A Research Of The Behavior Of Barn Swallow Birds

Abstract

Barn Swallows are common birds you see almost everywhere. They have a wide range in migration and their diet varies greatly. This study addresses variation in behavior during different times of the day over a study period of 10 hours. Results support a hypothesis that Barn Swallows exhibit behavior suggesting they spend most of their time foraging in the early-morning and evening. This behavior indicates that foraging behavior may be directly related to storing and replenishing energy reserves. Information on Barn Swallow activity in anthropogenic environments can assist in informing the public about the wildlife in their communities and be active in species management.

Introduction

Whether you realize it or not, you’ve seen Barn Swallows your entire life. From a distance the Barn Swallow appears to be just like any other bird; drab, small and almost unnoticeable. They are far from this. Up close this swallow is a striking slate blue with dark orange on both the throat and forehead with paler orange dragging down on the chest and underside. On top of all this, the Barn Swallow also has a very distinctive forked tail helping birders identify them. This observational study is done in the Central Texas region, but these swallows have quite a large range as long-distance migrants. Barn Swallows breed in Northern America and winter in Central and South America. Typically, you’ll find these birds darting across fields, open water or near man-made structures. Both male and female swallows play a role in nest building, they produce a cup-like nest using mud.

Barn Swallows are not dietary specialists when it comes to foraging, while their diet consists mainly of flies there are other constituents as well. Such as beetles, bees, wasps, butterflies, moths and other flying invertebrates. On top of these, birds are also known to ingest material left out by humans such as shells or small pebbles to aid in digestion or make up for a lack of calcium in the diet. The hypothesis is that Barn Swallows will exhibit behavior that suggests they spend most of their time foraging in the early-morning and evening. This study consists of 10 hours of observation recording data on the time spent by Barn Swallows in the designated study area. Time was evenly divided between 1) early-morning 2) mid-morning 3) afternoon and 4) evening. At the beginning behavior was documented via Ad Libitum, this was done to understand the basic behaviors these birds exhibited within the given time period. Once this was completed, a base knowledge was established on how these birds spend their time and use their energy budget.

Methods

Over a period of 10 hours throughout 4 different daily observations times, data was collected on Barn Swallow behavior within an apartment complex in Austin, TX. Daily observation times were split into hours early-morning, 2 hours mid-morning, 2 hours afternoon, and 3 hours in the evening. During each time slot, observations were done on the same bench roughly 10 meters away from the buildings where nests are present. With the use of binoculars and a field guide, ID was made both visually and auditorily. These methods allowed for observation of both individuals and groups of Barn Swallows. Data was collected on all behavior presented by the swallows for the first hour of every time slot. With this, categories were developed into the main 5 behaviors in which the swallows presented. All following observations were then placed into 1 of the 5 behavior categories so a time-budget could be produced.

Results

For this study; solitary flight, group flight, vocalization, preening and foraging are defined by the following. Through observation Barn Swallows appeared to spend a majority of their time in 1 of these 5 activities. Solitary flight is categorized as any time a Barn Swallow spends flying alone with no visual signs of foraging taking place. Group flight is the same as solitary flight but is cataloged when more than one Barn Swallow is present. Vocalization is defined by both calls and songs produced by the species. Preening is any time a bird spends cleaning themselves, and foraging is any time spent collecting food or actively eating food.

Discussion

Data supports the hypotheses that Barn Swallows spend most of their time foraging in both the early-morning and evening when compared to other times of the day. A close second to foraging in their time budget would be flight and vocalization. Also, swallows appear to spend a majority of their time in flight as a group when compared to solitary flight in this study. Foraging for food sustains the bird’s diet while flight and vocalization could be used to defend/establish territory as well as attract mates. Barn Swallows feed almost exclusively on their wings and while in flight.

While foraging is the most time-consuming activity it varies between the time of day. Early-morning behavior consists equally of foraging and vocalization. Birds are most vocal in the morning to display territory, to attract mates, and to notify other birds that they survived the night. Foraging behavior is high in the morning to replenish energy used throughout the night to sustain themselves. Mid-morning behavior differs slightly, birds tend to increase time spent vocalizing and decrease foraging for the time being. Preening continues to be high at this time, birds clean themselves throughout the day but most of my observations of this were in the morning times. Once afternoon observations began, I mostly notable observed an increase in flight (with the absence of foraging). Flight at this point could be solely for territorial defense, with it being the hottest part of the day, excluding foraging could be more beneficial than using energy to forage. Evening behavior exhibits a large amount of time spent in all 5 categories. With night approaching a wide range of behavior can help ensure survival. Foraging behavior is also peaking at this time, insect activity is high, and the birds need to create an energy reserve for the night. Shifts in behavior throughout the day are parallel to the needs of the birds at the specific times of day. Conserving energy, courting mates and territorial defense seem to be the focus each day. Further research on Barn Swallow group activity and how this affects foraging success would be an interesting topic to tackle next. No problems were encountered during the observational periods. From this study, we can better understand how Barn Swallows foraging behavior and how it benefits survival of the species in an anthropogenic environment. This information allows both researchers and the public to be knowledgeable and active in species management.