly hatched chick in nest

More alert chick just outside of nest

Both chicks

Below is an updated version of the proximity to nest table I included in the last post for PAJA Pair 2. According to these observations, they do indeed increase their defensive behavior as the eggs are closer to hatching and when they have young. I also saw this with Pair 1, and am thinking the day the fox was in the area, the chick may have been hatching or hatched. 

Date	Distance Observer from nest when pair began defense (in meters)
6/16/14	40
6/19/14	66
6/19/14	30*
6/23/14	78
6/27/14	95**
6/27/14	106**
7/4/14	129

* = distance I was able to stand from the nest when the bird went back to incubating, this could be due to cold weather

** = only observed the proximity to the nest when they began to defend, as I was busy doing the other surveys in the area for that day

Light-morph in flight

A Few Notes and Photos

Things have been very busy since my last observation. So aside from going by the nests and getting some points for proximity to the nest when the pairs begin to defend, I don't really have anything to report. I would have liked to get out there more, but of course, work comes first here when the season goes by so quickly. Below are just some tables I threw together with the distances I recorded for when each pair began their defensive behaviors as I approached their nests.

PAJA Pair 1

Date	Distance Observer from nest when pair began defense (in meters)
6/16/14	100
6/21/14	90
6/21/14	83*
6/29/14	105**
6/29/14	200**
6/29/14	110**
7/3/14	210
7/3/14	147

* = I was observing them from 83m when the Dark morph saw me and chased me off, to where I then observed them from 109m

** = day the Arctic Fox was in the area, the three points are varying times the PAJA pair defended against us when we were working on the other surveys in the area

PAJA Pair 2

Date	Distance Observer from nest when pair began defense (in meters)
6/16/14	40
6/19/14	66
6/19/14	30*
6/23/14	78
6/27/14	95**
6/27/14	106**

* = distance I was able to stand from the nest when the bird went back to incubating

** = only observed the proximity to the nest when they began to defend, as I was busy doing the other surveys in the area for that day

There are already baby birds (goslings and shorebirds) around. I have even seen some gull chicks, so likely the Jaeger chicks will be emerging soon. Even though I don't have more observations for this post I wanted to share some photos.

I observed a dead Red Phalarope near the nest of PAJA Pair 2. It is not uncommon for Jaegers to prey on shorebirds and passerines during the breeding season. I am not sure if it was a Jaeger kill, but I think it may have been because of the proximity of it to the nest.

Red Phalarope carcass

A mess of feathers where the phalarope must have been attacked.

I could have observed PAJA Pair 1 the other day, but there was an Arctic Fox in the area, and I did not want to unnecessarily draw attention to their nest with it around. 

Arctic Fox

I can officially confirm that one egg of PAJA Pair 2 hatched today. The other crew was doing work by it and was able to witness a chick emerging from the egg. The Parasitic Jaeger will incubate for a period ranging from 23-26 days. Incubation begins after the first egg is laid, and it can take 2.5 days for the second egg in a clutch to hatch after the first. I will be able to go over to that pair tomorrow and check it out for myself.

Jaeger hatching. Photo courtesy of Kayla Scheimreif