After ongoing observation at McConnell Lake (50.5227 degrees North, 120.4589 degrees West), I have located a marshy area at the north-western side of the lake. As I am familiar with the red-wing blackbird (Agelaius phoeniceus), a migratory song bird that is widely distributed across North America and commonly found in marshes, I decided to use this species for my study. I wanted to track its distribution and mating behaviours. Yet, several visits in—I determined that waiting for the birds to return to a lake that I was not certain would have red-winged blackbirds at, I ended up picking two supplementary locations to use as sites (Gamble Pond and Dufferin Park Wetlands) that I knew the red-winged blackbird returned to. I added a fourth site (Pineview Valley Park) when I was informed it was a haven for red-winged blackbirds. Throughout Jan-March I conducted 16 point counts over 8 visits at McConnell Lake to which no red-winged blackbird sightings were made. However, over February-March, red-winged black bird counts were performed at Dufferin Park Wetlands (50.6614 degrees North, 120.3951 degrees West). 5 minute counts were performed at each point and added up.
Field Journal Entries
Date: February 8, 2023
Time: 1030 H
Conditions: Sunny, 2 degrees Celsius, wetlands frozen
Location: Dufferin Park Wetlands
Red-winged blackbird count: 0 males/0 females
Date: February 17, 2023
Time: 0900 H
Conditions: Partially cloudy/sunny, -3 degrees Celsius, some ice cover on wetlands
Count: 48 male/0 female
Date: February 27, 2023
Time: 0900 H
Conditions: overcast/sunny, -8 degrees Celsius, frozen
Location: Dufferin Park Wetlands
Count: 20 male/0 females
Date: February 27, 2023
Time: 1230 H
Conditions: Sunny periods -6 pond frozen
Location: Gamble Pond
Count: 0 sighted but 2 heard
Date: February 28, 2023
Time: 0759 H
Conditions: snowing/overcast, -4, marsh frozen
Location: Dufferin Park Wetlands
Count: 10 males/0 females
Time: 0849 H
Conditions: overcast, -4, pond frozen
Location: Gamble Pond
Count: 3 males
Date: March 1, 2023
Time: 0854 H
Location: Dufferin Park Wetlands
Conditions: sunny, 1 degrees Celsius, wetlands mostly frozen
Count: 27 males/0 females
My counts continues following this. The distribution and abundance appears to reflect the temperature and other condition factors (e.g. openness, exposure to elements, etc.). Despite males being present females had not appeared. Further, avid birders (I personally know) suggest that red-winged blackbirds do not usually show up in the Kamloops area until March. I postulate that due to an uncommonly warm February that unseasonably warm weather incited male migration. During the warm weather in February the males were loud and aggressive (contrary to the cold snap that followed to which they were less active) at Dufferin Park Wetlands were there were highest densities of the species in comparison to the other sites (McConell Lake and Gamble Pond). Considering, time constraints, I won’t be able to explore whether this has any relationship to global warming: yet, I can explore if temperature reflects categorical densities and behaviour. My hypothesis would be that warmer weather increase male densities and activity.
The potential response variable would be categorical red-winged black bird densities. And, a potential explanatory variable would be temperature.
I love your interest in the topic and you have put a lot of time into your observations already! My one concern with your design is whether time will be a confounding factor. While some males may have arrived in February, I’m guessing that as time went on more males arrived to the breeding grounds. However, as you noted there was a cold snap after earlier warm weather. Do you have enough samples from that time period?
Thanks Robyn, it is very interesting to me. I have looked over the Christmas Bird Counts that Rick Howie posts and have noticed an increase in blackbirds from 2018 to 2021. Migratory processes including spawning amaze me because most of it seems innate. Unfortunately, I spent a lot of time up at McConnell before I realized that blackbirds had appeared at locations in Kamloops. As a result of this, I missed out on opportune times to be doing counts. My thoughts are maybe it will be better for me to look specifically at distribution and not temperature. The Atlas of Breeding birds has an article on how habitat loss in BC is causing extirpation (Ryder, 2015). Oddly, I have noticed that the highest densities were in areas where urban sprawl is surrounding their habitat. Perhaps, I could add locations and look at density and distribution instead.
Ryder, J.M. 2015. Red-winged Blackbird in Davidson, P.J.A., R.J. Cannings, A.R. Couturier, D. Lepage, and C.M. Di Corrado (eds.). The Atlas of the Breeding Birds of British Columbia, 2008-2012. Bird Studies Canada. Delta, B.C. http://www.birdatlas.bc.ca/accounts/speciesaccount.jsp?sp=RWBL&lang=en [11 Apr 2023].