Are you tired of hearing about poor weather conditions yet? Well, so are we! Yet another week of bad weather has produced the slowest week of the season thus far. We were out of commission for one full day and had to close early two days due to precipitation and high wind speeds. The days that we were open were mostly windy, which makes it difficult for raptors to hunt, leading to few raptors banded.
We started out the week by putting out three of the ten transmitters Nick has for his PhD research! I won’t go into too much detail as he will make a post later in the season, but this year he is aiming to put most of the transmitters on juvenile Red-tailed Hawks (RTHA) since it is unknown what they do during the breeding season until they are of breeding maturity. We are putting a few on larger third-year RTHA as well. When choosing if a RTHA is suitable for a transmitter, we check to see if it is in good health. To do this, we assess overall body condition to make sure that the RTHA isn’t underweight, and we also check to see how heavy their parasite load is. All raptors have parasites, such as feather lice, to some degree, but if a raptor has a heavy load of parasites it can indicate that the bird is unhealthy and hasn’t been taking care of itself. Unhealthy birds are not suitable candidates for a transmitter as they are already under a fair bit of stress due to their conditions. Putting a transmitter on such birds would only increase that stress, and that is something we aim to avoid. We put all three of those transmitters out on Tuesday, April 16th on birds that had healthy weights and minimal feather lice. It was a long day as attaching a transmitter to a bird requires meticulous attention to detail. We want these devices to be as comfortable as possible since they will be on the raptor for the remainder of its life. Check out the three RTHA that got outfitted below.
Note: at the time of these pictures the transmitters had not been attached yet.
Pictured above: our first transmitter of the season went on this third-year RTHA
Pictured above: our second transmitter of the season went on this second-year (juvenile) RTHA
Pictured above: our third transmitter of the season went on this third-year RTHA
While we are talking transmitters: we caught a Merlin (MERL) this past week that was outfitted with a transmitter of its own! This is the first time that this has happened since this project started in 2020. When I was bringing the MERL into the blind I told Nick that it had a transmitter on, and he thought I was joking. Catching birds that have transmitters on/ have been previously banded is very uncommon. Once inside the blind, we processed the MERL as we would any other raptor, excluding banding it as it already had a band on. Later, we learned that this bird had been banded in the Manitou Islands here in Michigan. There is currently a project going on where researchers are banding and putting transmitters on MERL on these islands and then relocating them. The purpose of this is to reduce predation on the Piping Plover populations on these islands and to see what the MERL do once being relocated.
Pictured above: the MERL with a transmitter attached; note the antennae on this transmitter which are used to pick up the raptor’s location
Each week we have banded a Northern Harrier (NOHA) of a different age or sex, and this week was no different. We ended up banding a second-year male NOHA. If you remember from the previous two weeks, I talked about how to tell apart adult males from females and juvenile males. Adult males have a gray plumage with bright yellow eyes while females and juvenile males both have brown plumage. The main difference is that females have dark brown eyes while the young males have light yellow eyes. Take a look below.
Pictured above: a second-year male NOHA
Our totals for the season are as follows:
Red-tailed Hawks: 31
Red-shouldered Hawks: 1
Northern Harriers: 3
Cooper’s Hawks: 2
Sharp-shinned Hawks: 24
Merlins: 3
American Kestrels: 1
Total: 65
