Monday, July 20, 2009

Avian Research Update

I continue to make progress on my research agenda. As noted in my research proposal, I am researching the coordinated migrational timing between avian predators and avian prey. The research is based upon fifteen years of migration data collected at the Idaho Bird Observatory.

While my research is based on historical data, I will be volunteering at the Idaho Bird Observatory in late summer and fall. This will enable me to better understand the data collection processes and gain my own perspectives. It will also help the observatory with their operations as they have been kind enough to provide me their data. From July 19th through the beginning of the school year, August 24th, I will be banding songbirds. After the beginning of school, I will be volunteering one day a week on the Hawkwatch, counting migrating raptors.

In preparation for my time at the Idaho Bird Observatory, I have been studying "Hawks from every Angle" by Jerry Liguori. This is a great book for true bird nerds. It describes in intricate detail the various species, their similarities and their differences.

I did get my hands on the historical hawkwatch data. It appears that the last three years worth is still in paper form. I believe I will be working a while on data entry. The glamorous side of research! Anyway, I will be able to use my computer skills to help the organization and future researchers.

I have continued to search and read background research which I will cite in my final paper. I have a list of approximately 15 sources so far with notes regarding their relevance.

One of the first analysis tasks I will focus on is replicating a study performed at Hawk Mountain Pennsylvannia regarding the timing of raptor migration as it relates to cold front passage. They used 60 years worth of data in their research. Amazing! Their analysis determined that the migration numbers of various raptor species are significantly effected by the passage of cold fronts by the monitoring site. For example, one of my study species the Sharp-shinned Hawk (Accipiter striatus) has a significantly higher likelihood of reaching peak migration numbers the day after the cold front passes than any other day. They then decrease each day afterwards. Similar patterns are followed by my other study species the Cooper's Hawk (Accipiter cooperii) and Northern Goshawk (Accipiter gentilis). My intent is to determine if their findings apply to Idaho. So far, I have followed their procedure for collecting the historical cold front passage data from the government. The good news is that the data is all online. This is performed by looking at the daily weather maps for each of the seasons. That's over 1400 daily weather maps! I have completed this step. One interesting finding is that Idaho on average has half the number of cold fronts passing as does Hawk Mountain. I expect this will cause the correlation with cold front passage to be less significant, but we will have to see what the statistics tells us.

Following a few other research papers, one from the Eastern US and one from Western, I will determine if our data support their conclusions about specific species, age and sex migration. The two studies found that the general order for each accipiter species during migration season is juvenile females, juvenile males, adult females, and then adult males. On average Cooper's Hawks migrate through before Sharp-shinned Hawks. The challenge here is that we do not have nearly as much data on age and sex. I might have to use capture data for that which greatly reduces my data points. Something to be investigated.

Songbirds. A big task on the agenda is to get my hands on the songbird data and see what kind of shape it is in. I may be doing some data entry here as well.

An area that I am currently investigating is whether I should use total songbird numbers, or if I should separate out specific species which are most likely to constitute prey for my target predators.

Lots to do, but its great stuff.

2 comments:

John said...

I really like Liguori's book. It has so much useful information.

Research Papers said...

Many institutions limit access to their online information. Making this information available will be an asset to all.