The Brown Thrasher (Toxostoma rufum) is a bird species native to North America. They are medium-sized songbirds that belong to the family Mimidae, which also includes mockingbirds and catbirds. Brown Thrashers are year-round residents throughout much of the eastern and central United States, wintering in southern areas and moving north for the warmer summer months. An interesting aspect of Brown Thrashers biology is their breeding and nesting habits, including the timing of egg laying. In this article, we will explore the question: What month do Brown Thrashers lay eggs?
Brown Thrasher overview
Brown Thrashers are slender songbirds approximately 11-14 inches in length with long tails and legs. They have brown upperparts with a white-colored belly and heavily streaked underparts. Their eyes are yellow and they have slightly curved bills that are black on top with a yellow lower mandible.
Some key facts about Brown Thrashers:
- They inhabit open areas with dense shrubs and thickets, forest edges, overgrown fields, and suburban yards with lots of plant cover.
- Omnivorous, feeding on insects, arachnids, snails, fruits and seeds. They forage by rummaging through leaf litter on the ground.
- Males are highly territorial during breeding season, defending nesting sites with threat displays and aggressive attacks on intruders.
- Females typically lay 3-5 eggs per clutch and may have 2-3 broods per year from April to August.
- Only the female incubates the eggs and cares for hatchlings, but both parents feed the fledglings.
Breeding season and nesting
The bulk of a Brown Thrasher’s breeding season takes place during the spring and summer months, which is when nest construction, egg laying, incubation and rearing of young occurs. However, the exact timing varies across their range:
- In northern areas, breeding occurs from late April to late July.
- In central regions, it runs from mid-April to August.
- In southern parts of their range, the season is shifted earlier from March to mid-July.
Female Brown Thrashers typically lay one clutch of 3-5 eggs per nesting attempt. The female alone incubates the eggs for 10-16 days before they hatch. The chicks leave the nest 9-11 days after hatching, but remain dependent on their parents for an additional two weeks.
Some key facts about Brown Thrasher nesting:
- Nests are well-concealed in dense shrubs or small trees, between 2-15 feet above ground.
- The nest is a bulky cup built from twigs, bark, dried leaves and grasses, lined with finer materials.
- Females may raise 2-3 broods per season, moving to a new nest for each clutch.
- Only the female incubates eggs and broods hatchlings.
- Both parents feed nestlings and fledglings.
Egg laying details
Now that we’ve covered some background on breeding season timing and nesting, we can focus on the specifics of when female Brown Thrashers lay eggs.
Within their overall breeding season, most egg laying takes place from late April through June. But there are some variations:
- In northern regions, first clutches are laid in late April and early May.
- Farther south, first broods may start in March.
- Second broods are laid from late May through late June.
- Southern birds that raise 3 broods begin third clutches in July.
The precise egg laying date for an individual female depends on many factors:
- Location within the Thrasher’s breeding range
- Weather conditions in a given year
- Age and health of the female
- Availability of a suitable nesting site and food resources
- Outcome of previous nest attempts that season
But in most cases for Brown Thrashers across North America, peak egg laying takes place from mid-April through the month of May, with some regional and individual variation.
Conclusion
To summarize the key points:
- Brown Thrashers breed during spring and summer, with exact timing varying across their range.
- Females typically lay one clutch of 3-5 eggs per nesting attempt.
- Most egg laying occurs from late April through June.
- First broods are initiated in late April/early May in the north, and March in the south.
- Peak egg laying takes place from mid-April through May for most Brown Thrasher populations.
So in answer to the original question, the typical month for Brown Thrashers to lay eggs across most of their range is May, with some birds starting in April and others continuing into June or July, depending on their location and whether they raise multiple broods. The female’s egg laying date is influenced by many environmental and physiological factors, but May represents the peak egg laying period for this songbird species.
Frequently Asked Questions
How many eggs does a female Brown Thrasher lay?
Female Brown Thrashers typically lay between 3-5 eggs per clutch, with 4 eggs being the most common. They may raise 2-3 broods per breeding season.
How many days does it take a Brown Thrasher egg to hatch?
The incubation period for Brown Thrasher eggs averages 10-16 days. The female alone incubates the eggs until they hatch.
At what age do Brown Thrasher chicks leave the nest?
Brown Thrasher chicks fledge from the nest around 9-11 days after hatching. However, they remain dependent on parental care for an additional 2 weeks after leaving the nest.
How can I attract nesting Brown Thrashers to my yard?
You can make your yard attractive to nesting Brown Thrashers by providing dense shrubs and thickets, allowing edge areas with overgrown vegetation, and minimizing disturbances during nesting season. Leaving brush piles gives them nesting materials.
Where does the Brown Thrasher get its name?
The Brown Thrasher gets its common name from its reddish-brown coloration and thrashing movements through leaf litter while foraging. Its scientific name Toxostoma rufum means “red mouth” referring to the bright color of its lower mandible.
Key Facts
- Brown Thrashers breed during spring and summer across eastern and central North America.
- Females typically lay one clutch of 3-5 eggs per nest attempt.
- Most egg laying occurs from late April through June.
- Peak egg laying is in May for most populations.
- Exact timing depends on location and individual factors.
- Some birds may have 2-3 broods per season.
