Although the calendar says it is spring, and certainly the temperature as I write this would agree, for the birders, we are still awaiting spring. Many of our indicators of spring are late arriving this year. Whether it is the effects of the prolonged drought and last year’s non-existent monsoon or other factors at play, many species are running days to weeks behind their expected arrival dates. Just like it might take longer to take a prolonged car trip during times of a gas shortage or rationing, migration might take longer when the resources along the way up from Mexico have been affected by the drought.
We are able to quantify the effects on hummingbird migration thanks to long-term monitoring along the San Pedro River conducted by staff and volunteers of the Southeastern Arizona Bird Observatory. For over 25 years we have been banding hummingbirds at the San Pedro House. One of the goals of the project when we began in 1995 was to document the timing of migration, nesting and fledging of hummingbirds along the river. Our study design called for beginning the monitoring the first week in April to document the arrival of hummingbirds returning from Mexico. For many years, we saw very few, if any, birds until the third or fourth week of the banding season. Over the years, however, the birds began arriving earlier and earlier, until we moved our first banding session back into March to meet the early arrivals.
The comparison of banding sessions can show us how atypical this year appears. We suspended our project last year due to COVID concerns, but in 2019 we caught twenty-two birds the first weekend of banding in late March. This year we caught one. By the second week of banding this year, there were a respectable number of birds around, but still nowhere as many as in recent years in early April. At our Ash Canyon Bird Sanctuary, the lucifer hummingbird (the star attraction there) usually arrives in late March and this year didn’t arrive until April 5.
This is going to be a difficult year for many of our local birds as well as all wildlife. Insect populations are down and many insectivorous birds, including our small owls, will have a difficult nesting season.
When the birds do arrive, you may notice an abundance of birds at backyard habitats and feeders due to the poor conditions in the wild. You see swarms of hummingbirds at your feeders and initially think “It’s a good year for hummingbirds this year” when in reality the lack of wildflowers and insects make the local birds more likely to visit your feeders. Water features will be increasingly important for a wide variety of birds and other wildlife.
We’ve also done regular walks on the San Pedro River each spring for 25 years, watching the spectacle that is migration along this, one of the most important migratory corridors in western North America. Early surveys after the establishment of the San Pedro Riparian National Conservation Area estimated between two and four million songbirds migrate north along the San Pedro each spring. We’ve seen a slight decline over the years similar to the noted decline in songbirds across the continent. We may have lost three billion songbirds, 30% of total birds, since 1970. Those of us who have been birding here for many years can recognize that, as wonderful as a hike along the river or in the Huachucas can be, there are not as many birds as there used to be.
Every generation has what is called a “shifting baseline,” where their expectations are based on their own initial experiences. People don’t miss what they never had. So, for the new generations of birders and naturalists, these are “the good old days.” And for all of us, the spectacle is still amazing to watch.
Last year with our public walks cancelled because of COVID-19, we took solace in watching as the natural world continued to function even as our human world shut down. Birds still arrived, found mates and nested and raised young along the river as they have for millennia. Deer and Javelina still were seen in the grassland and edges. The river still flowed. We also felt very fortunate to live in a place where we could walk the trails socially distanced, breathe the fresh air and be reminded that life goes on.
Take time this year to feel and enjoy the “pulse of the planet” -migration along the river and into our sky island mountain ranges. Stay safe and healthy.